Analysis of phosphorylation-dependent modulation of Kv1.1 potassium channels.

The voltage-gated potassium channel Kv1.1 contains phosphorylation sites for protein kinase A (PKA) and protein kinase C (PKC). To study Kv1.1 protein expression and cellular distribution in regard to its level of phosphorylation, the effects of PKA and PKC activation on Kv1.1 were investigated in HEK 293 cells stably transfected with Kv1.1 (HEK 293/1). Without kinase activation, HEK 293/1 cells carry unphosphorylated Kv1.1 protein in the plasma membranes, whereas large amounts of phosphorylated and unphosphorylated Kv1.1 protein were located intracellularly. Activation of PKA resulted in phosphorylation of intracellular Kv1.1 protein, followed by a rapid translocation of Kv1.1 into the pla…