Enzymatic Function & Lipid Metabolism

Question: What is the critical role of ACACA in the cellular fatty acid synthesis pathway?

Answer: ACACA, or Acetyl-CoA Carboxylase 1 (ACC1), is a multi-subunit enzyme that catalyzes the ATP-dependent carboxylation of acetyl-CoA to malonyl-CoA. This [ACACA-mediated malonyl-CoA production] is the first and rate-limiting step in de novo lipogenesis, providing the essential building blocks for long-chain fatty acid synthesis and simultaneously regulating mitochondrial fatty acid oxidation.