Related Experiment Video
Updated: Jun 25, 2026
14:56
Imaging Replicative Domains in Ultrastructurally Preserved Chromatin by Electron Tomography
Published on: May 20, 2022
Replicating chromatin: a tale of histones
1Biotech Research and Innovation Centre (BRIC), University of Copenhagen, Ole Maaloes Vej 5, DK-2200 Copenhagen, Denmark. anja.groth@bric.ku.dk
Biochemistry and Cell Biology = Biochimie Et Biologie Cellulaire
|February 24, 2009
Summary
This review explores how histones, the proteins that package DNA into chromatin, are managed during DNA replication. It examines the recycling and deposition of histones to maintain epigenetic information on new DNA strands.
Area of Science:
- Molecular Biology
- Epigenetics
- Genetics
Background:
- Chromatin structure is vital for genome stability and gene expression.
- Epigenetic information encoded by chromatin must be faithfully inherited during DNA replication.
- Nucleosomes, the basic units of chromatin, are disrupted by replication forks.
Purpose of the Study:
- To review the mechanisms of histone handling at the replication fork.
- To highlight recent mechanistic insights into histone recycling and deposition.
- To re-evaluate established paradigms in chromatin replication.
Main Methods:
- Literature review of chromatin replication and histone dynamics.
- Analysis of experimental data on histone fate during S-phase.
- Synthesis of current understanding of histone chaperones and deposition factors.
Main Results:
- Histones are transiently displaced by replication forks.
- Both old (recycled) and new histones contribute to re-establishing nucleosomes on daughter DNA strands.
- Specific histone chaperones play critical roles in mediating histone-parental strand segregation and re-deposition.
Conclusions:
- Faithful inheritance of chromatin structure relies on efficient histone management during replication.
- Understanding histone dynamics at the fork is key to comprehending epigenetic memory.
- Further research is needed to fully elucidate the intricate mechanisms of histone recycling and deposition.
Related Concept Videos
02:05Duplication of Chromatin Structure
The process of chromosome duplication during cell division requires genome-wide disruption and re-assembly of chromatin. The chromatin structure must be accurately inherited, reassembled, and maintained in the daughter cells to ensure lineage propagation.
The basic unit of the chromatin is the nucleosome, consisting of DNA wrapped around octameric histone proteins and short stretches of linker DNA separating individual nucleosomes. The histone proteins within the nucleosome have their...
The basic unit of the chromatin is the nucleosome, consisting of DNA wrapped around octameric histone proteins and short stretches of linker DNA separating individual nucleosomes. The histone proteins within the nucleosome have their...
02:31Chromosome Replication
Before a cell can divide, it must accurately replicate all of its chromosomes, including the DNA and its associated histone and non-histone proteins. This process begins at numerous origins of replication during the S phase of the cell cycle in each of a cell’s chromosomes simultaneously. Certain nucleotides can act as origins of replication, but these sequences are not well defined - especially in complex, multi-cellular, eukaryotic species. The length of DNA that spans an origin of...
03:17Inheritance of Chromatin Structures
Epigenetics is the study of inherited changes in a cell's phenotype without changing the DNA sequences. It provides a form of memory for the differential gene expression pattern to maintain cell lineage, position-effect variegation, dosage compensation, and maintenance of chromatin structures such as telomeres and centromeres. For example, the structure and location of the centromere on chromosomes are epigenetically inherited. Its functionality is not dictated or ensured by the underlying DNA...
02:25Spreading of Chromatin Modifications
The histone proteins in the nucleosomes are post-translationally modified (PTM) to increase or decrease access to DNA. The commonly observed PTMs are methylation, acetylation, phosphorylation, and ubiquitination of lysine amino acids in the histone H3 tail region. These histone modifications have specific meaning for the cell. Hence, they are called "histone code". The protein complex involved in histone modification is termed as "reader-writer" complex.
Writers
The writer is an enzyme that can...
Writers
The writer is an enzyme that can...
01:12The Nucleosome Core Particle
Nucleosomes are the DNA-histone complex, where the DNA strand is wound around the histone core. The histone core is an octamer containing two copies of H2A, H2B, H3, and H4 histone proteins.
Nucleosomes, paradoxically, perform two opposite functions simultaneously. On the one hand, their primary aim is to protect the delicate DNA strands from physical damage and help achieve a higher compaction ratio. On the other hand, they must allow polymerase enzymes to access histone-bound DNA during...
Nucleosomes, paradoxically, perform two opposite functions simultaneously. On the one hand, their primary aim is to protect the delicate DNA strands from physical damage and help achieve a higher compaction ratio. On the other hand, they must allow polymerase enzymes to access histone-bound DNA during...
02:10The Nucleosome Core Particle
Nucleosomes are the DNA-histone complex, where the DNA strand is wound around the histone core. The histone core is an octamer containing two copies of H2A, H2B, H3, and H4 histone proteins.
The paradox
Nucleosomes, paradoxically, perform two opposite functions simultaneously. On the one hand, their main responsibility is to protect the delicate DNA strands from physical damage and help achieve a higher compaction ratio. While on the other hand, they must allow polymerase enzymes to access DNA...
The paradox
Nucleosomes, paradoxically, perform two opposite functions simultaneously. On the one hand, their main responsibility is to protect the delicate DNA strands from physical damage and help achieve a higher compaction ratio. While on the other hand, they must allow polymerase enzymes to access DNA...