目的 筛选影响胆固醇调节元件结合蛋白1a(cholesterol regulatory element binding protein，SREBP1a)蛋白稳定性的去泛素化酶，并探索其调控机制。方法 通过去泛素化酶库筛选显著影响SREBP1a表达的去泛素化酶，免疫蛋白印记实验和实时荧光定量PCR(qRT-PCR)评估去泛素化酶对SREBP1a以及升脂基因表达的影响;通过红色荧光蛋白标记人源低密度脂蛋白(human Dil-low density lipoprotein，Human Dil-LDL)摄取和油红O染色等实验技术检测细胞摄取低密度脂蛋白(LDL)和脂质沉积情况。结果 去泛素化酶库筛选发现泛素特异肽酶37(ubiquitin specific pepti-dase 37，USP37)可显著增加肝细胞SREBP1a蛋白表达水平，促进胆固醇摄取及脂质沉积。USP37基因敲除可显著降低SREBP1a蛋白表达水平，抑制升脂基因表达及脂质沉积。结论 去泛素化酶USP37通过稳定SREBP1a蛋白表达，促进胆固醇摄取及脂质沉积，揭示了 SREBP1a翻译后调控的新模式。
USP37 Promotes Cholesterol Uptake and Lipid Deposition by Stabilizing SREBP1a
Objective To explore the role of deubiquitination enzymes in the post-translational regulation of cholesterol regulatory element binding protein 1a(SREBP1a)and the corresponding mechanisms.Methods The effects of deubiquitination enzyme on the ex-pression of SREBP1a and lipid-raising gene were investigated by immunoprotein imprinting and real-time fluorescent quantitative PCR(qRT-PCR).The ubiquitization level of SREBP1a was evaluated by immunoprecipitation.LDL uptake and lipid deposition were detected by human Dil-low density lipoprotein(Dil-LDL)uptake and oil red O staining.Results SREBP1a promoted cholesterol uptake and lipid deposition.Ubiquitin specific peptidase 37(USP37)could increase the protein expression level of SREBP1a and promote cholesterol up-take and lipid deposition.USP37 gene knockout could inhibit the expression of lipid-raising gene and lipid deposition.Conclusion Deu-biquitination enzyme USP37 promotes cholesterol uptake and cellular lipid deposition by stabilizing SREBP1a protein expression,revea-ling the post-translational regulation mode of SREBP1a gene expression.
deubiquitinationlipid depositionlow density lipid uptakeUSP37SREBP1a
NETL
NSTL
万方数据
