Computational Insights Into Voltage Dependence of Polyamine Block in a Strong Inwardly Rectifying K⁺ Channel.

ABSTRACT: Inwardly rectifying potassium (K_IR) channels play important roles in controlling cellular excitability and K⁺ ion homeostasis. Under physiological conditions, K_IR channels allow large K⁺ influx at potentials negative to the equilibrium potential of K⁺ but permit little outward current at potentials positive to the equilibrium potential of K⁺, due to voltage dependent block of outward K⁺ flux by cytoplasmic polyamines. These polycationic molecules enter the K_IR channel pore from the intracellular side. They block K⁺ ion movement through the channel at depolarized potentials, thereby ensuring, for instance, the long plateau phase of the cardiac action potential. Key questions concerning how dee

SUBMITTER: Chen X 

PROVIDER: S-EPMC7243266 | biostudies-literature | 2020

REPOSITORIES: biostudies-literature