The structure of a human voltage-gated potassium Kv10.2 channel which lacks a cytoplasmic PAS domain

Abstract

The three-dimensional structure of a human voltage-gated potassium Kv10.2 channel which lacks a cytoplasmic N-terminal PAS-domain was determined, and its distribution in eukaryotic cells was investigated. The channel protein was expressed in the COS7 cell line and purified by affinity chromatography. The channel distribution on the cell surface was determined by the immunofluorescence method using the antibodies against its C-terminus. PAS-domain truncation was shown to cause a decrease the expression of the channels on the cell surface. In order to reveal the positions of the channel cytoplasmic domains, the threedimensional structure of the protein lacking the cytoplasmic PAS-domain was compared to the previously obtained full-length structure. We demonstrated that the C-terminal CNBD-domain of the Kv10.2 channel undergoes conformational rearrangements in the absence of its N-terminal PAS-domain.