8S3E

Structure of rabbit Slo1 in complex with gamma1/LRRC26

Summary for 8S3E

• Entry DOI: 10.2210/pdb8s3e/pdb
• EMDB information: 19691
• Descriptor: Calcium-activated potassium channel subunit alpha-1, Leucine-rich repeat-containing protein 26, CHOLESTEROL, ... (8 entities in total)
• Functional Keywords: ion channel, potassium transport, membrane protein
• Biological source: Oryctolagus cuniculus (rabbit); More
• Total number of polymer chains: 8
• Total formula weight: 682105.46

Authors

Redhardt, M.,Raunser, S.,Raisch, T. (deposition date: 2024-02-20, release date: 2024-04-10, Last modification date: 2024-05-01)

Primary citation

Redhardt, M.,Raunser, S.,Raisch, T.
Cryo-EM structure of the Slo1 potassium channel with the auxiliary gamma 1 subunit suggests a mechanism for depolarization-independent activation.
Febs Lett., 598:875-888, 2024

PubMed Abstract: Mammalian Ca-dependent Slo K channels can stably associate with auxiliary γ subunits which fundamentally alter their behavior. By a so far unknown mechanism, the four γ subunits reduce the need for voltage-dependent activation and, thereby, allow Slo to open independently of an action potential. Here, using cryo-EM, we reveal how the transmembrane helix of γ1/LRRC26 binds and presumably stabilizes the activated voltage-sensor domain of Slo1. The activation is further enhanced by an intracellular polybasic stretch which locally changes the charge gradient across the membrane. Our data provide a possible explanation for Slo1 regulation by the four γ subunits and also their different activation efficiencies. This suggests a novel activation mechanism of voltage-gated ion channels by auxiliary subunits.

PubMed: 38553946
DOI: 10.1002/1873-3468.14863

Experimental method

ELECTRON MICROSCOPY (2.39 Å)