Structural basis of the activation of AKT1 K+ Channel

Abstract

The Food and Agriculture Organization of the United Nations warned that population growth will drive food needs up by 40% by 2050. One of the major threats to achieve the objective is the climate change. To overcome this problem, it is required the understanding of the mechanisms for plant adaptation to stresses such as drought, the concomitant soil salinity, floods or frosts. The primary consequence of these stresses is the unbalance of K+ ion homeostasis (Pardo; 2010; Cherel & Gaillard; 2019). To cope to this situation, plants regulate the activity of plant-specific voltage-gated K+ channels. The high-resolution structure of these channels will unravel the mechanisms underlying their regulation; so that it will be possible to identify hot-spots in the structure suitable for mutagenesis that would lead to channel variants with altered activity. We have determined the structure of the complex between the ankyrin domain of the cytosolic side of the inward-rectifier K channel AKT1 and the activating kinase CIPK23 and showed that this interaction regulates channel activation. Point mutations on this domain specifically alter binding to CIPK23, enhancing or impairing the ability of CIPK23 to regulate channel activity (Sanchez-Barrena et al, 2020). These modified versions will be effectively used to engineer plants with improved performance under abiotic stresses.