Analysis of Voltage-gated Ion Channels in Antarctic Fish

We also studied the molecular evolution and expression of water-passing channels, the aquaporins, to determine if these show signs of evolutionary change in notothenioids. We noted apparent amino acid substitutions at a number of sites in a muscle-expressing potassium channel (Kv1.3).

We were surprised to find that although the AAs at these sites appeared highly conserved in teleosts and even in tetrapods, reverting them singly, in pairs, or all together back to the ancestral condition had no effect on the biophysical properties of the channels that we measured (voltage-sensitivity; rate of activation) at room temperature as well as over a range of temperatures down to 4oC. The results for the TRP channels and aquaporins can be accessed in their publications.