Enzyme redundancy and the importance of 2-oxoglutarate in plant ammonium assimilation
Enzyme redundancy and the importance of 2-oxoglutarate in plant ammonium assimilation
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DOI：
10.1093/jexbot/53.370.905
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发表时间：
2002-04-01
影响因子：
6.9
通讯作者：
Hodges, M
中科院分区：
文献类型：
--
作者：
Hodges, M
铵是植物可以吸收成氨基酸的还原态氮。这是通过GS/GOGAT途径实现的，该途径需要2-氧戊二酸盐形式的碳骨架。迄今为止，这种有机酸用于植物铵同化的确切酶源尚不清楚。异柠檬酸脱氢酶和天冬氨酸转氨酶被认为具有这一功能。由于植物细胞内存在不同的（iso）形式，位于几个亚细胞区室中，最近的努力集中在评估这些酶在铵同化中的作用。此外，一些观察结果表明，2-氧戊二酸盐是一个很好的候选代谢信号，以调节和N代谢的协调。这将与细菌信号传导过程的最新进展有关，包括称为PII的2-氧戊二酸结合蛋白。
Ammonium is the reduced nitrogen form available to plants for assimilation into amino acids. This is achieved by the GS/GOGAT pathway that requires carbon skeletons in the form of 2-oxoglutarate. To date, the exact enzymatic origin of this organic acid for plant ammonium assimilation is unknown. Isocitrate dehydrogenases and aspartate aminotransferases have been proposed to carry out this function. Since different (iso)forms located in several subcellular compartments are present within a plant cell, recent efforts have concentrated on evaluating the involvement of these enzymes in ammonium assimilation. Furthermore, several observations indicate that 2-oxoglutarate is a good candidate as a metabolic signal to regulate the co-ordination of and N metabolism. This will be discussed with respect to recent advances in bacterial signalling processes involving a 2-oxoglutarate binding protein called PII.