FASn

FASN, also known as fatty acid synthase, is a multifunctional enzyme that plays a crucial role in cellular metabolism. It is responsible for the de novo synthesis of fatty acids from acetyl-CoA and malonyl-CoA. This enzymatic complex is composed of seven distinct domains, each catalyzing a specific step in the fatty acid synthesis pathway. The primary function of FASN is to produce palmitate, a saturated fatty acid with a 16-carbon chain, which is a fundamental building block for cellular membranes, energy storage, and the synthesis of other lipids.

The expression and activity of FASN are tightly regulated by various physiological and hormonal signals. Insulin, for example, promotes FASN expression, particularly in tissues like the liver and adipose tissue, where fatty acid synthesis is active. Conversely, fasting and glucagon tend to suppress its activity. FASN is particularly abundant in tissues actively involved in lipogenesis, such as the lactating mammary gland, developing brain, and certain cancer cells.

Dysregulation of FASN has been implicated in several pathological conditions. Its overexpression is frequently observed in various types of cancer, where it contributes to the increased lipid demand of rapidly proliferating tumor cells, promoting cell growth, survival, and metastasis. Consequently, FASN has emerged as a potential therapeutic target for cancer treatment, with several inhibitors currently under investigation. Beyond cancer, aberrant FASN activity is also associated with metabolic disorders like obesity and type 2 diabetes, highlighting its central role in lipid homeostasis.