Acetyl-CoA carboxylase

Function

In muscle cells, the function of ACAC is to regulate the fatty mechanism. When the enzyme is active, the product, malonyl-CoA is produced and inhibit the transfer of the fatty acyl group from acyl CoA to carnitine with carnitine acyltransferase, which inhibits the beta-oxidation of the fatty acid in mitochondria.

Regulation

The inactive dimer form of this enzyme is induced to polymerize by citrate, resulting in the active polymer form.

The activity of the enzyme is controlled by the reversible phosphorylation. The activities of the enzyme is inhibited if phosphorylated; the phosphorylation takes place when the hormones, glucagon or epinephrine bind to the receptors or the energy status of the cell is low, leading to the activation of the AMP-activated protein kinase.

The presence of fatty acid inhibits the activities of the enzyme.

When insulin binds to its receptors of the cell, it activates a phosphatase to dephosphorylate the enzyme; the activities of the acetyl-CoA carboxylase is thus enhanced.

Clinical implications

Bacterial Acetyl-CoA carboxylase has recently become a target in the design of new anti-obesity and antibiotic drugs.

ee also

* Malonyl-CoA decarboxylase

References

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