Graded contribution of the Gβγ binding domains to GIRK channel activation

摘要

G protein coupled inwardly rectifying K~+ channels (GIRK/Kir3.x) are mainly activated by a direct interaction with Gβγ subunits, released upon the activation of inhibitory neurotransmitter recep- tors. Although Gβγ binding domains on all four subunits have been found, the relative contribution of each of these binding sites to channel gating has not yet been defined. It is also not known whether GIRK channels open once all Gβγ sites are occupied, or whether gating is a graded process.