Fig. 8.

Prolines in the extended C-terminal tail, permit CO₂ sensitive opening of hemichannels. a Sequences of: modified human Cx32 C-terminal tail with glycine in place of proline; and Lepidosiren Cx26 C-terminal tail, showing the glycines that were changed to proline. b Human Cx32 hemichannels can be opened by CO₂. Mutation of prolines in the extended C-terminal tail abolishes CO₂ sensitivity (Human Pro to Gly). Introduction of two prolines into the Lepidosiren C-terminal tail gives a gain of CO₂ sensitivity (compare to Fig. 3b, c). c Summary data showing the change in median pixel intensity compared to the control (PCO₂ 35 mmHg) from five independent replications for each connexin. KW, Kruskal–Wallis ANOVA, pairwise comparisons Mann Whitney. Box and whisker plots: box, first and third quartiles; horizontal line, median; whiskers, the furthest point that lies no more than 1.5 times the interquartile range from the median. Each point represents result from an independent transfection. Scale bar 20 µm