Liver-specific mRNA for Insig-2 down-regulated by insulin: implications for fatty acid synthesis.

ABSTRACT: Insig-1 and -2 are closely related proteins of the endoplasmic reticulum (ER) that block proteolytic activation of sterol regulatory element-binding proteins (SREBPs), transcription factors that activate the synthesis of cholesterol and fatty acids in liver and other organs. When cellular cholesterol levels are high, Insig proteins bind and trap SREBP cleavage-activating protein (SCAP), retaining it in the ER and preventing it from escorting SREBPs from ER to the site of proteolytic activation in the Golgi complex. Here, we report the discovery of a liver-specific transcript of Insig-2, designated Insig-2a. This transcript and the ubiquitous transcript, designated Insig-2b, differ through the use of different promoters that produce different noncoding first exons that splice into a common

SUBMITTER: Yabe D 

PROVIDER: S-EPMC152262 | biostudies-literature | 2003 Mar

REPOSITORIES: biostudies-literature