Kvβ1 Subunit Binding Specific for Shaker-Related Potassium Channel α Subunits

AbstractVoltage-activated potassium (Kv) channels from mammalian brain are hetero-oligomers containing α and β subunits. Coexpression of Kv1α and Kvβ1 subunits confers rapid A-type inactivation on noninactivating potassium channels (delayed rectifiers) in expression systems in vitro. We have delineated a Kv1.5 amino-terminal region of up to 90 amino acids (residues 112–201) that is sufficient for interactions of Kv1.5α and Kvβ1 subunits. Within this region of the Kv1.5 amino terminus (residues 193–201), a Kvβ1 interaction site necessary for Kvβ1-mediated rapid inactivation of Kv1.5 currents was detected. This interaction site motif (FYE/QLGE/DEAM/L) is found exclusively in the Shaker-related subfamily (Kv1). The results show that hetero-oligomerization between α and Kvβ1 subunits is restricted to Shaker-related potassium channel α subunits