... accompa-nied by a reduction in the amount of cytosolic Sp1. In order to determine whether glutamine increases the binding of Sp1 to the SREBP-1a promoter regioncontaining the Sp1-binding elements, we performed ... containing amutated sequence of the SRE, pSQS containing the humanSQS promoter, pSQS SREKO containing two mutatedSREs, pLDLR containing the human LDL receptor pro-moter, and pMTP containing the ... proteolytic processing of SREBPs is tightly regulated by the interactionbetween two ER membrane proteins, SREBP cleav-age-activating protein (SCAP) and the insulin-induc-ing gene (Insig). When cells...