Processing pathway for protease B of Saccharomyces cerevisiae.
The vacuolar protease B of Saccharomyces cerevisiae is a subtilisin-like protease encoded by the PRB1 gene. Antibodies raised against a synthetic peptide and an Escherichia coli-derived PRB1 open reading frame (ORF) protein cross-react with authentic protease B from yeast. By using these antibodies, the posttranslational biosynthetic pathway of protease B has been elucidated. Preproprotease B is a 76-kD unglycosylated precursor that enters the endoplasmic reticulum (ER), where it receives one asparagine-linked (Asn-linked) and an undetermined number of non-Asn-linked carbohydrate side chains. The large glycosylated intermediate is proteolytically processed to a 39-kD form before exiting the ER. In the Golgi complex, the 39-kD form becomes 40 kD, due to elaboration of the Asn-linked side chain. The carboxyterminal end of the 40-kD proprotease B undergoes protease A-mediated processing to a 37-kD intermediate, which in turn is quickly processed to 31-kD mature protease B. The ultimate processing step removes a peptide containing the Asn-linked chain; mature PrB has only non-Asn-linked carbohydrate.
Moehle
C M
CM
Department of Biological Sciences, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213.
Dixon
C K
CK
Jones
E W
EW
D001216:Asparagine / Q000378:metabolism; D003593:Cytoplasm / Q000201:enzymology; D004721:Endoplasmic Reticulum / Q000201:enzymology; D004792:Enzyme Precursors / Q000378:metabolism; D004926:Escherichia coli / Q000201:enzymology / Q000235:genetics; D006031:Glycosylation; D006056:Golgi Apparatus / Q000201:enzymology; D015151:Immunoblotting; D007163:Immunosorbent Techniques; D009154:Mutation; D011499:Protein Processing, Post-Translational; D012441:Saccharomyces cerevisiae / Q000201:enzymology* / Q000235:genetics; D012697:Serine Endopeptidases / Q000096:biosynthesis* / Q000235:genetics; D014617:Vacuoles / Q000201:enzymology; D029701:Saccharomyces cerevisiae Proteins
D001216:Asparagine; D004792:Enzyme Precursors; D012697:Serine Endopeptidases; C023302:yeast proteinase B; D029701:Saccharomyces cerevisiae Proteins