Analysis of Conserved Glutamate and Aspartate Residues in Drosophila Rhodopsin 1 and Their Influence on Spectral Tuning.

ABSTRACT: The molecular mechanisms that regulate invertebrate visual pigment absorption are poorly understood. Studies of amphioxus Go-opsin have demonstrated that Glu-181 functions as the counterion in this pigment. This finding has led to the proposal that Glu-181 may function as the counterion in other invertebrate visual pigments as well. Here we describe a series of mutagenesis experiments to test this hypothesis and to also test whether other conserved acidic amino acids in Drosophila Rhodopsin 1 (Rh1) may serve as the counterion of this visual pigment. Of the 5 Glu and Asp residues replaced by Gln or Asn in our experiments, none of the mutant pigments shift the absorption of Rh1 by more than 6 nm. In combination with prior studies, these results suggest that the counterion in Drosophila Rh1 m

SUBMITTER: Zheng L 

PROVIDER: S-EPMC4571949 | biostudies-literature | 2015 Sep

REPOSITORIES: biostudies-literature