CXC chemokine receptor type 3, member of the class A family of seven-transmembrane G protein-coupled receptors
CXCR3 is an inflammatory chemotactic receptor for a group of CXC chemokines distinguished by the presence of the amino acid motif ELR immediately adjacent to their CXC motif. CXCR3 specifically binds three chemokines CXCL9 (monokine induced by gamma-interferon), CXCL10 (interferon induced protein of 10 kDa), and CXCL11 (interferon inducible T-cell alpha-chemoattractant, I-TAC). CXC3R is expressed on CD4+ Th1 and CD8+ cytotoxic T lymphocytes as well as highly on innate lymphocytes, such as NK cells and NK T cells, where it may mediate the recruitment of these cells to the sites of infection and inflammation. 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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