Protein Kinases, catalytic domain; The protein kinase superfamily is mainly composed of the catalytic domains of serine/threonine-specific and tyrosine-specific protein kinases. It also includes RIO kinases, which are atypical serine protein kinases, aminoglycoside phosphotransferases, and choline kinases. These proteins catalyze the transfer of the gamma-phosphoryl group from ATP to hydroxyl groups in specific substrates such as serine, threonine, or tyrosine residues of proteins.

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gi 961554815   1 YQTMLDCWHGEPSQRPTFSELVEHLGNLLQAN 32
Cdd:cd05103  312 YQTMLDCWHGEPSQRPTFSELVEHLGNLLQAN 343

Catalytic domain of the Protein Tyrosine Kinase, Vascular Endothelial Growth Factor Receptor 2; PTKs catalyze the transfer of the gamma-phosphoryl group from ATP to tyrosine (tyr) residues in protein substrates. VEGFR2 (or Flk1) binds the ligands VEGFA, VEGFC, VEGFD and VEGFE. VEGFR2 signaling is implicated in all aspects of normal and pathological vascular endothelial cell biology. It induces a variety of cellular effects including migration, survival, and proliferation. It is critical in regulating embryonic vascular development and angiogenesis. VEGFR2 is the major signal transducer in pathological angiogenesis including cancer and diabetic retinopathy, and is a target for inhibition in cancer therapy. The carboxyl terminus of VEGFR2 plays an important role in its autophosphorylation and activation. VEGFR2 is a member of the VEGFR subfamily of proteins, which are receptor PTKs (RTKs) containing an extracellular ligand-binding region with seven immunoglobulin (Ig)-like domains, a transmembrane segment, and an intracellular catalytic domain. The binding of VEGFRs to their ligands, the VEGFs, leads to receptor dimerization, activation, and intracellular signaling. The VEGFR2 subfamily is part of a larger superfamily that includes the catalytic domains of other kinases such as protein serine/threonine kinases, RIO kinases, aminoglycoside phosphotransferase, choline kinase, and phosphoinositide 3-kinase.

                         10        20        30
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gi 961554815   1 YQTMLDCWHGEPSQRPTFSELVEHLGNLLQAN 32
Cdd:cd05103  312 YQTMLDCWHGEPSQRPTFSELVEHLGNLLQAN 343

Tyrosine kinase, catalytic domain; Phosphotransferases. Tyrosine-specific kinase subfamily.

                           10        20
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gi 961554815     1 YQTMLDCWHGEPSQRPTFSELVEHL 25
Cdd:smart00219 233 YDLMLQCWAEDPEDRPTFSELVEIL 257

Catalytic domain of the Protein Tyrosine Kinase, Vascular Endothelial Growth Factor Receptor 2; PTKs catalyze the transfer of the gamma-phosphoryl group from ATP to tyrosine (tyr) residues in protein substrates. VEGFR2 (or Flk1) binds the ligands VEGFA, VEGFC, VEGFD and VEGFE. VEGFR2 signaling is implicated in all aspects of normal and pathological vascular endothelial cell biology. It induces a variety of cellular effects including migration, survival, and proliferation. It is critical in regulating embryonic vascular development and angiogenesis. VEGFR2 is the major signal transducer in pathological angiogenesis including cancer and diabetic retinopathy, and is a target for inhibition in cancer therapy. The carboxyl terminus of VEGFR2 plays an important role in its autophosphorylation and activation. VEGFR2 is a member of the VEGFR subfamily of proteins, which are receptor PTKs (RTKs) containing an extracellular ligand-binding region with seven immunoglobulin (Ig)-like domains, a transmembrane segment, and an intracellular catalytic domain. The binding of VEGFRs to their ligands, the VEGFs, leads to receptor dimerization, activation, and intracellular signaling. The VEGFR2 subfamily is part of a larger superfamily that includes the catalytic domains of other kinases such as protein serine/threonine kinases, RIO kinases, aminoglycoside phosphotransferase, choline kinase, and phosphoinositide 3-kinase.

                         10        20        30
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gi 961554815   1 YQTMLDCWHGEPSQRPTFSELVEHLGNLLQAN 32
Cdd:cd05103  312 YQTMLDCWHGEPSQRPTFSELVEHLGNLLQAN 343

Catalytic domain of the Protein Tyrosine Kinase, Vascular Endothelial Growth Factor Receptor 3; PTKs catalyze the transfer of the gamma-phosphoryl group from ATP to tyrosine (tyr) residues in protein substrates. VEGFR3 (or Flt4) preferentially binds the ligands VEGFC and VEGFD. VEGFR3 is essential for lymphatic endothelial cell (EC) development and function. It has been shown to regulate adaptive immunity during corneal transplantation. VEGFR3 is upregulated on blood vascular ECs in pathological conditions such as vascular tumors and the periphery of solid tumors. It plays a role in cancer progression and lymph node metastasis. Missense mutations in the VEGFR3 gene are associated with primary human lymphedema. VEGFR3 is a member of the VEGFR subfamily of proteins, which are receptor PTKs (RTKs) containing an extracellular ligand-binding region with seven immunoglobulin (Ig)-like domains, a transmembrane segment, and an intracellular catalytic domain. In VEGFR3, the fifth Ig-like domain is replaced by a disulfide bridge. The binding of VEGFRs to their ligands, the VEGFs, leads to receptor dimerization, activation, and intracellular signaling. The VEGFR3 subfamily is part of a larger superfamily that includes the catalytic domains of other kinases such as protein serine/threonine kinases, RIO kinases, aminoglycoside phosphotransferase, choline kinase, and phosphoinositide 3-kinase.

                         10        20        30
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gi 961554815   1 YQTMLDCWHGEPSQRPTFSELVEHLGNLLQAN 32
Cdd:cd05102  305 YRIMLSCWHGDPKERPTFSDLVEILGDLLQEN 336

Catalytic domain of the Protein Tyrosine Kinases, Fibroblast Growth Factor Receptors; PTKs catalyze the transfer of the gamma-phosphoryl group from ATP to tyrosine (tyr) residues in protein substrates. The FGFR subfamily consists of FGFR1, FGFR2, FGFR3, FGFR4, and similar proteins. They are receptor PTKs (RTKs) containing an extracellular ligand-binding region with three immunoglobulin-like domains, a transmembrane segment, and an intracellular catalytic domain. The binding of FGFRs to their ligands, the FGFs, and to heparin/heparan sulfate (HS) results in the formation of a ternary complex, which leads to receptor dimerization and activation, and intracellular signaling. There are at least 23 FGFs and four types of FGFRs. The binding of FGFs to FGFRs is promiscuous, in that a receptor may be activated by several ligands and a ligand may bind to more that one type of receptor. FGF/FGFR signaling is important in the regulation of embryonic development, homeostasis, and regenerative processes. Depending on the cell type and stage, FGFR signaling produces diverse cellular responses including proliferation, growth arrest, differentiation, and apoptosis. Aberrant signaling leads to many human diseases such as skeletal, olfactory, and metabolic disorders, as well as cancer. The FGFR subfamily is part of a larger superfamily that includes the catalytic domains of other kinases such as protein serine/threonine kinases, RIO kinases, aminoglycoside phosphotransferase, choline kinase, and phosphoinositide 3-kinase .

                         10        20
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gi 961554815   1 YQTMLDCWHGEPSQRPTFSELVEHLGNLL 29
Cdd:cd05053  265 YMLMRDCWHEVPSQRPTFKQLVEDLDRIL 293

Catalytic domain of the Protein Tyrosine Kinase, Fibroblast Growth Factor Receptor 1; PTKs catalyze the transfer of the gamma-phosphoryl group from ATP to tyrosine (tyr) residues in protein substrates. Alternative splicing of FGFR1 transcripts produces a variety of isoforms, which are differentially expressed in cells. FGFR1 binds the ligands, FGF1 and FGF2, with high affinity and has also been reported to bind FGF4, FGF6, and FGF9. FGFR1 signaling is critical in the control of cell migration during embryo development. It promotes cell proliferation in fibroblasts. Nuclear FGFR1 plays a role in the regulation of transcription. Mutations, insertions or deletions of FGFR1 have been identified in patients with Kallman's syndrome (KS), an inherited disorder characterized by hypogonadotropic hypogonadism and loss of olfaction. Aberrant FGFR1 expression has been found in some human cancers including 8P11 myeloproliferative syndrome (EMS), breast cancer, and pancreatic adenocarcinoma. FGFR1 is part of the FGFR subfamily, which are receptor PTKs (RTKs) containing an extracellular ligand-binding region with three immunoglobulin-like domains, a transmembrane segment, and an intracellular catalytic domain. The binding of FGFRs to their ligands, the FGFs, results in receptor dimerization and activation, and intracellular signaling. The binding of FGFs to FGFRs is promiscuous, in that a receptor may be activated by several ligands and a ligand may bind to more that one type of receptor. The FGFR1 subfamily is part of a larger superfamily that includes the catalytic domains of other kinases such as protein serine/threonine kinases, RIO kinases, aminoglycoside phosphotransferase, choline kinase, and phosphoinositide 3-kinase.

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gi 961554815   1 YQTMLDCWHGEPSQRPTFSELVEHLGNLLQANAQQ 35
Cdd:cd05098  267 YMMMRDCWHAVPSQRPTFKQLVEDLDRIVALTSNQ 301

Tyrosine kinase, catalytic domain; Phosphotransferases. Tyrosine-specific kinase subfamily.

                           10        20
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gi 961554815     1 YQTMLDCWHGEPSQRPTFSELVEHL 25
Cdd:smart00219 233 YDLMLQCWAEDPEDRPTFSELVEIL 257

Catalytic domain of the Protein Tyrosine Kinase, Fibroblast Growth Factor Receptor 4; PTKs catalyze the transfer of the gamma-phosphoryl group from ATP to tyrosine (tyr) residues in protein substrates. Unlike other FGFRs, there is only one splice form of FGFR4. It binds FGF1, FGF2, FGF6, FGF19, and FGF23. FGF19 is a selective ligand for FGFR4. Although disruption of FGFR4 in mice causes no obvious phenotype, in vivo inhibition of FGFR4 in cultured skeletal muscle cells resulted in an arrest of muscle progenitor differentiation. FGF6 and FGFR4 are uniquely expressed in myofibers and satellite cells. FGF6/FGFR4 signaling appears to play a key role in the regulation of muscle regeneration. A polymorphism in FGFR4 is found in head and neck squamous cell carcinoma. FGFR4 is part of the FGFR subfamily, which are receptor PTKs (RTKs) containing an extracellular ligand-binding region with three immunoglobulin-like domains, a transmembrane segment, and an intracellular catalytic domain. The binding of FGFRs to their ligands, the FGFs, results in receptor dimerization and activation, and intracellular signaling. The binding of FGFs to FGFRs is promiscuous, in that a receptor may be activated by several ligands and a ligand may bind to more that one type of receptor. The FGFR4 subfamily is part of a larger superfamily that includes the catalytic domains of other kinases such as protein serine/threonine kinases, RIO kinases, aminoglycoside phosphotransferase, choline kinase, and phosphoinositide 3-kinase.

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gi 961554815   1 YQTMLDCWHGEPSQRPTFSELVEHLGNLLQANAQQ 35
Cdd:cd05099  266 YMLMRECWHAVPTQRPTFKQLVEALDKVLAAVSEE 300

Catalytic domain of the Protein Tyrosine Kinase, Fibroblast Growth Factor Receptor 3; PTKs catalyze the transfer of the gamma-phosphoryl group from ATP to tyrosine (tyr) residues in protein substrates. Many FGFR3 splice variants have been reported with the IIIb and IIIc isoforms being the predominant forms. FGFR3 IIIc is the isoform expressed in chondrocytes, the cells affected in dwarfism, while IIIb is expressed in epithelial cells. FGFR3 ligands include FGF1, FGF2, FGF4, FGF8, FGF9, and FGF23. It is a negative regulator of long bone growth. In the cochlear duct and in the lens, FGFR3 is involved in differentiation while it appears to have a role in cell proliferation in epithelial cells. Germline mutations in FGFR3 are associated with skeletal disorders including several forms of dwarfism. Some missense mutations are associated with multiple myeloma and carcinomas of the bladder and cervix. Overexpression of FGFR3 is found in thyroid carcinoma. FGFR3 is part of the FGFR subfamily, which are receptor PTKs (RTKs) containing an extracellular ligand-binding region with three immunoglobulin-like domains, a transmembrane segment, and an intracellular catalytic domain. The binding of FGFRs to their ligands, the FGFs, results in receptor dimerization and activation, and intracellular signaling. The binding of FGFs to FGFRs is promiscuous, in that a receptor may be activated by several ligands and a ligand may bind to more that one type of receptor. The FGFR3 subfamily is part of a larger superfamily that includes the catalytic domains of other kinases such as protein serine/threonine kinases, RIO kinases, aminoglycoside phosphotransferase, choline kinase, and phosphoinositide 3-kinase.

                         10        20
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gi 961554815   1 YQTMLDCWHGEPSQRPTFSELVEHLGNLL 29
Cdd:cd05100  266 YMIMRECWHAVPSQRPTFKQLVEDLDRVL 294

Catalytic domain of Ephrin Receptor Protein Tyrosine Kinases; PTKs catalyze the transfer of the gamma-phosphoryl group from ATP to tyrosine (tyr) residues in protein substrates. EphRs comprise the largest subfamily of receptor PTKs (RTKs). They can be classified into two classes (EphA and EphB), according to their extracellular sequences, which largely correspond to binding preferences for either GPI-anchored ephrin-A ligands or transmembrane ephrin-B ligands. Vertebrates have ten EphA and six EphB receptors, which display promiscuous ligand interactions within each class. EphRs contain an ephrin binding domain and two fibronectin repeats extracellularly, a transmembrane segment, and a cytoplasmic tyr kinase domain. Binding of the ephrin ligand to EphR requires cell-cell contact since both are anchored to the plasma membrane. This allows ephrin/EphR dimers to form, leading to the activation of the intracellular tyr kinase domain. The resulting downstream signals occur bidirectionally in both EphR-expressing cells (forward signaling) and ephrin-expressing cells (reverse signaling). The main effect of ephrin/EphR interaction is cell-cell repulsion or adhesion. Ephrin/EphR signaling is important in neural development and plasticity, cell morphogenesis and proliferation, cell-fate determination, embryonic development, tissue patterning, and angiogenesis.The EphR subfamily is part of a larger superfamily that includes the catalytic domains of other kinases such as protein serine/threonine kinases, RIO kinases, aminoglycoside phosphotransferase, choline kinase, and phosphoinositide 3-kinase.

                         10        20
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gi 961554815   1 YQTMLDCWHGEPSQRPTFSELVEHLGNLL 29
Cdd:cd05033  238 YQLMLDCWQKDRNERPTFSQIVSTLDKMI 266

Catalytic domain of the Protein Tyrosine Kinases, Met and Ron; PTKs catalyze the transfer of the gamma-phosphoryl group from ATP to tyrosine (tyr) residues in protein substrates. Met and Ron are receptor PTKs (RTKs) composed of an alpha-beta heterodimer. The extracellular alpha chain is disulfide linked to the beta chain, which contains an extracellular ligand-binding region with a sema domain, a PSI domain and four IPT repeats, a transmembrane segment, and an intracellular catalytic domain. Binding to their ligands leads to receptor dimerization, autophosphorylation, activation, and intracellular signaling. Met binds to the ligand, hepatocyte growth factor/scatter factor (HGF/SF), and is also called the HGF receptor. HGF/Met signaling plays a role in growth, transformation, cell motility, invasion, metastasis, angiogenesis, wound healing, and tissue regeneration. Aberrant expression of Met through mutations or gene amplification is associated with many human cancers including hereditary papillary renal and gastric carcinomas. The ligand for Ron is macrophage stimulating protein (MSP). Ron signaling is important in regulating cell motility, adhesion, proliferation, and apoptosis. Aberrant Ron expression is implicated in tumorigenesis and metastasis. The Met/Ron subfamily is part of a larger superfamily that includes the catalytic domains of other kinases such as protein serine/threonine kinases, RIO kinases, aminoglycoside phosphotransferase, choline kinase, and phosphoinositide 3-kinase.

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gi 961554815   1 YQTMLDCWHGEPSQRPTFSELV 22
Cdd:cd05058  232 YEVMLSCWHPKPEMRPTFSELV 253

Catalytic domain of the Protein Tyrosine Kinase, Focal Adhesion Kinase; PTKs catalyze the transfer of the gamma-phosphoryl group from ATP to tyrosine (tyr) residues in protein substrates. FAK is a cytoplasmic (or nonreceptor) PTK that contains an autophosphorylation site and a FERM domain at the N-terminus, a central tyr kinase domain, proline-rich regions, and a C-terminal FAT (focal adhesion targeting) domain. FAK activity is dependent on integrin-mediated cell adhesion, which facilitates N-terminal autophosphorylation. Full activation is achieved by the phosphorylation of its two adjacent A-loop tyrosines. FAK is important in mediating signaling initiated at sites of cell adhesions and at growth factor receptors. Through diverse molecular interactions, FAK functions as a biosensor or integrator to control cell motility. It is a key regulator of cell survival, proliferation, migration and invasion, and thus plays an important role in the development and progression of cancer. Src binds to autophosphorylated FAK forming the FAK-Src dual kinase complex, which is activated in a wide variety of tumor cells and generates signals promoting growth and metastasis. FAK is being developed as a target for cancer therapy. The FAK subfamily is part of a larger superfamily that includes the catalytic domains of other kinases such as protein serine/threonine kinases, RIO kinases, aminoglycoside phosphotransferase, choline kinase, and phosphoinositide 3-kinase.

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gi 961554815   1 YQTMLDCWHGEPSQRPTFSELVEHLGNLLQ 30
Cdd:cd05056  238 YSLMTKCWAYDPSKRPRFTELKAQLSDILQ 267

Catalytic domain of Src kinase-like Protein Tyrosine Kinases; PTKs catalyze the transfer of the gamma-phosphoryl group from ATP to tyrosine (tyr) residues in protein substrates. Src subfamily members include Src, Lck, Hck, Blk, Lyn, Fgr, Fyn, Yrk, and Yes. Src (or c-Src) proteins are cytoplasmic (or non-receptor) PTKs which are anchored to the plasma membrane. They contain an N-terminal SH4 domain with a myristoylation site, followed by SH3 and SH2 domains, a tyr kinase domain, and a regulatory C-terminal region containing a conserved tyr. They are activated by autophosphorylation at the tyr kinase domain, but are negatively regulated by phosphorylation at the C-terminal tyr by Csk (C-terminal Src Kinase). Src proteins are involved in signaling pathways that regulate cytokine and growth factor responses, cytoskeleton dynamics, cell proliferation, survival, and differentiation. They were identified as the first proto-oncogene products, and they regulate cell adhesion, invasion, and motility in cancer cells and tumor vasculature, contributing to cancer progression and metastasis. Src kinases are overexpressed in a variety of human cancers, making them attractive targets for therapy. They are also implicated in acute inflammatory responses and osteoclast function. Src, Fyn, Yes, and Yrk are widely expressed, while Blk, Lck, Hck, Fgr, and Lyn show a limited expression pattern. The Src-like subfamily is part of a larger superfamily that includes the catalytic domains of other kinases such as serine/threonine kinases, RIO kinases, aminoglycoside phosphotransferase, choline kinase, and phosphoinositide 3-kinase.

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gi 961554815   1 YQTMLDCWHGEPSQRPTFSELVEHL 25
Cdd:cd05034  223 YDIMLQCWKKEPEERPTFEYLQSFL 247

Catalytic domain of Fyn-related kinase-like Protein Tyrosine Kinases; PTKs catalyze the transfer of the gamma-phosphoryl group from ATP to tyrosine (tyr) residues in protein substrates. Frk and Srk are members of the Src subfamily of proteins, which are cytoplasmic (or non-receptor) PTKs. Frk, also known as Rak, is specifically expressed in liver, lung, kidney, intestine, mammary glands, and the islets of Langerhans. Rodent homologs were previously referred to as GTK (gastrointestinal tyr kinase), BSK (beta-cell Src-like kinase), or IYK (intestinal tyr kinase). Studies in mice reveal that Frk is not essential for viability. It plays a role in the signaling that leads to cytokine-induced beta-cell death in Type I diabetes. It also regulates beta-cell number during embryogenesis and early in life. Src kinases contain an N-terminal SH4 domain with a myristoylation site, followed by SH3 and SH2 domains, a tyr kinase domain, and a regulatory C-terminal region containing a conserved tyr. They are activated by autophosphorylation at the tyr kinase domain, but are negatively regulated by phosphorylation at the C-terminal tyr by Csk (C-terminal Src Kinase). The Frk-like subfamily is part of a larger superfamily that includes the catalytic domains of other kinases such as serine/threonine kinases, RIO kinases, aminoglycoside phosphotransferase, choline kinase, and phosphoinositide 3-kinase.

                         10        20
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gi 961554815   1 YQTMLDCWHGEPSQRPTFSEL 21
Cdd:cd05068  236 YDIMLECWKADPMERPTFETL 256

Catalytic domain of the Protein Tyrosine Kinases, Class EphA Ephrin Receptors; PTKs catalyze the transfer of the gamma-phosphoryl group from ATP to tyrosine (tyr) residues in protein substrates. This subfamily is composed of most class EphA receptors including EphA3, EphA4, EphA5, and EphA7, but excluding EphA1, EphA2 and EphA10. Class EphA receptors bind GPI-anchored ephrin-A ligands. There are ten vertebrate EphA receptors (EphA1-10), which display promiscuous interactions with six ephrin-A ligands. One exception is EphA4, which also binds ephrins-B2/B3. EphA receptors and ephrin-A ligands are expressed in multiple areas of the developing brain, especially in the retina and tectum. They are part of a system controlling retinotectal mapping. EphRs comprise the largest subfamily of receptor PTKs (RTKs). EphRs contain an ephrin-binding domain and two fibronectin repeats extracellularly, a transmembrane segment, and a cytoplasmic tyr kinase domain. Binding of the ephrin ligand to EphR requires cell-cell contact since both are anchored to the plasma membrane. The resulting downstream signals occur bidirectionally in both EphR-expressing cells (forward signaling) and ephrin-expressing cells (reverse signaling). Ephrin/EphR interaction mainly results in cell-cell repulsion or adhesion, making it important in neural development and plasticity, cell morphogenesis, cell-fate determination, embryonic development, tissue patterning, and angiogenesis. The EphA subfamily is part of a larger superfamily that includes the catalytic domains of other kinases such as serine/threonine kinases, RIO kinases, aminoglycoside phosphotransferase, choline kinase, and phosphoinositide 3-kinase.

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gi 961554815   1 YQTMLDCWHGEPSQRPTFSELVEHLGNLL 29
Cdd:cd05066  239 HQLMLDCWQKDRNERPKFEQIVSILDKLI 267

Catalytic Domain of the Protein Tyrosine Kinase, Mer; PTKs catalyze the transfer of the gamma-phosphoryl group from ATP to tyrosine (tyr) residues in protein substrates. Mer (or Mertk) is named after its original reported expression pattern (monocytes, epithelial, and reproductive tissues). It is required for the ingestion of apoptotic cells by phagocytes such as macrophages, retinal pigment epithelial cells, and dendritic cells. Mer is also important in maintaining immune homeostasis. Mer is a member of the TAM subfamily, composed of receptor PTKs (RTKs) containing an extracellular ligand-binding region with two immunoglobulin-like domains followed by two fibronectin type III repeats, a transmembrane segment, and an intracellular catalytic domain. Binding to their ligands, Gas6 and protein S, leads to receptor dimerization, autophosphorylation, activation, and intracellular signaling. The Mer subfamily is part of a larger superfamily that includes the catalytic domains of other kinases such as serine/threonine kinases, RIO kinases, aminoglycoside phosphotransferase, choline kinase, and phosphoinositide 3-kinase.

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gi 961554815   1 YQTMLDCWHGEPSQRPTFSELVEHLGNLLQA 31
Cdd:cd14204  252 YDIMYSCWRSDPTDRPTFTQLRENLEKLLES 282

Catalytic domain of Tec-like Protein Tyrosine Kinases; PTKs catalyze the transfer of the gamma-phosphoryl group from ATP to tyrosine (tyr) residues in protein substrates. The Tec-like subfamily is composed of Tec, Btk, Bmx (Etk), Itk (Tsk, Emt), Rlk (Txk), and similar proteins. They are cytoplasmic (or nonreceptor) PTKs with similarity to Src kinases in that they contain Src homology protein interaction domains (SH3, SH2) N-terminal to the catalytic tyr kinase domain. Unlike Src kinases, most Tec subfamily members except Rlk also contain an N-terminal pleckstrin homology (PH) domain, which binds the products of PI3K and allows membrane recruitment and activation. In addition, some members contain the Tec homology (TH) domain, which contains proline-rich and zinc-binding regions. Tec kinases form the second largest subfamily of nonreceptor PTKs and are expressed mainly by haematopoietic cells, although Tec and Bmx are also found in endothelial cells. B-cells express Btk and Tec, while T-cells express Itk, Txk, and Tec. Collectively, Tec kinases are expressed in a variety of myeloid cells such as mast cells, platelets, macrophages, and dendritic cells. Each Tec kinase shows a distinct cell-type pattern of expression. Tec kinases play important roles in the development, differentiation, maturation, regulation, survival, and function of B-cells and T-cells. Mutations in Btk cause the severe B-cell immunodeficiency, X-linked agammaglobulinaemia (XLA). The Tec-like subfamily is part of a larger superfamily that includes the catalytic domains of other kinases such as protein serine/threonine kinases, RIO kinases, aminoglycoside phosphotransferase, choline kinase, and phosphoinositide 3-kinase.

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gi 961554815   1 YQTMLDCWHGEPSQRPTFSELVEHLG 26
Cdd:cd05059  231 YTIMYSCWHEKPEERPTFKILLSQLT 256

Catalytic domain of Fes-like Protein Tyrosine Kinases; Protein Tyrosine Kinase (PTK) family; Fes subfamily; catalytic (c) domain. Fes subfamily members include Fes (or Fps), Fer, and similar proteins. The PTKc family is part of a larger superfamily that includes the catalytic domains of other kinases such as protein serine/threonine kinases, RIO kinases, and phosphoinositide 3-kinase (PI3K). PTKs catalyze the transfer of the gamma-phosphoryl group from ATP to tyrosine (tyr) residues in protein substrates. Fes subfamily proteins are cytoplasmic (or nonreceptor) tyr kinases containing an N-terminal region with FCH (Fes/Fer/CIP4 homology) and coiled-coil domains, followed by a SH2 domain, and a C-terminal catalytic domain. The genes for Fes (feline sarcoma) and Fps (Fujinami poultry sarcoma) were first isolated from tumor-causing retroviruses. The viral oncogenes encode chimeric Fes proteins consisting of Gag sequences at the N-termini, resulting in unregulated tyr kinase activity. Fes and Fer kinases play roles in haematopoiesis, inflammation and immunity, growth factor signaling, cytoskeletal regulation, cell migration and adhesion, and the regulation of cell-cell interactions. Fes and Fer show redundancy in their biological functions.

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gi 961554815   1 YQTMLDCWHGEPSQRPTFSELVEHL 25
Cdd:cd05041  226 YRLMLQCWAYDPENRPSFSEIYNEL 250

Catalytic domain of the Protein Tyrosine Kinase, Ephrin Receptor A10; PTKs catalyze the transfer of the gamma-phosphoryl group from ATP to tyrosine (tyr) residues in protein substrates. EphA10, which contains an inactive tyr kinase domain, may function to attenuate signals of co-clustered active receptors. EphA10 is mainly expressed in the testis. Ephrin/EphR interaction results in cell-cell repulsion or adhesion, making it important in neural development and plasticity, cell morphogenesis, cell-fate determination, embryonic development, tissue patterning, and angiogenesis. EphRs comprise the largest subfamily of receptor tyr kinases (RTKs). In general, class EphA receptors bind GPI-anchored ephrin-A ligands. There are ten vertebrate EphA receptors (EphA1-10), which display promiscuous interactions with six ephrin-A ligands. EphRs contain an ephrin binding domain and two fibronectin repeats extracellularly, a transmembrane segment, and a cytoplasmic tyr kinase domain. Binding of the ephrin ligand to EphR requires cell-cell contact since both are anchored to the plasma membrane. The resulting downstream signals occur bidirectionally in both EphR-expressing cells (forward signaling) and ephrin-expressing cells (reverse signaling). The EphA10 subfamily is part of a larger superfamily that includes the catalytic domains of other kinases such as serine/threonine kinases, RIO kinases, aminoglycoside phosphotransferase, choline kinase, and phosphoinositide 3-kinase.

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gi 961554815   1 YQTMLDCWHGEPSQRPTFSELVEHLGNLL 29
Cdd:cd05064  238 HQLMLDCWQKERGERPRFSQIHSILSKMV 266

Catalytic domain of the Protein Tyrosine Kinase, Abelson kinase; PTKs catalyze the transfer of the gamma-phosphoryl group from ATP to tyrosine (tyr) residues in protein substrates. Abl (or c-Abl) is a ubiquitously-expressed cytoplasmic (or nonreceptor) PTK that contains SH3, SH2, and tyr kinase domains in its N-terminal region, as well as nuclear localization motifs, a putative DNA-binding domain, and F- and G-actin binding domains in its C-terminal tail. It also contains a short autoinhibitory cap region in its N-terminus. Abl function depends on its subcellular localization. In the cytoplasm, Abl plays a role in cell proliferation and survival. In response to DNA damage or oxidative stress, Abl is transported to the nucleus where it induces apoptosis. In chronic myelogenous leukemia (CML) patients, an aberrant translocation results in the replacement of the first exon of Abl with the BCR (breakpoint cluster region) gene. The resulting BCR-Abl fusion protein is constitutively active and associates into tetramers, resulting in a hyperactive kinase sending a continuous signal. This leads to uncontrolled proliferation, morphological transformation and anti-apoptotic effects. BCR-Abl is the target of selective inhibitors, such as imatinib (Gleevec), used in the treatment of CML. Abl2, also known as ARG (Abelson-related gene), is thought to play a cooperative role with Abl in the proper development of the nervous system. The Tel-ARG fusion protein, resulting from reciprocal translocation between chromosomes 1 and 12, is associated with acute myeloid leukemia (AML). The TEL gene is a frequent fusion partner of other tyr kinase oncogenes, including Tel/Abl, Tel/PDGFRbeta, and Tel/Jak2, found in patients with leukemia and myeloproliferative disorders. The Abl subfamily is part of a larger superfamily that includes the catalytic domains of other kinases such as protein serine/threonine kinases, RIO kinases, aminoglycoside phosphotransferase, choline kinase, and phosphoinositide 3-kinase.

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gi 961554815   1 YQTMLDCWHGEPSQRPTFSELVEHLGNL 28
Cdd:cd05052  235 YELMRACWQWNPSDRPSFAEIHQALETM 262

Catalytic domain of the Protein Tyrosine Kinases, Bruton's tyrosine kinase and Bone marrow kinase on the X chromosome; PTKs catalyze the transfer of the gamma-phosphoryl group from ATP to tyrosine (tyr) residues in protein substrates. Btk and Bmx (also named Etk) are members of the Tec-like subfamily of proteins, which are cytoplasmic (or nonreceptor) PTKs with similarity to Src kinases in that they contain Src homology protein interaction domains (SH3, SH2) N-terminal to the catalytic tyr kinase domain. Unlike Src kinases, most Tec subfamily members except Rlk also contain an N-terminal pleckstrin homology (PH) domain, which binds the products of PI3K and allows membrane recruitment and activation. In addition, Btk contains the Tec homology (TH) domain with proline-rich and zinc-binding regions. Btk is expressed in B-cells, and a variety of myeloid cells including mast cells, platelets, neutrophils, and dendrictic cells. It interacts with a variety of partners, from cytosolic proteins to nuclear transcription factors, suggesting a diversity of functions. Stimulation of a diverse array of cell surface receptors, including antigen engagement of the B-cell receptor, leads to PH-mediated membrane translocation of Btk and subsequent phosphorylation by Src kinase and activation. Btk plays an important role in the life cycle of B-cells including their development, differentiation, proliferation, survival, and apoptosis. Mutations in Btk cause the primary immunodeficiency disease, X-linked agammaglobulinaemia (XLA) in humans. Bmx is primarily expressed in bone marrow and the arterial endothelium, and plays an important role in ischemia-induced angiogenesis. It facilitates arterial growth, capillary formation, vessel maturation, and bone marrow-derived endothelial progenitor cell mobilization. The Btk/Bmx subfamily is part of a larger superfamily that includes the catalytic domains of other kinases such as protein serine/threonine kinases, RIO kinases, aminoglycoside phosphotransferase, choline kinase, and phosphoinositide 3-kinase.

                         10        20
                 ....*....|....*....|..
gi 961554815   1 YQTMLDCWHGEPSQRPTFSELV 22
Cdd:cd05113  231 YTIMYSCWHEKADERPTFKILL 252

Catalytic domain of the Protein Tyrosine Kinase, REarranged during Transfection protein; PTKs catalyze the transfer of the gamma-phosphoryl group from ATP to tyrosine (tyr) residues in protein substrates. RET is a receptor PTK (RTK) containing an extracellular region with four cadherin-like repeats, a calcium-binding site, and a cysteine-rich domain, a transmembrane segment, and an intracellular catalytic domain. It is part of a multisubunit complex that binds glial-derived neurotropic factor (GDNF) family ligands (GFLs) including GDNF, neurturin, artemin, and persephin. GFLs bind RET along with four GPI-anchored coreceptors, bringing two RET molecules together, leading to autophosphorylation, activation, and intracellular signaling. RET is essential for the development of the sympathetic, parasympathetic and enteric nervous systems, and the kidney. RET disruption by germline mutations causes diseases in humans including congenital aganglionosis of the gastrointestinal tract (Hirschsprung's disease) and three related inherited cancers: multiple endocrine neoplasia type 2A (MEN2A), MEN2B, and familial medullary thyroid carcinoma. The RET subfamily is part of a larger superfamily that includes the catalytic domains of other kinases such as protein serine/threonine kinases, RIO kinases, aminoglycoside phosphotransferase, choline kinase, and phosphoinositide 3-kinase.

                         10        20        30
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gi 961554815   1 YQTMLDCWHGEPSQRPTFSELVEHLGNLLQAN 32
Cdd:cd05045  259 YNLMLTCWKQEPDKRPTFADISKELEKMMVKS 290

Catalytic domain of the Serine/Threonine Kinase, Transforming Growth Factor beta Activated Kinase-1; STKs catalyze the transfer of the gamma-phosphoryl group from ATP to serine/threonine residues on protein substrates. TAK1 is also known as mitogen-activated protein kinase kinase kinase 7 (MAPKKK7 or MAP3K7), TAK, or MEKK7. As a MAPKKK, it is an important mediator of cellular responses to extracellular signals. It regulates both the c-Jun N-terminal kinase and p38 MAPK cascades by activating the MAPK kinases, MKK4 and MKK3/6. In addition, TAK1 plays diverse roles in immunity and development, in different biological contexts, through many signaling pathways including TGFbeta/BMP, Wnt/Fz, and NF-kB. It is also implicated in the activation of the tumor suppressor kinase, LKB1. The TAK1 subfamily is part of a larger superfamily that includes the catalytic domains of other STKs, protein tyrosine kinases, RIO kinases, aminoglycoside phosphotransferase, choline kinase, and phosphoinositide 3-kinase.

                         10        20        30
                 ....*....|....*....|....*....|.
gi 961554815   2 QTMLDCWHGEPSQRPTFSELVEHLGNLLQAN 32
Cdd:cd14058  222 SLMTRCWSKDPEKRPSMKEIVKIMSHLMQFF 252

Catalytic domain of the Protein Tyrosine Kinase, C-terminal Src kinase; PTKs catalyze the transfer of the gamma-phosphoryl group from ATP to tyrosine (tyr) residues in protein substrates. Csk catalyzes the tyr phosphorylation of the regulatory C-terminal tail of Src kinases, resulting in their inactivation. Csk is expressed in a wide variety of tissues. As a negative regulator of Src, Csk plays a role in cell proliferation, survival, and differentiation, and consequently, in cancer development and progression. Csk is a cytoplasmic (or nonreceptor) PTK containing the Src homology domains, SH3 and SH2, N-terminal to the catalytic tyr kinase domain. To inhibit Src kinases, Csk is translocated to the membrane via binding to specific transmembrane proteins, G-proteins, or adaptor proteins near the membrane. In addition, Csk also shows Src-independent functions. It is a critical component in G-protein signaling, and plays a role in cytoskeletal reorganization and cell migration. The Csk subfamily is part of a larger superfamily that includes the catalytic domains of other kinases such as protein serine/threonine kinases, RIO kinases, aminoglycoside phosphotransferase, choline kinase, and phosphoinositide 3-kinase.

                         10        20
                 ....*....|....*....|....*
gi 961554815   1 YQTMLDCWHGEPSQRPTFSELVEHL 25
Cdd:cd05082  229 YDVMKNCWHLDAAMRPSFLQLREQL 253

Catalytic domain of the Protein Tyrosine Kinases, Discoidin Domain Receptors; PTKs catalyze the transfer of the gamma-phosphoryl group from ATP to tyrosine (tyr) residues in protein substrates. The DDR subfamily consists of homologs of mammalian DDR1, DDR2, and similar proteins. They are receptor PTKs (RTKs) containing an extracellular discoidin homology domain, a transmembrane segment, an extended juxtamembrane region, and an intracellular catalytic domain. The binding of the ligand, collagen, to DDRs results in a slow but sustained receptor activation. DDRs regulate cell adhesion, proliferation, and extracellular matrix remodeling. They have been linked to a variety of human cancers including breast, colon, ovarian, brain, and lung. There is no evidence showing that DDRs act as transforming oncogenes. They are more likely to play a role in the regulation of tumor growth and metastasis. The DDR subfamily is part of a larger superfamily that includes the catalytic domains of other kinases such as protein serine/threonine kinases, RIO kinases, aminoglycoside phosphotransferase, choline kinase, and phosphoinositide 3-kinase.

                         10        20
                 ....*....|....*....|.
gi 961554815   1 YQTMLDCWHGEPSQRPTFSEL 21
Cdd:cd05051  271 YELMLECWRRDEEDRPTFREI 291

Catalytic domain of the Serine/Threonine Kinases, Mixed Lineage Kinases; STKs catalyze the transfer of the gamma-phosphoryl group from ATP to serine/threonine residues on protein substrates. MLKs act as mitogen-activated protein kinase kinase kinases (MAP3Ks, MKKKs, MAPKKKs), which phosphorylate and activate MAPK kinases (MAPKKs or MKKs or MAP2Ks), which in turn phosphorylate and activate MAPKs during signaling cascades that are important in mediating cellular responses to extracellular signals. Mammals have four MLKs (MLK1-4), mostly conserved in vertebrates, which contain an SH3 domain, a catalytic kinase domain, a leucine zipper, a proline-rich region, and a CRIB domain that mediates binding to GTP-bound Cdc42 and Rac. MLKs play roles in immunity and inflammation, as well as in cell death, proliferation, and cell cycle regulation. The MLK subfamily is part of a larger superfamily that includes the catalytic domains of other STKs, protein tyrosine kinases, RIO kinases, aminoglycoside phosphotransferase, choline kinase, and phosphoinositide 3-kinase.

                         10        20
                 ....*....|....*....|....*..
gi 961554815   2 QTMLDCWHGEPSQRPTFSELVEHLGNL 28
Cdd:cd14061  232 QLMKDCWQPDPHDRPSFADILKQLENI 258

Catalytic domain of the Protein Tyrosine Kinase, Ephrin Receptor A2; PTKs catalyze the transfer of the gamma-phosphoryl group from ATP to tyrosine (tyr) residues in protein substrates. The EphA2 receptor is overexpressed in tumor cells and tumor blood vessels in a variety of cancers including breast, prostate, lung, and colon. As a result, it is an attractive target for drug design since its inhibition could affect several aspects of tumor progression. EphRs comprise the largest subfamily of receptor PTKs (RTKs). Class EphA receptors bind GPI-anchored ephrin-A ligands. There are ten vertebrate EphA receptors (EphA1-10), which display promiscuous interactions with six ephrin-A ligands. EphRs contain an ephrin binding domain and two fibronectin repeats extracellularly, a transmembrane segment, and a cytoplasmic tyr kinase domain. Binding of the ephrin ligand to EphR requires cell-cell contact since both are anchored to the plasma membrane. The resulting downstream signals occur bidirectionally in both EphR-expressing cells (forward signaling) and ephrin-expressing cells (reverse signaling). Ephrin/EphR interaction mainly results in cell-cell repulsion or adhesion, making it important in neural development and plasticity, cell morphogenesis, cell-fate determination, embryonic development, tissue patterning, and angiogenesis. The EphA2 subfamily is part of a larger superfamily that includes the catalytic domains of other kinases such as protein serine/threonine kinases, RIO kinases, and phosphoinositide 3-kinase (PI3K).

                         10        20
                 ....*....|....*....|....*....
gi 961554815   1 YQTMLDCWHGEPSQRPTFSELVEHLGNLL 29
Cdd:cd05063  240 YQLMLQCWQQDRARRPRFVDIVNLLDKLL 268

Catalytic (repeat 2) domain of the Protein Tyrosine Kinase, Tyrosine kinase 2; PTKs catalyze the transfer of the gamma-phosphoryl group from ATP to tyrosine (tyr) residues in protein substrates. Tyk2 is widely expressed in many tissues. It is involved in signaling via the cytokine receptors IFN-alphabeta, IL-6, IL-10, IL-12, IL-13, and IL-23. It mediates cell surface urokinase receptor (uPAR) signaling and plays a role in modulating vascular smooth muscle cell (VSMC) functional behavior in response to injury. Tyk2 is also important in dendritic cell function and T helper (Th)1 cell differentiation. A homozygous mutation of Tyk2 was found in a patient with hyper-IgE syndrome (HIES), a primary immunodeficiency characterized by recurrent skin abscesses, pneumonia, and elevated serum IgE. This suggests that Tyk2 may play important roles in multiple cytokine signaling involved in innate and adaptive immunity. Tyk2 is a member of the Janus kinase (Jak) subfamily of proteins, which are cytoplasmic (or nonreceptor) PTKs containing an N-terminal FERM domain, followed by a Src homology 2 (SH2) domain, a pseudokinase domain, and a C-terminal tyr kinase catalytic domain. Jaks are crucial for cytokine receptor signaling. They are activated by autophosphorylation upon cytokine-induced receptor aggregation, and subsequently trigger downstream signaling events such as the phosphorylation of signal transducers and activators of transcription (STATs). The Tyk2 subfamily is part of a larger superfamily that includes the catalytic domains of other kinases such as protein serine/threonine kinases, RIO kinases, aminoglycoside phosphotransferase, choline kinase, and phosphoinositide 3-kinase.

                         10        20
                 ....*....|....*....|....*
gi 961554815   1 YQTMLDCWHGEPSQRPTFSELVEHL 25
Cdd:cd05080  254 YHLMKNCWETEASFRPTFENLIPIL 278

Catalytic domain of the Protein Tyrosine Kinase, Csk homologous kinase; PTKs catalyze the transfer of the gamma-phosphoryl group from ATP to tyrosine (tyr) residues in protein substrates. Chk is also referred to as megakaryocyte-associated tyrosine kinase (Matk). Chk inhibits Src kinases using a noncatalytic mechanism by simply binding to them. As a negative regulator of Src kinases, Chk may play important roles in cell proliferation, survival, and differentiation, and consequently, in cancer development and progression. Chk is expressed in brain and hematopoietic cells. Like Csk, it is a cytoplasmic (or nonreceptor) tyr kinase containing the Src homology domains, SH3 and SH2, N-terminal to the catalytic tyr kinase domain. To inhibit Src kinases that are anchored to the plasma membrane, Chk is translocated to the membrane via binding to specific transmembrane proteins, G-proteins, or adaptor proteins near the membrane. Studies in mice reveal that Chk is not functionally redundant with Csk and that it plays an important role as a regulator of immune responses. Chk also plays a role in neural differentiation in a manner independent of Src by enhancing Mapk activation via Ras-mediated signaling. The Chk subfamily is part of a larger superfamily that includes the catalytic domains of other kinases such as protein serine/threonine kinases, RIO kinases, aminoglycoside phosphotransferase, choline kinase, and phosphoinositide 3-kinase.

                         10        20
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gi 961554815   1 YQTMLDCWHGEPSQRPTFSELVEHL 25
Cdd:cd05083  227 YSIMTSCWEAEPGKRPSFKKLREKL 251

Catalytic domain of the Protein Tyrosine Kinase, Platelet Derived Growth Factor Receptor beta; PTKs catalyze the transfer of the gamma-phosphoryl group from ATP to tyrosine (tyr) residues in protein substrates. PDGFR beta is a receptor PTK (RTK) containing an extracellular ligand-binding region with five immunoglobulin-like domains, a transmembrane segment, and an intracellular catalytic domain. The binding to its ligands, the PDGFs, leads to receptor dimerization, trans phosphorylation and activation, and intracellular signaling. PDGFR beta forms homodimers or heterodimers with PDGFR alpha, depending on the nature of the PDGF ligand. PDGF-BB and PDGF-DD induce PDGFR beta homodimerization. PDGFR signaling plays many roles in normal embryonic development and adult physiology. PDGFR beta signaling leads to a variety of cellular effects including the stimulation of cell growth and chemotaxis, as well as the inhibition of apoptosis and GAP junctional communication. It is critical in normal angiogenesis as it is involved in the recruitment of pericytes and smooth muscle cells essential for vessel stability. Aberrant PDGFR beta expression is associated with some human cancers. The continuously-active fusion proteins of PDGFR beta with COL1A1 and TEL are associated with dermatofibrosarcoma protuberans (DFSP) and a subset of chronic myelomonocytic leukemia (CMML), respectively. The PDGFR beta subfamily is part of a larger superfamily that includes the catalytic domains of other kinases such as protein serine/threonine kinases, RIO kinases, aminoglycoside phosphotransferase, choline kinase, and phosphoinositide 3-kinase.

                         10        20
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gi 961554815   1 YQTMLDCWHGEPSQRPTFSELVEHLGNLL 29
Cdd:cd05107  372 YEIMQKCWEEKFEIRPDFSQLVHLVGDLL 400

Catalytic domain of Epidermal Growth Factor Receptor-like Protein Tyrosine Kinases; PTKs catalyze the transfer of the gamma-phosphoryl group from ATP to tyrosine (tyr) residues in protein substrates. EGFR (HER, ErbB) subfamily members include EGFR (HER1, ErbB1), HER2 (ErbB2), HER3 (ErbB3), HER4 (ErbB4), and similar proteins. They are receptor PTKs (RTKs) containing an extracellular EGF-related ligand-binding region, a transmembrane helix, and a cytoplasmic region with a tyr kinase domain and a regulatory C-terminal tail. Unlike other PTKs, phosphorylation of the activation loop of EGFR proteins is not critical to their activation. Instead, they are activated by ligand-induced dimerization, resulting in the phosphorylation of tyr residues in the C-terminal tail, which serve as binding sites for downstream signaling molecules. Collectively, they can recognize a variety of ligands including EGF, TGFalpha, and neuregulins, among others. All four subfamily members can form homo- or heterodimers. HER3 contains an impaired kinase domain and depends on its heterodimerization partner for activation. EGFR subfamily members are involved in signaling pathways leading to a broad range of cellular responses including cell proliferation, differentiation, migration, growth inhibition, and apoptosis. Gain of function alterations, through their overexpression, deletions, or point mutations in their kinase domains, have been implicated in various cancers. These receptors are targets of many small molecule inhibitors and monoclonal antibodies used in cancer therapy. The EGFR subfamily is part of a larger superfamily that includes the catalytic domains of other kinases such as protein serine/threonine kinases, RIO kinases, aminoglycoside phosphotransferase, choline kinase, and phosphoinositide 3-kinase.

                         10        20
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gi 961554815   1 YQTMLDCWHGEPSQRPTFSELVEHL 25
Cdd:cd05057  241 YMVLVKCWMIDAESRPTFKELANEF 265

Catalytic (repeat 2) domain of the Protein Tyrosine Kinase, Janus kinase 3; PTKs catalyze the transfer of the gamma-phosphoryl group from ATP to tyrosine (tyr) residues in protein substrates. Jak3 is expressed only in hematopoietic cells. It binds the shared receptor subunit common gamma chain and thus, is essential in the signaling of cytokines that use it such as IL-2, IL-4, IL-7, IL-9, IL-15, and IL-21. Jak3 is important in lymphoid development and myeloid cell differentiation. Inactivating mutations in Jak3 have been reported in humans with severe combined immunodeficiency (SCID). Jak3 is a member of the Janus kinase (Jak) subfamily of proteins, which are cytoplasmic (or nonreceptor) PTKs containing an N-terminal FERM domain, followed by a Src homology 2 (SH2) domain, a pseudokinase domain, and a C-terminal catalytic tyr kinase domain. Jaks are crucial for cytokine receptor signaling. They are activated by autophosphorylation upon cytokine-induced receptor aggregation, and subsequently trigger downstream signaling events such as the phosphorylation of signal transducers and activators of transcription (STATs). The PTKc family is part of a larger superfamily that includes the catalytic domains of other kinases such as protein serine/threonine kinases, RIO kinases, aminoglycoside phosphotransferase, choline kinase, and phosphoinositide 3-kinase.

                         10        20
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gi 961554815   1 YQTMLDCWHGEPSQRPTFSEL 21
Cdd:cd05081  255 HELMKLCWAPSPQDRPSFSAL 275

Catalytic domain of the Serine/Threonine Kinase, Mixed Lineage Kinase 3; STKs catalyze the transfer of the gamma-phosphoryl group from ATP to serine/threonine residues on protein substrates. MLK3 is a mitogen-activated protein kinase kinase kinases (MAP3K, MKKK, MAPKKK), which phosphorylates and activates MAPK kinases (MAPKKs or MKKs or MAP2Ks), which in turn phosphorylate and activate MAPKs during signaling cascades that are important in mediating cellular responses to extracellular signals. MLK3 activates multiple MAPK pathways and plays a role in apoptosis, proliferation, migration, and differentiation, depending on the cellular context. It is highly expressed in breast cancer cells and its signaling through c-Jun N-terminal kinase has been implicated in the migration, invasion, and malignancy of cancer cells. MLK3 also functions as a negative regulator of Inhibitor of Nuclear Factor-KappaB Kinase (IKK) and consequently, it also impacts inflammation and immunity. Mammals have four MLKs, mostly conserved in vertebrates, which contain an SH3 domain, a catalytic kinase domain, a leucine zipper, a proline-rich region, and a CRIB domain that mediates binding to GTP-bound Cdc42 and Rac. MLKs play roles in immunity and inflammation, as well as in cell death, proliferation, and cell cycle regulation.The MLK3 subfamily is part of a larger superfamily that includes the catalytic domains of other STKs, protein tyrosine kinases, RIO kinases, aminoglycoside phosphotransferase, choline kinase, and phosphoinositide 3-kinase.

                         10        20
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gi 961554815   2 QTMLDCWHGEPSQRPTFSELVEHLGNL 28
Cdd:cd14147  241 QLMADCWAQDPHRRPDFASILQQLEAL 267

Catalytic domain of the Protein Tyrosine Kinase, Fes; PTKs catalyze the transfer of the gamma-phosphoryl group from ATP to tyrosine (tyr) residues in protein substrates. Fes (or Fps) is a cytoplasmic (or nonreceptor) PTK containing an N-terminal region with FCH (Fes/Fer/CIP4 homology) and coiled-coil domains, followed by a SH2 domain, and a C-terminal catalytic domain. The genes for Fes (feline sarcoma) and Fps (Fujinami poultry sarcoma) were first isolated from tumor-causing retroviruses. The viral oncogenes encode chimeric Fes proteins consisting of Gag sequences at the N-termini, resulting in unregulated PTK activity. Fes kinase is expressed in myeloid, vascular endothelial, epithelial, and neuronal cells. It plays important roles in cell growth and differentiation, angiogenesis, inflammation and immunity, and cytoskeletal regulation. A recent study implicates Fes kinase as a tumor suppressor in colorectal cancer. The Fes subfamily is part of a larger superfamily that includes the catalytic domains of other kinases such as protein serine/threonine kinases, RIO kinases, aminoglycoside phosphotransferase, choline kinase, and phosphoinositide 3-kinase.

                         10        20
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gi 961554815   1 YQTMLDCWHGEPSQRPTFSELVEHLG 26
Cdd:cd05084  227 YRLMEQCWEYDPRKRPSFSTVHQDLQ 252

Catalytic domain of the Protein Tyrosine Kinase, Fer; Protein Tyrosine Kinase (PTK) family; Fer kinase; catalytic (c) domain. The PTKc family is part of a larger superfamily that includes the catalytic domains of other kinases such as protein serine/threonine kinases, RIO kinases, and phosphoinositide 3-kinase (PI3K). PTKs catalyze the transfer of the gamma-phosphoryl group from ATP to tyrosine (tyr) residues in protein substrates. Fer kinase is a member of the Fes subfamily of proteins which are cytoplasmic (or nonreceptor) tyr kinases containing an N-terminal region with FCH (Fes/Fer/CIP4 homology) and coiled-coil domains, followed by a SH2 domain, and a C-terminal catalytic domain. Fer kinase is expressed in a wide variety of tissues, and is found to reside in both the cytoplasm and the nucleus. It plays important roles in neuronal polarization and neurite development, cytoskeletal reorganization, cell migration, growth factor signaling, and the regulation of cell-cell interactions mediated by adherens junctions and focal adhesions. Fer kinase also regulates cell cycle progression in malignant cells.

                         10        20
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gi 961554815   1 YQTMLDCWHGEPSQRPTFSELVEHL 25
Cdd:cd05085  225 YKIMQRCWDYNPENRPKFSELQKEL 249

Catalytic domain of the Protein Tyrosine Kinase, Tie2; PTKs catalyze the transfer of the gamma-phosphoryl group from ATP to tyrosine (tyr) residues in protein substrates. Tie2 is a receptor PTK (RTK) containing an extracellular region, a transmembrane segment, and an intracellular catalytic domain. The extracellular region contains an immunoglobulin (Ig)-like domain, three epidermal growth factor (EGF)-like domains, a second Ig-like domain, and three fibronectin type III repeats. Tie2 is expressed mainly in endothelial cells and hematopoietic stem cells. It is also found in a subset of tumor-associated monocytes and eosinophils. The angiopoietins (Ang-1 to Ang-4) serve as ligands for Tie2. The binding of Ang-1 to Tie2 leads to receptor autophosphorylation and activation, promoting cell migration and survival. In contrast, Ang-2 binding to Tie2 does not result in the same response, suggesting that Ang-2 may function as an antagonist. Tie2 signaling plays key regulatory roles in vascular integrity and quiescence, and in inflammation. The Tie2 subfamily is part of a larger superfamily that includes the catalytic domains of other kinases such as protein serine/threonine kinases, RIO kinases, aminoglycoside phosphotransferase, choline kinase, and phosphoinositide 3-kinase.

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gi 961554815   1 YQTMLDCWHGEPSQRPTFSELVEHLGNLLQ 30
Cdd:cd05088  253 YDLMRQCWREKPYERPSFAQILVSLNRMLE 282

Catalytic domain of Tie Protein Tyrosine Kinases; PTKs catalyze the transfer of the gamma-phosphoryl group from ATP to tyrosine (tyr) residues in protein substrates. Tie proteins, consisting of Tie1 and Tie2, are receptor PTKs (RTKs) containing an extracellular region, a transmembrane segment, and an intracellular catalytic domain. The extracellular region contains an immunoglobulin (Ig)-like domain, three epidermal growth factor (EGF)-like domains, a second Ig-like domain, and three fibronectin type III repeats. Tie receptors are specifically expressed in endothelial cells and hematopoietic stem cells. The angiopoietins (Ang-1 to Ang-4) serve as ligands for Tie2, while no specific ligand has been identified for Tie1. The binding of Ang-1 to Tie2 leads to receptor autophosphorylation and activation, promoting cell migration and survival. In contrast, Ang-2 binding to Tie2 does not result in the same response, suggesting that Ang-2 may function as an antagonist. In vivo studies of Tie1 show that it is critical in vascular development. The Tie subfamily is part of a larger superfamily that includes the catalytic domains of other kinases such as protein serine/threonine kinases, RIO kinases, aminoglycoside phosphotransferase, choline kinase, and phosphoinositide 3-kinase.

                         10        20        30
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gi 961554815   1 YQTMLDCWHGEPSQRPTFSELVEHLGNLLQ 30
Cdd:cd05047  241 YDLMRQCWREKPYERPSFAQILVSLNRMLE 270

Catalytic domain of the Protein Tyrosine Kinase, Insulin Receptor; PTKs catalyze the transfer of the gamma-phosphoryl group from ATP to tyrosine (tyr) residues in protein substrates. InsR is a receptor PTK (RTK) that is composed of two alphabeta heterodimers. Binding of the insulin ligand to the extracellular alpha subunit activates the intracellular tyr kinase domain of the transmembrane beta subunit. Receptor activation leads to autophosphorylation, stimulating downstream kinase activities, which initiate signaling cascades and biological function. InsR signaling plays an important role in many cellular processes including glucose homeostasis, glycogen synthesis, lipid and protein metabolism, ion and amino acid transport, cell cycle and proliferation, cell differentiation, gene transcription, and nitric oxide synthesis. Insulin resistance, caused by abnormalities in InsR signaling, has been described in diabetes, hypertension, cardiovascular disease, metabolic syndrome, heart failure, and female infertility. The InsR subfamily is part of a larger superfamily that includes the catalytic domains of other kinases such as serine/threonine kinases, RIO kinases, aminoglycoside phosphotransferase, choline kinase, and phosphoinositide 3-kinase.

                         10        20        30
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gi 961554815   4 MLDCWHGEPSQRPTFSELVEHLGNLLQANAQQ 35
Cdd:cd05061  254 MRMCWQFNPKMRPTFLEIVNLLKDDLHPSFPE 285

Catalytic domain of the Protein Tyrosine Kinase, HER2; PTKs catalyze the transfer of the gamma-phosphoryl group from ATP to tyrosine (tyr) residues in protein substrates. HER2 (ErbB2, HER2/neu) is a member of the EGFR (HER, ErbB) subfamily of proteins, which are receptor PTKs (RTKs) containing an extracellular EGF-related ligand-binding region, a transmembrane helix, and a cytoplasmic region with a tyr kinase domain and a regulatory C-terminal tail. Unlike other PTKs, phosphorylation of the activation loop of EGFR proteins is not critical to their activation. Instead, they are activated by ligand-induced dimerization, leading to the phosphorylation of tyr residues in the C-terminal tail, which serve as binding sites for downstream signaling molecules. HER2 does not bind to any known EGFR subfamily ligands, but contributes to the kinase activity of all possible heterodimers. It acts as the preferred partner of other ligand-bound EGFR proteins and functions as a signal amplifier, with the HER2-HER3 heterodimer being the most potent pair in mitogenic signaling. HER2 plays an important role in cell development, proliferation, survival and motility. Overexpression of HER2 results in its activation and downstream signaling, even in the absence of ligand. HER2 overexpression, mainly due to gene amplification, has been shown in a variety of human cancers. Its role in breast cancer is especially well-documented. HER2 is up-regulated in about 25% of breast tumors and is associated with increases in tumor aggressiveness, recurrence and mortality. HER2 is a target for monoclonal antibodies and small molecule inhibitors, which are being developed as treatments for cancer. The first humanized antibody approved for clinical use is Trastuzumab (Herceptin), which is being used in combination with other therapies to improve the survival rates of patients with HER2-overexpressing breast cancer. The HER2 subfamily is part of a larger superfamily that includes the catalytic domains of other kinases such as protein serine/threonine kinases, RIO kinases, aminoglycoside phosphotransferase, choline kinase, and phosphoinositide 3-kinase.

                         10        20
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gi 961554815   1 YQTMLDCWHGEPSQRPTFSELVEHLGNL 28
Cdd:cd05109  241 YMIMVKCWMIDSECRPRFRELVDEFSRM 268

Catalytic domain of the Protein Tyrosine Kinases, Tropomyosin Related Kinases; PTKs catalyze the transfer of the gamma-phosphoryl group from ATP to tyrosine (tyr) residues in protein substrates. The Trk subfamily consists of TrkA, TrkB, TrkC, and similar proteins. They are receptor PTKs (RTKs) containing an extracellular region with arrays of leucine-rich motifs flanked by two cysteine-rich clusters followed by two immunoglobulin-like domains, a transmembrane segment, and an intracellular catalytic domain. Binding to their ligands, the nerve growth factor (NGF) family of neutrotrophins, leads to Trk receptor oligomerization and activation of the catalytic domain. Trk receptors are mainly expressed in the peripheral and central nervous systems. They play important roles in cell fate determination, neuronal survival and differentiation, as well as in the regulation of synaptic plasticity. Altered expression of Trk receptors is associated with many human diseases. The Trk subfamily is part of a larger superfamily that includes the catalytic domains of other kinases such as protein serine/threonine kinases, RIO kinases, aminoglycoside phosphotransferase, choline kinase, and phosphoinositide 3-kinase.

                         10        20
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gi 961554815   1 YQTMLDCWHGEPSQRPTFSELVEHL 25
Cdd:cd05049  254 YAVMLGCWKREPQQRLNIKDIHKRL 278

Catalytic domain of the Serine/Threonine Kinases, Mitogen-Activated Protein Kinase Kinase Kinases 12 and 13; STKs catalyze the transfer of the gamma-phosphoryl group from ATP to serine/threonine residues on protein substrates. MAP3K12 is also called MAPK upstream kinase (MUK), dual leucine zipper-bearing kinase (DLK) or leucine-zipper protein kinase (ZPK). It is involved in the c-Jun N-terminal kinase (JNK) pathway that directly regulates axonal regulation through the phosphorylation of microtubule-associated protein 1B (MAP1B). It also regulates the differentiation of many cell types including adipocytes and may play a role in adipogenesis. MAP3K13, also called leucine zipper-bearing kinase (LZK), directly phosphorylates and activates MKK7, which in turn activates the JNK pathway. It also activates NF-kB through IKK activation and this activity is enhanced by antioxidant protein-1 (AOP-1). MAP3Ks (MKKKs or MAPKKKs) phosphorylate and activate MAP2Ks (MAPKKs or MKKs), which in turn phosphorylate and activate MAPKs during signaling cascades that are important in mediating cellular responses to extracellular signals. The MAP3K12/13 subfamily is part of a larger superfamily that includes the catalytic domains of other STKs, protein tyrosine kinases, RIO kinases, aminoglycoside phosphotransferase, choline kinase, and phosphoinositide 3-kinase.

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gi 961554815   4 MLDCWHGEPSQRPTFSELVEHL 25
Cdd:cd14059  213 MKQCWNSKPRNRPSFRQILMHL 234

Catalytic domain of the Protein Tyrosine Kinase, Discoidin Domain Receptor 1; PTKs catalyze the transfer of the gamma-phosphoryl group from ATP to tyrosine (tyr) residues in protein substrates. DDR1 is a receptor PTK (RTK) containing an extracellular discoidin homology domain, a transmembrane segment, an extended juxtamembrane region, and an intracellular catalytic domain. The binding of the ligand, collagen, to DDR1 results in a slow but sustained receptor activation. DDR1 binds to all collagens tested to date (types I-IV). It is widely expressed in many tissues. It is abundant in the brain and is also found in keratinocytes, colonic mucosa epithelium, lung epithelium, thyroid follicles, and the islets of Langerhans. During embryonic development, it is found in the developing neuroectoderm. DDR1 is a key regulator of cell morphogenesis, differentiation and proliferation. It is important in the development of the mammary gland, the vasculator and the kidney. DDR1 is also found in human leukocytes, where it facilitates cell adhesion, migration, maturation, and cytokine production. The DDR1 subfamily is part of a larger superfamily that includes the catalytic domains of other kinases such as protein serine/threonine kinases, RIO kinases, aminoglycoside phosphotransferase, choline kinase, and phosphoinositide 3-kinase.

                         10        20
                 ....*....|....*....|.
gi 961554815   1 YQTMLDCWHGEPSQRPTFSEL 21
Cdd:cd05096  278 YELMLQCWSRDCRERPSFSDI 298