Pub1 acts as an E6-AP-like protein ubiquitiin ligase in the degradation of cdc25

Nefsky, B., Beach, D. (March 1996) Pub1 acts as an E6-AP-like protein ubiquitiin ligase in the degradation of cdc25. Embo J, 15 (6). pp. 1301-12. ISSN 0261-4189 (Print)



The level of the mitotic activating tyrosine phosphatase cdc25 is regulated by both transcriptional and post-transcriptional mechanisms in the fission yeast Schizosaccharomyces pombe. We have found that cdc25 is ubiquitinated and have cloned pub1, a gene which regulates this event. Pub1 contains a region highly homologous to the putative catalytic domain of the human protein ubiquitin ligase E6-AP. Disruption of pub1 elevates the level of cdc25 protein in vivo rendering cells relatively resistant to the cdc25-opposing tyrosine kinases wee1 and mik1. In addition, loss of wee1 activity in a pub1-disruption background results in a lethal premature entry into mitosis which can be rescued by loss of cdc25 function. A ubiquitin-thioester adduct of pub1 was isolated from fission yeast and disruption of pub1 dramatically reduced ubiquitination of cdc25 in vivo. These results suggest that pub1 directly ubiquitinates cdc25 in vivo.

Item Type: Paper
Uncontrolled Keywords: Amino Acid Sequence Carbon-Nitrogen Ligases Cell Cycle/ physiology Cell Cycle Proteins/ metabolism Esters/metabolism Fungal Proteins/genetics/ metabolism Gene Expression Regulation, Fungal Ligases/genetics/ metabolism Molecular Sequence Data Nuclear Proteins Phosphoprotein Phosphatase/ metabolism Protein-Tyrosine Kinase/genetics/metabolism RNA Processing, Post-Transcriptional Schizosaccharomyces/genetics/ metabolism Schizosaccharomyces pombe Proteins Sequence Homology, Amino Acid Sulfhydryl Compounds/metabolism Ubiquitins/ metabolism cdc25 Phosphatase
Subjects: bioinformatics > genomics and proteomics > genetics & nucleic acid processing > protein structure, function, modification > protein types > enzymes > ubiquitin ligase
CSHL Authors:
Communities: CSHL labs > Beach lab
Depositing User: Matt Covey
Date: 15 March 1996
Date Deposited: 22 May 2014 15:59
Last Modified: 22 May 2014 15:59
PMCID: PMC450033

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