title: One-step processing of the amphibian vasotocin precursor: structure of a frog (Rana esculenta) "big" neurophysin.
abstract: Vasotocin-associated neurophysin (MSEL-neurophysin) from the frog Rana esculenta has been isolated and sequenced through tryptic and staphylococcal proteinase peptides and cyanogen bromide fragments. This protein appears homologous to the mammalian vasopressin-associated neurophysin with a C-terminal glycopeptide extension homologous to the mammalian copeptin. In contrast to the two-step processing of mammalian vasopressin/MSEL-neurophysin/copeptin precursor, a single cleavage is therefore involved in the processing of the amphibian vasotocin/neurophysin precursor. It appears that the physiological release of the vasopressin-like hormone from the N-terminal end of the protein precursor is not dependent upon a previous trimming of the C-terminal copeptin-like moiety.
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D005091:Exons; D008969:Molecular Sequence Data; D009481:Neurophysins / Q000032:analysis* / Q000235:genetics; D011487:Protein Conformation; D011498:Protein Precursors / Q000378:metabolism*; D011893:Rana esculenta; D014668:Vasotocin / Q000096:biosynthesis*
chemical_list: D009481:Neurophysins; D011498:Protein Precursors; D014668:Vasotocin