Component

11-cis-retinal

11-cis retinaldehyde chromophore of visual pigments.

9 recorded relationships. Experimental role, claim status and evidence remain attached to each record.

Read recorded mechanisms Open recursive mind map

How nutrients influence it

Every nutrient with a recorded effect on this component, credited to the nutrient that acted rather than the chapter that recorded it. Open a nutrient to see the findings and the conditions they were measured under.

How nutrients reach it in more than one step

Chains of two or more recorded steps that end here, grouped by the nutrient they start from. Each step is a separate finding, so a chain is a route a mechanism could take, not proof that it does.

Tracing routes…

What it does

Every recorded relationship this component is part of, grouped by its role. Plain wording comes first; the technical statement follows.

Recorded relationships

What it acts on

  1. Bovine rhodopsin crystallography identifies 11-cis-retinal within the inactive seven-helix receptor.

    11-cis-retinal → Rhodopsin source_derived_draftungraded
    Experimental context and source evidence
    experimental_model
    2.8-angstrom crystal structure
    limitations
    A static ground-state structure does not measure dietary requirements.
    nutrient_topic
    Vitamin A research collection; topical membership is not evidence of a direct dietary effect. · Vitamin A
    organism
    Bos taurus
    plain_language
    The cis retinal isomer is the rod pigment chromophore.
    primary_references
    [palczewski-2000] Crystal structure of rhodopsin: A G protein-coupled receptor (2000). https://pubmed.ncbi.nlm.nih.gov/10926528/ DOI: 10.1126/science.289.5480.739
    tissue_or_cell_type
    Rod photopigment

    Vitamin A: forms, mechanisms, deficiency and excess (2026-09-17) · lines 644–653

    AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · 2.8-angstrom crystal structure · source_derived_draft · unverified_draft

    ### a-vision-chromophore Bovine rhodopsin crystallography identifies 11-cis-retinal within the inactive seven-helix receptor. Condition category: normal nutrient_topic: Vitamin A research collection; topical membership is not evidence of a direct dietary effect. plain_language: The cis retinal isomer is the rod pigment chromophore. organism: Bos taurus tissue_or_cell_type: Rod photopigment experimental_model: 2.8-angstrom crystal structure limitations: A static ground-state structure does not measure dietary requirements. [palczewski-2000] Crystal structure of rhodopsin: A G protein-coupled receptor (2000). https://pubmed.ncbi.nlm.nih.gov/10926528/ DOI: 10.1126/science.289.5480.739
    Complete structured claim and evidence

  2. Light activation changes rhodopsin-bound 11-cis-retinal into its all-trans geometry, coupled to receptor activation.

    11-cis-retinal → All-trans-retinal source_derived_draftungraded
    Experimental context and source evidence
    experimental_model
    Solid-state NMR before/after illumination
    limitations
    Bound chromophore conversion precedes release of free retinal.
    nutrient_topic
    Vitamin A research collection; topical membership is not evidence of a direct dietary effect. · Vitamin A
    organism
    Bos taurus
    plain_language
    A photon changes the bound retinoid shape and starts the signal.
    primary_references
    [grobner-2000] Observations of light-induced structural changes of retinal within rhodopsin (2000). https://www.nature.com/articles/35015604 DOI: 10.1038/35015604
    tissue_or_cell_type
    Purified rhodopsin

    Vitamin A: forms, mechanisms, deficiency and excess (2026-09-17) · lines 655–664

    AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Solid-state NMR before/after illumination · source_derived_draft · unverified_draft

    ### a-vision-photoisomerization Light activation changes rhodopsin-bound 11-cis-retinal into its all-trans geometry, coupled to receptor activation. Condition category: normal nutrient_topic: Vitamin A research collection; topical membership is not evidence of a direct dietary effect. plain_language: A photon changes the bound retinoid shape and starts the signal. organism: Bos taurus tissue_or_cell_type: Purified rhodopsin experimental_model: Solid-state NMR before/after illumination limitations: Bound chromophore conversion precedes release of free retinal. [grobner-2000] Observations of light-induced structural changes of retinal within rhodopsin (2000). https://www.nature.com/articles/35015604 DOI: 10.1038/35015604
    Complete structured claim and evidence

What acts on it

  1. Adding native CRALBP increased the accumulation of light-generated 11-cis-retinal in bovine RPE microsomal assays compared with denatured CRALBP.

    Cellular retinaldehyde-binding protein / CRALBP → 11-cis-retinal source_derived_draftungraded
    Experimental context and source evidence
    cross_nutrient
    false
    evidence_location
    Results: Impact of CRALBP on the RPE photoisomerase activity; Figure 3d
    experimental_model
    Native versus denatured CRALBP in RPE microsomes
    exposure
    530-nm illumination; retinal substrate; Figure 3d comparison.
    limitations
    Product protection was inferred from yield; these assays do not establish supplement effects.
    nutrient
    Vitamin A · Vitamin A
    nutrient_topic
    Vitamin A expansion research collection; topical membership is not evidence of a direct dietary effect. · Vitamin A
    organism
    Bos taurus; recombinant human CRALBP reagent
    plain_language
    The retinoid-binding protein helps retain RGR pathway product.
    primary_references
    [vav-zhang2019] Photic generation of 11-cis-retinal in bovine retinal pigment epithelium. (2019). https://pubmed.ncbi.nlm.nih.gov/31694912/ DOI: 10.1074/jbc.ra119.011169
    tissue_or_cell_type
    RPE microsomes

    Vitamin A expansion: reproduction, light-driven vision and shared mechanisms (2026-09-17) · lines 438–451

    AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Native versus denatured CRALBP in RPE microsomes · source_derived_draft · unverified_draft

    ### vae-cralbp-rgr-product-accumulation Adding native CRALBP increased the accumulation of light-generated 11-cis-retinal in bovine RPE microsomal assays compared with denatured CRALBP. Condition category: normal nutrient_topic: Vitamin A expansion research collection; topical membership is not evidence of a direct dietary effect. plain_language: The retinoid-binding protein helps retain RGR pathway product. organism: Bos taurus; recombinant human CRALBP reagent tissue_or_cell_type: RPE microsomes experimental_model: Native versus denatured CRALBP in RPE microsomes limitations: Product protection was inferred from yield; these assays do not establish supplement effects. exposure: 530-nm illumination; retinal substrate; Figure 3d comparison. cross_nutrient: false evidence_location: Results: Impact of CRALBP on the RPE photoisomerase activity; Figure 3d nutrient: Vitamin A [vav-zhang2019] Photic generation of 11-cis-retinal in bovine retinal pigment epithelium. (2019). https://pubmed.ncbi.nlm.nih.gov/31694912/ DOI: 10.1074/jbc.ra119.011169
    Complete structured claim and evidence

  2. Bovine RGR K255A produced little 11-cis-retinal under illumination despite expression comparable to wild-type RGR in HEK293S GnTI-negative cells.

    RGR K255A variant → 11-cis-retinal source_derived_draftungraded
    Experimental context and source evidence
    availability_state
    machinery_impairment Imported condition classification; unverified.
    cross_nutrient
    false
    evidence_location
    Results/Figure 7a-c
    experimental_model
    Recombinant bovine wild-type/K255A RGR comparison
    exposure
    All-trans-retinal and 530-nm light, with CRALBP; Figure 7.
    limitations
    Construct-specific assay; K255A numbering is retained from this paper.
    nutrient
    Vitamin A · Vitamin A
    nutrient_topic
    Vitamin A expansion research collection; topical membership is not evidence of a direct dietary effect. · Vitamin A
    organism
    Bos taurus protein in Homo sapiens cells
    plain_language
    Disrupting the retinal-binding lysine impaired the light-driven reaction.
    primary_references
    [vav-zhang2019] Photic generation of 11-cis-retinal in bovine retinal pigment epithelium. (2019). https://pubmed.ncbi.nlm.nih.gov/31694912/ DOI: 10.1074/jbc.ra119.011169
    tissue_or_cell_type
    HEK293S GnTI-negative homogenates
    trigger_kind
    machinery_impairment Imported condition classification; unverified.

    Vitamin A expansion: reproduction, light-driven vision and shared mechanisms (2026-09-17) · lines 453–466

    AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Recombinant bovine wild-type/K255A RGR comparison · source_derived_draft · unverified_draft

    ### vae-rgr-k255a-photoactivity Bovine RGR K255A produced little 11-cis-retinal under illumination despite expression comparable to wild-type RGR in HEK293S GnTI-negative cells. Condition category: machinery_impairment nutrient_topic: Vitamin A expansion research collection; topical membership is not evidence of a direct dietary effect. plain_language: Disrupting the retinal-binding lysine impaired the light-driven reaction. organism: Bos taurus protein in Homo sapiens cells tissue_or_cell_type: HEK293S GnTI-negative homogenates experimental_model: Recombinant bovine wild-type/K255A RGR comparison limitations: Construct-specific assay; K255A numbering is retained from this paper. exposure: All-trans-retinal and 530-nm light, with CRALBP; Figure 7. cross_nutrient: false evidence_location: Results/Figure 7a-c nutrient: Vitamin A [vav-zhang2019] Photic generation of 11-cis-retinal in bovine retinal pigment epithelium. (2019). https://pubmed.ncbi.nlm.nih.gov/31694912/ DOI: 10.1074/jbc.ra119.011169
    Complete structured claim and evidence

  3. Illuminating native bovine RGR converted its bound all-trans-retinal stereospecifically to the 11-cis configuration.

    All-trans-retinal → 11-cis-retinal source_derived_draftungraded
    Experimental context and source evidence
    cross_nutrient
    false
    evidence_location
    Abstract: irradiation and isomer analysis
    experimental_model
    Purified native RGR photochemistry
    exposure
    470-nm monochromatic or near-UV irradiation; duration absent from the abstract.
    limitations
    Abstract-limited; the finding does not establish relative flux in living human eyes.
    nutrient
    Vitamin A · Vitamin A
    nutrient_topic
    Vitamin A expansion research collection; topical membership is not evidence of a direct dietary effect. · Vitamin A
    organism
    Bos taurus
    plain_language
    Light lets RGR reverse the retinal isomer change used in visual pigments.
    primary_references
    [vav-hao1999] The endogenous chromophore of retinal G protein-coupled receptor opsin from the pigment epithelium. (1999). https://pubmed.ncbi.nlm.nih.gov/10037690/ DOI: 10.1074/jbc.274.10.6085
    tissue_or_cell_type
    RPE-derived protein

    Vitamin A expansion: reproduction, light-driven vision and shared mechanisms (2026-09-17) · lines 423–436

    AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Purified native RGR photochemistry · source_derived_draft · unverified_draft

    ### vae-rgr-photoisomerization Illuminating native bovine RGR converted its bound all-trans-retinal stereospecifically to the 11-cis configuration. Condition category: normal nutrient_topic: Vitamin A expansion research collection; topical membership is not evidence of a direct dietary effect. plain_language: Light lets RGR reverse the retinal isomer change used in visual pigments. organism: Bos taurus tissue_or_cell_type: RPE-derived protein experimental_model: Purified native RGR photochemistry limitations: Abstract-limited; the finding does not establish relative flux in living human eyes. exposure: 470-nm monochromatic or near-UV irradiation; duration absent from the abstract. cross_nutrient: false evidence_location: Abstract: irradiation and isomer analysis nutrient: Vitamin A [vav-hao1999] The endogenous chromophore of retinal G protein-coupled receptor opsin from the pigment epithelium. (1999). https://pubmed.ncbi.nlm.nih.gov/10037690/ DOI: 10.1074/jbc.274.10.6085
    Complete structured claim and evidence

  4. After photoisomerization in native bovine RPE microsomes, the RGR 11-cis-retinylidene Schiff base hydrolyzed with an estimated 7.5-second half-life at 20 degrees Celsius.

    Retinal G protein-coupled receptor / RGR opsin → 11-cis-retinal source_derived_draftungraded
    Experimental context and source evidence
    cross_nutrient
    false
    evidence_location
    Figure 1D-F; STAR Methods: hydrolysis kinetics
    experimental_model
    LC-MS/MS and retinoid analysis of native microsomes
    exposure
    20 micromolar all-trans-retinal; 10-second 530-nm exposure, followed by dark incubation at 20 degrees Celsius.
    limitations
    Temperature-specific membrane kinetics do not directly specify a human whole-eye rate.
    nutrient
    Vitamin A · Vitamin A
    nutrient_topic
    Vitamin A expansion research collection; topical membership is not evidence of a direct dietary effect. · Vitamin A
    organism
    Bos taurus
    plain_language
    RGR released regenerated retinal within seconds in the membrane preparation.
    primary_references
    [vav-tworak2023] Rapid RGR-dependent visual pigment recycling is mediated by the RPE and specialized Müller glia. (2023). https://pubmed.ncbi.nlm.nih.gov/37585292/ DOI: 10.1016/j.celrep.2023.112982
    tissue_or_cell_type
    RPE microsomes

    Vitamin A expansion: reproduction, light-driven vision and shared mechanisms (2026-09-17) · lines 498–511

    AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · LC-MS/MS and retinoid analysis of native microsomes · source_derived_draft · unverified_draft

    ### vae-rgr-photoproduct-release After photoisomerization in native bovine RPE microsomes, the RGR 11-cis-retinylidene Schiff base hydrolyzed with an estimated 7.5-second half-life at 20 degrees Celsius. Condition category: normal nutrient_topic: Vitamin A expansion research collection; topical membership is not evidence of a direct dietary effect. plain_language: RGR released regenerated retinal within seconds in the membrane preparation. organism: Bos taurus tissue_or_cell_type: RPE microsomes experimental_model: LC-MS/MS and retinoid analysis of native microsomes limitations: Temperature-specific membrane kinetics do not directly specify a human whole-eye rate. exposure: 20 micromolar all-trans-retinal; 10-second 530-nm exposure, followed by dark incubation at 20 degrees Celsius. cross_nutrient: false evidence_location: Figure 1D-F; STAR Methods: hydrolysis kinetics nutrient: Vitamin A [vav-tworak2023] Rapid RGR-dependent visual pigment recycling is mediated by the RPE and specialized Müller glia. (2023). https://pubmed.ncbi.nlm.nih.gov/37585292/ DOI: 10.1016/j.celrep.2023.112982
    Complete structured claim and evidence

  5. Bovine RDH5 expressed in COS cells oxidized 11-cis-retinol using NAD+; NADP did not support the tested activity.

    11-cis-retinol dehydrogenase / RDH5 → 11-cis-retinal source_derived_draftungraded
    Experimental context and source evidence
    experimental_model
    Recombinant p32/RDH5 activity assay
    limitations
    Cofactor specificity is biochemical; no niacin-deficiency phenotype was tested.
    nutrient_topic
    Vitamin A research collection; topical membership is not evidence of a direct dietary effect. · Vitamin A
    organism
    Bos taurus protein; COS cells
    plain_language
    RDH5 oxidizes the cis alcohol into the visual chromophore.
    primary_references
    [simon-1995] The retinal pigment epithelial-specific 11-cis retinol dehydrogenase belongs to the family of short chain alcohol dehydrogenases (1995). https://pubmed.ncbi.nlm.nih.gov/7836368/ DOI: 10.1074/jbc.270.3.1107
    tissue_or_cell_type
    RPE-derived enzyme

    Vitamin A: forms, mechanisms, deficiency and excess (2026-09-17) · lines 723–732

    AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Recombinant p32/RDH5 activity assay · source_derived_draft · unverified_draft

    ### a-vision-rdh5-oxidation Bovine RDH5 expressed in COS cells oxidized 11-cis-retinol using NAD+; NADP did not support the tested activity. Condition category: normal nutrient_topic: Vitamin A research collection; topical membership is not evidence of a direct dietary effect. plain_language: RDH5 oxidizes the cis alcohol into the visual chromophore. organism: Bos taurus protein; COS cells tissue_or_cell_type: RPE-derived enzyme experimental_model: Recombinant p32/RDH5 activity assay limitations: Cofactor specificity is biochemical; no niacin-deficiency phenotype was tested. [simon-1995] The retinal pigment epithelial-specific 11-cis retinol dehydrogenase belongs to the family of short chain alcohol dehydrogenases (1995). https://pubmed.ncbi.nlm.nih.gov/7836368/ DOI: 10.1074/jbc.270.3.1107
    Complete structured claim and evidence

Where it participates (unsigned role)

  1. Müller-cell-directed CRALBP restoration in Rlbp1-null/Gnat1-null mice improved cone recovery in the isolated-retina paradigm.

    Cellular retinaldehyde-binding protein / CRALBP → Cone dark adaptation source_derived_draftungraded
    Experimental context and source evidence
    experimental_model
    Cell-directed AAV rescue; ex vivo cone ERG
    intervention
    AAV protein restoration in genetic knockout
    limitations
    Rescue from global deletion is not equivalent to deleting only Müller CRALBP in an intact eye.
    nutrient_topic
    Vitamin A research collection; topical membership is not evidence of a direct dietary effect. · Vitamin A
    organism
    Mus musculus
    plain_language
    Müller-cell CRALBP can support a retinal route for cone pigment renewal.
    primary_references
    [xue-2015] CRALBP supports the mammalian retinal visual cycle and cone vision (2015). https://pmc.ncbi.nlm.nih.gov/articles/PMC4319437/ DOI: 10.1172/JCI79651
    tissue_or_cell_type
    Müller glia and cone retina

    Vitamin A: forms, mechanisms, deficiency and excess (2026-09-17) · lines 882–892

    AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Cell-directed AAV rescue; ex vivo cone ERG · source_derived_draft · unverified_draft

    ### a-vision-muller-cralbp-cones Müller-cell-directed CRALBP restoration in Rlbp1-null/Gnat1-null mice improved cone recovery in the isolated-retina paradigm. Condition category: normal nutrient_topic: Vitamin A research collection; topical membership is not evidence of a direct dietary effect. plain_language: Müller-cell CRALBP can support a retinal route for cone pigment renewal. organism: Mus musculus tissue_or_cell_type: Müller glia and cone retina experimental_model: Cell-directed AAV rescue; ex vivo cone ERG limitations: Rescue from global deletion is not equivalent to deleting only Müller CRALBP in an intact eye. intervention: AAV protein restoration in genetic knockout [xue-2015] CRALBP supports the mammalian retinal visual cycle and cone vision (2015). https://pmc.ncbi.nlm.nih.gov/articles/PMC4319437/ DOI: 10.1172/JCI79651
    Complete structured claim and evidence

  2. RPE-selective CRALBP deletion slowed bulk visual chromophore regeneration approximately 15-fold in mice.

    RPE-selective CRALBP loss → 11-cis-retinal regeneration source_derived_draftungraded
    Experimental context and source evidence
    availability_state
    machinery_impairment Imported condition classification; unverified.
    experimental_model
    Timed RPE-selective knockout; post-bleach HPLC
    limitations
    Bulk recovery mainly reflects rods; not a direct human effect size.
    nutrient_topic
    Vitamin A research collection; topical membership is not evidence of a direct dietary effect. · Vitamin A
    organism
    Mus musculus
    plain_language
    RPE CRALBP strongly supports replenishment of cis retinal.
    primary_references
    [bassetto-2024] Dominant role for pigment epithelial CRALBP in supplying visual chromophore to photoreceptors (2024). https://pubmed.ncbi.nlm.nih.gov/38676924/ DOI: 10.1016/j.celrep.2024.114143
    tissue_or_cell_type
    RPE/whole-eye retinoids
    trigger_kind
    machinery_impairment Imported condition classification; unverified.

    Vitamin A: forms, mechanisms, deficiency and excess (2026-09-17) · lines 860–869

    AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Timed RPE-selective knockout; post-bleach HPLC · source_derived_draft · unverified_draft

    ### a-vision-rpe-cralbp-chromophore RPE-selective CRALBP deletion slowed bulk visual chromophore regeneration approximately 15-fold in mice. Condition category: machinery_impairment nutrient_topic: Vitamin A research collection; topical membership is not evidence of a direct dietary effect. plain_language: RPE CRALBP strongly supports replenishment of cis retinal. organism: Mus musculus tissue_or_cell_type: RPE/whole-eye retinoids experimental_model: Timed RPE-selective knockout; post-bleach HPLC limitations: Bulk recovery mainly reflects rods; not a direct human effect size. [bassetto-2024] Dominant role for pigment epithelial CRALBP in supplying visual chromophore to photoreceptors (2024). https://pubmed.ncbi.nlm.nih.gov/38676924/ DOI: 10.1016/j.celrep.2024.114143
    Complete structured claim and evidence

In the sources

Preserved passages that mention this component, quoted exactly. Open one to read it in context.

    This is a research prototype built from draft material. It is not medical advice, and its statements still await verification against the original studies.

    Evidence, AI assistance and curation standards