A novel Epac-Rap-PP2A signaling module controls cAMP-dependent Akt regulation

doi:10.1074/jbc.M800478200

CORC > 上海药物研究所 > 中国科学院上海药物研究所 > 药理学第一研究室

	A novel Epac-Rap-PP2A signaling module controls cAMP-dependent Akt regulation
	Hong, Kyoungja 3; Lou, Liguang1,3 ; Gupta, Sandhya 3; Ribeiro-Neto, Fernando 3; Altschuler, Daniel L.2,3
刊名	Journal of Biological Chemistry
	2008-08-22
卷号	283 期号:34 页码:23129-23138
ISSN号	00219258
DOI	10.1074/jbc.M800478200
文献子类	Article
英文摘要	Rap1b has been implicated in the transduction of the cAMP mitogenic signal. It is phosphorylated and activated by cAMP, and its expression in models where cAMP is mitogenic leads to proliferation and tumorigenesis. Akt is a likely downstream effector of cAMP-Rap1 action. cAMP elevation induced a rapid and transient Akt inhibition that required activated and phosphorylated Rap1b. However, the mechanism(s) by which cAMPRap regulates Akt remains unclear. Here we show that (i) upstream regulators, PIK and PDK1, are not the target(s) of the cAMP inhibitory action; (ii) constitutively active Akt and calyculin A-stimulated Akt are resistant to cAMP inhibition, suggesting the action of a phosphatase; (iii) cAMP increases the rate of Akt dephosphorylation, directly implicating an Akt-phosphatase; (iv) Epac- and protein kinase A (PKA)-specific analogs synergistically inhibit Akt, indicating the involvement of both cAMP-dependent effector pathways; (v) H89 and dominant negative Epac 279E block cAMP-inhibitory action; (vi) Epac associates in a complex with Akt and PP2A, and the associated-phosphatase activity is positively modulated by cAMP in a PKA- and Rap1-dependent manner; (vii) like its action on Akt inhibition, PKA- and Epac-specific analogs synergistically activate Epac-associated PP2A; and (viii) dominant negative PP2A blocks cAMP-inhibitory action. Thus, we uncovered a novel cAMP-Epac/PKA-Rap1b-PP2A signaling module involved in Akt regulation that may represent a physiological event in the process of cAMP stimulation of thyroid mitogenesis.
语种	英语
出版者	American Society for Biochemistry and Molecular Biology Inc.
内容类型	期刊论文
源URL	[http://119.78.100.183/handle/2S10ELR8/266999]
专题	药理学第一研究室
通讯作者	Altschuler, Daniel L.
作者单位	1.Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai 200031, China; 2.Dept. of Pharmacology and Chemical Biology, School of Medicine, University of Pittsburgh, 200 Lothrop St., Pittsburgh, PA 15261, United States 3.Department of Pharmacology and Chemical Biology, School of Medicine, University of Pittsburgh, Pittsburgh, PA 15261, United States;
推荐引用方式 GB/T 7714	Hong, Kyoungja,Lou, Liguang,Gupta, Sandhya,et al. A novel Epac-Rap-PP2A signaling module controls cAMP-dependent Akt regulation[J]. Journal of Biological Chemistry,2008,283(34):23129-23138.
APA	Hong, Kyoungja,Lou, Liguang,Gupta, Sandhya,Ribeiro-Neto, Fernando,&Altschuler, Daniel L..(2008).A novel Epac-Rap-PP2A signaling module controls cAMP-dependent Akt regulation.Journal of Biological Chemistry,283(34),23129-23138.
MLA	Hong, Kyoungja,et al."A novel Epac-Rap-PP2A signaling module controls cAMP-dependent Akt regulation".Journal of Biological Chemistry 283.34(2008):23129-23138.