atypical chemokine receptor 2, member of the class A family of seven-transmembrane G protein-coupled receptors
ACKR2 (also known as D6) binds non-selectively to all inflammatory CC-chemokines, but not to homeostatic CC-chemokines involved in controlling the migration of cells. Unlike the classical chemokine receptors that contain a conserved DRYLAIV motif in the second intracellular loop, which is required for G-protein coupling, the ACKRs lack this conserved motif and fail to couple to G-proteins and induce classical GPCR signaling. Five receptors have been identified for the ACKR family, including CC-chemokine receptors like 1 and 2 (CCRL1 and CCRL2), CXCR7, Duffy antigen receptor for chemokine (DARC), and D6. Both ACKR1 (DARC) and ACKR3 (CXCR7) show low sequence homology to the classic chemokine receptors.