Fig. 4.

Regulation of SCD-1 expression during de novo lipogenesis. Excess glucose converted to acetyl-CoA is channeled into de novo lipid synthesis through the products of sterol regulatory element-binding protein (SREBP)-1c and liver X receptor (LXR) activity. Increased SREBP-1c and LXR activity upregulate SCD-1 gene expression, whereby the conversion of 16:0 and 18:0 to 16:1 and 18:1 is increased. The products of SCD-1 activity are incorporated into phospholipids (PL), wax esters (WE), and CE. HMG-CoA, 3-hydroxy-3-methylglutaryl coenzyme A; ACC, acetyl-CoA carboxylase; FAS, fatty acid synthase; GPAT, glycerophosphate acyltransferase; WS, wax ester synthase.