Transcriptomic changes following CENP-E partial depletion in normal human fibroblasts
Ontology highlight
ABSTRACT:
ORGANISM(S): Homo sapiens
PROVIDER: GSE181191 | GEO | 2021/10/06
REPOSITORIES: GEO
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Project description:Centromeric localization of the evolutionarily conserved histone H3 variant, CENP-A. is essential for chromosomal stability. CENP-A overexpression (OE) causesd its mislocalization to non-centromeric regions resulting in chromosomal instability (CIN) in yeast, flies and human cells. CENP-A OE and mislocalization have been observed in cancers and correlates with poor prognosis. However, the molecular consequences of CENP-A OE on CIN and aneuploidy have not been defined. Here, we overexpressed YFP-CENP-A in a pseudodiploid DLD1 cell line and showed that CENP-A OE leads to its mislocalization and CIN due to defects in kinetochore integrity and kinetochore-microtubule attachments. CENP-A OE also leads to its mislocalization and CIN in a xenograft mouse model. Under these conditions, it contributes to aneuploidy with karyotypic heterogeneity in human cells and xenograft mouse model. In summary, our studies provide a molecular link between CENP-A OE and aneuploidy, and suggest that karyotypic heterogeneity may contribute to the aggressive phenotype of CENP-A overexpressing cancers.
2020-07-16 | GSE154460 | GEO
Project description:We find that CENP-T acts as a bridge between two well-positioned CENP-A nucleosomes that are present on young alpha-satellite dimers that dominate functional human centromeres. CENP-T is centered over the CENP-B box, where it interacts with the CENP-B/CENP-C complex. Upon cross-linking, the entire CENP-A/CENP-C/CENP-T-containing complex is recovered as a nuclease-protected particle over an alpha-satellite dimer that comprises the fundamental unit of kinetochore chromatin. Our work reveals that CENP-A/CENP-C and CENP-T branches of kinetochore assembly are physically integrated.
2016-05-24 | GSE69839 | GEO
Project description:CENP-A overexpression promotes aneuploidy and karyotypic heterogeneity
| PRJNA646383 | ENA
Project description:Restricting the localization of the centromeric histone H3 variant CENP-A to centromeres is essential to prevent chromosomal instability (CIN). Mislocalization of overexpressed CENP-A contributes to CIN in yeast, fly, and human cells. CENP-A is overexpressed in many cancers. Therefore, defining mechanisms that prevent CENP-A mislocalization will help us understand how CENP-A overexpression contributes to CIN in cancer. A genome-wide screen to characterize essential genes required for growth when CENP-A is overexpressed identified the replication initiation Dbf4-Dependent Kinase (DDK) complex. We show that DDK regulates ubiquitin-mediated proteolysis of Cse4 and prevents mislocalization of Cse4 independently of its role in DNA replication.
2020-04-04 | GSE148068 | GEO
Project description:ChIP-seq of CENP-A in S. pombe
2013-01-04 | E-MTAB-1435 | biostudies-arrayexpress
Project description:Organisms invest significant effort into maintaining genome stability. However, in diverse groups of eukaryotes, portions or entire chromosomes are lost in early development or during sex determination, a process known as programmed DNA elimination. Little is known about how different segments of the genome are reproducibly retained and discarded during programmed DNA elimination. We tested the hypothesis that selective retention is mediated by regulation of centromere-mediated association of chromosome segments with the mitotic spindle. We report that on the holocentric chromosomes of the nematode Ascaris, the core centromeric histone CENP-A is localized differently in cells undergoing DNA elimination from those undergoing germline mitosis. Prior to DNA elimination, CENP-A is significantly reduced in chromosome regions that will be lost. CENP-A reduction in eliminated genomic regions leads to the absence of kinetochores and microtubule attachment sites necessary for chromosome segregation, and thus the loss of these DNA regions during Ascaris programmed DNA elimination. Our results show that holocentric chromosome organization in Ascaris is regulated and that changes in CENP-A deposition specify which portions of chromosomes will be eliminated during programmed DNA elimination. A total of 62 samples are analyzed. These include: (1). CENP-A ChIP-seq on 12 developmental stages with input and replicates (12 x 2 x 2 samples); (2). CENP-C ChIP-seq on 3 developmental stages with input and replicates (total 8 samples); and (3). Histone marks ChIP-seq with 6 samples
2016-07-15 | E-GEOD-76914 | biostudies-arrayexpress
Project description:CENP-A is a centromere-specific histone 3 variant essential for centromere specification. CENP-A partially replaces canonical histone H3 at the centromeres. How the particular CENP-A/H3 ratio at centromeres is precisely maintained is unknown. It also remains unclear how CENP-A is excluded from non-centromeric chromatin. Here we identify Ccp1, an uncharacterized NAP family protein in fission yeast that antagonizes CENP-A loading at both centromeric and non-centromeric regions. Like the CENP-A loading factor HJURP, Ccp1 interacts with CENP-A, and is recruited to centromeres at the end of mitosis in a Mis16-dependent manner. These data indicate that factors with opposing CENP-A loading activities are recruited to centromeres. Furthermore, Ccp1 also cooperates with H2A.Z to evict CENP-A assembled in euchromatin. Structural analyses indicate that Ccp1 forms a homodimer that is required for its anti-CENP-A loading activity. Our study establishes mechanisms for maintenance of CENP-A homeostasis at centromeres and the prevention of ectopic assembly of centromeres. Examination of cnp1 distribution in one wild type (wt) and two ccp1 mutants.
2016-08-04 | E-GEOD-85166 | biostudies-arrayexpress
Project description:CENP-A is a centromere-specific histone 3 variant essential for centromere specification. CENP-A partially replaces canonical histone H3 at the centromeres. How the particular CENP-A/H3 ratio at centromeres is precisely maintained is unknown. It also remains unclear how CENP-A is excluded from non-centromeric chromatin. Here we identify Ccp1, an uncharacterized NAP family protein in fission yeast that antagonizes CENP-A loading at both centromeric and non-centromeric regions. Like the CENP-A loading factor HJURP, Ccp1 interacts with CENP-A, and is recruited to centromeres at the end of mitosis in a Mis16-dependent manner. These data indicate that factors with opposing CENP-A loading activities are recruited to centromeres. Furthermore, Ccp1 also cooperates with H2A.Z to evict CENP-A assembled in euchromatin. Structural analyses indicate that Ccp1 forms a homodimer that is required for its anti-CENP-A loading activity. Our study establishes mechanisms for maintenance of CENP-A homeostasis at centromeres and the prevention of ectopic assembly of centromeres.
2016-08-04 | GSE85166 | GEO
Project description:Background: Centromeres are crucial for proper chromosomes segregation during cell division. Centromeres in most eukaryotes are epigenetically specified by the histone 3 (H3) variant, CENP-A. How CENP-A precisely targets to centromeres remains elusive. Centromeres are typically transcribed into non-coding RNAs, which have been implicated in centromere functions. But the exact role of centromeric RNA in CENP-A loading is still poorly understood. In addition, centromere transcription induce formation of R-loops consisting of a DNA:RNA hybrid and a displaced single-stranded DNA. Excessive R-loops lead to genome instability. Little is known about the mechanism used for safeguarding centromeres against R-loops. Results: Here we show that through a visual genetic screen, we identified a conserved RNA binding protein Dbp7 that plays a critical role in CENP-A loading to centromeres. Deletion of dbp7+ results in CENP-A mislocalization and defects in chromosome segregation and centromere silencing. We found that Dbp7 associates with centromere transcripts, and further showed that Dbp7 prevents accumulation of R-loops at centromeres. Our domain-deletion analysis demonstrated that the DEAD-box helicase domain and the C-terminal extension motif of Dbp7 contribute to its role in centromere function. In addition, Dbp7 interacts with the key exosome subunit Dis3. Importantly, we found that Dis3 promotes CENP-A centromere loading by interacting the CENP-A chaperone Sim3. Conclusions: Together, this study uncovered a previously unrecognized CENP-A loading mechanism, by which Dbp7 and Dis3 bind to centromeric transcripts and in turn mediate recruitment of CENP-A via recruiting Sim3. Our work also provides mechanistic insight into R-loop resolution at centromeres.
2025-01-15 | GSE285031 | GEO