Using Molecular Simulation and Quantum Mechanics tools to answer unsolved questions about gating of plant voltage gated potassium channels

Abstract

Voltage gated potassium (Kv) channels are membrane proteins that allow voltage-driven potassium (K+) flux across cellular membranes. Kv channels in plants participate in multiple events, which include stomatal movements and ion uptake from the soil. Plant Kv channels show a similar topology as their counterpart in animals: four subunits with six transmembrane segments (S1-S6) each one; where S4 is the voltage sensor and S5-S6 constitute the pore.Electrophysiology and structural bioinformatics tools have revealed partially the molecular mechanisms that regulate Kv channels gating in animals. To date, Kv channels in plants have been studied experimentally, but structural information about them does not exist.We used Molecular Simulation and Quantum Mechanics methods to answer unsolved questions in plant Kv channels gating. Computational approaches helped to clarify the differences between KAT1 channel gating mediated by a membrane hyperpolarization and SKOR channel gating mediated by a membrane despolarization. We studied also the opening of KAT1 channel mediated by an apoplasm acidification of stomatal complex.