RNA Editing Underlies Temperature Adaptation in K + Channels from Polar Octopuses

Abstract

Adapting to the Cold The gating of potassium channels is temperature sensitive, suggesting that these channels must adapt to function efficiently in the extreme cold. Garrett and Rosenthal (p. 848 , published online 5 January; see the Perspective by Ö hman ) show that the coding sequences for delayed rectifier potassium channels from an Antarctic and a tropical octopus differed at only four positions and gave functionally identical channels when expressed in Xenopus oocytes. A variation in temperature responses instead came from extensive messenger RNA editing. In particular, an edit that recoded an isoleucine to a valine in the pore of the Antarctic octopus channel greatly accelerated gating kinetics.