14-3-3 protein is a regulator of the mitochondrial and chloroplast ATP synthase
14-3-3 protein is a regulator of the mitochondrial and chloroplast ATP synthase
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DOI：
10.1073/pnas.061437498
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发表时间：
2001-03-27
影响因子：
11.1
通讯作者：
de Boer, AH
中科院分区：
文献类型：
--
作者：
Bunney, TD;van Walraven, HS;de Boer, AH
线粒体和叶绿体 ATP 合酶是植物代谢中的关键酶，为细胞提供 ATP（通用能量货币）。 ATP 合成酶利用跨膜电化学质子梯度来驱动 ATP 的合成。酶复合物起到微型旋转发动机的作用，确保能量耦合非常高效。尽管近年来我们对合酶的结构和功能的理解取得了巨大进展，但我们对调节机制的理解仍然相当初步。在这里，我们报告了14-3-3蛋白在ATP合酶调节中的作用，这些14-3-3蛋白是高度保守的磷酸丝氨酸/磷酸苏氨酸结合蛋白，调节植物、动物和酵母中的多种酶。最近，叶绿体中存在 14-3-3 蛋白，我们在此表明植物线粒体在内部线粒体膜室中含有 14-3-3。在那里，发现 14-3-3 蛋白通过与 F-1 β 亚基直接相互作用，以磷酸化依赖性方式与 ATP 合酶相关。重组 14-3-3 大大降低了两个细胞器中 ATP 合酶的活性。含有 14-3-3 相互作用基序的磷酸肽可阻止暗适应过程中叶绿体 ATP 酶活性的快速降低，这证明了内源性 14-3-3 在下调 CFoF1 活性中的作用。 Mle 得出结论，14-3-3 对 ATP 合酶的调节代表了植物适应环境变化的机制，例如光/暗转变、根部缺氧和养分供应波动。
Mitochondrial and chloroplast ATP synthases are key enzymes in plant metabolism, providing cells with ATP, the universal energy currency. ATP synthases use a transmembrane electrochemical proton gradient to drive synthesis of ATP. The enzyme complexes function as miniature rotary engines, ensuring energy coupling with very high efficiency. Although our understanding of the structure and functioning of the synthase has made enormous progress in recent years, our understanding of regulatory mechanisms is still rather preliminary, Here we report a role for 14-3-3 proteins in the regulation of ATP synthases, These 14-3-3 proteins are highly conserved phosphoserine/phosphothreonine-binding proteins that regulate a wide range of enzymes in plants, animals, and yeast. Recently, the presence of 14-3-3 proteins in chloroplasts was illustrated, and we show here that plant mitochondria harbor 14-3-3s within the inner mitochondrial-membrane compartment. There, the 14-3-3 proteins were found to be associated with the ATP synthases, in a phosphorylation-dependent manner, through direct interaction with the F-1 beta -subunit. The activity of the ATP synthases in both organelles is drastically reduced by recombinant 14-3-3. The rapid reduction in chloroplast ATPase activity during dark adaptation was prevented by a phosphopeptide containing the 14-3-3 interaction motif, demonstrating a role for endogenous 14-3-3 in the down-regulation of the CFoF1 activity. Mle conclude that regulation of the ATP synthases by 14-3-3 represents a mechanism for plant adaptation to environmental changes such as light/dark transitions, anoxia in roots, and fluctuations in nutrient supply.