Alterations in nucleosome structure affect the accessibility of the DNA and can generate specialized domains of chromatin in the genome. Such changes can be introduced by posttranslational modifications of histones, by chromatin remodeling, or by the incorporation of variants of H2A and H3 into nucleosomes. In contrast to the canonical histones, which are deposited behind the replication fork during S phase, histone variants are incorporated in a process that is independent of DNA replication. Recent studies have shown that distinct multiprotein complexes are responsible for the targeted deposition of histone variants at active genes, centromeres and silent loci. The incorporation of histone variants most probably has epigenetic consequences and contributes to architectural changes in chromosomes.
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http://dx.doi.org/10.1016/j.tibs.2005.10.003 | DOI Listing |
Nucleic Acids Res
January 2025
Institute of Reproductive Medicine, School of Medicine, Nantong University, Nantong 226001, China.
Chromatin remodeling, which involves the histone-to-protamine exchange process during spermiogenesis, is crucial for sperm nuclear condensation and male fertility. However, the key regulators and underlying molecular mechanisms involved in this process remain largely unexplored. In this study, we discovered that deficiency in the family with sequence similarity 170 member A (Fam170a) led to abnormal sperm nuclear morphology and male infertility in mice, mirroring the observation of very low Fam170a transcription levels in sperm of infertile men with teratozoospermia.
View Article and Find Full Text PDFJ Exp Bot
January 2025
Institute of Plant Sciences Paris-Saclay, Centre Nationale de la Recherche Scientifique, Institut National de la Recherche Agronomique, Université Evry, Université Paris-Saclay, 91405 Orsay, France.
Nucleosomes, the chromatin building blocks, play an important role in controlling DNA and chromatin accessibility. Nucleosome remodeling and the incorporation of distinct histone variants confer unique structural and biochemical properties, influencing the targeting of multiple epigenetic pathways, particularly DNA methylation. This stable epigenetic mark suppresses transposable element expression in plants and mammals, serving as an additional layer of chromatin regulation.
View Article and Find Full Text PDFInt Rev Cell Mol Biol
January 2025
Posgrado en Ciencias Genómicas, Laboratorio de Patogenesis Celular y Molecular Humana y Veterinaria, Universidad Autónoma de la Ciudad de México, Ciudad de México, México. Electronic address:
The critical role of a subset of Human Papillomavirus in cervical cancer has been widely acknowledged and studied. Despite progress in our understanding of the viral molecular mechanisms of pathogenesis, knowledge of how infection with HPV oncogenic variants progresses from latent infection to incurable cancer has not been completely elucidated. In this paper we reviewed the relationship between HPV infection and epigenetic mechanisms such as histone acetylation and deacetylation, DNA methylation and non-coding RNAs associated with this infection and the carcinogenic process.
View Article and Find Full Text PDFInt J Cancer
January 2025
Princess Margaret Cancer Centre, University Health Network, Toronto, Canada.
Prostate cancer is a common malignancy that in 5%-30% leads to treatment-resistant and highly aggressive disease. Metastasis-potential and treatment-resistance is thought to rely on increased plasticity of the cancer cells-a mechanism whereby cancer cells alter their identity to adapt to changing environments or therapeutic pressures to create cellular heterogeneity. To understand the molecular basis of this plasticity, genomic studies have uncovered genetic variants to capture clonal heterogeneity of primary tumors and metastases.
View Article and Find Full Text PDFLife 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.
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