Component

Dihydroceramide desaturase 1 / DES1

DEGS1 protein, also called DES1; sphingolipid desaturase proposed to have retinol-isomerase activity in specific assays.

6 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. Homogenates of DES1-expressing HEK293T cells formed 11-cis-retinol from all-trans-retinol, alongside more abundant alternative cis isomers.

    Dihydroceramide desaturase 1 / DES1 → 11-cis-retinol source_derived_draftungraded
    Experimental context and source evidence
    cross_nutrient
    false
    evidence_location
    Figure 3a-d; Results: DES1 catalyzes equilibrium isomerization
    experimental_model
    Recombinant human DES1 expression; HPLC isomer analysis
    exposure
    Retinol isomerase assays in darkness at 37 degrees Celsius.
    limitations
    Activity in homogenates does not establish its quantitative contribution or necessity in an intact visual cycle.
    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
    Homo sapiens protein/cells
    plain_language
    DES1-associated activity made some 11-cis-retinol in biochemical assays.
    primary_references
    [vav-kaylor2013] Identification of DES1 as a vitamin A isomerase in Müller glial cells of the retina. (2013). https://pubmed.ncbi.nlm.nih.gov/23143414/ DOI: 10.1038/nchembio.1114
    tissue_or_cell_type
    HEK293T homogenates

    Vitamin A expansion: reproduction, light-driven vision and shared mechanisms (2026-09-17) · lines 558–571

    AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Recombinant human DES1 expression; HPLC isomer analysis · source_derived_draft · unverified_draft

    ### vae-des1-retinol-isomerization Homogenates of DES1-expressing HEK293T cells formed 11-cis-retinol from all-trans-retinol, alongside more abundant alternative cis isomers. Condition category: normal nutrient_topic: Vitamin A expansion research collection; topical membership is not evidence of a direct dietary effect. plain_language: DES1-associated activity made some 11-cis-retinol in biochemical assays. organism: Homo sapiens protein/cells tissue_or_cell_type: HEK293T homogenates experimental_model: Recombinant human DES1 expression; HPLC isomer analysis limitations: Activity in homogenates does not establish its quantitative contribution or necessity in an intact visual cycle. exposure: Retinol isomerase assays in darkness at 37 degrees Celsius. cross_nutrient: false evidence_location: Figure 3a-d; Results: DES1 catalyzes equilibrium isomerization nutrient: Vitamin A [vav-kaylor2013] Identification of DES1 as a vitamin A isomerase in Müller glial cells of the retina. (2013). https://pubmed.ncbi.nlm.nih.gov/23143414/ DOI: 10.1038/nchembio.1114
    Complete structured claim and evidence

Where it participates (unsigned role)

  1. CRALBP coexpression increased 11-cis-retinol production approximately threefold in homogenates of cells stably expressing chicken DES1.

    Cellular retinaldehyde-binding protein / CRALBP → 11-cis-retinol source_derived_draftungraded
    Experimental context and source evidence
    cross_nutrient
    false
    evidence_location
    Figure 5b
    experimental_model
    Chicken CRALBP transfection into stable DES1-expressing 293T cells
    exposure
    All-trans-retinol substrate; CRALBP plasmid versus empty-vector comparison.
    limitations
    An assay yield effect does not prove physiological transport or human supplementation benefit.
    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
    Gallus gallus proteins in Homo sapiens cells
    plain_language
    The binding protein shifted the measured output toward the visual-cycle alcohol.
    primary_references
    [vav-kaylor2013] Identification of DES1 as a vitamin A isomerase in Müller glial cells of the retina. (2013). https://pubmed.ncbi.nlm.nih.gov/23143414/ DOI: 10.1038/nchembio.1114
    tissue_or_cell_type
    cell homogenates

    Vitamin A expansion: reproduction, light-driven vision and shared mechanisms (2026-09-17) · lines 573–586

    AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Chicken CRALBP transfection into stable DES1-expressing 293T cells · source_derived_draft · unverified_draft

    ### vae-cralbp-des1-isomer-yield CRALBP coexpression increased 11-cis-retinol production approximately threefold in homogenates of cells stably expressing chicken DES1. Condition category: normal nutrient_topic: Vitamin A expansion research collection; topical membership is not evidence of a direct dietary effect. plain_language: The binding protein shifted the measured output toward the visual-cycle alcohol. organism: Gallus gallus proteins in Homo sapiens cells tissue_or_cell_type: cell homogenates experimental_model: Chicken CRALBP transfection into stable DES1-expressing 293T cells limitations: An assay yield effect does not prove physiological transport or human supplementation benefit. exposure: All-trans-retinol substrate; CRALBP plasmid versus empty-vector comparison. cross_nutrient: false evidence_location: Figure 5b nutrient: Vitamin A [vav-kaylor2013] Identification of DES1 as a vitamin A isomerase in Müller glial cells of the retina. (2013). https://pubmed.ncbi.nlm.nih.gov/23143414/ DOI: 10.1038/nchembio.1114
    Complete structured claim and evidence

  2. Müller-directed Degs1 deletion did not slow cone dark adaptation after greater than 90% pigment bleaching in isolated mouse retinas or intact eyes.

    Müller-directed DES1 loss → Cone dark adaptation source_derived_draftungraded
    Experimental context and source evidence
    availability_state
    machinery_impairment Imported condition classification; unverified.
    cross_nutrient
    false
    evidence_location
    Figure 7C-D
    experimental_model
    Degs1-flox/Pdgfra-Cre conditional knockout on Gnat1-null background
    exposure
    505-nm ex vivo or 520-nm in vivo bleach; mutant versus heterozygous littermate controls.
    limitations
    Does not exclude other DES1 functions, residual extra-Müller activity, or species-specific contributions.
    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
    Mus musculus
    plain_language
    The tested mice regenerated cone pigment normally despite targeted DES1 loss.
    primary_references
    [vav-kiser2019] Conditional deletion of Des1 in the mouse retina does not impair the visual cycle in cones. (2019). https://pubmed.ncbi.nlm.nih.gov/30645148/ DOI: 10.1096/fj.201802493r
    tissue_or_cell_type
    neural retina and intact-eye recordings
    trigger_kind
    machinery_impairment Imported condition classification; unverified.

    Vitamin A expansion: reproduction, light-driven vision and shared mechanisms (2026-09-17) · lines 618–631

    AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Degs1-flox/Pdgfra-Cre conditional knockout on Gnat1-null background · source_derived_draft · unverified_draft

    ### vae-des1-deletion-cone-recovery Müller-directed Degs1 deletion did not slow cone dark adaptation after greater than 90% pigment bleaching in isolated mouse retinas or intact eyes. Condition category: machinery_impairment nutrient_topic: Vitamin A expansion research collection; topical membership is not evidence of a direct dietary effect. plain_language: The tested mice regenerated cone pigment normally despite targeted DES1 loss. organism: Mus musculus tissue_or_cell_type: neural retina and intact-eye recordings experimental_model: Degs1-flox/Pdgfra-Cre conditional knockout on Gnat1-null background limitations: Does not exclude other DES1 functions, residual extra-Müller activity, or species-specific contributions. exposure: 505-nm ex vivo or 520-nm in vivo bleach; mutant versus heterozygous littermate controls. cross_nutrient: false evidence_location: Figure 7C-D nutrient: Vitamin A [vav-kiser2019] Conditional deletion of Des1 in the mouse retina does not impair the visual cycle in cones. (2019). https://pubmed.ncbi.nlm.nih.gov/30645148/ DOI: 10.1096/fj.201802493r
    Complete structured claim and evidence

  3. Müller-directed Degs1 conditional mutants showed slightly faster cone photoresponse termination than controls in ex vivo retinal recordings.

    Müller-directed DES1 loss → Cone photoresponse termination source_derived_draftungraded
    Experimental context and source evidence
    availability_state
    machinery_impairment Imported condition classification; unverified.
    cross_nutrient
    false
    evidence_location
    Figure 7A-B; Discussion
    experimental_model
    Degs1-flox/Pdgfra-Cre conditional knockout on Gnat1-null background
    exposure
    Dark-adapted transretinal cone flash responses.
    limitations
    The responsible cellular or lipid mechanism was unresolved; do not equate termination kinetics with pigment regeneration.
    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
    Mus musculus
    plain_language
    The response switched off faster even though pigment recovery was preserved.
    primary_references
    [vav-kiser2019] Conditional deletion of Des1 in the mouse retina does not impair the visual cycle in cones. (2019). https://pubmed.ncbi.nlm.nih.gov/30645148/ DOI: 10.1096/fj.201802493r
    tissue_or_cell_type
    isolated retina
    trigger_kind
    machinery_impairment Imported condition classification; unverified.

    Vitamin A expansion: reproduction, light-driven vision and shared mechanisms (2026-09-17) · lines 633–646

    AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Degs1-flox/Pdgfra-Cre conditional knockout on Gnat1-null background · source_derived_draft · unverified_draft

    ### vae-des1-deletion-cone-termination Müller-directed Degs1 conditional mutants showed slightly faster cone photoresponse termination than controls in ex vivo retinal recordings. Condition category: machinery_impairment nutrient_topic: Vitamin A expansion research collection; topical membership is not evidence of a direct dietary effect. plain_language: The response switched off faster even though pigment recovery was preserved. organism: Mus musculus tissue_or_cell_type: isolated retina experimental_model: Degs1-flox/Pdgfra-Cre conditional knockout on Gnat1-null background limitations: The responsible cellular or lipid mechanism was unresolved; do not equate termination kinetics with pigment regeneration. exposure: Dark-adapted transretinal cone flash responses. cross_nutrient: false evidence_location: Figure 7A-B; Discussion nutrient: Vitamin A [vav-kiser2019] Conditional deletion of Des1 in the mouse retina does not impair the visual cycle in cones. (2019). https://pubmed.ncbi.nlm.nih.gov/30645148/ DOI: 10.1096/fj.201802493r
    Complete structured claim and evidence

  4. Intravitreal adenovirus expressing human DES1 increased retinal 9-cis-retinal in Rpe65-null mice relative to the RFP control virus.

    Adenoviral DES1 expression → 9-cis-retinal source_derived_draftungraded
    Experimental context and source evidence
    availability_state
    machinery_impairment Imported condition classification; unverified.
    cross_nutrient
    false
    evidence_location
    Figure 4a; Results: Gene therapy of rpe65-null mice
    experimental_model
    Adenoviral human DES1 versus RFP in Rpe65-null mice
    exposure
    Retinoids measured one day after injection; Figure 4a without added intravitreal retinol.
    limitations
    11-cis-retinoids remained undetectable in this comparison; viral cell targeting was not exclusive.
    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
    Homo sapiens transgene in Mus musculus
    plain_language
    Extra DES1 increased an alternative cis-retinal isomer in the mutant eyes.
    primary_references
    [vav-kaylor2013] Identification of DES1 as a vitamin A isomerase in Müller glial cells of the retina. (2013). https://pubmed.ncbi.nlm.nih.gov/23143414/ DOI: 10.1038/nchembio.1114
    tissue_or_cell_type
    retina
    trigger_kind
    machinery_impairment Imported condition classification; unverified.

    Vitamin A expansion: reproduction, light-driven vision and shared mechanisms (2026-09-17) · lines 603–616

    AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Adenoviral human DES1 versus RFP in Rpe65-null mice · source_derived_draft · unverified_draft

    ### vae-des1-gene-transfer-9cis Intravitreal adenovirus expressing human DES1 increased retinal 9-cis-retinal in Rpe65-null mice relative to the RFP control virus. Condition category: machinery_impairment nutrient_topic: Vitamin A expansion research collection; topical membership is not evidence of a direct dietary effect. plain_language: Extra DES1 increased an alternative cis-retinal isomer in the mutant eyes. organism: Homo sapiens transgene in Mus musculus tissue_or_cell_type: retina experimental_model: Adenoviral human DES1 versus RFP in Rpe65-null mice limitations: 11-cis-retinoids remained undetectable in this comparison; viral cell targeting was not exclusive. exposure: Retinoids measured one day after injection; Figure 4a without added intravitreal retinol. cross_nutrient: false evidence_location: Figure 4a; Results: Gene therapy of rpe65-null mice nutrient: Vitamin A [vav-kaylor2013] Identification of DES1 as a vitamin A isomerase in Müller glial cells of the retina. (2013). https://pubmed.ncbi.nlm.nih.gov/23143414/ DOI: 10.1038/nchembio.1114
    Complete structured claim and evidence

  5. DES1-targeted siRNA reduced 11-cis-retinol formation from all-trans-retinol in homogenates of primary chicken Müller cultures compared with nonsilencing RNA.

    DES1 siRNA reduction → 11-cis-retinol source_derived_draftungraded
    Experimental context and source evidence
    availability_state
    machinery_impairment Imported condition classification; unverified.
    cross_nutrient
    false
    evidence_location
    Supplementary Figure 8; Results: RNAi knockdown
    experimental_model
    Targeted RNA interference with nonsilencing control
    exposure
    Approximately 50% DES1 expression reduction; retinol-substrate homogenate assay.
    limitations
    Neither complete gene deletion nor a physiological necessity test in an intact retina.
    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
    Gallus gallus
    plain_language
    Reducing DES1 lowered the culture preparation’s isomerase output.
    primary_references
    [vav-kaylor2013] Identification of DES1 as a vitamin A isomerase in Müller glial cells of the retina. (2013). https://pubmed.ncbi.nlm.nih.gov/23143414/ DOI: 10.1038/nchembio.1114
    tissue_or_cell_type
    primary Müller cultures
    trigger_kind
    machinery_impairment Imported condition classification; unverified.

    Vitamin A expansion: reproduction, light-driven vision and shared mechanisms (2026-09-17) · lines 588–601

    AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Targeted RNA interference with nonsilencing control · source_derived_draft · unverified_draft

    ### vae-des1-sirna-isomerization DES1-targeted siRNA reduced 11-cis-retinol formation from all-trans-retinol in homogenates of primary chicken Müller cultures compared with nonsilencing RNA. Condition category: machinery_impairment nutrient_topic: Vitamin A expansion research collection; topical membership is not evidence of a direct dietary effect. plain_language: Reducing DES1 lowered the culture preparation’s isomerase output. organism: Gallus gallus tissue_or_cell_type: primary Müller cultures experimental_model: Targeted RNA interference with nonsilencing control limitations: Neither complete gene deletion nor a physiological necessity test in an intact retina. exposure: Approximately 50% DES1 expression reduction; retinol-substrate homogenate assay. cross_nutrient: false evidence_location: Supplementary Figure 8; Results: RNAi knockdown nutrient: Vitamin A [vav-kaylor2013] Identification of DES1 as a vitamin A isomerase in Müller glial cells of the retina. (2013). https://pubmed.ncbi.nlm.nih.gov/23143414/ DOI: 10.1038/nchembio.1114
    Complete structured claim and evidence

In the sources

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