1. Rio1 downregulates centromeric RNA levels to promote the timely assembly of structurally fit kinetochores.
- Author
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Smurova K, Damizia M, Irene C, Stancari S, Berto G, Perticari G, Iacovella MG, D'Ambrosio I, Giubettini M, Philippe R, Baggio C, Callegaro E, Casagranda A, Corsini A, Polese VG, Ricci A, Dassi E, and De Wulf P more...
- Subjects
- Humans, Saccharomyces cerevisiae genetics, Saccharomyces cerevisiae metabolism, RNA metabolism, Chromosomal Proteins, Non-Histone genetics, Chromosomal Proteins, Non-Histone metabolism, Centromere genetics, Centromere metabolism, Nucleosomes metabolism, Exoribonucleases metabolism, Protein Serine-Threonine Kinases genetics, Protein Serine-Threonine Kinases metabolism, Kinetochores metabolism, Saccharomyces cerevisiae Proteins genetics, Saccharomyces cerevisiae Proteins metabolism
- Abstract
Kinetochores assemble on centromeres via histone H3 variant CENP-A and low levels of centromere transcripts (cenRNAs). The latter are ensured by the downregulation of RNA polymerase II (RNAPII) activity, and cenRNA turnover by the nuclear exosome. Using S. cerevisiae, we now add protein kinase Rio1 to this scheme. Yeast cenRNAs are produced either as short (median lengths of 231 nt) or long (4458 nt) transcripts, in a 1:1 ratio. Rio1 limits their production by reducing RNAPII accessibility and promotes cenRNA degradation by the 5'-3'exoribonuclease Rat1. Rio1 similarly curtails the concentrations of noncoding pericenRNAs. These exist as short transcripts (225 nt) at levels that are minimally two orders of magnitude higher than the cenRNAs. In yeast depleted of Rio1, cen- and pericenRNAs accumulate, CEN nucleosomes and kinetochores misform, causing chromosome instability. The latter phenotypes are also observed with human cells lacking orthologue RioK1, suggesting that CEN regulation by Rio1/RioK1 is evolutionary conserved., (© 2023. The Author(s).) more...
- Published
- 2023
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