UniProt: Q99788. G-protein coupled receptor ChemR23 is a 373 amino acid protein that belongs to the G-protein coupled receptor 1 family, with two potential glycosylation sites and one disulfide bond. The ligand chemerin (or retinoic acid receptor responder protein 2, RARRES2) is a 14 kDa protein found to stimulate chemotaxis of dendritic cells, monocytes/macrophages and natural killer cells to the site of inflammation. Accordingly, there is abundant expression of the receptor on these cells. ChemR23 is prominently expressed in developing osseous and cartilaginous tissue, as well as in tissues associated with hematopoietic and immune function including spleen, thymus, appendix, lymph node, bone marrow and fetal liver. The receptor is also found in adult parathyroid glands, in the cardiovascular system, brain, kidney, gastrointestinal and myeloid tissues and on endothelial cells. ChemR23 acts as a coreceptor for several SIV strains, as well as a primary HIV-1 strain. Application: IHC (p)