title: Occurrence of a furin-like prohormone processing enzyme in Aplysia neuroendocrine bag cells.
abstract: 1. Strong evidence is accumulating that the endoproteases which process prohormones at dibasic residue cleavage sites are members of a subtilisin-related class of proteases. 2. Using the polymerase chain reaction (PCR), we have isolated and characterized an Aplysia californica neuroendocrine bag cell cDNA product (270 base pairs) that encodes a sequence which is highly homologous to the subtilisin-related class of processing proteases that includes yeast Kex2, human/mouse/Drosophila furin, human PC2, and mouse PC1/PC3 and PC2. 3. The characterized cDNA PCR product showed the highest degree of residue identity with the furin-related group of proteins (human/mouse furin 71%; Drosophila furin 63%). 4. These results establish that Aplysia contain a subtilisin-like gene and suggest that the expression of this gene may play a role in processing Aplysia precursor proteins in the bag cells and likely also in the exocrine atrial gland. 5. Furthermore, the Aplysia nucleotide sequence results, together with available sequence information from human, mouse, and Drosophila furins, provide reasonable evidence that the furin-like enzymes may represent a separate subclass of the subtilisin-like processing enzymes.
authors.affiliation: Marine Biomedical Institute, University of Texas Medical Branch, Galveston 77555.
authors.forename: G T
authors.initials: GT
authors.lastname: Nagle
authors.forename: W R
authors.initials: WR
authors.lastname: van Heumen
authors.forename: S L
authors.initials: SL
authors.lastname: Knock
authors.forename: A T
authors.initials: AT
authors.lastname: Garcia
authors.forename: D A
authors.initials: DA
authors.lastname: McCullough
authors.forename: A
authors.initials: A
authors.lastname: Kurosky
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001048:Aplysia / Q000201:enzymology* / Q000235:genetics; D001483:Base Sequence; D004247:DNA / Q000737:chemistry / Q000235:genetics; D004587:Electrophoresis, Agar Gel; D045683:Furin; D006801:Humans; D008969:Molecular Sequence Data; D016133:Polymerase Chain Reaction; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D013381:Subtilisins / Q000737:chemistry* / Q000235:genetics / Q000302:isolation & purification
chemical_list: D004247:DNA; D013381:Subtilisins; D045683:Furin