Histone acetylation

Definition

Histone acetylation is the addition of an acetyl group to histone proteins, leading to a more relaxed chromatin structure and increased gene expression. This process is crucial for regulating access to DNA by transcriptional machinery.

5 Must Know Facts For Your Next Test

1. Histone acetylation typically occurs on lysine residues of histone tails.
2. Acetylation neutralizes the positive charge on histones, reducing their affinity for negatively charged DNA.
3. Histone acetyltransferases (HATs) are the enzymes responsible for adding acetyl groups, while histone deacetylases (HDACs) remove them.
4. Increased histone acetylation is generally associated with active gene transcription.
5. Abnormal regulation of histone acetylation can lead to diseases such as cancer due to misregulation of gene expression.

Review Questions

• What effect does histone acetylation have on chromatin structure and gene expression?
• Which enzymes are responsible for adding and removing acetyl groups from histones?
• How can abnormal histone acetylation contribute to the development of cancer?

Related terms

Chromatin: The complex of DNA and proteins that forms chromosomes within the nucleus of eukaryotic cells.

Epigenetics: The study of heritable changes in gene function that do not involve changes in the DNA sequence.

Histone Deacetylase (HDAC): An enzyme that removes acetyl groups from histones, leading to a closed chromatin structure and reduced gene expression.