Cryo-EM studies on C-type Inactivation in Kv channels
EMSL Project ID
50913
Abstract
Voltage gated K+ (Kv) channels discriminate K+ from Na+ in the selectivity filter, which consists of four K+ binding sites. In addition to the selective conduction of K+, the selectivity filter participates in a gating process called C-type inactivation that converts the selectivity filter from a conductive to a non-conductive conformation thereby turning off the flow of K+ ions. C-type inactivation is a physiologically important process that plays a central role in determining cellular excitability. The structural changes that take place in the selectivity filter during C-type inactivation are presently not known. Determining the structure of a Kv channel in the C-type inactivated state is a key requirement for understanding the mechanism of C-type inactivation. Our overarching goal is to determine the structure of a Kv channel in the C-type inactivated state. For our structural studies we are using the W362F mutant of the Kv1.2- channel that shows a highly enhanced (~200 fold) rate of inactivation compared to the native channel. Previous attempts at structural studies on W362F mutant of the Kv1.2 channel were stymied by the difficulties in protein expression and purification. We have overcome these challenges and obtained a monodisperse and stable sample of the Kv1.2-W362F channel. This rapid access proposal is to obtain preliminary data to establish the feasibility of using cryo-EM for structure determination of this channel.
The structure determined will be highly impactful for the important insights it will provide into the mechanism of C-type inactivation in Kv channels.
Project Details
Start Date
2019-05-15
End Date
2019-08-14
Status
Closed
Released Data Link
Team
Principal Investigator
Team Members