The sigma-2 receptor (σ2R) is a sigma receptor subtype that has attracted attention due to its involvement in diseases such as neurological diseases, neurodegenerative, neuro-ophthalmic and cancer. It is currently [when?] under investigation for its potential diagnostic and therapeutic uses.[5]
Although the sigma-2 receptor was identified as a separate pharmacological entity from the sigma-1 receptor in 1990,[6] the gene that codes for the receptor was identified as TMEM97 only in 2017.[7]TMEM97 was shown to regulate the cholesterol transporter NPC1 and to be involved in cholesterol homeostasis.[8][9] The sigma-2 receptor is a four-pass transmembrane protein located in the endoplasmic reticulum. It has been found to play a role in both hormone signaling and calcium signaling, in neuronal signaling, in cell proliferation and death, and in binding of antipsychotics.[10]
^Hellewell SB, Bowen WD (September 1990). "A sigma-like binding site in rat pheochromocytoma (PC12) cells: decreased affinity for (+)-benzomorphans and lower molecular weight suggest a different sigma receptor form from that of guinea pig brain". Brain Research. 527 (2): 244–253. doi:10.1016/0006-8993(90)91143-5. PMID2174717. S2CID24546226.
^Ahmed IS, Chamberlain C, Craven RJ (March 2012). "S2R(Pgrmc1): the cytochrome-related sigma-2 receptor that regulates lipid and drug metabolism and hormone signaling". Expert Opinion on Drug Metabolism & Toxicology. 8 (3): 361–370. doi:10.1517/17425255.2012.658367. PMID22292588. S2CID207491179.