Molecular cloning and immunolocalization of a novel vertebrate trp homologue from Xenopus

We report the sequence, structure and distribution of a novel transient rec eptor potential (trp) homologue from Xenopus, Xtrp, determined by screening an oocyte cDNA library. On the basis of sequence similarity and predicted structure, Xtrp appears to be a homologue of mammalian trp1 proteins. Two p olyclonal antibodies raised against distinct regions of the Xtrp sequence r evealed Xtrp expression in various Xenopus tissues, and the localization of Xtrp at the plasma membrane of Xenopus oocytes and HeLa cells. Since capac itative calcium entry into Xenopus oocytes has been shown previously to be substantially inhibited by trp1 antisense oligonucleotides [Tomita, Kaneko, Funayama, Kondo, Satoh and Akaike (1998) Neurosci. Lett. 248, 195-198] we suggest that Xtrp may underlie capacitative calcium entry in Xenopus tissue s.