CC chemokine receptor type 3, member of the class A family of seven-transmembrane G protein-coupled receptors
CCR3 is a highly promiscuous receptor that binds a variety of inflammatory CC-type chemokines, including CCL11 (eotaxin-1), CCL3L1, CCL5 (regulated on activation, normal T cell expressed and secreted; RANTES), CCL7 (monocyte-specific chemokine 3 or MCP-3), CCL8 (MCP-2), CCL11, CCL13 (MCP-4), CCL15, CCL24 (eotaxin-2), CCL26 (eotaxin-3), and CCL28. Among these, the eosinophil chemotactic chemokines (CCL11, CCL24, and CCL26) are the most potent and specific ligands. In addition to eosinophil, CCR3 is expressed on cells involved in allergic responses, such as basophils, Th2 lymphocytes, and mast cells. Chemokines are principal regulators for leukocyte trafficking, recruitment, and activation. Chemokine family membership is defined on the basis of sequence homology and on the presence of variations on a conserved cysteine motif, which allows the family to further divide into four subfamilies (CC, CXC, XC, and CX3C). Chemokines interact with seven-transmembrane receptors which are typically coupled to G protein for signaling. Currently, there are ten known receptors for CC chemokines, seven for CXC chemokines, and single receptors for the XC and CX3C chemokines.
Comment:Small-molecule chemical ligands tend to bind deeper within the receptor core, compared to a peptide ligand neurotensin, which binds towards the extracellular surface of its receptor.
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