TRPC1, a human homolog of a Drosophila store-operated channel.
In many vertebrate and invertebrate cells, inositol 1,4,5-trisphospate production induces a biphasic Ca2+ signal. Mobilization of Ca2+ from internal stores drives the initial burst. The second phase, referred to as store-operated Ca2+ entry (formerly capacitative Ca2+ entry), occurs when depletion of intracellular Ca2+ pools activates a non-voltage-sensitive plasma membrane Ca2+ conductance. Despite the prevalence of store-operated Ca2+ entry, no vertebrate channel responsible for store-operated Ca2+ entry has been reported. trp (transient receptor potential), a Drosophila gene required in phototransduction, encodes the only known candidate for such a channel throughout phylogeny. In this report, we describe the molecular characterization of a human homolog of trp, TRPC1. TRPC1 (transient receptor potential channel-related protein 1) was 40% identical to Drosophila TRP over most of the protein and lacked the charged residues in the S4 transmembrane region proposed to be required for the voltage sensor in many voltage-gated ion channels. TRPC1 was expressed at the highest levels in the fetal brain and in the adult heart, brain, testis, and ovaries. Evidence is also presented that TRPC1 represents the archetype of a family of related human proteins.
Wes
P D
PD
Department of Biological Chemistry, Johns Hopkins University, School of Medicine, Baltimore, MD 21205, USA.
Chevesich
J
J
Jeromin
A
A
Rosenberg
C
C
Stetten
G
G
Montell
C
C
D000328:Adult; D000595:Amino Acid Sequence; D000818:Animals; D005075:Biological Evolution; D015220:Calcium Channels / Q000235:genetics*; D002893:Chromosomes, Human, Pair 3; D017124:Conserved Sequence; D018076:DNA, Complementary / Q000235:genetics; D004330:Drosophila; D029721:Drosophila Proteins; D004622:Embryo, Mammalian; D004625:Embryo, Nonmammalian; D015698:Genomic Library; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D007301:Insect Hormones / Q000235:genetics*; D019476:Insect Proteins; D007473:Ion Channels / Q000235:genetics*; D008565:Membrane Proteins / Q000235:genetics*; D008969:Molecular Sequence Data; D005810:Multigene Family; D011487:Protein Conformation; D051381:Rats; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid; D050052:TRPC Cation Channels; D014018:Tissue Distribution; D050051:Transient Receptor Potential Channels
D015220:Calcium Channels; D018076:DNA, Complementary; D029721:Drosophila Proteins; D007301:Insect Hormones; D019476:Insect Proteins; D007473:Ion Channels; D008565:Membrane Proteins; D050052:TRPC Cation Channels; D050051:Transient Receptor Potential Channels; C096351:transient receptor potential cation channel, subfamily C, member 1; C063169:trp protein, Drosophila