title: Dual functions of Insig proteins in cholesterol homeostasis.
abstract: The molecular mechanism of how cells maintain cholesterol homeostasis has become clearer for the understanding of complicated association between sterol regulatory element-binding proteins (SREBPs), SREBP cleavage-activating protein (SCAP), 3-hydroxy-3-methylglutaryl coenzyme A reductase (HMG-CoA reductase) and Insuin induced-genes (Insigs). The pioneering researches suggested that SREBP activated the transcription of genes encoding HMG-CoA reductase and all of the other enzymes involved in the synthesis of cholesterol and lipids. However, SREBPs can not exert their activities alone, they must form a complex with another protein, SCAP in the endoplasmic reticulum (ER) and translocate to Golgi. Insigs are sensors and mediators that regulate cholesterol homeostasis through binding to SCAP and HMG-CoA reductase in diverse tissues such as adipose tissue and liver, as well as the cultured cells. In this article, we aim to review on the dual functions of Insig protein family in cholesterol homeostasis.
authors.affiliation: College of Veterinary Medicine, South China Agricultural University, No,483 Wu Shan Road, Tian He District, Guangzhou, 510642, China. jdchen@scau.edu.cn.
authors.forename: Xiao-Ying
authors.initials: XY
authors.lastname: Dong
authors.forename: Sheng-Qiu
authors.initials: SQ
authors.lastname: Tang
authors.forename: Jin-Ding
authors.initials: JD
authors.lastname: Chen
mesh_terms: D002784:Cholesterol / Q000235:genetics / Q000378:metabolism; D006056:Golgi Apparatus; D006706:Homeostasis / Q000235:genetics; D006801:Humans; D006903:Hydroxymethylglutaryl CoA Reductases / Q000235:genetics / Q000378:metabolism; D007328:Insulin / Q000235:genetics* / Q000378:metabolism; D047908:Intracellular Signaling Peptides and Proteins / Q000235:genetics / Q000378:metabolism; D050356:Lipid Metabolism / Q000235:genetics; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism; D021381:Protein Transport; D051779:Sterol Regulatory Element Binding Proteins / Q000235:genetics / Q000378:metabolism
chemical_list: D007328:Insulin; D047908:Intracellular Signaling Peptides and Proteins; D008565:Membrane Proteins; C102196:SREBP cleavage-activating protein; D051779:Sterol Regulatory Element Binding Proteins; D002784:Cholesterol; D006903:Hydroxymethylglutaryl CoA Reductases