Epac and PKA: a tale of two intracellular cAMP receptors

• 来源期刊: 生物化学与生物物理学报（英文版）
• 关键词: cAMP exchange protein directly activated by cAMP (Epac)/cAMP-regulated guanine exchange factor protein kinase A (PKA)/cAMP-dependent protein kinase signal transduction
• 年，卷（期）: 2008,（7）
• 页码范围: 651-662
• 页数: 12页
• 语种: 英文

摘要

cAMP-mediated signaling pathways regulate a multitude of important biological processes under both physiological and pathological conditions,including diabetes,heart failure and cancer.In eukaryotic cells,the effects of cAMP are mediated by two ubiquitously expressed intracellular cAMP receptors,the classic protein kinase A (PKA)/cAMP-dependent protein kinase and the recently discovered exchange protein directly activated by cAMP(Epac)/cAMP-regulated guanine nucleotide exchange factors.Like PKA,Epac contains an evolutionally conserved cAMP binding domain that acts as a molecular switch for sensing intracellular second messenger cAMP levels to control diverse biological functions.The existence of two families of cAMP effectors provides a mechanism for a more precise and integrated control of the cAMP signaling pathways in a spatial and temporal manner.Depending upon the specific cellular environments as well as their relative abundance,distrbution and localization,Epac and PKA may act independently,converge synergistically or oppose each other in regulating a specific cellular function.