Amphioxus homologs of Go‐coupled rhodopsin and peropsin having 11‐cis‐ and all‐trans‐retinals as their chromophores

  title={Amphioxus homologs of Go‐coupled rhodopsin and peropsin having 11‐cis‐ and all‐trans‐retinals as their chromophores},
  author={Mitsumasa Koyanagi and Akihisa Terakita and Kaoru Kubokawa and Yoshinori Shichida},
  journal={FEBS Letters},

Microbial and Animal Rhodopsins: Structures, Functions, and Molecular Mechanisms

Rhodopsins found in Eukaryotes, Bacteria, and Archaea consist of opsin apoproteins and a covalently linked retinal which is employed to absorb photons for energy conversion or the initiation of intra- or intercellular signaling.

Rhodopsins at a glance.

An overview of the diversity of functions, structures, color discrimination mechanisms and optogenetic applications of these two rhodopsin families is provided, and a third distinctive rhodopin family is highlighted, heliorhodopsins.

A rhodopsin exhibiting binding ability to agonist all-trans-retinal.

It is shown that unlike vertebrate rhodopsin, amphioxus r Rhodopsin is still able to bind the agonist all-trans-retinal, and an additional mechanism was acquired in vertebrates to prevent completely the binding of exogenous all-Trans-Retinal during molecular evolution.

Homologs of vertebrate Opn3 potentially serve as a light sensor in nonphotoreceptive tissue

It is demonstrated that mammalian cultured cells transfected with the MosOpn3 or PufTMT became light sensitive without the addition of 11-cis retinal and the photosensitivity retained after the continuous light exposure, showing a reusable pigment formation with retinal endogenously contained in culture medium.

An all-trans-retinal-binding opsin peropsin as a potential dark-active and light-inactivated G protein-coupled receptor

It is found that peropsin potentially generates an “active form” that drives G-protein signalling in the dark by binding to all-trans-retinal and that the active form photo-converts to an inactive form containing 11-cis- retinal.

Gq‐coupled Rhodopsin Subfamily Composed of Invertebrate Visual Pigment and Melanopsin †

Research into the Gq‐coupled rhodopsin subfamily, especially invertebrate melanopsins, will provide an opportunity to investigate the evolution of various physiologic functions, based on orthologous genes, during animal evolution.

Evaluation of the role of the retinal G protein‐coupled receptor (RGR) in the vertebrate retina in vivo

RGR and RDH5 are likely to function in the retinoid cycle, although their role is not essential and regeneration of visual pigment is only mildly affected by the absence of both proteins in rod‐dominated mice.

Evolution and diversity of opsins

Mutational analyses of the both types of pigments implied that during molecular evolution of the vertebrae visual pigments, displacement of the counterion, important amino acid residue for visible light absorption of opsin-based pigment, resulted in not only unique bleaching property but also acquisition of red-sensitive visual pigment and higher G-protein activation ability generated by larger light-induced conformational change of the pigment.

Diversity of animal opsin-based pigments and their optogenetic potential.

Evolution and the origin of the visual retinoid cycle in vertebrates

Comparison of visual retinoid cycles between different photoreceptors of vertebrates, including rods, cones and non-visual photoreceptor cells, as well as between vertebrates and invertebrates is compared.



A photic visual cycle of rhodopsin regeneration is dependent on Rgr

RGR is involved in the formation of 11-cis-retinal in mice and functions in a light-dependent pathway of the rod visual cycle and Mutations in the human gene encoding RGR are associated with retinitis pigmentosa.

Partial Agonist Activity of 11-cis-Retinal in Rhodopsin Mutants*

Mutation of Gly121 in rhodopsin causes 11-cis-retinal to act as a partial agonist rather than an inverse agonist, allowing the mutant pigment to activate transducin in the dark.

Movement of retinal along the visual transduction path.

Movement of the ligand/receptor complex in rhodopsin (Rh) has been traced and it is likely that these movements involving a flip-over of the chromophoric ring trigger changes in cytoplasmic membrane loops resulting in heterotrimeric guanine nucleotide-binding protein (G protein) activation.

Functional Interaction between Bovine Rhodopsin and G Protein Transducin*

Results suggest that the binding of loop 3 of bovine rhodopsin to region A in Gαt is one of the mechanisms of specific Gt activation by bovines r Rhodopsin.

Light- and GTP-regulated interaction of GTPase and other proteins with bovine photoreceptor membranes

It is found that light induces profound changes in the interaction of rhodopsin kinase11, GTPase, and other proteins with the photoreceptor membrane that are reversible in the dark, are strongly influenced by GTP, and are thought to be involved in the regulation of enzyme activity by light.

Peropsin, a novel visual pigment-like protein located in the apical microvilli of the retinal pigment epithelium.

Observations suggest that peropsin may play a role in RPE physiology either by detecting light directly or by monitoring the concentration of retinoids or other photoreceptor-derived compounds.

A Novel Go-mediated Phototransduction Cascade in Scallop Visual Cells*

The phototransduction cascade in the scallop hyperpolarizing cell provides an alternative system to investigate Go-mediated transduction pathways in the nervous system and Molecular phylogenetic analysis strongly suggests that the Go- mediated phototranduction system emerged before the divergence of animals into vertebrate and invertebrate in the course of evolution.