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：1980
卷号：77
期号：12
页码：6996-6999
DOI：10.1073/pnas.77.12.6996
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：In Dictyostelium discoideum, the chemoattractant cyclic AMP activates the enzyme guanylate cyclase, giving a brief up to 10-fold increase in the intracellular cyclic GMP content. The addition of physiological cyclic GMP concentrations to a homogenate of D. discoideum cells markedly increased the incorporation of the 3H-labeled methyl group from S-adenosyl-L-[methyl-3H]methionine into mono- and dimethylated phosphatidylethanolamine and phosphatidylcholine. Lipid methylation was inhibited by S-adenosyl-L-homocysteine, which inhibits transmethylation. When whole cells prelabeled with L-[methyl-3H]methionine were exposed to cyclic AMP, a rapid transient increase in the amount of [methyl-3H]phosphatidylcholine was observed. The time course of [methyl-3H]phosphatidylcholine formation agrees with its being mediated by the intracellular increase in cyclic GMP originating during chemotactic stimulation. Addition of the 8-Br derivative of cyclic GMP to whole cells also increased the levels of labeled phosphatidylcholine. It is therefore likely that cyclic GMP contributes to chemotaxis by regulating membrane function via phospholipid methylation.
