REGULATION OF APOPROTEIN E BIOSYNTHESIS IN HEPATOTYCTES & ASSOC W/LIPOPROTEIN

肝细胞中脱蛋白E生物合成的调控

• 批准号: 5213150
• 负责人: GODFREY S GETZ
• 金额: --
• 依托单位国家: 美国
• 资助国家: 美国
• 起止时间: 至
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/5213150
• 关键词: apolipoproteins; blood lipoprotein; blood lipoprotein biosynthesis; chemical association; chimeric proteins; cholesterol; genetic regulation; genetically modified animals; heparin; high density lipoproteins; human tissue; laboratory mouse; laboratory rat; liver cells; low density lipoprotein; mutant; peptides; phospholipids; posttranscriptional RNA processing; protein sequence; protein structure function; receptor mediated endocytosis; secretion; tissue /cell culture; very low density lipoprotein

In this project, the three aspects of apoprotein E availability will be studied: the determinants of apoprotein E association with lipoprotein, the post-transcriptional regulation of apoprotein E secretion as stimulated by exogenous lipoproteins and the transcriptional regulation of apoprotein E production in hepatocytes. Apoprotein E associates with triglyceride- rich lipoproteins (VLDL and chylomicron remnants) and with larger HDL particles. The apoprotein sequences that determine these associations will be studied using domain specific mutagenesis and expression in hepatocytes and in heterogeneous systems (baculovirus). Mutant apoprotein E association with nascent and mature VLDL and HDL will be examined. HDL and LDL stimulates apoprotein E production 4-5 fold in steroidogenic cells, without effecting apoprotein E gene transcription. Mechanisms of this stimulation will be studied in a steroidogenic cell line. The domains of apoprotein E required for this effect will be delineated. Finally, the effects of cholesterol loading of hepatocytes and of modifying intracellular sterol balance on the transcription of the apoprotein E gene will be explored in detail. Two agonists -progesterone and 25 hydroxycholesterol will be studied. Efforts will be made to define the cis-acting sequences of apoprotein E gene and the trans-acting factors responsible for this regulation.

在这个项目中，脱辅基蛋白 E 可用性的三个方面将是 研究：脱辅基蛋白 E 与脂蛋白关联的决定因素， 受刺激时脱辅基蛋白 E 分泌的转录后调节 通过外源脂蛋白和脱辅基蛋白的转录调控 肝细胞中E的产生。 载脂蛋白 E 与甘油三酯相关 丰富的脂蛋白（VLDL 和乳糜微粒残余物）和较大的 HDL 颗粒。 决定这些关联的脱辅基蛋白序列将 使用肝细胞中的域特异性诱变和表达进行研究 以及异质系统（杆状病毒）。 突变型脱辅基蛋白E 将检查与新生和成熟 VLDL 和 HDL 的关联。 高密度脂蛋白和 LDL 刺激类固醇生成细胞中脱辅基蛋白 E 的产生 4-5 倍， 不影响脱辅基蛋白E基因转录。 这方面的机制 将在类固醇生成细胞系中研究刺激作用。 的域 将描述这种作用所需的脱辅基蛋白E。 最后，肝细胞胆固醇负荷和修饰的影响 细胞内甾醇平衡对脱辅基蛋白E基因转录的影响 将进行详细探讨。 两种激动剂——黄体酮和25 将研究羟基胆固醇。 将努力定义 脱辅基蛋白E基因顺式作用序列及反式作用因子 负责本规定。