DOLICHOL PHOSPHATE METABOLISM AND GLYCOPROTEIN SYNTHESIS

磷酸多醇代谢和糖蛋白合成

• 批准号: 3289669
• 负责人: Charles J Waechter
• 金额: $ 14.22万
• 依托单位: UNIVERSITY OF KENTUCKY
• 依托单位国家: 美国
• 财政年份: 1981
• 资助国家: 美国
• 起止时间: 1981-06-01 至 1992-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/3289669
• 关键词: B lymphocyte; cell differentiation; cell growth regulation; dolichol; enzyme mechanism; glycosylation; human tissue; immunoglobulins; ionomycin; laboratory mouse; lipopolysaccharides; phosphoric ester; protein biosynthesis; protein kinase C; tritium

The activation of B-lymphocytes (B-cells) leads to increased synthesis of membrane-bound and secretory glycoproteins. This application proposes studies on the regulation of N-glycosylation activity when membrane glycoprotein synthesis is stimulated in resting B-cells induced to proliferate by bacterial lipopolysaccharide (LPS). The control of N-glycosylation will also be investigated in the human B lymphoblastoid cell line (CESS) stimulated to differentiate and secrete large amounts of immunoglobulins by exposure to B-cell differentiation factor (BCDF). Changes in N-glycosylation activity in response to the induction of proliferation or differentiation of the B-cells will be correlated with changes in several enzymes involved in dolichyl phosphate (Do1-P) metabolism and the synthesis of dolichol-linked oligosaccharides. Dolichol kinase and Dol-P phosphatase activity will be assayed in vitro to determine if Dol-P levels could be altered by shifting the balance in a phosphorylation- dephosphorylation scheme during the proliferation of B-cells or the differentiation of the CESS line. The requirement for de novo synthesis of dolichol or Dol-P during the proliferative and differentiative changes will be explored by metabolic labeling experiments with (3H)mevalonate, and studies with exogenously supplied dolichol and capactin, the competitive inhibitor of HMG- CoA reductase. The possible involvement of Ca++-mobilization and protein kinase C in the activation processes will be explored by cellular studies with ionomycin and phorbol diesters. The proposed experiments could shed new light on the control of the N-glycosylation apparatus in B-cells, and extend the current knowledge of the biochemical events occurring during the proliferation and differentiation of B-lymphocytes.

B 淋巴细胞（B 细胞）的激活导致 膜结合糖蛋白和分泌糖蛋白的合成。 这 申请提出N-糖基化调控研究 当膜糖蛋白合成受到刺激时的活性 细菌诱导静息 B 细胞增殖 脂多糖（LPS）。 N-糖基化的控制也将 在人 B 类淋巴母细胞系 (CESS) 中进行研究 刺激分化并分泌大量 通过接触 B 细胞分化因子获得免疫球蛋白 （BCDF）。 N-糖基化活性的变化响应 诱导 B 细胞增殖或分化 与参与多萜醇的几种酶的变化相关 磷酸盐 (Do1-P) 代谢和多羟基化合物的合成 寡糖。 Dolichol 激酶和 Dol-P 磷酸酶活性 将在体外进行测定以确定 Dol-P 水平是否可以 通过改变磷酸化平衡来改变 B细胞增殖过程中的去磷酸化方案或 CESS线的差异化。 从头开始的要求 增殖和增殖过程中多醇或 Dol-P 的合成 将通过代谢标记探索差异性变化 (3H)甲羟戊酸实验和外源性研究 提供多醇和 capactin（HMG 的竞争性抑制剂） CoA还原酶。 Ca++ 动员的可能参与 和蛋白激酶C在激活过程中的作用将被探索 通过离子霉素和佛波二酯的细胞研究。 这 拟议的实验可以为控制 B细胞中的N-糖基化装置，并延长电流 期间发生的生化事件的知识 B淋巴细胞的增殖和分化。