DOLICHOL PHOSPHATE METABOLISM AND GLYCOPROTEIN SYNTHESIS

磷酸多醇代谢和糖蛋白合成

• 批准号: 3289671
• 负责人: Charles J Waechter
• 金额: $ 15.8万
• 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/3289671
• 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.

活化的b淋巴细胞（b细胞）导致增加