CXCR5 (C-X-Chemokine Receptor Type 5, CD185) also known as Burkitt lymphoma receptor 1 (BLR1) belongs to the CXC chemokine receptor family. CXCR5 is a G protein-coupled seven transmembrane receptor for chemokine BLC. CXCR5 gene is specifically expressed in Burkitt's lymphoma and lymphatic tissues, such as follicles in lymph nodes, as well as in spleen. Studies of CXCR5 suggest that it plays an essential role in B cell migration. CXCR5 expression has been reported in human blood and salivary gland and in animal lymphatic organs, blood, bone marrow, brain, liver, lymph node, skin, spleen, stomach, and tonsil. ESTs (expressed sequence tags) have been isolated from human brain, germ cell, lung, lymph, and pancreas. G-protein Coupled Receptors (GPCRs) comprise one of the largest families of signaling molecules with more than a thousand members currently predicted to exist. All GPCRs share a structural motif consisting of seven membrane-spanning helices, and exist in both active and inactive forms. An array of activating ligands participate in the conformation of GPCRs which leads to signaling via G-proteins and downstream effectors. Research studies have also shown the vast series of reactions which participate in the negative regulation of GPCRs. This "turn-off" activity in GPCRs have tremendous implications for the physiological action of the cell, and continues to drive pharmacological research for new drug candidates. Two blockbuster drugs which have been developed as GPCR-targeted pharmaceuticals are Zyprexa (Eli Lilly) and Claritin (Schering-Plough) which are used in mental health and allergy applications, respectively.
Blr-1; Burkitt lymphoma receptor 1 homolog; C Cmotif chemokine; C X C motif chemokine; C-X-C chemokine receptor type 5; CC motif chemokine; CCmotif chemokine; CD185; CD185 antigen; chemochine (C-X-C motif) receptor 5; CXC; CXC motif chemokine; CXC-R5; GPR9; HUMSTR