Epistatic interactions influence terrestrial-marine functional shifts in cetacean rhodopsin.

ABSTRACT: Like many aquatic vertebrates, whales have blue-shifting spectral tuning substitutions in the dim-light visual pigment, rhodopsin, that are thought to increase photosensitivity in underwater environments. We have discovered that known spectral tuning substitutions also have surprising epistatic effects on another function of rhodopsin, the kinetic rates associated with light-activated intermediates. By using absorbance spectroscopy and fluorescence-based retinal release assays on heterologously expressed rhodopsin, we assessed both spectral and kinetic differences between cetaceans (killer whale) and terrestrial outgroups (hippo, bovine). Mutation experiments revealed that killer whale rhodopsin is unusually resilient to pleiotropic effects on retinal release from key blue-shifting substit

SUBMITTER: Dungan SZ 

PROVIDER: S-EPMC5360924 | biostudies-literature | 2017 Mar

REPOSITORIES: biostudies-literature