Surface expression of Kv1 channels is governed by a C-terminal motif

Voltage-gated K+ channel subunits must reach the plasma membrane to repolar ize action potentials. Yet the efficiency of cell surface targeting varies among Kv subunits with some requiring auxiliary subunits for optimal expres sion. Here we identify a conserved motif located in the variable C-terminal region of Kv1 channels that controls the efficiency of functional channel expression. Variations among wild type channels in the optimal sequence VXY SL produce differences in distribution and the requirement for auxiliary su bunits. Furthermore, deletion of this motif decreases subunit glycosylation and surface localization but does not prohibit subunit multimerization. Fi nally, the action of the essential sequence is shown to be independent of t he chaperone effect of Kv beta subunits. Thus, the newly identified C-termi nal motif governs processing and cell surface expression of Kv1 voltage-gat ed K+ channels.