title: Sequence analysis of a cDNA encoding an isotocin precursor and localization of the corresponding mRNA in the brain of the cartilaginous fish Torpedo marmorata.
abstract: The nucleotide sequence of a cDNA encoding an isotocin hormone precursor has been elucidated by analyzing a lambda ZAPII library constructed using poly(A)+ RNA from the brain of the cartilaginous fish Torpedo marmorata. The sequence predicts a precursor of 126 amino acid residues that consists of a signal peptide, the isotocin moiety, and a neurophysin carrier protein. In contrast to other known fish isotocin precursor sequences, the Torpedo neurophysin moiety is not extended at its carboxy-terminus by a copeptin-like sequence. The T. marmorata isotocin precursor exhibits highest amino acid sequence identity (61%) to the toad mesotocin precursor. As demonstrated by in situ hybridization, the isotocin mRNA is present in neurons of the preoptic area of the Torpedo brain.
authors.affiliation: Institut für Zellbiochemie und klinische Neurobiologie, UKE, Universität Hamburg, Germany.
authors.forename: H
authors.initials: H
authors.lastname: Buchholz
authors.forename: C
authors.initials: C
authors.lastname: Schönrock
authors.forename: S
authors.initials: S
authors.lastname: Fehr
authors.forename: D
authors.initials: D
authors.lastname: Richter
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D018076:DNA, Complementary / Q000235:genetics; D017403:In Situ Hybridization; D008969:Molecular Sequence Data; D009481:Neurophysins / Q000235:genetics* / Q000302:isolation & purification; D010121:Oxytocin / Q000031:analogs & derivatives* / Q000235:genetics / Q000302:isolation & purification; D016133:Polymerase Chain Reaction; D011301:Preoptic Area / Q000737:chemistry*; D011498:Protein Precursors / Q000235:genetics*; D021382:Protein Sorting Signals / Q000235:genetics; D012333:RNA, Messenger / Q000302:isolation & purification; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid; D013045:Species Specificity; D014018:Tissue Distribution; D014101:Torpedo / Q000235:genetics*
chemical_list: D018076:DNA, Complementary; D009481:Neurophysins; D011498:Protein Precursors; D021382:Protein Sorting Signals; D012333:RNA, Messenger; D010121:Oxytocin; C008215:isotocin