EXPRESSION AND CHARACTERIZATION OF A TRPL HOMOLOG FROM RAT

Mammalian homologues of the Drosophila trp/trpl-gene-family code for ' 'Ca2+-store-operated'' channels. Here we describe the cloning and expr ession of a trp/trpl homologous gene from rat brain. The clone is name d Rtrp3 because of its high homology to the recently described Htrp3 ( Zhu et al (1996) Cell 85:661-671). Expression of Rtrp3 in the mammalia n COS-1 cell line leads to 100% increase of capacitative Ca2+ entry as compared to the controls. This capacitative calcium entry can be comp letely blocked with La3+ (10 mu M). We conclude that Rtrp3, a new memb er of the growing family of trp/trpl homologues in mammalians, is invo lved in ''Ca2+-store-operated'' Ca2+ entry into the cell. (C) 1997 Aca demic Press.