title: Molecular evolution of retinal and nonretinal opsins.
abstract: Vision and the circadian rhythms of various biological functions are triggered by phototransduction. The retinal and nonretinal (pineal gland-specific) opsins are traced back to a single common ancestor. Evolutionary analyses of these opsins identify amino acid changes that are potentially important in the regulation of wavelength absorption of photosensitive molecules-visual pigments. Such theoretical predictions can now be tested experimentally using site-directed mutagenesis; expressing the mutagenized opsins in tissue culture cells, reconstituting with 11-cis retinal, and measuring the absorption spectra of the regenerated visual pigments.
authors.affiliation: Department of Biology, Syracuse University, NY 13244, USA.
authors.forename: S
authors.initials: S
authors.lastname: Yokoyama
mesh_terms: D000818:Animals; D002940:Circadian Rhythm / Q000235:genetics; D019143:Evolution, Molecular; D006801:Humans; D016297:Mutagenesis, Site-Directed; D010802:Phylogeny; D017434:Protein Structure, Tertiary; D012160:Retina; D017299:Rod Opsins / Q000235:genetics*; D014785:Vision, Ocular / Q000235:genetics
chemical_list: D017299:Rod Opsins