Are isocitrate dehydrogenases and 2-oxoglutarate involved in the regulation of glutamate synthesis?

In plants, nitrogen assimilation into amino acids relies on the availability of the reduced form of nitrogen, ammonium, The glutamine synthetase-glutamate synthase pathway, which requires carbon skeletons in the form of P-oxoglutarate, achieves this. To date, the exact enzymatic origin of 2-oxoglutarate for plant ammonium assimilation is unknown. Isocitrate dehydrogenases synthesize a-oxoglutarate, Recent efforts have concentrated on evaluating the involvement of different isocitrate dehydrogenases, distinguished by co-factor specificity and sub-cellular localization. Furthermore, several observations indicate that a-oxoglutarate is likely to be a metabolic signal that regulates the coordination of carbon:nitrogen metabolism, This is discussed in the context of recent advances in bacterial signalling processes.