title: In vivo processing of nonanchored Yapsin 1 (Yap3p).
abstract: A C-terminally truncated form of yapsin 1 (yeast aspartic protease 3) was overexpressed in yeast and its processing through the secretory pathway was followed by pulse-labeling and immunoprecipitation studies. In the soluble cell extract, three forms of yapsin 1-87, 74, and 18 kDa-were found. Identification of these forms of yapsin 1 using different antisera suggests that the 87-kDa form is pro-yapsin 1, which is processed into two subunits, alpha (18 kDa) and beta (74 kDa), by cleavage at a loop region not found in traditional aspartic proteases. By use of a temperature-sensitive mutant strain, sec18, the generation of the two subunits was found to occur in the endoplasmic reticulum. An active site-mutated yapsin 1 was not processed into the two subunits, suggesting that this process occurs in an autocatalytic manner.
authors.affiliation: Section on Cellular Neurobiology, Laboratory of Developmental Neurobiology, National Institute of Child Health and Human Development, Building 49, Room 5A38, Bethesda, Maryland, 20892, USA. ypl@codon.nih.gov
authors.forename: V
authors.initials: V
authors.lastname: Olsen
authors.forename: Y P
authors.initials: YP
authors.lastname: Loh
mesh_terms: D000251:Adenosine Triphosphatases; D000595:Amino Acid Sequence; D016282:Aspartic Acid Endopeptidases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D001665:Binding Sites; D002384:Catalysis; D017077:Culture Media, Conditioned / Q000737:chemistry; D004721:Endoplasmic Reticulum / Q000201:enzymology / Q000378:metabolism; D005656:Fungal Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism / Q000502:physiology; D005800:Genes, Fungal / Q000235:genetics / Q000502:physiology; D006031:Glycosylation; D008954:Models, Biological; D008969:Molecular Sequence Data; D008970:Molecular Weight; D009154:Mutation / Q000235:genetics; D010446:Peptide Fragments / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D011233:Precipitin Tests; D011498:Protein Precursors / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D011499:Protein Processing, Post-Translational; D012441:Saccharomyces cerevisiae / Q000166:cytology / Q000201:enzymology* / Q000235:genetics / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins; D013696:Temperature; D033921:Vesicular Transport Proteins
chemical_list: D017077:Culture Media, Conditioned; D005656:Fungal Proteins; D010446:Peptide Fragments; D011498:Protein Precursors; D029701:Saccharomyces cerevisiae Proteins; D033921:Vesicular Transport Proteins; C022325:aspartic proteinase A; D016282:Aspartic Acid Endopeptidases; C499266:YPS1 protein, S cerevisiae; D000251:Adenosine Triphosphatases; C064404:SEC18 protein, S cerevisiae