Update: The SnRK1 kinase as central mediator of energy signalling between different organelles
By
Abstract
The evolutionary conserved SnRK1 kinase complex is a key regulator in adjusting cellular metabolism during starvation, stress conditions and growth promoting conditions. Over the last two decades extensive genetic evidence for a widespread SnRK1 signalling network has accumulated. It is now well established that SnRK1 is a central integrator of energy signalling. However, little is known about connections between the cytoplasmic and nuclear localized SnRK1 and plastids and mitochondria as the main energy producing compartments in the cell. Here we review recent findings indicating how SnRK1 affects metabolic adaptation including plastidial and mitochondrial functions. Special emphasis is put on identified direct targets of SnRK1, which would eventually enable cross talk with organelles. In this context a number of transcription factors are emerging as mediators of SnRK1 signalling, potentially linking SnRK1 activity to organellar functions. Furthermore, many SnRK1 targets act in various hormonal signalling pathways, which are at least partly localized in plastids. With this review, we summarize the current knowledge on SnRK1 organelle interaction and provide ideas on the potential molecular mechanisms governing these interactions.
