When first discovered it was named CAT1, or ECaC2. The name TRPV6 was confirmed in 2005.
TRPV6 is a member of the transient receptor potential (TRP) family of membrane proteins. Unlike most TRP channels, TRPV6 is selective for Ca2+ ions, a property shared with its close homologue, TRPV5, which is mainly expressed in the kidney and plays a role in renal Ca2+ reabsorption.
TRPV6 expression has been described in the intestine in several species, including humans. The protein is located in the apical brush-border membrane of the intestinal enterocyte where it regulates calcium entry into the cell. It is most abundant in the proximal small intestine (duodenum and jejunum), along with the other calcium transport proteins, calbindin and the calcium-pumping ATPase, PMCA1. The TRPV6 calcium transporter also found in the human placenta, pancreas and prostate gland and in some species in the kidney, where the related channel TRPV5 is strongly expressed.
Regulation of expression
Expression of TRPV6 is vitamin D dependent in mice and humans. Its expression was greatly reduced in animals that do not express the vitamin D receptor.
Vitamin D treatment of human colon cancer cells, Caco-2, increased expression of TRPV6 transcripts, and also stimulated the transport of calcium, probably through increased TRPV6 expression. In human duodenal explants, TRPV6 transcript expression was increased 3-fold after 6h incubation with the active form of vitamin D, 1,25-dihydroxycholecalciferol.
^Peng JB, Chen XZ, Berger UV, Vassilev PM, Tsukaguchi H, Brown EM, Hediger MA (August 1999). "Molecular cloning and characterization of a channel-like transporter mediating intestinal calcium absorption". J. Biol. Chem. 274 (32): 22739–46. doi:10.1074/jbc.274.32.22739. PMID10428857.
^Weber K, Erben RG, Rump A, Adamski J (December 2001). "Gene structure and regulation of the murine epithelial calcium channels ECaC1 and 2". Biochem. Biophys. Res. Commun. 289 (5): 1287–94. doi:10.1006/bbrc.2001.6121. PMID11741335.
^Clapham DE, Julius D, Montell C, Schultz G (December 2005). "International Union of Pharmacology. XLIX. Nomenclature and structure-function relationships of transient receptor potential channels". Pharmacol. Rev. 57 (4): 427–50. doi:10.1124/pr.57.4.6. PMID16382100.
Clapham DE, Julius D, Montell C, Schultz G (2006). "International Union of Pharmacology. XLIX. Nomenclature and structure-function relationships of transient receptor potential channels". Pharmacol. Rev. 57 (4): 427–50. doi:10.1124/pr.57.4.6. PMID16382100.