SEL1L-HRD1 ER相关的降解促进了前激素转化酶2的成熟和岛屿α细胞中的葡萄糖生成
Wenzhen Zhu1, Linxiu Pan1,2, Xianwei Cui3
1Division of Metabolism, Endocrinology & Diabetes, Department of Internal Medicine, University of Michigan Medical School, Ann Arbor, MI 48105, USA.
bioRxiv : the preprint server for biology
|April 1, 2025
概括
细胞内膜网关联降解 (ERAD) 调节了前激素转化酶2 (PC2) 的成熟,这对岛屿α细胞中葡萄糖的产生至关重要. 这种蛋白质质量控制途径对于维持正常的葡萄糖分和α细胞功能至关重要.
科学领域:
- 分子生物学分子生物学
- 内分泌学 在内分泌学.
- 细胞生物学 细胞生物学
背景情况:
- 岛屿α细胞的葡萄糖生成依赖于由前激素转化酶2 (PC2) 进行葡萄糖的蛋白质分解裂变.
- 管理PC2成熟和活动的监管机制仍然不完全理解.
- 蛋白质质量控制系统,如内质网关联降解 (ERAD),对于细胞平衡至关重要.
研究的目的:
- 研究SEL1L-HRD1 ERAD系统在调节前激素转化酶2 (PC2) 处理中的作用.
- 确定ERAD介导的PC2周转率对葡萄糖生产和α细胞功能的影响.
主要方法:
- 使用了一种小鼠模型,在表达前葡萄糖的细胞中删除了SEL1L.
- 评估葡萄糖分泌和胰腺葡萄糖含量.
- 研究了proPC2与SEL1L-HRD1 ERAD通路之间的相互作用.
主要成果:
- 阿尔法细胞中的SEL1L丧失导致刺激葡萄糖分泌量减少和胰腺葡萄糖含量降低.
- 内源的proPC2被确定为SEL1L-HRD1 ERAD通路的基质.
- 发现ERAD对错误折叠的proPC2的降解对于生成激活能力强的PC2至关重要.
结论:
- SEL1L-HRD1 ERAD通路是PC2生物学的一个新型调节器.
- 通过ERAD介导的proPC2的循环转化对于维持α细胞功能和确保足够的葡萄糖生产至关重要.
- 这项研究强调了蛋白质质量控制作为内分泌激素调节的关键机制.
相关概念视频
Insulin Secretory Vesicles
4.8K
Insulin secretory vesicles release insulin to stimulate blood glucose uptake and regulate carbohydrate metabolism. When the blood glucose levels increase, glucose enters the pancreatic β-islet cells through glucose transporters. Once inside, glucose is metabolized through glycolysis, the citric acid cycle, and the electron transport chain, producing ATP. This increase in ATP concentration closes ATP-sensitive potassium channels, leading to depolarization of the membrane and the opening of...
4.8K
Glucose Homeostasis: Pancreatic Islets and Insulin Secretion
1.0K
The pancreatic islets comprising only 1%-2% of the volume are highly vascularized and innervated mini-organs. They contain five endocrine cell types, including β cells that secrete insulin, which is synthesized as a single polypeptide chain, preproinsulin, processed to proinsulin, and finally to insulin and C-peptide. This process is complex and regulated, involving the Golgi complex, the endoplasmic reticulum, and the secretory granules of the β cell.
Insulin and C-peptide are...
Insulin and C-peptide are...
1.0K
Hormones Regulating Blood Glucose
2.9K
Insulin is released by beta cells of the pancreas when blood glucose levels are high. It facilitates glucose absorption and utilization in insulin-dependent cells with insulin receptors on their plasma membranes. Insulin promotes glucose uptake by increasing the number of glucose transport proteins in the cell membrane, allowing glucose to enter the cell. As a result, glucose utilization and ATP production are enhanced.
In addition to accelerating glucose uptake and utilization, insulin has...
In addition to accelerating glucose uptake and utilization, insulin has...
2.9K
Glucagon-like Receptor Agonists
272
Incretins include glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP), which stimulate insulin secretion post-meals. In type 2 diabetes, GIP's efficacy is reduced, making GLP-1 a viable drug target. GIP originates from preproGIP.
GLP-1, when administered in high doses intravenously, triggers insulin secretion, inhibits glucagon release, slows gastric emptying, reduces food intake, and restores normal insulin secretion. However, its rapid inactivation by...
GLP-1, when administered in high doses intravenously, triggers insulin secretion, inhibits glucagon release, slows gastric emptying, reduces food intake, and restores normal insulin secretion. However, its rapid inactivation by...
272
Insulin: Biosynthesis, Chemistry, and Preparation
322
The endoplasmic reticulum (ER) of pancreatic β-cells synthesizes preproinsulin, which consists of a signal peptide, A and B chains, and a C-peptide. Preproinsulin is then cleaved and folded into proinsulin, which translocates to the Golgi apparatus for sorting and packaging into secretory granules. In these granules, enzymatic clipping generates insulin and C-peptide.
Damage or functional impairment of β-cells inhibits insulin production, leading to diabetes. Diabetes treatment...
Damage or functional impairment of β-cells inhibits insulin production, leading to diabetes. Diabetes treatment...
322
Insulin: The Receptor and Signaling Pathways
1.0K
Insulin action is mediated through a receptor tyrosine kinase, akin to the IGF-1 receptor. The number of receptors per cell varies significantly, from 40 on erythrocytes to 300,000 on adipocytes and hepatocytes. The insulin receptor consists of linked α/β subunit dimers, forming a heterotetramer glycoprotein with two extracellular α subunits and two β subunits spanning the membrane. The α subunits inhibit the inherent tyrosine kinase activity of the β subunits, but...
1.0K


