title: Phototransduction motifs and variations.
abstract: Seeing begins in the photoreceptors, where light is absorbed and signaled to the nervous system. Throughout the animal kingdom, photoreceptors are diverse in design and purpose. Nonetheless, phototransduction-the mechanism by which absorbed photons are converted into an electrical response-is highly conserved and based almost exclusively on a single class of photoproteins, the opsins. In this Review, we survey the G protein-coupled signaling cascades downstream from opsins in photoreceptors across vertebrate and invertebrate species, noting their similarities as well as differences.
authors.affiliation: Solomon H. Snyder Department of Neuroscience and Center for Sensory Biology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA. kwyau@mail.jhmi.edu
authors.forename: King-Wai
authors.initials: KW
authors.lastname: Yau
authors.forename: Roger C
authors.initials: RC
authors.lastname: Hardie
mesh_terms: D000818:Animals; D006801:Humans; D055537:Light Signal Transduction; D017956:Photoreceptor Cells, Invertebrate / Q000378:metabolism; D020419:Photoreceptor Cells, Vertebrate; D043562:Receptors, G-Protein-Coupled / Q000378:metabolism*
chemical_list: D043562:Receptors, G-Protein-Coupled