The 20S proteasome mediates the degradation of mouse and yeast ornithine decarboxylase in yeast cells.
Ornithine decarboxylase (ODC), a key enzyme in the biosynthesis of polyamines, is one of the most rapidly degraded proteins in mammalian cells. Recently it has been demonstrated that mammalian ODC is degraded in vitro by the 26S protease that contains the 20S proteasome as its catalytic core, in a reaction that does not require ubiquitin. Here, we show that yeast and mouse ODC are both rapidly degraded in yeast cells and that their degradation severely inhibited in a mutant yeast cell line defective in the chymotryptic activity of proteinase yscE, the yeast 20S proteasome. These results provide compelling genetic support to previous biochemical studies suggesting the involvement of the 20S proteasome in the degradation of ornithine decarboxylase.
Mamroud-Kidron
E
E
Department of Molecular Genetics and Virology, Weizmann Institute of Science, Rehovot, Israel.
Rosenberg-Hasson
Y
Y
Rom
E
E
Kahana
C
C
D000818:Animals; D003001:Cloning, Molecular; D003546:Cysteine Endopeptidases / Q000235:genetics / Q000378:metabolism*; D018014:Gene Transfer Techniques; D051379:Mice; D009097:Multienzyme Complexes / Q000378:metabolism*; D009154:Mutation; D009955:Ornithine Decarboxylase / Q000235:genetics / Q000378:metabolism*; D046988:Proteasome Endopeptidase Complex; D011994:Recombinant Proteins / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000201:enzymology* / Q000235:genetics; D014170:Transformation, Genetic
D009097:Multienzyme Complexes; D011994:Recombinant Proteins; D003546:Cysteine Endopeptidases; C043418:proteinase yscE; D046988:Proteasome Endopeptidase Complex; D009955:Ornithine Decarboxylase