Prostaglandin D2 receptor (PTGDR) is a receptor for prostoglandin D2, and is functionally involved in promoting allergic response. It is mediated by G(s) proteins that stimulate adenylate cyclase, resulting in an elevation of intracellular cAMP. A mobilization of calcium is also observed, but without formation of inositol 1,4,5-trisphosphate. In the central nervous system, this receptor regulates non-rapid eye movement sleep. In immunohistochemistry, PTGDR has membranous positivity in platelets, glandular cells in gastrointestinal tissue, and the pons and medulla, olfactory region, basal ganglia and spinal cord in the brain and nervous system. References: The UniProt Consortium. Nucleic Acids Res. 47: D506-515 (2019); Nucleic Acids Res. 2016 Jan 4;44(D1):D733-45, PMID:26553804