The Drosophila transient receptor potential (trp) gene and its homolog
ue, trpl, have been suggested to mediate calcium entry during the inse
ct's phototransduction process. We isolated a human cDNA, human trp-1
(Htrp-1), encoding a polypeptide of 793 amino acids that is 37% identi
cal (62% similar) to Drosophila trp and trpl, Northern analysis showed
that the Htrp-1 transcript is approximately 5.5 kb and expressed in m
ost human tissues, with higher amounts in ovary, testis, heart, and br
ain, Isolation of Htrp-1 suggests that a tip-type protein is present i
n mammals and should provide a useful tool in studying calcium-depleti
on induced calcium influx processes.