The vertebrate kinetochore complex assembles at the centromere on alpha-satellite DNA. In humans, alpha-satellite DNA has a repeat length of 171 bp slightly longer than the DNA in the chromatosome containing the linker histone H1. The centromere-binding protein CENP-B binds specifically to alpha-satellite DNA with properties of a centromeric-linker histone. Here, we analysed if linker histone H1 is present at or excluded from centromeric chromatin by CENP-B. By immunostaining we detected the presence, but no enrichment or depletion of five different H1 subtypes at centromeric chromatin. The binding dynamics of H1 at centromeric sites were similar to that at other locations in the genome. These dynamics did not change in CENP-B depleted cells, suggesting that CENP-B and H1 co-exist in centromeric chromatin with no or little functional overlap. By bimolecular fluorescence complementation (BiFC) and Förster resonance energy transfer (FRET), we revealed that the linker histone H1 subtypes H1 degrees and H1.2 bind to centromeric chromatin in interphase nuclei in direct neighbourhood to inner kinetochore proteins.

Download full-text PDF

Source
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2691837PMC
http://dx.doi.org/10.1093/nar/gkp199DOI Listing

Publication Analysis

Top Keywords

centromeric chromatin
20
linker histone
16
alpha-satellite dna
12
inner kinetochore
8
kinetochore proteins
8
centromeric
6
chromatin
5
linker
4
histone centromeric
4
chromatin living
4

Similar Publications

HP1 Promotes the Centromeric Localization of ATRX and Protects Cohesion by Interfering Wapl Activity in Mitosis.

Front Biosci (Landmark Ed)

January 2025

The Key Laboratory of Model Animals and Stem Cell Biology in Hunan Province, Hunan Normal University Health Science Center, 410013 Changsha, Hunan, China.

Background: α thalassemia/mental retardation syndrome X-linked (ATRX) serves as a part of the sucrose nonfermenting 2 (SNF2) chromatin-remodeling complex. In interphase, ATRX localizes to pericentromeric heterochromatin, contributing to DNA double-strand break repair, DNA replication, and telomere maintenance. During mitosis, most ATRX proteins are removed from chromosomal arms, leaving a pool near the centromere region in mammalian cells, which is critical for accurate chromosome congression and sister chromatid cohesion protection.

View Article and Find Full Text PDF

Cytogenomics of (Hymenoptera: Apidae) and the Sharing of a Satellite DNA Family in Several Neotropical Meliponini Genera.

Genes (Basel)

January 2025

Laboratório de Citogenética de Insetos, Departamento de Biologia Geral, Universidade Federal de Viçosa, Campus Universitário, Viçosa 36570-900, Minas Gerais, Brazil.

Background/objectives: A striking feature of the karyotypes of stingless bees is the large amount of heterochromatin present in most species. Cytogenomic studies performed in some Meliponini species have suggested that evolutionary events related to the diversification and amplification of satellite DNA families in the heterochromatin may reflect the structuring of phylogenetic clades in this tribe. In this study, we performed a genomic analysis in to characterize different satDNA families in its genome.

View Article and Find Full Text PDF

Centromeric chromatin clearings demarcate the site of kinetochore formation.

Cell

January 2025

Department of Biochemistry and Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA; Biochemistry, Biophysics, Chemical Biology Graduate Group, University of Pennsylvania, Philadelphia, PA, USA; Institute of Structural Biology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA; Penn Center for Genome Integrity, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA; Epigenetics Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA. Electronic address:

The centromere is the chromosomal locus that recruits the kinetochore, directing faithful propagation of the genome during cell division. Using cryo-ET on human mitotic chromosomes, we reveal a distinctive architecture at the centromere: clustered 20- to 25-nm nucleosome-associated complexes within chromatin clearings that delineate them from surrounding chromatin. Centromere components CENP-C and CENP-N are each required for the integrity of the complexes, while CENP-C is also required to maintain the chromatin clearing.

View Article and Find Full Text PDF

High-resolution analysis of human centromeric chromatin.

Life Sci Alliance

April 2025

National Cancer Institute, Center for Cancer Research, Laboratory of Receptor Biology and Gene Expression, Bethesda, MD, USA

Centromeres are marked by the centromere-specific histone H3 variant CENP-A/CENH3. Throughout the cell cycle, the constitutive centromere-associated network is bound to CENP-A chromatin, but how this protein network modifies CENP-A nucleosome conformations in vivo is unknown. Here, we purify endogenous centromeric chromatin associated with the CENP-C complex across the cell cycle and analyze the structures by single-molecule imaging and biochemical assays.

View Article and Find Full Text PDF

Chromosome segregation relies on kinetochores that assemble on specialized centromeric chromatin containing a histone H3 variant. In budding yeast, a single centromeric nucleosome containing Cse4 assembles at a sequence-defined 125 bp centromere. Yeast centromeric sequences are poor templates for nucleosome formation in vitro, suggesting the existence of mechanisms that specifically stabilize Cse4 nucleosomes in vivo.

View Article and Find Full Text PDF

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!