Acetylation is the reversible addition of an acetyl group to lysine residues on histones and many non-histone proteins. It is written by histone acetyltransferases (HATs) and erased by histone deacetylases (HDACs).
-Histone acetylation → relaxed chromatin → gene activation
-Deacetylation → compact chromatin → gene repression
Key writers include EP300 and CREBBP; erasers include multiple HDACs.
Acetylation controls:
-Cell cycle (e.g., acetylation of p53, E2F programs)
-Differentiation vs stemness
-DNA damage response
-Immune visibility (antigen presentation genes)
-Metabolic adaptation (acetylation of metabolic enzymes)
Thus, acetylation is a state regulator, not a single pathway switch.
Therapeutic Relevance
HDAC inhibitors exploit acetylation imbalance to:
-Re-activate silenced genes
-Promote differentiation/apoptosis
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