{"doi":"10.1073/pnas.0500378102","title":"A rhodopsin exhibiting binding ability to agonist\n                    <i>all-trans-retinal</i>","abstract":"<jats:p>\n                    Rhodopsins are the members of the family of G protein-coupled receptors that have diverged from ligand-binding receptors into photoreceptive pigments. Vertebrate rhodopsins are able to bind the inverse agonist 11-\n                    <jats:italic>cis</jats:italic>\n                    -retinal but are unable to bind the agonist\n                    <jats:italic>all-trans</jats:italic>\n                    -retinal, indicating that vertebrate rhodopsin changed its binding ability during the course of molecular evolution. Here, we show that unlike vertebrate rhodopsin, amphioxus rhodopsin is still able to bind the agonist\n                    <jats:italic>all-trans</jats:italic>\n                    -retinal. The opsin of amphioxus rhodopsin can also bind 11-\n                    <jats:italic>cis</jats:italic>\n                    -retinal to form a photoreceptive pigment that can convert to a red-shifted photoproduct through\n                    <jats:italic>cis-trans</jats:italic>\n                    isomerization of the chromophore upon photon absorption. The red-shifted photoproduct is the stable G protein activating state. Incubation of the opsin with\n                    <jats:italic>all-trans</jats:italic>\n                    -retinal produces a G protein activating state that is spectroscopically and biochemically indistinguishable from the red-shifted photoproduct, indicating that the opsin possesses agonist-binding ability. The opsin exhibits an ≈50-fold higher affinity for 11-\n                    <jats:italic>cis</jats:italic>\n                    -retinal than for\n                    <jats:italic>all-trans</jats:italic>\n                    -retinal, and mutational analyses revealed that Trp-265 situated in helix VI is important for the increase in binding affinity to 11-\n                    <jats:italic>cis</jats:italic>\n                    -retinal. These properties of amphioxus rhodopsin suggest that an ancestral rhodopsin increased the affinity for 11-\n                    <jats:italic>cis</jats:italic>\n                    -retinal by rearrangement of a structure including Trp-265 to act as a photoreceptor. In addition, an additional mechanism was acquired in vertebrate rhodopsin to prevent completely the binding of exogenous\n                    <jats:italic>all-trans</jats:italic>\n                    -retinal during molecular evolution.\n                  </jats:p>","journal":"Proceedings of the National Academy of Sciences","year":2005,"id":632576,"datarank":0.5926865577872142,"base_score":3.9512437185814275,"endowment":3.9512437185814275,"self_citation_contribution":0.5926865577872142,"citation_network_contribution":0.0,"self_endowment_contribution":0.5926865577872142,"citer_contribution":0.0,"corpus_percentile":null,"corpus_rank":null,"citation_count":51,"citer_count":0,"citers_with_citation_signal":0,"citers_with_endowment":0,"datacite_reuse_total":0,"is_dataset":false,"is_dataset_confidence":null,"is_data_producer":false,"deposit_databanks":null,"is_oa":false,"file_count":0,"downloads":0,"has_version_chain":false,"published_date":null,"fair_score":null,"fair_percentile":null,"algorithm_id":"datarank_citation_only_1hop_v6","ranking_scope":"data_only","authors":[{"id":1177769,"name":"Akihisa Terakita","orcid":"0000-0002-8379-8913","position":1,"is_corresponding":false},{"id":1639795,"name":"Yoshinori Shichida","orcid":null,"position":2,"is_corresponding":false},{"id":140310,"name":"Hisao Tsukamoto","orcid":null,"position":0,"is_corresponding":false}],"reference_count":0,"raw_metadata":{"has_enrichment":true,"resolved":true,"title":"A rhodopsin exhibiting binding ability to agonist\n                    <i>all-trans-retinal</i>","abstract":"<jats:p>\n                    Rhodopsins are the members of the family of G protein-coupled receptors that have diverged from ligand-binding receptors into photoreceptive pigments. Vertebrate rhodopsins are able to bind the inverse agonist 11-\n                    <jats:italic>cis</jats:italic>\n                    -retinal but are unable to bind the agonist\n                    <jats:italic>all-trans</jats:italic>\n                    -retinal, indicating that vertebrate rhodopsin changed its binding ability during the course of molecular evolution. Here, we show that unlike vertebrate rhodopsin, amphioxus rhodopsin is still able to bind the agonist\n                    <jats:italic>all-trans</jats:italic>\n                    -retinal. The opsin of amphioxus rhodopsin can also bind 11-\n                    <jats:italic>cis</jats:italic>\n                    -retinal to form a photoreceptive pigment that can convert to a red-shifted photoproduct through\n                    <jats:italic>cis-trans</jats:italic>\n                    isomerization of the chromophore upon photon absorption. The red-shifted photoproduct is the stable G protein activating state. Incubation of the opsin with\n                    <jats:italic>all-trans</jats:italic>\n                    -retinal produces a G protein activating state that is spectroscopically and biochemically indistinguishable from the red-shifted photoproduct, indicating that the opsin possesses agonist-binding ability. The opsin exhibits an ≈50-fold higher affinity for 11-\n                    <jats:italic>cis</jats:italic>\n                    -retinal than for\n                    <jats:italic>all-trans</jats:italic>\n                    -retinal, and mutational analyses revealed that Trp-265 situated in helix VI is important for the increase in binding affinity to 11-\n                    <jats:italic>cis</jats:italic>\n                    -retinal. These properties of amphioxus rhodopsin suggest that an ancestral rhodopsin increased the affinity for 11-\n                    <jats:italic>cis</jats:italic>\n                    -retinal by rearrangement of a structure including Trp-265 to act as a photoreceptor. In addition, an additional mechanism was acquired in vertebrate rhodopsin to prevent completely the binding of exogenous\n                    <jats:italic>all-trans</jats:italic>\n                    -retinal during molecular evolution.\n                  </jats:p>","is_dataset_classified":null,"base_score":3.9512437185814275,"endowment":3.9512437185814275,"datacite_reuse_total":0,"file_count":0,"downloads":0,"views":0,"has_version_chain":false,"is_dataset":false,"is_oa":false,"pmid":"15851682","pmcid":"PMC1088369","openalex_id":"https://openalex.org/W2064087835","authors":[],"funders":[],"total_grants":0,"fwci":1.1876,"citation_percentile":0.76408513,"influential_citations":0,"citation_trend":[{"year":2012,"count":1},{"year":2013,"count":2},{"year":2014,"count":3},{"year":2015,"count":2},{"year":2017,"count":5},{"year":2018,"count":5},{"year":2020,"count":1},{"year":2021,"count":3},{"year":2022,"count":5},{"year":2023,"count":2},{"year":2024,"count":2},{"year":2025,"count":2}],"oa_status":"green","license":null,"oa_locations":[{"url":"https://www.pnas.org/doi/pdf/10.1073/pnas.0500378102","host_type":"repository"},{"url":"https://europepmc.org/articles/pmc1088369?pdf=render","host_type":"GREEN"},{"url":"https://www.pnas.org/doi/pdf/10.1073/pnas.0500378102","host_type":"repository"},{"url":"https://pnas.org/doi/pdf/10.1073/pnas.0500378102","host_type":"publisher"},{"url":"http://dx.doi.org/10.1073/pnas.0500378102","host_type":"repository"},{"url":"https://doi.org/10.1073/pnas.0500378102","host_type":"journal"},{"url":"https://pubmed.ncbi.nlm.nih.gov/15851682","host_type":"repository"},{"url":"http://europepmc.org/articles/PMC1088369","host_type":"repository"}],"fields_of_study":["Receptor Mechanisms and Signaling","Retinal Development and Disorders","Photoreceptor and optogenetics research","Biology","Medicine","Chemistry"],"mesh_terms":["Animals","Binding, Competitive","Chordata, Nonvertebrate","Chromatography, High Pressure Liquid","Photochemistry","Protein Binding","Retinaldehyde","Rhodopsin","Spectrophotometry, Ultraviolet","Evolution, Molecular","GTP-Binding Proteins"],"keywords":["Rhodopsin","Opsin","Retinaldehyde","Retinal","Biology","Agonist","G protein-coupled receptor","Visual phototransduction","Receptor","Biophysics","Biochemistry"],"sdg_mappings":[],"linked_datasets":[],"clinical_trials":[],"software_tools":[],"database_accessions":[],"source":"live","citation_network_status":"fetched"},"created_at":"2026-08-06T10:00:43.917354Z","pmid":null,"pmcid":null,"fwci":null,"citation_percentile":null,"influential_citations":0,"oa_status":null,"license":null,"views":0,"total_file_size_bytes":0,"version_count":0,"fair_f":null,"fair_a":null,"fair_i":null,"fair_r":null,"fair_zscore":null,"fair_rationale":null,"fair_model":null,"fair_agent_version":null,"fair_fulltext_source":null,"fair_has_llm":null,"fair_computed_at":null,"clinical_trials":[],"software_tools":[],"db_accessions":[],"linked_datasets":[],"topics":[]}