H4K12ac

H4K12ac

Lysine acetylation process

H4K12ac refers to the acetylation of the 12th lysine residue on the histone protein H4. 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 package and order DNA into structural units called nucleosomes. The histone H4 is one of the core histones, and its N-terminal tail is subject to various post-translational modifications, including acetylation. The acetylation of lysine 12 on histone H4 (H4K12ac) is a reversible modification that is catalyzed by histone acetyltransferases (HATs) and removed by histone deacetylases (HDACs).

Acetylation of H4K12 reduces the positive charge on the histone, decreasing its affinity for the negatively charged DNA. This alteration in charge can lead to a more relaxed chromatin structure, facilitating access for transcription factors and other proteins involved in transcription.

Biological Significance

H4K12ac is associated with active transcription and is often found in regions of the genome that are being actively transcribed. It is a marker of euchromatin, the less condensed form of chromatin that is accessible for transcription. The presence of H4K12ac is crucial for the regulation of genes involved in various cellular processes, including cell cycle progression, DNA repair, and cell differentiation.

In addition to its role in transcriptional activation, H4K12ac is involved in the regulation of DNA replication and chromatin remodeling. It is also implicated in the cellular response to DNA damage, where it may help recruit repair proteins to sites of damage.

Clinical Implications

Alterations in histone acetylation patterns, including H4K12ac, have been linked to various diseases, particularly cancer. Aberrant acetylation can lead to dysregulation of gene expression, contributing to oncogenesis. As a result, H4K12ac and other histone modifications are being studied as potential biomarkers for cancer diagnosis and prognosis, as well as targets for therapeutic intervention.

Histone deacetylase inhibitors (HDAC inhibitors) are a class of drugs that can alter acetylation patterns and are being explored as treatments for cancer and other diseases. By inhibiting HDACs, these drugs can increase acetylation levels, including H4K12ac, potentially restoring normal gene expression patterns.

Related Pages

• Histone acetylation
• Epigenetics
• Chromatin
• Gene expression
• Histone deacetylase
• Histone acetyltransferase