H3K14ac

H3K14ac

Lysine acetylation process

H3K14ac refers to the acetylation of the 14th lysine residue on the histone H3 protein. This post-translational modification is a key epigenetic marker that plays a significant role in the regulation of gene expression.

Structure and Function

Histones are proteins that help package DNA into structural units called nucleosomes. The histone H3 protein is one of the core histones, and it is subject to various post-translational modifications, including acetylation, methylation, phosphorylation, and ubiquitination. The acetylation of lysine residues, such as H3K14, is a reversible modification that is catalyzed by histone acetyltransferases (HATs) and removed by histone deacetylases (HDACs).

H3K14ac is associated with active transcription. The addition of an acetyl group to the lysine residue neutralizes its positive charge, reducing the interaction between the histone and the negatively charged DNA. This results in a more relaxed chromatin structure, allowing transcription factors and other regulatory proteins to access the DNA more easily.

Biological Significance

H3K14ac is involved in various cellular processes, including:

• Gene Expression Regulation: H3K14ac is commonly found near the promoters of actively transcribed genes. It serves as a marker for transcriptional activation and is often used in chromatin immunoprecipitation (ChIP) assays to identify active regions of the genome.

• DNA Repair: Acetylation of H3K14 is also implicated in the DNA damage response. It facilitates the recruitment of repair proteins to sites of DNA damage, promoting efficient repair processes.

• Cell Cycle Control: H3K14ac levels fluctuate during the cell cycle, indicating a role in cell cycle regulation and progression.

Mechanism of Action

The acetylation of H3K14 is mediated by specific histone acetyltransferases, such as p300/CBP and GCN5. These enzymes transfer an acetyl group from acetyl-CoA to the ε-amino group of the lysine residue. The removal of the acetyl group is catalyzed by histone deacetylases, which restore the positive charge of the lysine, leading to chromatin condensation and transcriptional repression.

Clinical Implications

Alterations in H3K14ac levels have been linked to various diseases, including cancer. Aberrant acetylation patterns can lead to dysregulation of gene expression, contributing to oncogenesis. As a result, histone acetylation is a target for therapeutic intervention, with HDAC inhibitors being explored as potential cancer treatments.

Related Pages

• Histone acetylation
• Epigenetics
• Chromatin
• Gene expression
• Histone modification