MOLECULAR-CLONING OF A NOVEL PUTATIVE CA2+ CHANNEL PROTEIN (TRPC7) HIGHLY EXPRESSED IN BRAIN

We have isolated cDNA clones for a novel human protein, TRPC7 (transie nt receptor potential-related channels), which consists of 1503 amino acid residues from the fetal brain and caudate nucleus cDNA libraries. Northern blot analysis indicated that the TRPC7 gene is highly expres sed as a 6.5-kb transcript in brain. The TRPC7 protein has significant homology with Caenorhabditis elegans hypothetical proteins T01H8.5, C 05C12.3, and F54D1.5 and with Drosophila and human transient receptor potential (trp) proteins. The TRPC7 protein has seven putative transme mbrane domains that probably constitute a Ca2+ channel as in the above -mentioned proteins. Genomic sequencing revealed that the TRPC7 gene c onsists of 32 exons spanning approximately 90 kb. The TRPC7 gene was m apped between D21S400 and D21S171 on human chromosome 21q22.3, 14 kb d istal to a NotI site in D21S400. This novel TRPC7 gene could be a cand idate gene for genetic disorders such as bipolar affective disorder, n onsyndromic hereditary deafness, Knobloch syndrome, and holoprosenceph aly, which were mapped to this region, (C) 1998 Academic Press.