Biogenesis of the yeast vacuole (lysosome) Active site mutation in the vacuolar aspartate proteinase yscA blocks maturation of vacuolar proteinases

FEBS Letters

Hirsch, Hans H.¹  Rupp, Steffen²  Wolf, Dieter H.² 

[1] Institut für Medizinische Mikrobiologie, Universität Basel, Petersplatz 10, CH-4003 Basel, Switzerland;Institut für Biochemie der Universität Stuttgart, Pfaffenwaldring 55, D-7000 Stuttgart 80, Germany

关键词: Proteolysis: Aspartate proteinase;    Active site mutant;    Yeast;    Saccharomyces cerevisiae;    ER;    endoplasmatic reticulum;    CpY;    carboxypeptidase yscY;    PrA;    proteinase yscA;    PrB;    proteinase yscB;   

DOI  :  10.1016/0014-5793(91)81153-Y

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

The activation process of vacuolar (lysosomal) proteinases in the yeast Saccharomyces cerevisiae is initiated by the PRAI (PEP4) gene product, proteinase yscA. To elucidate the activation process of proteinase yscA the catalytically active amino acid Asp²⁹⁴ of the enzyme was exchanged with Ala²⁹⁴ using site directed mutagenesis. The resulting proteinase yscA-Ala²⁹⁴ showed no proteolytic activity against the substrate hemoglobin. The mutant protein did not undergo processing in vivo. This phenomenon is in good agreement with the hypothesis that maturation of proteinase yscA is due to self-processing or pro-proteinase yscA. Furthermore, proteinase yscA-Ala²⁹⁴ is not able to convert the zymogens pro-proteinase yscB and pro-carboxypeptidase yscY to the mature enzymes.

【 授权许可】

Unknown