Structure reveals a regulation mechanism of plant outward-rectifying K⁺ channel GORK by structural rearrangements in the CNBD-Ankyrin bridge.

ABSTRACT: Guard cells, which regulate stomatal apertures in plants, possess a sophisticated mechanism for regulating turgor pressure. The outward-rectifying "K⁺_out" channel GORK, expressed in guard cells of the plant Arabidopsis thaliana, is a central component that promotes stomatal closure by releasing K⁺ to the extracellular space, thereby lowering turgor pressure. To date, the structural basis underlying the regulation of the K⁺ transport activity of GORK is unclear. Using cryo-EM, we determined the structures of the GORK outward-rectifying K⁺ channel with a resolution of 3.16 to 3.27 Å in five distinct conformations that differ significantly in their C-terminal cyclic nucleotide binding domain (CNBD) and ankyrin repeat (ANK) domain.

SUBMITTER: Yamanashi T 

PROVIDER: S-EPMC12318183 | biostudies-literature | 2025 Jul

REPOSITORIES: biostudies-literature