期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：1979
卷号：76
期号：2
页码：791-795
DOI：10.1073/pnas.76.2.791
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：Using tunicamycin, we have investigated the role of glycoproteins in membrane transport. Tunicamycin is a glucosamine-containing antibiotic that specifically inhibits dolichol pyrophosphate-mediated glycosylation of asparaginyl residues of glycoproteins. Inhibition of protein glycosylation in chick embryo fibroblasts by tunicamycin or other inhibitors of glycosylation resulted in defective transport of glucose, uridine, and amino acid analogs (alpha-aminoisobutyrate and cycloleucine). The defect in glucose transport is accompanied by decreased glucose metabolism, as determined by rates of CO2 and lactate production. In contrast, tunicamycin treatment did not affect other membrane-associated processes, such as secretion of fibronectin and procollagen, uptake of glucose by passive diffusion, Na+/K+ ATPase and adenylate cyclase activities, or stimulation of adenylate cyclase by prostaglandin and cholera toxin. Two glucose/glycosylation-regulated membrane proteins with apparent subunit molecular weights of 95,000 and 75,000 were induced by tunicamycin treatment. Our results indicate that glycoprotein glycosylation is required for membrane transport.
