文章基本信息

标题：Cyclic AMP-dependent protein kinase mediates a cyclic AMP-stimulated decrease in ornithine and S-adenosylmethionine decarboxylase activities
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作者：P A Insel ; J Fenno
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：1978
卷号：75
期号：2
页码：862-865
DOI：10.1073/pnas.75.2.862
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：Incubation of S49 lymphoma cells with N6,O2'-dibutyryl cyclic AMP (Bt2cAMP) decreases the activities of ornithine decarboxylase (L-ornithine carboxy-lyase; EC 4.1.1.17 ) and S-adenosylmethionine decarboxylase (S-adenosyl-L-methionine carboxy-lyase; EC 4.1.1.50 ), the two principal enzymes in the pathway of polyamine synthesis. This decrease is dose-dependent, commences after a 3-hr delay, virtually abolishes the assayable activities of the two enzymes, and is not associated with a soluble inhibitor of the enzyme activities. Studies in mutant S49 clones that have altered protein kinase indicate that cAMP-dependent protein kinase mediates the decreases in enzyme activities. The dose-response pattern for the cAMP-stimulated decrease in enzyme activities parallels the pattern for the cAMP-stimulated, cell cycle-specific (G1) growth arrest of S49 cells. The activity of ornithine decarboxylase decreases faster than Bt2cAMP arrests wild-type S49 cells and, similarly, release of cells from the cAMP-stimulated arrest in G1 increases the activity of ornithine decarboxylase faster than cells exit from G1. These findings contrast with reports that cAMP induces ornithine decarboxylase in other cell types and further suggest that passage of cells through cell cycle is required for maintaining the activities of ornithine and S-adenosylmethionine decarboxylases.