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Imaging Replicative Domains in Ultrastructurally Preserved Chromatin by Electron Tomography
Published on: May 20, 2022
Dynamic changes in chromatin structure through post-translational modifications of histone H3 during replication
E Rampakakis1, D Di Paola, M K Chan
1Rosalind and Morris Goodman Cancer Center, Department of Biochemistry, McGill University, Montreal, Quebec, Canada H3A 1A3.
Journal of Cellular Biochemistry
|July 9, 2009
Summary
Dynamic histone modifications at replication origins are crucial for DNA replication. These epigenetic changes differ between early and late origins and species, highlighting their role in temporal activation and replication fork progression.
Area of Science:
- Molecular Biology
- Epigenetics
- Genomics
Background:
- Genome duplication requires timely activation of replication origins during S phase.
- Pre-replication complexes (pre-RCs) assemble at origins, enabling DNA replication machinery access.
- Epigenetic marks are maintained during DNA replication by enzymes traveling with the replisome.
Purpose of the Study:
- To investigate chromatin structure changes at replication origins during activation.
- To analyze dynamic histone modifications at early (LB2, mOrs8) and late (hOrs8) replication origins.
- To compare these changes between human and monkey cell lines.
Main Methods:
- Measurement of post-translationally modified histone H3 abundance at replication origin loci.
- Analysis of chromatin structure changes during DNA replication initiation.
Main Results:
- Dynamic changes in acetylated, methylated, and phosphorylated histone H3 were observed at all three origin loci.
- Histone modification patterns differed between early- and late-firing origins.
- Significant differences were noted in histone modifications between human and monkey cell lines.
Conclusions:
- Specific histone modifications are associated with replication origin firing and temporal activation.
- Replication fork progression is influenced by these dynamic epigenetic changes.
- Species-specific differences in histone modifications underscore their importance in replication regulation.
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