ABSTRACT
The family of transient receptor potential canonical (TRPC) proteins was the —rst group of TRP homologs cloned in mammals1 after discovery of the TRP protein in Drosophila.2 There are seven members in this family (TRPC1-7). The TRPC channels formed by homo-or heteromeric TRPC proteins are Ca2+-permeable nonselective cation channels. According to the similarity in amino acid sequence, the mammalian TRPCs can be classi—ed into four subgroups: TRPC1, TRPC2, TRPC3/6/7, and TRPC4/5,3 while the TRPC2 is a pseudogene in primates.4 The TRPC proteins have six transmembrane domains, and both N-and C-termini of these proteins are intracellular, suggesting that these channels can be regulated by intra cellular signaling molecules. These channels can be activated in various cell types by G-protein-coupled receptors (GPCR) and receptor tyrosine kinases (RTK) through a phospholipase C (PLC)-dependent mechanism. Therefore, TRPC channels may act as a sensor for environmental cues.
