1. Set2 regulates Ccp1 and Swc2 to ensure centromeric stability by retargeting CENP-A.
- Author
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Lim KK, Lam UTF, Li Y, Zeng YB, Yang H, and Chen ES
- Subjects
- Chromosome Segregation, Histone-Lysine N-Methyltransferase metabolism, Histone-Lysine N-Methyltransferase genetics, DNA, Ribosomal genetics, DNA, Ribosomal metabolism, Kinetochores metabolism, Aneuploidy, Histones metabolism, Histones genetics, DNA-Binding Proteins metabolism, DNA-Binding Proteins genetics, Centromere metabolism, Schizosaccharomyces pombe Proteins metabolism, Schizosaccharomyces pombe Proteins genetics, Centromere Protein A metabolism, Centromere Protein A genetics, Schizosaccharomyces genetics, Schizosaccharomyces metabolism, Chromosomal Proteins, Non-Histone metabolism, Chromosomal Proteins, Non-Histone genetics
- Abstract
Precise positioning of the histone-H3 variant, CENP-A, ensures centromere stability and faithful chromosomal segregation. Mislocalization of CENP-A to extra-centromeric loci results in aneuploidy and compromised cell viability associated with formation of ectopic kinetochores. The mechanism that retargets mislocalized CENP-A back to the centromere is unclarified. We show here that the downregulation of the histone H3 lysine 36 (H3K36) methyltransferase Set2 can preserve centromere localization of a temperature-sensitive mutant cnp1-1 Schizosaccharomyces pombe CENP-A (SpCENP-A) protein and reverse aneuploidy by redirecting mislocalized SpCENP-A back to centromere from ribosomal DNA (rDNA) loci, which serves as a sink for the delocalized SpCENP-A. Downregulation of set2 augments Swc2 (SWR1 complex DNA-binding module) expression and releases histone chaperone Ccp1 from the centromeric reservoir. Swc2 and Ccp1 are directed to the rDNA locus to excavate the SpCENP-Acnp1-1, which is relocalized to the centromere in a manner dependent on canonical SpCENP-A loaders, including Mis16, Mis17 and Mis18, thereby conferring cell survival and safeguarding chromosome segregation fidelity. Chromosome missegregation is a severe genetic instability event that compromises cell viability. This mechanism thus promotes CENP-A presence at the centromere to maintain genomic stability., (© The Author(s) 2024. Published by Oxford University Press on behalf of Nucleic Acids Research.)
- Published
- 2024
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