Molecular and functional diversity of the TRPC family of ion channels. TRPC channels and their role in ROCE/SOCE

摘要

The Drosophila trp mutation is responsible for the phenotype called "transient receptor potential", an alteration of the fly's electrorentinogram in which its sustained phase is missing (Pak et al. 1970; Hotta and Benzer 1970). The responsible gene was cloned in 1989 (Montell and Rubin 1989). Its could potentially fsequenceorm transmembrane segments. Purification and cloning of a calmodulin-binding protein from Drosophila heads showed it to be a homologue of trpamino acid predicted a protein with eight hydrophobic segments that. It received the name trp-like or trpl (Phillips et al. 1992). Its discoverers highlighted the existence of limited sequence similarities between trp/trpl and voltage-sensitive Na~+ and Ca~(2+) channels. Expression of trpl in silkworm cells of Spodoptera frugiperda (Sf9 cells) did indeed lead to the appearance of cation channels (Hu et al. 1994). In keeping with both a role for trp and trpl in insect phototransduction and with the fact that insect phototransduction is biochemically akin to mammalian signal transduction based on the Gq-PLC(beta) pathway instead of a transducin-phosphodiesterase (Gt-PDE) pathway (Devary et al. 1987; Selinger and Minke 1988), the trpl channels expressed in Sf9 cells could be activated by a Gq-coupled GPCR (Hu and Schilling 1995).