The proteinase yscA‐inhibitor, IA 3, gene Studies of cytoplasmic proteinase inhibitor deficiency on yeast physiology

FEBS Letters

Wolf, Dieter H.²  Schu, Peter¹ 

[1]Biochemisches Institut der Universität Freiburg, Hermann-Herder-Str. 7, D-7800 Freiburg, Germany

[2]Institut für Biochemie der Universität Stuttgart, Pfaffenwaldring 55, D-7000 Stuttgart 80, Germany

关键词: Proteolysis;    Proteinase inhibitor;    IA 3;    IB 2;    Null mutant;    Saccharomyces cerevisiae;   

DOI  :  10.1016/0014-5793(91)80558-K

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

The gene of the proteinase yscA inhibitor I^A ₃, , of the yeast Saccharamyces cerevisiae was isolated by oligonucleotide screening of a genomic DNA library and sequenced. The gene codes for a single protein of 68 amino acids. The structural gene was deleted in vitro by oligonucleotide-site-directed mutagenesis. The mutated allele was introduced via homologous recombination into the genome of wild-type yeast and into the genome of a yeast mutant, which lacks the second cytoplasmic proteinase-inhibitor, I^B ₂. The deficiency of either or of both inhibitors has no effect on the cell viability under various physiological conditions. The inhibitor mutants, however, show an increase in the general in vivo protein degradation rate. The I^A ₃ mutant has a 2–3-fold increased protein degradation rate in the first 6 h after a shift from rich medium onto starvation-medium, whereas the I^B ₂ mutant shows a constantly increased degradation rate of 20–50% under the same conditions. The inhibitor double null mutant has the same protein degradation rate as the I^A ₃ null mutant. These results suggest an in vivo interaction between the vacuolor endopeptidases and their cytoplasmic inhibitors.

【 授权许可】

Unknown