Abstract
The Saccharomyces cerevisiae PEP4 gene encodes proteinase A, an aspartyl protease. pep4 mutants are defective in the activation of many vacuolar hydrolases, including proteinase B. We have expressed a pep4 mutation which directs the accumulation of pro-proteinase A with a defective active site. Co-expression with PEP4 leads to normal processing, i.e. the mutant zymogen is functional as a substrate for the maturation reaction in trans. We conclude that wild-type pro-proteinase A has the ability to mediate its own activation. Elimination of the co-expressed PEP4 gene did not effectively stop the processing of the mutant zymogen, owing to a strong, proteinase-B-dependent, phenotypic lag. In a proteinase-B-negative strain, processing of pro-proteinase A led to an active form of a higher molecular mass than the normal mature form.
| Original language | English |
|---|---|
| Journal | European Journal of Biochemistry |
| Volume | 207 |
| Issue number | 1 |
| Pages (from-to) | 277-83 |
| Number of pages | 7 |
| ISSN | 0014-2956 |
| Publication status | Published - 1992 |
Keywords
- Alleles
- Amino Acid Sequence
- Aspartic Acid Endopeptidases
- Base Sequence
- Binding Sites
- Codon
- Enzyme Activation
- Enzyme Precursors
- Genes, Fungal
- Molecular Sequence Data
- Mutagenesis, Site-Directed
- Phenotype
- Plasmids
- Polymerase Chain Reaction
- Protein Processing, Post-Translational
- Restriction Mapping
- Saccharomyces cerevisiae
- Saccharomyces cerevisiae Proteins
- Vacuoles