Histone deacetylase

Histone deacetylase (HDAC) is a type of enzyme that plays a crucial role in the regulation of gene expression. HDACs are part of a larger family of proteins that are involved in the modification of histones, the proteins around which DNA is wound to form chromosomes.

Function

HDACs remove acetyl groups from the histones, which leads to the condensation of the DNA-histone complex and the suppression of gene expression. This process is known as histone deacetylation.

Types

There are four classes of HDACs:

• Class I includes HDACs 1, 2, 3, and 8. These are found in the nucleus and are involved in cell survival and proliferation.
• Class II includes HDACs 4, 5, 6, 7, 9, and 10. These can shuttle between the nucleus and the cytoplasm and are involved in a variety of cellular processes.
• Class III includes the sirtuins, which are involved in aging and metabolism.
• Class IV includes only HDAC11, which has properties of both Class I and II HDACs.

Role in Disease

Abnormal HDAC activity has been linked to a number of diseases, including cancer, neurodegenerative diseases, and cardiovascular diseases. In cancer, for example, increased HDAC activity can lead to the silencing of tumor suppressor genes.

HDAC Inhibitors

HDAC inhibitors are a class of drugs that block the activity of HDACs. They are being investigated for their potential to treat a variety of diseases, including cancer and neurodegenerative diseases.

See Also

• Epigenetics
• Gene expression
• Histone acetyltransferase

Histone deacetylase

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  Phylogenetic tree of histone deacetylases
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  Histone tails set for transcriptional activation
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  Histone tails set for transcriptional repression