FIGURE 3.
Syntaxin-1A inhibits rat pancreatic islet β-cell KATP channel activity via Walker regions of NBF1 and NBF2 of SUR1. A, representative whole cell currents after dialysis of indicated proteins. Tolbutamide (0.3 mm) was perfused through the extracellular solution. B, bar graph (mean ± S.E.) of the effects of syntaxin-1A (1 μm) co-dialyzed with truncated NBF proteins (1 μm) containing NBF1-WA (n = 5), NBF1-linker (n = 5), NBF1-WB (n = 5), NBF2-WA (n = 5), NBF2-linker (n = 5), and NBF2-WB (n = 5) regions alone with KATP currents normalized to cell capacitance (pA/pF). Positive (Syn-1A, n = 6) and negative controls (GST, n = 6) are shown. The cells were held at a resting potential of −70 mV and stimulated to −110 mV to elicit inward currents. *, significant difference when compared with the Syn-1A positive control (p < 0.05).