Regulation of chromatin condensation

Chromatin condensation is regulated by several mechanisms.

1. Histone modification

Histones can undergo:

Acetylation

Methylation

Phosphorylation

Ubiquitination

2. Histone acetylation

Histone acetylation generally reduces interaction between histones and DNA and promotes a more open chromatin structure.

3. DNA methylation

DNA methylation, particularly at CpG regions, is generally associated with transcriptional repression and condensed chromatin.

4. Chromatin-remodelling complexes

ATP-dependent complexes reposition or remove nucleosomes, changing DNA accessibility.

5. Histone H1

H1 contributes to higher-order chromatin organization and compaction.

Thus, chromatin condensation controls the accessibility of genes to transcription machinery.

Anju