Issues

Cover picture: Proposed relative motion between transmembrane helices S0 and S4 in the BK_Ca voltage sensor. At rest (top left), W203 (outside S4) quenches a fluorophore (TMRM) labeling S0. Upon depolarization, S0 and S4 move apart, separating W203 from TMRM (top right), causing a large fluorescence increase (bottom; red trace). In W203V mutants, TMRM is not quenched (middle) and exhibits a negligible fluorescence increase on depolarization (bottom; blue trace) (see article by Pantazis et al., 645–657).