?
Catalytic domain of the Serine/Threonine Kinase, Bone Morphogenetic Protein Type I Receptor STKs catalyze the transfer of the gamma-phosphoryl group from ATP to serine/threonine residues on protein substrates. BMPR1 functions as a receptor for morphogenetic proteins (BMPs), which are involved in the regulation of cell proliferation, survival, differentiation, and apoptosis. BMPs are able to induce bone, cartilage, ligament, and tendon formation, and may play roles in bone diseases and tumors. Vertebrates contain two type I BMP receptors, BMPR1a and BMPR1b. BMPR1 belongs to a group of receptors for the TGFbeta family of secreted signaling molecules that also includes TGFbeta, activins, growth and differentiation factors, and anti-Mullerian hormone, among others. These receptors contain an extracellular domain that binds ligands, a single transmembrane (TM) region, and a cytoplasmic catalytic kinase domain. Type I receptors, like BMPR1, are low-affinity receptors that bind ligands only after they are recruited by the ligand/type II high-affinity receptor complex. Following activation, they start intracellular signaling to the nucleus by phosphorylating SMAD proteins. Type I receptors contain an additional domain located between the TM and kinase domains called the GS domain, which contains the activating phosphorylation site and confers preference for specific SMAD proteins. The BMPR1 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.
|