A hyperosmotic stress-induced mRNA of carp cell encodes Na(+)- and Cl(-)-dependent high affinity taurine transporter.
A cDNA clone encoding a Na(+)- and Cl(-)-dependent high affinity taurine transporter was isolated from a common carp cell line, Epithelioma papulosum cyprini (EPC), as a hyperosmotic stress-inducible gene by RNA arbitrarily primed PCR. The clone contained a 2.5-kb cDNA fragment including an open reading frame of 1878 bp encoding a protein of 625 amino acids. The deduced amino acid sequence of carp taurine transporter shows 78-80% identity to those of cloned mammalian taurine transporters. The functional characteristics of the cloned transporter were analyzed by expression in COS-7 cells. Transfection with the cDNA induced Na(+)- and Cl(-)-dependent taurine transport activity with an apparent K(m) of 56 microM. The Na(+)/Cl(-)hepatopancreas. Taurine transporter mRNA level increased up to 7.5-fold on raising the ambient osmolality from 300 to 450 mosmol/kgH(2)O. These data suggest the significant role of taurine as an osmolyte in carp cells.
Takeuchi
K
K
Division of Applied Biosciences, Graduate School of Agriculture, Kyoto University, Kitashirakawa Oiwake-cho, Sakyo, Kyoto, Japan.
Toyohara
H
H
Sakaguchi
M
M
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D019556:COS Cells; D002347:Carps / Q000235:genetics*; D002352:Carrier Proteins / Q000096:biosynthesis / Q000737:chemistry / Q000235:genetics*; D002460:Cell Line; D002712:Chlorides / Q000494:pharmacology; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000302:isolation & purification; D006982:Hypertonic Solutions; D008562:Membrane Glycoproteins / Q000096:biosynthesis / Q000737:chemistry / Q000235:genetics*; D026901:Membrane Transport Proteins; D008969:Molecular Sequence Data; D012333:RNA, Messenger / Q000032:analysis / Q000096:biosynthesis*; D016415:Sequence Alignment; D012964:Sodium / Q000494:pharmacology; D013654:Taurine / Q000378:metabolism*; D014162:Transfection; D000099247:Taurine Transporters
D002352:Carrier Proteins; D002712:Chlorides; D018076:DNA, Complementary; D006982:Hypertonic Solutions; D008562:Membrane Glycoproteins; D026901:Membrane Transport Proteins; D012333:RNA, Messenger; D012964:Sodium; D013654:Taurine; D000099247:Taurine Transporters