Cloning and expression localization of cDNA for rat homolog of TRP protein, a possible store-operated calcium (Ca2+) channel.
A 3.2 kbp cDNA clone encoding a possible candidate for the store-operated Ca2+ channel was isolated from a rat brain cDNA library. The deduced amino acid sequence was 51.8% identical to TRP encoded by a Drosophila trp (transient receptor potential) gene and contained ankyrin motifs, a coiled-coil structure and six transmembrane segments similar to the previously identified TRP family and named as TRP-R (rat TRP). By in situ hybridization histochemistry of rat body on embryonic day 15, no significant expression signal for TRP-R was detected. On embryonic day 20 and postnatal day 1, the expression signals were most evident in the septum, cerebral cortical plate and hippocampal neuronal layers. On postnatal day 7 and thereafter the expression in the cerebral cortex and the septum decreased progressively, and weak expression remained only in the CA1 and CA2 neuronal layers of the hippocampus in the brain on postnatal day 21 and 49. This limited spatiotemporal expression of this novel molecule. TRP-R, suggests that it is involved in some specific functions related to the neuronal differentiation.