title: cDNA cloning and characterization of an osmotically sensitive TRP channel from ascidian eggs.
abstract: The transient receptor potential (TRP) ion channels are thought to be involved in the entry of calcium ion into cells. In this study, we isolated a cDNA clone, HrTRPV, that shows high homology to Caenorhabditis elegans OSM-9, a TRPV subfamily member of the TRP family, from a Halocynthia roretzi fertilized egg cDNA library. We analyzed its properties using HrTRPV-transfected cells. Upon reduction of extracellular osmolarity, the intracellular calcium concentration was found to increase in HrTRPV-transfected cells. This increase in intracellular calcium concentration was dependent on the presence of extracellular calcium ion and was inhibited by treatment with gadolinium ion, a stretch-activated calcium channel blocker. Thus, these results indicate that ascidian egg HrTRPV is an osmotically sensitive TRP channel.
authors.affiliation: Department of Biochemistry, Graduate School of Pharmaceutical Sciences, Hokkaido University, Sapporo 060-0812, Japan.
authors.forename: Masahiro
authors.initials: M
authors.lastname: Kondoh
authors.forename: Tomoyo
authors.initials: T
authors.lastname: Kasai
authors.forename: Masumi
authors.initials: M
authors.lastname: Shimada
authors.forename: Makoto
authors.initials: M
authors.lastname: Kashiwayanagi
authors.forename: Hideyoshi
authors.initials: H
authors.lastname: Yokosawa
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D015153:Blotting, Western; D002118:Calcium / Q000378:metabolism; D015220:Calcium Channels / Q000235:genetics* / Q000378:metabolism; D020013:Calcium Signaling / Q000502:physiology; D002460:Cell Line; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification; D004527:Egg Proteins / Q000235:genetics* / Q000378:metabolism; D016650:Fluorescein-5-isothiocyanate / Q000737:chemistry / Q000378:metabolism; D005455:Fluorescent Antibody Technique / Q000379:methods; D006801:Humans; D007473:Ion Channels / Q000235:genetics / Q000378:metabolism; D008969:Molecular Sequence Data; D009997:Osmotic Pressure; D010802:Phylogeny; D021122:Protein Subunits / Q000235:genetics; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA; D050052:TRPC Cation Channels; D014162:Transfection; D014561:Urochordata / Q000235:genetics*
chemical_list: D015220:Calcium Channels; D018076:DNA, Complementary; D004527:Egg Proteins; D007473:Ion Channels; D021122:Protein Subunits; D050052:TRPC Cation Channels; D016650:Fluorescein-5-isothiocyanate; D002118:Calcium