Different sterol regulatory element-binding protein-1 isoforms utilize distinct co-regulatory factors to activate the promoter for fatty acid synthase.

摘要: Sterol regulatory element-binding proteins (SREBPs) activate genes of cholesterol and fatty acid metabolism. In each case, a ubiquitous co-regulatory factor that binds to neighboring recognition site is also required for efficient promoter activation. It likely gene- pathway-specific regulation by the separate SREBP isoforms dependent on subtle differences in how individual function with specific co-regulators gene expression. studies reported here we extend these observations significantly demonstrating SREBPs are involved both sterol carbohydrate activation FAS promoter. We demonstrate previously implicated Sp1 largely dispensable established cultured cells, whereas CCAAT-binding factor/nuclear Y critically important. contrast, primary hepatocytes upon sites. Because 1c predominant isoform expressed 1a more abundant depleted cell lines, this suggests different utilize distinct factors target