H3K36ac

H3K36ac

Lysine acetylation process

H3K36ac refers to the acetylation of the lysine residue at position 36 on the histone H3 protein. This post-translational modification is a key epigenetic marker involved in the regulation of gene expression. Histone modifications, such as acetylation, play a crucial role in chromatin remodeling and the regulation of transcriptional activity.

Structure and Function

Histone H3 is one of the core histone proteins that form the nucleosome, the fundamental unit of chromatin. The acetylation of lysine residues on histones, including H3K36, is mediated by histone acetyltransferases (HATs). This modification neutralizes the positive charge on the lysine residue, reducing the interaction between histones and DNA, thereby facilitating a more open chromatin structure that is accessible to transcription factors and other DNA-binding proteins.

H3K36ac is associated with active transcription and is often found in the bodies of actively transcribed genes. It is thought to play a role in the regulation of alternative splicing and the prevention of cryptic transcription initiation.

Biological Significance

The acetylation of H3K36 is involved in various cellular processes, including:

• Gene Expression Regulation: H3K36ac is a marker of active transcription and is enriched in the coding regions of genes. It is associated with the elongation phase of transcription by RNA polymerase II.

• Chromatin Remodeling: By altering the interaction between histones and DNA, H3K36ac contributes to the dynamic remodeling of chromatin, facilitating access to the DNA for transcriptional machinery.

• DNA Repair: H3K36ac has been implicated in the DNA damage response, where it may help recruit repair proteins to sites of damage.

Enzymes Involved

The acetylation of H3K36 is catalyzed by specific histone acetyltransferases (HATs). These enzymes transfer an acetyl group from acetyl-CoA to the lysine residue on histone H3. Conversely, histone deacetylases (HDACs) can remove these acetyl groups, reversing the modification and leading to a more condensed chromatin state.

Clinical Implications

Alterations in histone acetylation patterns, including H3K36ac, have been linked to various diseases, including cancer. Aberrant acetylation can lead to dysregulation of gene expression, contributing to oncogenesis. As such, H3K36ac and other histone modifications are being explored as potential biomarkers for disease and targets for therapeutic intervention.

Related Pages

• Histone acetylation
• Chromatin
• Epigenetics
• Histone H3
• Histone acetyltransferase
• Histone deacetylase