asetyylCoAsta

AsetyylCoAsta, commonly known as acetyl-CoA, is a central metabolite in energy metabolism. It is a thioester formed between coenzyme A and an acetyl group. Acetyl-CoA acts as a versatile donor of acetyl groups in a wide range of biochemical pathways, linking carbohydrate, lipid, and protein metabolism. In many tissues, its availability influences both energy production and biosynthetic processes.

Acetyl-CoA is produced in several ways. In mitochondria, the pyruvate dehydrogenase complex converts pyruvate, derived from glycolysis, into acetyl-CoA, producing NADH in the process. Fatty acids undergo beta-oxidation to yield acetyl-CoA units, while certain ketogenic and other amino acids can also be degraded to acetyl-CoA. In the cytosol, acetyl-CoA is generated from citrate that is exported from mitochondria and cleaved by ATP citrate lyase, a key step for lipid and acetylation reactions.

In metabolism, acetyl-CoA feeds into the citric acid cycle by condensing with oxaloacetate to form citrate, catalyzed by citrate synthase. It also serves as the acetyl donor for fatty acid and cholesterol synthesis and, during fasting, contributes to ketone body formation in the liver. Nuclear and cytosolic pools of acetyl-CoA participate in histone acetylation and other acetylation-dependent regulatory processes, linking metabolic state to gene expression.

Regulation of acetyl-CoA production and consumption is tightly controlled by cellular energy status, via factors such as NADH/NAD+, ATP/ADP, and allosteric regulators of the pyruvate dehydrogenase complex. Defects in acetyl-CoA metabolism can disrupt energy production and biosynthesis, with broad physiological consequences.