GAP-releasing enzyme is a member of the pro-hormone convertase family of precursor protein processing enzymes.
The recent discovery of mammalian endoproteinases which show extensive sequence homology with the yeast Kex 2 gene product (kexin) has lead to the hypothesis that processing enzymes of pro-hormone precursor proteins belong to a family of calcium dependent, subtilisin-like serine proteinases. We previously showed that hypothalamic GAP-releasing enzyme shares these characteristics and possesses the requisite specificity to be considered as a processing enzyme of progonadotropin releasing hormone (pro-GnRH) precursor protein. Thus, GAP-releasing enzyme (and other non-related proteins) were tested for their immunological reactivity with antisera raised against pituitary pro-hormone convertase 1/3 (PC1/3) and insulinoma PC2. On the basis of indirect enzyme-linked immunosorbent (ELISA) and Western blot assays, GAP-releasing enzyme is now shown to be immunologically related to PC1/3. We can conclude that GAP-releasing enzyme is also likely to be a member of the pro-hormone convertase family and should be considered the physiologically relevant processing enzyme of pro-GnRH. It is possible that GAP-releasing enzyme represents bovine hypothalamic PC1/3.
Rangaraju
N S
NS
Virginia Commonwealth University, Dept. Biochem. and Molec. Biophys., Richmond 23298-0614.
Harris
R B
RB
D000595:Amino Acid Sequence; D000818:Animals; D016282:Aspartic Acid Endopeptidases / Q000145:classification / Q000378:metabolism*; D015153:Blotting, Western; D002417:Cattle; D010450:Endopeptidases / Q000145:classification / Q000378:metabolism*; D004797:Enzyme-Linked Immunosorbent Assay; D008969:Molecular Sequence Data; D045706:Proprotein Convertase 2; D043484:Proprotein Convertases; D011499:Protein Processing, Post-Translational; D013381:Subtilisins / Q000145:classification / Q000378:metabolism
D010450:Endopeptidases; D043484:Proprotein Convertases; D013381:Subtilisins; D045706:Proprotein Convertase 2; D016282:Aspartic Acid Endopeptidases; C052441:gonadotropin-associated-peptide releasing enzyme