The chromatin of the centromere provides the assembly site for the mitotic kinetochore that couples microtubule attachment and force production to chromosome movement in mitosis. The chromatin of the centromere is specified by nucleosomes containing the histone H3 variant CENP-A. The constitutive centromeric-associated network (CCAN) and kinetochore are assembled on CENP-A chromatin to enable chromosome separation. CENP-A chromatin is surrounded by pericentromeric heterochromatin and bound by the sequence specific binding protein CENP-B. We performed mechanical experiments on mitotic chromosomes while tracking CENP-A and CENP-B to observe the centromere's stiffness and the role of the CCAN. We degraded CENP-C and CENP-N using auxin-inducible degrons, which we verified compromises the CCAN via observation of CENP-T loss. Chromosome stretching revealed that the CENP-A domain does not visibly stretch, even in the absence of CENP-C and/or CENP-N. Pericentromeric chromatin deforms upon force application, stretching approximately 3-fold less than the entire chromosome. CENP-C and/or CENP-N loss has no impact on pericentromere stretching. Chromosome-disconnecting nuclease treatments showed no structural effects on CENP-A. Our experiments show that the core-centromeric chromatin is more resilient and likely mechanically disconnected from the underlying pericentromeric chromatin, while the pericentric chromatin is deformable yet stiffer than the chromosome arms.
Download full-text PDF |
Source |
|---|---|
| http://www.ncbi.nlm.nih.gov/pmc/articles/PMC11702632 | PMC |
| http://dx.doi.org/10.1101/2024.12.18.628896 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
The centromere effect (CE) is a meiotic phenomenon that ensures meiotic crossover suppression in pericentromeric regions. Despite being a critical safeguard against nondisjunction, the mechanisms behind the CE remain unknown. Previous studies have shown that various regions of the pericentromere, encompassing proximal euchromatin, beta and alpha heterochromatin, undergo varying levels of crossover suppression, raising the question of whether distinct mechanisms establish the CE in these different regions.
View Article and Find Full Text PDFThe chromatin of the centromere provides the assembly site for the mitotic kinetochore that couples microtubule attachment and force production to chromosome movement in mitosis. The chromatin of the centromere is specified by nucleosomes containing the histone H3 variant CENP-A. The constitutive centromeric-associated network (CCAN) and kinetochore are assembled on CENP-A chromatin to enable chromosome separation.
View Article and Find Full Text PDFA systematic quantitative approach comprehensively defines domain-specific functional pathways linked to Schizosaccharomyces pombe heterochromatin regulation.
Nucleic Acids Res
December 2024
Institute for Genetics, Justus-Liebig-University Giessen, Heinrich-Buff-Ring 17, 35392 Giessen, Germany.
Heterochromatin plays a critical role in regulating gene expression and maintaining genome integrity. While structural and enzymatic components have been linked to heterochromatin establishment, a comprehensive view of the underlying pathways at diverse heterochromatin domains remains elusive. Here, we developed a systematic approach to identify factors involved in heterochromatin silencing at pericentromeres, subtelomeres and the silent mating type locus in Schizosaccharomyces pombe.
View Article and Find Full Text PDFComparative analysis of predicted DNA secondary structures infers complex human centromere topology.
Am J Hum Genet
December 2024
Laboratory of Genome Evolution, Department of Biology and Biotechnology Charles Darwin, Sapienza University of Rome, 00185 Rome, Italy. Electronic address:
Article Synopsis
- - The text discusses how secondary structures, which are unique arrangements of nucleic acids caused by internal interactions, can occur in both RNA and single-stranded DNA, impacting key processes like DNA replication and transcription, thus affecting genome stability.
- - The study focuses on the comparison of secondary structures in linear single-stranded DNA from different specialized human loci, such as centromeres and coding regions, revealing that centromeres have the highest complexity and instability in their secondary structures.
- - Findings indicate that the intricate self-hybridizing properties of centromeric repeats may lead to chromosome missegregation when chromatin is disrupted, highlighting the functional importance of these structures in various DNA processes like transcription and recombination.
Mrc1 is essential for heterochromatin maintenance in Schizosaccharomyces pombe.
Genes Cells
December 2024
Department of Bioscience, School of Science and Technology, Kwansei Gakuin University, Sanda, Hyogo, Japan.
Article Synopsis
- The study investigates how heterochromatin, a form of tightly packed DNA that represses gene expression, is maintained in fission yeast during cell division to ensure cell identity.
- Researchers developed a reporter system to analyze the persistence of subtelomeric heterochromatin and discovered that once established, it tends to remain stable through cell proliferation.
- They identified 57 genes related to heterochromatin maintenance, focusing on Mrc1, which plays a crucial role in preserving heterochromatin structure and involves important processes like DNA replication and histone modification.
Want AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!