High affinity receptor for the C-C type chemokines CCL17/TARC and CCL22/MDC. The activity of this receptor is mediated by G(i) proteins which activate a phosphatidylinositol-calcium second messenger system. Can function as a chemoattractant homing receptor on circulating memory lymphocytes and as a coreceptor for some primary HIV-2 isolates. In the CNS, could mediate hippocampal-neuron survival.
Predominantly expressed in the thymus, in peripheral blood leukocytes, including T-cells, mostly CD4+ cells, and basophils, and in platelets; at lower levels, in the spleen and in monocytes. Detected also in macrophages, IL-2-activated natural killer cells and skin-homing memory T-cells, mostly the ones expressing the cutaneous lymphocyte antigen (CLA). Expressed in brain microvascular and coronary artery endothelial cells.
Belongs to the G-protein coupled receptor 1 family.
In natural killer cells, CCL22 binding induces phosphorylation on yet undefined Ser/Thr residues, most probably by beta-adrenergic receptor kinases 1 and 2.