title: Processing of the egg-laying hormone (ELH) precursor in the bag cell neurons of Aplysia.
abstract: Egg laying in Aplysia is mediated by a battery of neuropeptides released from the bag cell neurons. Predominant intermediates in the proteolytic processing of the Aplysia egg-laying hormone neuropeptide precursor were characterized using biochemical and immunological techniques. Following removal of the signal peptide, a rapid cleavage at the tetrabasic sequence Arg-Arg-Lys-Arg separates the amino and carboxyl regions of the prohormone. Processing of the carboxyl-terminal portion of the precursor then proceeds rapidly via two further cleavages at dibasic residues, resulting in a well defined product mixture within 4 h of chase. By contrast, processing of the amino-terminal side of the molecule proceeds only partially to completion after 20 h of chase and a well defined set of intermediates is not observed. Molecular genetic, physiological, and behavioral studies in conjunction with the biochemical investigations presented here are defining the information flow which governs the egg-laying behavior of Aplysia.
authors.affiliation: Department of Biological Sciences, Stanford University, California 94305.
authors.forename: R
authors.initials: R
authors.lastname: Newcomb
authors.forename: J M
authors.initials: JM
authors.lastname: Fisher
authors.forename: R H
authors.initials: RH
authors.lastname: Scheller
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001048:Aplysia / Q000378:metabolism*; D002851:Chromatography, High Pressure Liquid; D004591:Electrophoresis, Polyacrylamide Gel; D006863:Hydrogen-Ion Concentration; D007118:Immunoassay; D007447:Invertebrate Hormones / Q000378:metabolism*; D007532:Isoleucine / Q000378:metabolism; D007700:Kinetics; D007930:Leucine / Q000378:metabolism; D008666:Metalloendopeptidases / Q000378:metabolism; D008969:Molecular Sequence Data; D008970:Molecular Weight; D009474:Neurons / Q000378:metabolism*; D010446:Peptide Fragments / Q000378:metabolism; D010649:Phenylalanine / Q000378:metabolism; D011498:Protein Precursors / Q000378:metabolism*; D021382:Protein Sorting Signals / Q000378:metabolism; D014316:Tritium; D014357:Trypsin / Q000378:metabolism
chemical_list: D007447:Invertebrate Hormones; D010446:Peptide Fragments; D011498:Protein Precursors; D021382:Protein Sorting Signals; C026880:egg-laying hormone, Mollusca; D007532:Isoleucine; D014316:Tritium; D010649:Phenylalanine; D014357:Trypsin; D008666:Metalloendopeptidases; C022653:auR protein, Staphylococcus aureus; D007930:Leucine