固醇调节元件结合蛋白(Sterol Regulatory Element Binding proteins,SREBPs)是一类固定于内质网和核被膜上的膜连接蛋白,具有“碱性螺旋-环-螺旋-亮氨酸拉链”(basic Helix-Loop-Helix-Leucine Zipper,bHLH-Zip)结构,属于bHLH-Zip超家族的一员。已经确认的SREBPs成员有3种:SREBP-1a,SREBP-1c,SREBP-2。其中SREBP-1a,SREBP-1c主要调节脂肪酸(fatty acid synthase,FAS)、甘油三酯(triglyceride,TG)和葡萄糖代谢相关酶基因的表达,SREBP-2主要调控胆固醇代谢。SREBPs在内质网合成后是无功能的前体,与SREBPs裂解激活蛋白(SREBP Cleavage Activating Protein,SCAP)组成复合物,共同调控胞内胆固醇浓度的动态平衡。SCAP含有一个固醇敏感区,是哺乳动物脂质合成和摄入的中心调节因子。SREBP-1c又称脂肪细胞定向与分化因子1(Adipocyte Determination and Differentiati...
【英文摘要】
Sterol Regulatory Element Binding proteins (SREBPs), membrane-bound transcription factors that activate at least 30 genes encoding enzymes of lipogenesis and adipogenesis. SREBPs are embedded in membranes of the endoplasmic reticulum and the nuclear envelope. These membrane proteins are members of the bHLH-Zip (basic helix-loop-helix-leucine zipper) family of transcription factors.Three different SREBPs are known, SREBPs-1a, -1c and -2. SREBPs are synthesized as precursor proteins in the endoplasmic reticul...