Rio1 downregulates centromeric RNA levels to promote the timely assembly of structurally fit kinetochores.
Ontology highlight
ABSTRACT:
ORGANISM(S): Saccharomyces cerevisiae
PROVIDER: GSE189278 | GEO | 2022/12/31
REPOSITORIES: GEO
Similar Datasets
Project description:Kinetochores assemble on centromeres via histone H3 variant CENP-A and low levels of noncoding centromere transcripts (cenRNAs). The latter are ensured by downregulation of RNA polymerase II (RNAPII) and turnover by the nuclear exosome. Using S. cerevisiae, we now add kinase Rio1 to this scheme. Yeast cenRNAs are produced in very low amounts either as short (median lengths of 231nt) or long (4,458nt) transcripts, in a 1:1 ratio. Rio1 limits their production by reducing RNAPII access and transcription activity, and promotes their turnover by the 5’-3’exoribonuclease Rat1. Rio1 similarly curtails the concentrations of noncoding pericenRNAs, which also exist as short transcripts (225nt) at a magnitude higher level than the cenRNAs. In yeast depleted of Rio1, cen- and pericenRNAs accumulatre, and kinetochores misform causing chromosomal instability. The latter phenotypes were also observed with human cells lacking orthologue RioK1, suggesting that CEN regulation by Rio1/RioK1 is evolutionary conserved.
2023-04-20 | GSE218602 | GEO
Project description: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.
| S-EPMC10235086 | biostudies-literature
Project description:Kinetochores assemble on centromeres via histone H3 variant CENP-A and low levels of noncoding centromere transcripts (cenRNAs). The latter are ensured by transcription factor Cbf1 (S. cerevisiae), centromere-binding protein CENP-B (humans), and the local histone code downregulating RNA polymerase II (RNAPII) activity. CenRNAs levels are further adjusted by the nuclear exosome. Using S. cerevisiae, we now add kinase Rio1 to this scheme. Yeast cenRNAs are produced mostly from the periCEN regions as short (median lengths of 231nt) or long (4,458nt) transcripts, in a 1:1 ratio. Rio1 limits their production by reducing RNAPII access and transcription activity, and promotes their turnover by the 5’-3’exoribonuclease Rat1. Rio1 similarly curtails the concentrations of noncoding pericenRNAs, which nevertheless exist at a magnitude higher level than the cenRNAs. Similar to yeast, human cells depleted of orthologue RioK1 exhibit cenRNA buildup, kinetochore malformation, and chromosomal instability, suggesting that CEN regulation by Rio1/RioK1 is evolutionary conserved.
2023-07-20 | PXD038337 | Pride
Project description:Kinetochores assemble on centromeres (CENs) via histone H3 variant CENP-A and low levels of CEN transcripts. RNA polymerase II (RNAPII) activity is restrained by the CEN histone code, while CEN RNA concentrations are reduced by the nuclear exosome. Using S. cerevisiae, we add kinase Rio1 to this scheme as it downregulates RNAPII, and promotes CEN RNA turnover via exoribonuclease Rat1. Transcription factor Cbf1, and the assembled kinetochore further restrain CEN transcription. CEN transcripts exist as long (up to 11,000nt) and short RNAs (119±40nt), which may underlie CEN identity and kinetochore recruitment. While also curtailed by Rio1, Rat1, and the exosome, periCEN RNAs (<200nt) accumulate at levels that are one order of magnitude higher than the CEN transcripts. Depleting Rio1 causes CEN and periCEN RNA buildup, kinetochore malformation, and chromosome loss. Depleting human orthologue RioK1 leads to CEN RNA accumulation and micronuclei formation, suggesting that Rio1/RioK1 activity at centromeres is conserved.
2025-02-24 | PXD030623 | Pride
Project description:Rio1 downregulates centromeric RNA levels to promote the timely assembly of structurally fit kinetochores
| PRJNA904388 | ENA
Project description:Rio1 downregulates centromeric RNA levels to promote the timely assembly of structurally fit kinetochores.
| PRJNA782329 | ENA
Project description:BACKGROUND: Cells undergoing meiosis perform two consecutive divisions after a single round of DNA replication. During the first meiotic division, homologous chromosomes segregate to opposite poles. This is achieved by (1) the pairing of maternal and paternal chromosomes via recombination producing chiasmata, (2) coorientation of homologous chromosomes such that sister chromatids attach to the same spindle pole, and (3) resolution of chiasmata by proteolytic cleavage by separase of the meiotic-specific cohesin Rec8 along chromosome arms. Crucially, cohesin at centromeres is retained to allow sister centromeres to biorient at the second division. Little is known about how these meiosis I-specific events are regulated. RESULTS: Here, we show that Spo13, a centromere-associated protein produced exclusively during meiosis I, is required to prevent sister kinetochore biorientation by facilitating the recruitment of the monopolin complex to kinetochores. Spo13 is also required for the reaccumulation of securin, the persistence of centromeric cohesin during meiosis II, and the maintenance of a metaphase I arrest induced by downregulation of the APC/C activator CDC20. CONCLUSION: Spo13 is a key regulator of several meiosis I events. The presence of Spo13 at centromere-surrounding regions is consistent with the notion that it plays a direct role in both monopolin recruitment to centromeres during meiosis I and maintenance of centromeric cohesion between the meiotic divisions. Spo13 may also limit separase activity after the first division by ensuring securin reaccumulation and, in doing so, preventing precocious removal from chromatin of centromeric cohesin. Keywords: Meiosis, Cell cycle, Saccharomyces cerevisiae, Chromosome VI tiling array, Spo13, ChIP-chip
2006-05-16 | GSE4813 | GEO
Project description:Purpose: The goal is to determine the requirement for Chl4 in association of cohesin with the centromere and pericentromere boundaries
2020-01-13 | GSE104081 | GEO
Project description:The specialised structure of the centromere is critical for effective chromosome segregation, but its repetitive nature makes it vulnerable to rearrangements. Centromere fragility can drive tumorigenesis, but protective mechanisms preventing fragility are still not fully understood. The PBAF chromatin remodelling complex is frequently misregulated in cancer, but its role in cancer is incompletely characterized. Here, we identify PBAF as a protector of centromere and pericentromere structure with profound consequences for genome stability. A conserved feature of isogenic cell lines lacking PBRM1, a subunit of PBAF, is compromised centromere and pericentromere integrity. PBAF is present at these regions, and binding patterns of PBAF and H3K9 methylation change when PBRM1 is absent. PBRM1 loss creates a dependence on the spindle assembly checkpoint, which represents a therapeutic vulnerability. Importantly, we find that even in the absence of any perturbations, PBRM1 loss leads to centromere fragility, thus identifying a new player in centromere protection.
2025-01-05 | GSE235294 | GEO
Project description:The specialised structure of the centromere is critical for effective chromosome segregation, but its repetitive nature makes it vulnerable to rearrangements. Centromere fragility can drive tumorigenesis, but protective mechanisms preventing fragility are still not fully understood. The PBAF chromatin remodelling complex is frequently misregulated in cancer, but its role in cancer is incompletely characterized. Here, we identify PBAF as a protector of centromere and pericentromere structure with profound consequences for genome stability. A conserved feature of isogenic cell lines lacking PBRM1, a subunit of PBAF, is compromised centromere and pericentromere integrity. PBAF is present at these regions, and binding patterns of PBAF and H3K9 methylation change when PBRM1 is absent. PBRM1 loss creates a dependence on the spindle assembly checkpoint, which represents a therapeutic vulnerability. Importantly, we find that even in the absence of any perturbations, PBRM1 loss leads to centromere fragility, thus identifying a new player in centromere protection.
2025-01-05 | GSE235342 | GEO