 KCNE1 may bind to the outer part of the KCNQ1 pore domain, and slide from this position into the “activation cleft” which leads to greater current amplitudes

KCNE1 slows KCNQ1 activation several-fold, and there are ongoing discussions about the precise mechanisms underlying this.In a study in which KCNQ1 voltage sensor movement was monitored by site-directed fluorimetry and also by measuring the charge displacement associated with movement of charges within the S4 segment of the voltage sensor (gating current), KCNE1 was found to slow S4 movement so much that the gating current was no longer measurable.Fluorimetry measurements indicated that KCNQ1-KCNE1 channel S4 movement was 30-fold slower than that of the well-studied "Drosophila" "Shaker" Kv channel.