monoatomic cation channel activity potassium channel activity https://github.com/geneontology/go-ontology/issues/27521 Enables the energy-independent facilitated diffusion of a potassium ion through a transmembrane aqueous pore or channel. GO:0005267 molecular_function Reactome:R-HSA-1296024 Reactome:R-HSA-1296035 Reactome:R-HSA-1299297 Reactome:R-HSA-2534365 Reactome:R-HSA-1299318 Reactome:R-HSA-1299338 Reactome:R-HSA-1299359 Reactome:R-HSA-1299304 Reactome:R-HSA-1296037 Reactome:R-HSA-1296039 Reactome:R-HSA-1296348 Reactome:R-HSA-5578910 potassium ion transmembrane transporter activity