... Identification of the structural determinant responsible for the phosphorylation of G -protein activated potassium channel 1 by cAMP-dependent protein kinase Carmen Muăllner, Bibiane Steinecker, ... being activated by G -protein b ⁄ c subunits, G -protein activated potassium channels (GIRKs) are regulated by cAMP-dependent protein kinase. Back -phosphorylation experiments have revealed that the ... Sci USA 93, 14 193 14 198.28 Vivaudou M, Chan KW, Sui JL, Jan LY, Reuveny E &Logothetis DE (19 97) Probing the G -protein regulation of GIRK1 and GIRK4, the two subunits of the K-ACh channel, ...