Nε-lysine acetylation determines dissociation from GAP junctions and lateralization of connexin 43 in normal and dystrophic heart
Nε-lysine acetylation determines dissociation from GAP junctions and lateralization of connexin 43 in normal and dystrophic heart
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DOI：
10.1073/pnas.1013124108
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发表时间：
2011-02-15
影响因子：
11.1
通讯作者：
Gaetano, Carlo
中科院分区：
文献类型：
--
作者：
Colussi, Claudia;Rosati, Jessica;Gaetano, Carlo
为了探讨Duchenne型心肌病的表观遗传学基础，我们发现mdx心脏组蛋白乙酰化酶活性异常升高，乙酰化酶P300/CBP相关因子（PCAF）与连接蛋白43（Cx43）免疫共沉淀，Cx43被N-赖氨酸乙酰化并偏侧化。这一观察结果被Cx43从N-钙粘蛋白和闭锁小带1上解离所证实，而pp 60-c-Src的结合没有改变。用泛组蛋白乙酰化酶抑制剂漆树酸在体内处理mdx显著降低了Cx43 N-β-赖氨酸乙酰化，并恢复了其与闰盘GAP连接（GJ）的结合。值得注意的是，在正常以及mdx小鼠中，IIa类组蛋白脱乙酰酶4和5组成型共定位与Cx43无论是在GJ或在偏侧的车厢。I类组蛋白去乙酰化酶3也是复合物的一部分。用组蛋白去乙酰化酶泛抑制剂辛二酰苯胺异羟肟酸（MC 1568）或IIa类选择性抑制剂3-{4-[3-（3-氟苯基）-3-氧代-1-丙烯-1-基]-1-甲基-1H-吡咯-2-基}-N-羟基-2-丙烯酰胺（MC 1568）处理正常对照组，测定了Cx43的超乙酰化、从GJ中解离以及沿心室心肌细胞长轴的分布沿着。一致的是，组蛋白乙酰化酶激活剂pentadecylidenemalonate 1b（SPV 106）hyperacetylated心脏蛋白，包括Cx43，它假定了一个偏侧的位置，部分复制营养不良的表型。在辛二酰苯胺异羟肟酸的存在下，细胞对细胞的渗透性显着减少，这是在协议的结果超乙酰化的Cx43紧密构象。用Cx43乙酰化突变体进行的其他实验显示，对于乙酰化形式的分子，质膜定位显着减少，并且倾向于核积累。这些结果表明，Cx43 N-ε-赖氨酸乙酰化可能对细胞间偶联和心脏功能具有病理生理学后果。
Wanting to explore the epigenetic basis of Duchenne cardiomyopathy, we found that global histone acetylase activity was abnormally elevated and the acetylase P300/CBP-associated factor (PCAF) coimmunoprecipitated with connexin 43 (Cx43), which was N-epsilon-lysine acetylated and lateralized in mdx heart. This observation was paralleled by Cx43 dissociation from N-cadherin and zonula occludens 1, whereas pp60-c-Src association was unaltered. In vivo treatment of mdx with the pan-histone acetylase inhibitor anacardic acid significantly reduced Cx43 N-epsilon-lysine acetylation and restored its association to GAP junctions (GJs) at intercalated discs. Noteworthy, in normal as well as mdx mice, the class IIa histone deacetylases 4 and 5 constitutively colocalized with Cx43 either at GJs or in the lateralized compartments. The class I histone deacetylase 3 was also part of the complex. Treatment of normal controls with the histone deacetylase pan-inhibitor suberoylanilide hydroxamic acid (MC1568) or the class IIa-selective inhibitor 3-{4-[3-(3-fluorophenyl)-3-oxo-1- propen-1-yl]-1-methyl-1H-pyrrol-2-yl}-N-hydroxy-2-propenamide (MC1568) determined Cx43 hyperacetylation, dissociation from GJs, and distribution along the long axis of ventricular cardiomyocytes. Consistently, the histone acetylase activator pentadecylidenemalonate 1b (SPV106) hyperacetylated cardiac proteins, including Cx43, which assumed a lateralized position that partly reproduced the dystrophic phenotype. In the presence of suberoylanilide hydroxamic acid, cell to cell permeability was significantly diminished, which is in agreement with a Cx43 close conformation in the consequence of hyperacetylation. Additional experiments, performed with Cx43 acetylation mutants, revealed, for the acetylated form of the molecule, a significant reduction in plasma membrane localization and a tendency to nuclear accumulation. These results suggest that Cx43 N-epsilon-lysine acetylation may have physiopathological consequences for cell to cell coupling and cardiac function.