The unique N-terminal sequence of the BKCa channel α-subunit determines its modulation by β-subunits
Fig 2
BKCa α-subunit with distinct N-termini are differentially modulated by β1-β2 chimeric constructs.
Representative inside-out single-channel recordings from HEK293T cells transfected with MANG (A), MSSN (D) or MDAL (G) in the presence or absence of β1β2β1 or β2NDβ1β2, at different membrane potentials (-40 mV to +40 mV) with 10 μM Ca2+ in the bath. Dashed lines indicate closed (C) states of the channels. Voltage-activation of MANG (B and C), MSSN (E and F) or MDAL (H and I), in the absence (α, black symbols) or presence of β1 (blue symbols), β2ND (red symbols), β1β2β1 (orange symbols) or β2NDβ1β2 (purple symbols), expressed as open probability (Po) of the channel, in the presence of 10 μM (B, E and H) or 100 μM (C, F, and I) Ca2+ in the bath; n = 3–19, symbols are mean ± SEM.