Gating Mechanism of KATP Channels

Gating Mechanism of KATP Channels

Based initially on their prominence in the squid giant axon, their useful pharmacology, and subsequently on being the first cloned K channels, voltage-gated K (Kv) channels have received the lion’s share of attention to their biophysical properties. Kv and Ca-activated K channel kinetics and gating mechanisms have been analyzed, and modeled, in exquisite detail (Hille, 2001). Inward rectifier K...

Gating Mechanism of KATP Channels: Function Fits Form

Gating Mechanism of BK (Slo1) Channels

Large conductance calciumand voltage-activated K channels (Slo1), also referred to as “BK” or “maxi K” channels because of their high single channel conductance (250–300 pS in symmetrical 150 mM KCl), are widely distributed in many different tissues (Kaczorowski et al., 1996). A signature feature of BK channels, in addition to their high K selectivity and conductance, is that they are activated...

Control of Rectification and Gating of Cloned KATP Channels by the Kir6.2 Subunit

KATP channels are a functional complex of sulphonylurea receptor (SUR1, SUR2) and inward rectifier K+ (Kir6.1, Kir6.2) channel subunits. We have studied the role of the putative pore forming subunit (Kir6.2) in regulation of rectification and gating of KATP channels generated by transfection of SUR1 and Kir6.2 cDNAs in COSm6 cells. In the absence of internal polyvalent cations, the current-volt...

Mechanism of gating of T-type calcium channels

We have analyzed the gating kinetics of T-type Ca channels in 3T3 fibroblasts. Our results show that channel closing, inactivation, and recovery from inactivation each include a voltage-independent step which becomes rate limiting at extreme potentials. The data require a cyclic model with a minimum of two closed, one open, and two inactivated states. Such a model can produce good fits to our d...