Chapter 6 - Fatty acid desaturation and elongation in mammals

Abstract

Fatty acids (FAs), either synthesised de novo or obtained from the diet, are modified through desaturation and elongation reactions on the endoplasmic reticulum membrane. These reactions produce a variety of long-chain and very-long-chain saturated, monounsaturated and polyunsaturated FAs that have many fates and functions. FAs serve as substrates in the synthesis of complex lipid classes, such as triacylglycerols and phospholipids, or exist exclusively in their non-esterified form as free fatty acids. FAs facilitate energy storage, membrane fluidity, and act as signalling molecules. Here, we describe the function and regulation of mammalian FA desaturases (stearoyl-CoA desaturase, Δ5 desaturase and Δ6 desaturase) and elongases (elongase 1–7). Additionally, we illustrate the diverse physiological roles of specific mono- and polyunsaturated FAs and their relation to biochemical processes and diseases.