The 19S proteasome subunit Rpt3 regulates distribution of CENP-A by associating with centromeric chromatin.
CENP-A, a variant of histone H3, is incorporated into centromeric chromatin and plays a role during kinetochore establishment. In fission yeast, the localization of CENP-A is limited to a region spanning 10-20 kb of the core domain of the centromere. Here, we report a mutant (rpt3-1) in which this region is expanded to 40-70 kb. Likely due to abnormal distribution of CENP-A, this mutant exhibits chromosome instability and enhanced gene silencing. Interestingly, the rpt3(+) gene encodes a subunit of the 19S proteasome, which localizes to the nuclear membrane. Although Rpt3 associates with centromeric chromatin, the mutant protein has lost this localization. A loss of the cut8(+) gene encoding an anchor of the proteasome to the nuclear membrane causes similar phenotypes as observed in the rpt3-1 mutant. Thus, we propose that the proteasome (or its subcomplex) associates with centromeric chromatin and regulates distribution of CENP-A.
Graduate School of Biostudies, Kyoto University, Yoshida-Konoe cho, Sakyo ku, Kyoto 606-8501, Japan.
Teppei
T
Kitagawa
1] Graduate School of Frontier Biosciences, Osaka University, Osaka 565-0871, Japan [2] Institute for Academic Initiatives, Osaka University, Osaka 565-0871, Japan.
Kojiro
K
Ishii
1] Institute for Integrative Neurobiology, Graduate School of Natural Science, Konan University, Kobe, Hyogo 658-8501, Japan [2] Department of Biology, Faculty of Science and Engineering, Konan University, Kobe, Hyogo 658-8501, Japan.
Kojiro
K
Takeda
1] Graduate School of Biostudies, Kyoto University, Yoshida-Konoe cho, Sakyo ku, Kyoto 606-8501, Japan [2] Radiation Biology Center, Kyoto University, Yoshida-Konoe cho, Sakyo ku, Kyoto 606-8501, Japan.
Tomohiro
T
Matsumoto
D018797:Cell Cycle Proteins / Q000235:genetics*; D002503:Centromere / Q000378:metabolism*; D002843:Chromatin / Q000378:metabolism*; D002868:Chromosomal Proteins, Non-Histone / Q000378:metabolism*; D009154:Mutation; D046988:Proteasome Endopeptidase Complex / Q000235:genetics* / Q000378:metabolism; D012568:Schizosaccharomyces; D029702:Schizosaccharomyces pombe Proteins / Q000235:genetics* / Q000378:metabolism
D018797:Cell Cycle Proteins; D002843:Chromatin; D002868:Chromosomal Proteins, Non-Histone; C410349:Cnp1 protein, S pombe; C088892:Cut8 protein, S pombe; D029702:Schizosaccharomyces pombe Proteins; D046988:Proteasome Endopeptidase Complex; C061553:ATP dependent 26S protease; C000601632:Rpt3 protein, S pombe