What is the function of malonyl-CoA?

Malonyl-CoA has long been recognized as an important precursor of fatty acid biosynthesis in lipogenic tissues such as the liver and has an important role in regulating fatty acid oxidation in heart and skeletal muscle. Malonyl-CoA has also recently emerged as an important regulator of food intake and energy balance.

What does malonyl CoA decarboxylase do?

Malonyl-CoA decarboxylase is responsible for the chemical reaction that converts a molecule called malonyl-CoA to a molecule called acetyl-CoA. This reaction is an important step in the breakdown of fatty acids. Acetyl-CoA is then used to make new fatty acids and can also be used to produce energy.

What enzyme does malonyl-CoA regulate?

carnitine palmitoyltransferase I
Abstract. Malonyl-CoA is an inhibitor of carnitine palmitoyltransferase I, the enzyme that controls the oxidation of fatty acids by regulating their transfer into the mitochondria. Despite this, knowledge of how malonyl-CoA levels are regulated in skeletal muscle, the major site of fatty acid oxidation, is limited.

What is the role of malonyl-CoA in fatty acid synthesis?

Malonyl-CoA is a key intermediary metabolite in fatty acid synthesis. In de novo fatty acid synthesis, malonyl-coenzyme A (CoA) is the substrate that provides the primary carbon source for the formation of palmitate (C16) catalyzed by fatty acid synthase (FASN).

Does malonyl-CoA inhibit fatty acid synthesis?

The fall in malonyl-CoA stops fatty acid synthesis and activates CPT1 and ketogenesis (8). We also showed that the malonyl-CoA system functions in skeletal and cardiac muscle, although these tissues do not make ketones (9). Regulation of malonyl-CoA determines the switch between fatty acid synthesis and oxidation.

Where is malonyl-CoA formed?

4.1 Two forms of acetyl-CoA carboxylase In plants, malonyl-CoA for fatty acid synthesis is provided by a plastid-localized ACC, while a cytosolic ACC contributes malonyl units for fatty acid elongation beyond C18 as well as for synthesis of flavonoids, polyketides, and other metabolites.

Which hormone increases the level of malonyl-CoA?

Leptin inhibits AMP-activated kinase (AMPK) that inhibits ACC. This leads to activation of ACC resulting in increase in malonyl-CoA level. Glucose activates ACC by inhibiting AMPK, and increases availability of acetyl-CoA. Both effects result in increases in malonyl-CoA level.

What activates fatty acid synthesis?

Fatty acids are activated by reaction with CoA to form fatty acyl CoA. The reaction normally occurs in the endoplasmic reticulum or the outer mitochondrial membrane. This is an ATP-requiring reaction, yielding AMP and pyrophosphate (PPi). Different enzymes are specific for fatty acids of different chain length.

How is malonyl-CoA produced?

Malonyl-CoA is formed by carboxylating acetyl-CoA using the enzyme acetyl-CoA carboxylase. One molecule of acetyl-CoA joins with a molecule of bicarbonate, requiring energy rendered from ATP. Malonyl-CoA is utilised in fatty acid biosynthesis by the enzyme malonyl coenzyme A:acyl carrier protein transacylase (MCAT).

Does insulin promote lipolysis?

One of the key physiological functions of insulin as the major anabolic hormone in the body is to restrain lipolysis and to promote fat storage in adipose tissue in the postprandial state.