CC chemokine receptor type 1, member of the class A family of seven-transmembrane G protein-coupled receptors
CCR1 is widely expressed on both hematopoietic and non-hematopoietic cells and binds to the inflammatory CC chemokines CCL3, CCL5, CCL6, CCL9, CCL15, and CCL23. CCR1 activates the typical chemokine signaling pathway through the G(i/o) type of G proteins, causing inhibition of adenylate cyclase and stimulation of phospholipase C, PKC, calcium flux, and PLA2. 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.