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The regulatory function of the plant cysteine synthase protein complex for cellular cysteine homeostasis

植物半胱氨酸合酶蛋白复合物对细胞半胱氨酸稳态的调节功能

基本信息

批准号：
115487487
负责人：
Professor Dr. Rüdiger Hell
金额：
--
依托单位：
Centre for Organismal Studies (COS)
依托单位国家：
德国
项目类别：
Research Grants
财政年份：
2009
资助国家：
德国
起止时间：
2008-12-31 至 2014-12-31
项目状态：
已结题

来源：
https://gepris.dfg.de/gepris/projekt/115487487?language=en
关键词：
regulatory function plant cysteine synthase

项目摘要

Cysteine synthesis provides the only entry of assimilated sulfur into plant metabolism and forms one essential step for human and animal nutrition. Biochemical evidence suggests that cellular homeostasis of cysteine in plants is controlled by a unique sensing mechanism and subcellular organisation. The hetero-oligomeric cysteine synthase protein complex is located in cytosol, plastids and mitochondria. Its reversible activation/inactivation depends on whether its subunits are inside or outside the complex and this equilibrium is determined by the inverse effects of the pathway intermediates sulfide and O-acetylserine. The central function of the cysteine synthase complex will be addressed in two independent approaches. One, the reversible association of the complex and its response to changes in homeostasis will be investigated in vivo using fluorescence resonance energy transfer (FRET). Two, artificial microRNA interference and T-DNA mutants will be used to evaluate the hypothesis that mitochondria, and not plastids, are most important for the rate of cysteine synthesis. The results will clarify the current hypothesis of dynamic flux control by the cysteine synthase complex and unravel the role of cellular compartments in cysteine homeostasis. They will be significant for understanding of regulatory protein interactions in metabolism in general.

半胱氨酸的合成是硫进入植物代谢的唯一途径，也是人类和动物营养的一个重要步骤。生物化学证据表明，植物中半胱氨酸的细胞内稳态由独特的传感机制和亚细胞组织控制。异源寡聚半胱氨酸合酶蛋白复合物位于细胞质、质体和线粒体中。它的可逆活化/失活取决于它的亚基是在复合物内部还是外部，并且这种平衡由途径中间体硫化物和O-乙酰丝氨酸的反向作用决定。半胱氨酸合酶复合物的中心功能将在两个独立的方法解决。第一，可逆协会的复杂性和它的反应，在体内稳态的变化将研究使用荧光共振能量转移（FRET）。第二，人工microRNA干扰和T-DNA突变体将用于评估线粒体而不是质体对半胱氨酸合成速率最重要的假设。这些结果将澄清目前的假设，动态流量控制的半胱氨酸合酶复合物和解开的半胱氨酸稳态的细胞室的作用。它们对于理解一般代谢中的调节蛋白质相互作用具有重要意义。