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Nin1p, a regulatory subunit of the 26S proteasome, is necessary for activation of Cdc28p kinase of Saccharomyces cerevisiae.

ABSTRACT: The nin1-1 mutant of Saccharomyces cerevisiae cannot perform the G1/S and G2/M transitions at restrictive temperatures. At such temperatures, nin1-1 strains fail to activate histone H1 kinase after release from alpha factor-imposed G1 block and after release from hydroxyurea-imposed S block. The nin1-1 mutation shows synthetic lethality with certain cdc28 mutant alleles such as cdc28-IN. Two lines of evidence indicate that Nin1p is a component of the 26S proteasome complex: (i) Nin1p, as well as the known component of the 26S proteasome, shifted to the 26S proteasome peak in the glycerol density gradient after preincubation of crude extract with ATP-Mg2+, and (ii) nin1-1 cells accumulated polyubiquitinated proteins under restrictive conditions. These results suggest that activation of Cdc28p kinase requires proteolysis. We have cloned a human cDNA encoding a regulatory subunit of the 26S proteasome, p31, which was found to be a homolog of Nin1p.

SUBMITTER: Kominami K

PROVIDER: S-EPMC394372 | biostudies-other | 1995 Jul

REPOSITORIES: biostudies-other

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Nin1p, a regulatory subunit of the 26S proteasome, is necessary for activation of Cdc28p kinase of Saccharomyces cerevisiae.

Kominami K K DeMartino G N GN Moomaw C R CR Slaughter C A CA Shimbara N N Fujimuro M M Yokosawa H H Hisamatsu H H Tanahashi N N Shimizu Y Y

The EMBO journal 19950701 13

The nin1-1 mutant of Saccharomyces cerevisiae cannot perform the G1/S and G2/M transitions at restrictive temperatures. At such temperatures, nin1-1 strains fail to activate histone H1 kinase after release from alpha factor-imposed G1 block and after release from hydroxyurea-imposed S block. The nin1-1 mutation shows synthetic lethality with certain cdc28 mutant alleles such as cdc28-IN. Two lines of evidence indicate that Nin1p is a component of the 26S proteasome complex: (i) Nin1p, as well as ...[more]

PMID: 7621825

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Dataset Information

Nin1p, a regulatory subunit of the 26S proteasome, is necessary for activation of Cdc28p kinase of Saccharomyces cerevisiae.

Publications

Nin1p, a regulatory subunit of the 26S proteasome, is necessary for activation of Cdc28p kinase of Saccharomyces cerevisiae.

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