H3S10P

Phosphorylation of serine 10 on histone H3

H3S10P

H3S10P refers to the phosphorylation of the serine residue at position 10 on the histone H3 protein. This post-translational modification plays a crucial role in the regulation of chromatin structure and function, impacting processes such as gene expression, mitosis, and DNA repair.

Amino acid phosphorylations

Structure and Function

Histone H3 is one of the core histone proteins that form the nucleosome, the fundamental unit of chromatin. The phosphorylation of serine 10 (S10) on histone H3 is a reversible modification that is catalyzed by specific kinases. This modification is often associated with chromatin condensation during mitosis and is also involved in the regulation of gene transcription.

Role in Mitosis

During mitosis, H3S10 phosphorylation is a key event that facilitates chromatin condensation, allowing for the proper segregation of chromosomes. The phosphorylation of H3S10 is typically initiated in the late G2 phase and peaks during metaphase. This modification is crucial for the recruitment of other proteins that are involved in chromatin remodeling and mitotic progression.

Role in Gene Expression

H3S10 phosphorylation is also implicated in the regulation of gene expression. It is often found in conjunction with other histone modifications, such as acetylation, which together can influence the transcriptional activity of genes. The presence of H3S10P can mark active transcription sites and is involved in the rapid response to external stimuli, such as stress or growth factors.

Enzymes Involved

Several kinases are known to phosphorylate H3S10, including Aurora B kinase and MSK1/2. These kinases are activated in response to various cellular signals and play roles in both mitotic and interphase cells. The dephosphorylation of H3S10 is mediated by specific phosphatases, which remove the phosphate group, allowing for the dynamic regulation of this modification.

Biological Implications

The phosphorylation of H3S10 is a marker of active chromatin and is involved in the regulation of various cellular processes. Aberrations in H3S10 phosphorylation have been linked to several diseases, including cancer, where it may contribute to uncontrolled cell proliferation and tumor progression.

Related Pages

• Histone modification
• Chromatin
• Gene expression
• Mitosis
• Kinase