Molecular basis of AKAP specificity for PKA regulatory subunits
Molecular basis of AKAP specificity for PKA regulatory subunits
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DOI：
10.1016/j.molcel.2006.09.006
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发表时间：
2006-11-03
期刊：
影响因子：
16
通讯作者：
Barford, David
中科院分区：
文献类型：
--
作者：
Gold, Matthew G.;Lygren, Birgitte;Barford, David
A激酶锚定蛋白（AKAP）对环腺苷酸（cAMP）依赖性蛋白激酶（PKA）的定位限制了这种广泛特异性激酶的作用。PKA的RII α调节亚基的对接和二聚化（D/D）结构域的高分辨率晶体结构，无论是在载脂蛋白状态还是与高亲和力锚定肽AKAP-IS复合，都解释了AKAP调节亚基识别的分子基础。AKAP-IS折叠成两亲性α螺旋，其接合RII二聚体D/D结构域表面上基本上预先形成的浅凹槽。保守的AKAP脂肪族残基占主导地位的相互作用，RII在主要的疏水界面，而极性残基是重要的，赋予R亚基亚型特异性。使用肽筛选方法，我们开发了SuperAKAP-IS，这是一种对RII亚型的选择性比RI高10，000倍的肽，可用于评估PKA亚型选择性锚定对细胞内cAMP反应事件的影响。
Localization of cyclic AMP (cAMP)-dependent protein kinase (PKA) by A kinase-anchoring proteins (AKAPs) restricts the action of this broad specificity kinase. The high-resolution crystal structures of the docking and dimerization (D/D) domain of the RII alpha regulatory subunit of PKA both in the apo state and in complex with the high-affinity anchoring peptide AKAP-IS explain the molecular basis for AKAP-regulatory subunit recognition. AKAP-IS folds into an amphipathic a helix that engages an essentially preformed shallow groove on the surface of the RII dimer D/D domains. Conserved AKAP aliphatic residues dominate interactions to RII at the predominantly hydrophobic interface, whereas polar residues are important in conferring R subunit isoform specificity. Using a peptide screening approach, we have developed SuperAKAP-IS, a peptide that is 10,000-fold more selective for the RII isoform relative to RI and can be used to assess the impact of PKA isoform-selective anchoring on cAMP-responsive events inside cells.