Cloning and characterization of an arginine vasotocin receptor from the euryhaline flounder Platichthys flesus.
A sequence coding for an arginine vasotocin (AVT) receptor has been identified by the screening of a hepatic cDNA library from the teleost Platichthys flesus. The 2701-bp receptor sequence is predicted to yield a 384-amino acid peptide, analysis of which indicates a seven-transmembrane spanning sequence typical of G-protein-coupled receptors with the N terminus on the outer surface of the cell membrane. Sequence analysis showed this sequence to have a high homology with the Catostomus commersoni AVT receptor (76%) and mammalian vasopressin V(1)-type receptor (62%), but only 55% homology with the C. commersoni isotocin receptor. A two-electrode voltage clamp was used to characterize the receptor expressed in Xenopus laevis oocytes. AVT induced an inward current which was dose dependent over the range 16.7 fmol to 5 pmol; isotocin was without effect over the same dose range. The mammalian vasopressin V(1)-type receptor agonist ([Phe(2), Orn(8)] oxytocin)() induced an inward current but was less potent than AVT, whereas the mammalian vasopressin V(2)-type receptor agonist ([Deamino(1), Val(4), D-Arg(8)] AVP) was without effect. Injection of oocytes with heparin or BAPTA suppressed the response to AVT, indicating receptor linkage to the phospholipase C-phosphatidylinositol pathway. Northern analysis demonstrated the presence of this AVT receptor mRNA in the brain, kidney, and gill of flounder.
Warne
J M
JM
School of Biological Sciences, University of Manchester, Oxford Road, Manchester, M13 9PT, United Kingdom.
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000737:chemistry / Q000235:genetics; D005260:Female; D005432:Flounder / Q000235:genetics*; D015723:Gene Library; D008099:Liver / Q000737:chemistry; D008969:Molecular Sequence Data; D009865:Oocytes / Q000187:drug effects / Q000502:physiology; D010121:Oxytocin / Q000031:analogs & derivatives / Q000502:physiology; D018408:Patch-Clamp Techniques; D012313:RNA / Q000737:chemistry / Q000302:isolation & purification; D051381:Rats; D017483:Receptors, Vasopressin / Q000737:chemistry / Q000235:genetics*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid; D014668:Vasotocin / Q000494:pharmacology / Q000502:physiology; D014982:Xenopus laevis
D018076:DNA, Complementary; D017483:Receptors, Vasopressin; C034862:vasotocin receptor; D010121:Oxytocin; C008215:isotocin; D012313:RNA; D014668:Vasotocin