Medical Anatomy Commons^™

Gating Charge Immobilization In Kv4.2 Channels: The Basis Of Closed-State Inactivation., Kevin Dougherty, Jose A De Santiago-Castillo, Manuel Covarrubias

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

Kv4 channels mediate the somatodendritic A-type K+ current (I(SA)) in neurons. The availability of functional Kv4 channels is dynamically regulated by the membrane potential such that subthreshold depolarizations render Kv4 channels unavailable. The underlying process involves inactivation from closed states along the main activation pathway. Although classical inactivation mechanisms such as N- and P/C-type inactivation have been excluded, a clear understanding of closed-state inactivation in Kv4 channels has remained elusive. This is in part due to the lack of crucial information about the interactions between gating charge (Q) movement, activation, and inactivation. To overcome this limitation, we engineered a charybdotoxin …