Histone acetylation

Histone acetylation is a critical epigenetic post-translational modification involving the enzymatic addition of an acetyl group to lysine residues on histone tails, primarily mediated by histone acetyltransferases (HATs) and reversed by histone deacetylases (HDACs) [1][2]. This modification neutralizes the positive charge on the histones, reducing their affinity for the negatively charged DNA and leading to a more open, transcriptionally active chromatin state known as euchromatin [1][4]. In various pathologies, especially oncology, the balance of acetylation is often disrupted, leading to the silencing of essential tumor suppressor genes [2][3]. Pharmacological intervention largely focuses on HDAC inhibitors, which restore acetylation levels to induce cell cycle arrest, differentiation, and apoptosis in malignant cells [5]. Beyond cancer, the modulation of histone acetylation is being investigated for its potential in treating neurodegenerative disorders, such as Alzheimer's disease, and chronic inflammatory conditions [3][6]. Because 'Histone acetylation' refers to a biological process and modification rather than a single protein molecule, it is classified as a broader pathway or mechanism of action rather than a specific therapeutic target like an enzyme or receptor [4].

Other names

Histone lysine acetylationHistone H3 acetylationHistone H4 acetylationHAT/HDAC pathwayChromatin acetylation

The primary mechanism for drugs modulating this process is the inhibition of histone deacetylases (HDACs), which prevents the removal of acetyl groups from lysine residues on histone tails [2]. This leads to an accumulation of acetylated histones, promoting a relaxed euchromatin structure that allows the re-expression of genes previously silenced in disease states, such as tumor suppressor genes and cell cycle inhibitors like p21 [2][5]. Other approaches include the use of bromodomain inhibitors to block 'reader' proteins from binding to acetylated lysines or the modulation of histone acetyltransferases (HATs) [6].