RNA editing and cold adaptation in cephalopods

• Main Author: Garrett, Sandra C.
• Format: Thesis
• Language: English
• Published: University of Puerto Rico, Rio Piedras (Puerto Rico) 2012
• Subjects: Molecular biology|Neurosciences; Antarctic; Arctic; Antarc*
• Online Access: http://pqdtopen.proquest.com/#viewpdf?dispub=3540325

The process of A-to-I RNA editing can recode messenger RNAs, thereby changing their encoded proteins, and greatly expanding protein diversity. Here I show that octopus use a novel protein form made by editing to adapt to the cold. Arctic and Antarctic species of octopus strongly favor a particular isoleucine to valine edit which makes their Kv1 channels close much faster. This was the first time that RNA editing had been implicated in adaptation to an environmental variable. However, a review of the literature revealed that, for a range of organisms, the amino acid changes produced by A-to-I RNA editing are the same as the amino acid substitutions favored in cold adapted organisms. This suggests that RNA editing may be an inherently suitable mechanism for cold adaptation. An open question is whether cold adaptive RNA editing occurs only on a slow, evolutionary time scale, or whether it can respond quickly, allowing organisms to acclimate to variable temperatures.