C-C chemokine receptor type 4; C-C CKR-4; CC-CKR-4; CCR-4; CCR4; K5-5; CD194 (CCR4, CMKBR4)

Function

• high affinity receptor for the C-C type chemokines CCL17/TARC & CCL22/MDC
• activity is mediated by Gi proteins which activate a phosphatidylinositol-Ca+2 second messenger system
• can function as a chemoattractant homing receptor on circulating memory lymphocytes
• in the CNS, could mediate hippocampal-neuron survival
• in natural killer cells, CCL22 binding induces phosphorylation on yet undefined Ser/Thr residues, probably by beta-adrenergic receptor kinases BARK1 & BARK2

Structure

belongs to the G-protein coupled receptor 1 family

Compartment

cell membrane

Expression

• expressed in the thymus, in peripheral blood leukocytes, including T-cells, mostly CD4+ cells, & basophils, & in platelets > spleen, monocytes
• also detected in macrophages, IL-2-activated NK cells & skin-homing memory T-cells, mostly expressing cutaneous lymphocyte antigen (CLA)
• expressed in brain microvascular & coronary artery endothelial cells

Pathology

• coreceptor for some primary HIV-2 isolates

More general terms

• CC chemokine receptor
• CD antigen
• glycoprotein

Database

• Kegg: http://www.genome.jp/dbget-bin/www_bget?hsa:1233
• OMIM: https://mirror.omim.org/entry/604836
• UniProt: http://www.uniprot.org/uniprot/P51679.html
• Entrez gene: http://www.ncbi.nlm.nih.gov/sites/entrez?db=gene&cmd=Retrieve&dopt=Graphics&list_uids=1233