Publicitad R▼
acetylation (n.)
1.the process of introducing an acetyl group into a compound"the acetylation of cyclooxygenase-2 by aspirin"
Acetylation (n.)
1.(MeSH)Formation of an acetyl derivative. (Stedman, 25th ed)
Publicidad ▼
⇨ definición de Acetylation (Wikipedia)
Publicidad ▼
acetylation (n.)
acylation[Hyper.]
acetylate, acetylise, acetylize - acetylate, acetylise, acetylize[Dérivé]
Wikipedia
Acetylation (or in IUPAC nomenclature ethanoylation) describes a reaction that introduces an acetyl functional group into a chemical compound. (Deacetylation is the removal of the acetyl group.)
Specifically, acetylation refers to that process of introducing an acetyl group (resulting in an acetoxy group) into a compound, to be specific, the substitution of an acetyl group for an active hydrogen atom. A reaction involving the replacement of the hydrogen atom of a hydroxyl group with an acetyl group (CH3 CO) yields a specific ester, the acetate. Acetic anhydride is commonly used as an acetylating agent reacting with free hydroxyl groups. For example, it is used in the synthesis of aspirin and heroin.
Contents |
In biology, i.e., in living cells, acetylation occurs as a co-translational and post-translational modification of proteins, for example, histones, p53, and tubulins. In fact, proteomics studies have identified thousands of acetylated mammalian proteins.[1] Among these proteins, chromatin proteins and metabolic enzymes are highly represented, indicating that acetylation has a considerable impact on gene expression and metabolism. In bacteria, 90% of proteins involved in central metabolism of Salmonella enterica are acetylated.[2]
Acetylation of the amino terminus occurs in about 50% of yeast proteins and more than 80% of human proteins. The reaction is catalyzed by N-terminal acetyltransferases, occurs predominantly during protein synthesis and appears to be irreversible.[3] Acetylation of the amino terminus of a protein can function as degradation signal (degron).[4]
Proteins are typically acetylated on lysine residues and this reaction relies on acetyl-coenzyme A as the acetyl group donor. In histone acetylation and deacetylation, histone proteins are acetylated and deacetylated on lysine residues in the N-terminal tail as part of gene regulation. Typically, these reactions are catalyzed by enzymes with histone acetyltransferase (HAT) or histone deacetylase (HDAC) activity, although HATs and HDACs can modify the acetylation status of non-histone proteins as well.[5]
The regulation of transcription factors, effector proteins, molecular chaperones, and cytoskeletal proteins by acetylation and deacetylation is a significant post-translational regulatory mechanism [6] These regulatory mechanisms are analogous to phosphorylation and dephosphorylation by the action of kinases and phosphatases. Not only can the acetylation state of a protein modify its activity, there has been recent suggestion that this post-translational modification may also crosstalk with phosphorylation, methylation, ubiquitination, sumoylation, and others for dynamic control of cellular signaling.[7]
The regulation of tubulin protein is an example of this in mouse neurons and astroglia.[8][9] A tubulin acetyltransferase is located in the axoneme, and acetylates the α-tubulin subunit in an assembled microtubule. Once disassembled, this acetylation is removed by another specific deacetylase in the cell cytosol. Thus axonemal microtubules, which have a long half-life, carry a "signature acetylation" which is absent from cytosolic microtubules which have a shorter half-life.
|
Contenido de sensagent
computado en 0,031s