Cloning, expression and subcellular localization of two novel splice variants of mouse transient receptor potential channel 2

Citation
T. Hofmann et al., Cloning, expression and subcellular localization of two novel splice variants of mouse transient receptor potential channel 2, BIOCHEM J, 351, 2000, pp. 115-122
Citations number
38
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Biochemistry & Biophysics
Journal title
BIOCHEMICAL JOURNAL
ISSN journal
0264-6021 → ACNP
Volume
351
Year of publication
2000
Part
1
Pages
115 - 122
Database
ISI
SICI code
0264-6021(20001001)351:<115:CEASLO>2.0.ZU;2-0
Abstract
Transient receptor potential channels (TRPCs) are known as candidate molecu lar correlates of receptor-activated or store-operated calcium entry. While functional roles for most TRPCs have been suggested, the physiological rel evance of TRPC2 remains obscure. Whereas human and bovine TRPC2 are candida te pseudogenes, full-length rodent TRPC2 transcripts have been reported. Th ere is, however, considerable controversy concerning mRNA splicing, tissue distribution and the function of these proteins. We report the molecular cl oning of two novel murine TRPC2 splice variants, mTRPC2 alpha and mTRPC2 be ta. mTRPC2 alpha RNA is expressed at low levels in many tissues and cell sy stems, while mTRPC2 beta is exclusively and abundantly expressed in the vom eronasal organ (VNO). When expressed in human embryonic kidney (HEK)-293 ce lls, mTRPC2 did not enhance receptor- or store-activated calcium entry. In order to investigate the: basis of such a functional defect, mTRPC2-green f luorescent protein fusion proteins were examined by confocal microscopy. Fu sion proteins were retained in endomembranes when expressed in HEK-293 or o ther cells of epithelial or neuronal origin. Go-expression of TRPC2 with ot her TRPCs did not restore plasma-membrane trafficking. We conclude that TRP C2 may form functional channels in the cellular context of the VNO, but is unlikely to have a physiological function in other tissues.