cDNA cloning and characterization of an osmotically sensitive TRP channel from ascidian eggs.
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.
Kondoh
Masahiro
M
Department of Biochemistry, Graduate School of Pharmaceutical Sciences, Hokkaido University, Sapporo 060-0812, Japan.
Kasai
Tomoyo
T
Shimada
Masumi
M
Kashiwayanagi
Makoto
M
Yokosawa
Hideyoshi
H
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*
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