Figure 2
From: Expression of truncated Kir6.2 promotes insertion of functionally inverted ATP-sensitive K+ channels
SUR1 affects orientation of Kir6.2 in the membrane. (A) Representative inside-out recording of channel currents from an oocyte injected with mRNA encoding Kir6.2ΔC26. Inset shows channel activity at an expanded time scale. Two populations of channel openings are observed, −3.8 ± 0.5 pA and −2.2 ± 0.3 pA (arrow). (B) Amplitude histogram of inside-out current traces from patches excised from oocytes injected with Kir6.2ΔC26 alone (left) or together with SUR1 (right). Data were obtained in the presence of 1 mM ATP in the bath solution (i.e. intracellular side). Arrow indicates additional population of channel openings seen in the absence of SUR1. A total of 22 × 103 and 38 × 103 events were obtained, respectively. (C) Representative recordings from Kir6.2ΔC26 channel activity from an outside-out patch, subsequently exposed to 1 mM ATP. (D) Summary of outside-out patches from oocytes injected with Kir6.2ΔC26 + SUR1 (n = 3) and Kir6.2ΔC26 (n = 4), and the effect of extracellularly 1 mM ATP expressed as the ratio between the current measured before and during ATP. Arrowhead indicated zero current level, error bars are ± SD and ** represents P < 0.01.
