RRC ID 21928
Author Fujiwara H, Tanaka N, Yamashita I, Kitamura K.
Title Essential role of Ubr11, but not Ubr1, as an N-end rule ubiquitin ligase in Schizosaccharomyces pombe.
Journal Yeast
Abstract The N-end rule pathway degrades proteins bearing a destabilization-inducing amino acid at the N-terminus. In this proteolytic system, Ubr ubiquitin ligases recognize and ubiquitylate substrates intended for degradation. Schizosaccharomyces pombe has two similar Ubr proteins, Ubr1 and Ubr11. Both proteins have unique roles in various cellular processes, although the ubr1∆ strain shows more severe defects. However, their involvement in the N-end rule pathway is unclear, and even the N-end rule pathway-dependent proteolytic activity has not been demonstrated in Sz. pombe. Here, we show that: (a) Sz. pombe has the N-end rule pathway in which only Ubr11, but not Ubr1, is responsible; and (b) the C-terminal fragment of the meiotic cohesin Rec8 (denoted as Rec8c) generated by separase-mediated cleavage is an endogenous substrate of the N-end rule pathway. Forced overexpression of stable Rec8c was deleterious in mitosis and caused a loss of the mini-chromosome. In unperturbed mitosis without overexpression, the rate of mini-chromosome loss was five-fold higher in the ubr11∆ strain. Since Rec8 is normally produced in meiosis, we examined whether meiosis and sporulation were affected in the ubr11∆ strain. In unperturbed meiosis, chromosome segregation occurred almost normally and viable spores were produced in the ubr11∆ cells, irrespective of the presence of undegraded endogenous Rec8c peptides.
Volume 30(1)
Pages 1-11
Published 2013-1-1
DOI 10.1002/yea.2936
PMID 23348717
MeSH Fungal Proteins / metabolism* Gene Deletion Phosphoproteins / metabolism Proteolysis Schizosaccharomyces / enzymology* Schizosaccharomyces pombe Proteins / metabolism* Ubiquitin-Protein Ligases / metabolism* Ubiquitination
IF 3.143
Times Cited 5
WOS Category MYCOLOGY BIOTECHNOLOGY & APPLIED MICROBIOLOGY MICROBIOLOGY BIOCHEMISTRY & MOLECULAR BIOLOGY
Resource
Yeast