Deduced amino acid sequence from the bovine oxytocin-neurophysin I precursor cDNA.
The nonapeptide hormone oxytocin-like arginine-vasopressin (AVP) is synthesized as part of a larger precursor polypeptide. The precursor also includes the neurophysin molecule with which the hormone is associated in the neurosecretory granules of the hypothalamo-pituitary tract. A protein of molecular weight (Mr) approximately 20,000 has been isolated from supraoptic nuclei of rat hypothalami which, after tryptic cleavage, released a neurophysin-like molecule of Mr approximately 10,000 and an oligopeptide related to oxytocin. This result was complemented by in vitro translation of bovine hypothalamic mRNA. Among the primary translation products a single polypeptide of Mr approximately 16,500 was shown to contain antigenic determinants recognized by specific antisera against bovine neurophysin I and oxytocin. Here we report the amino acid sequence of the bovine oxytocin-neurophysin I (OT-NpI) precursor which was derived from sequence analysis of the cloned cDNA. As is the case for the bovine arginine-vasopressin-neurophysin II (AVP-NpII) precursor, the signal sequence of the OT-NpI precursor is immediately followed by the nonapeptide hormone which is connected to neurophysin I by a Gly-Lys-Arg sequence. A striking feature of the nucleic acid sequence is the 197-nucleotide long perfect homology with the AVP-NpII precursor mRNA sequence encoding the conserved middle part of neurophysins I and II.
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D002417:Cattle; D004247:DNA / Q000235:genetics; D009481:Neurophysins / Q000235:genetics*; D010121:Oxytocin / Q000235:genetics*; D010455:Peptides / Q000235:genetics; D011498:Protein Precursors / Q000235:genetics*; D021382:Protein Sorting Signals; D012333:RNA, Messenger / Q000235:genetics
D009481:Neurophysins; D010455:Peptides; D011498:Protein Precursors; D021382:Protein Sorting Signals; D012333:RNA, Messenger; D010121:Oxytocin; D004247:DNA