Component

Human lysosomal cystine transporter / CTNS

Context-specific entity; species, compartment and exposure are stated on each claim.

4 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. The human CTNS N288K variant altered conformation and suppressed engagement with Ragulator–Rag, linking transporter state with a nutrient-signaling complex.

    Human lysosomal cystine transporter / CTNS → Human Ragulator–Rag complex source_derived_draftungraded
    Experimental context and source evidence
    evidence_access
    Primary full text
    experimental_model
    Human cystinosin cryo-EM and interaction experiments.
    limitations
    This does not demonstrate that oral cysteine directly activates mTORC1.
    nutrient_topic
    L-Cysteine collection; species, compartment, exposure, co-substrates and manipulation remain explicit. · L-Cysteine
    plain_language
    Transport machinery can also affect how the cell senses nutrient availability.
    primary_references
    Structure and mechanism of human cystine exporter cystinosin. · 2022 · https://pubmed.ncbi.nlm.nih.gov/36113465/ · DOI 10.1016/j.cell.2022.08.020

    L-Cysteine: sulfur allocation, redox supply and cross-nutrient mechanisms (2026-09-19) · lines 52–58

    AI-assisted research curation; primary references, access levels and experimental limitations individually identified. Not publisher full text. · supports · Human cystinosin cryo-EM and interaction experiments. · source_derived_draft · unverified_draft

    ## l-cysteine-ctns-ragulator Transport machinery can also affect how the cell senses nutrient availability. The human CTNS N288K variant altered conformation and suppressed engagement with Ragulator–Rag, linking transporter state with a nutrient-signaling complex. Model: Human cystinosin cryo-EM and interaction experiments. Limitations: This does not demonstrate that oral cysteine directly activates mTORC1. Evidence access: Primary full text Structure and mechanism of human cystine exporter cystinosin. · 2022 · https://pubmed.ncbi.nlm.nih.gov/36113465/ · DOI 10.1016/j.cell.2022.08.020
    Complete structured claim and evidence

  2. Human cystinosin structures and functional assays support proton-coupled cystine export from the lysosomal lumen toward the cytosol.

    Human lysosomal cystine transporter / CTNS → Cystine source_derived_draftungraded
    Experimental context and source evidence
    evidence_access
    Primary full text
    experimental_model
    Human CTNS crystallography, cryo-EM, transport and spectroscopic assays.
    limitations
    Transport was assayed with engineered constructs; normal dietary intake does not bypass a defective lysosomal exporter.
    nutrient_topic
    L-Cysteine collection; species, compartment, exposure, co-substrates and manipulation remain explicit. · L-Cysteine
    plain_language
    Protein recycling supplies sulfur only if its breakdown products can leave the lysosome.
    primary_references
    Structure and mechanism of human cystine exporter cystinosin. · 2022 · https://pubmed.ncbi.nlm.nih.gov/36113465/ · DOI 10.1016/j.cell.2022.08.020
    transport_effect
    raises Recorded as proton-coupled export from the lysosomal lumen toward the cytosol. The lysosomal pool falls in the same step.
    transport_pool
    cytosolic cystine Recorded as proton-coupled export from the lysosomal lumen toward the cytosol. The lysosomal pool falls in the same step.

    L-Cysteine: sulfur allocation, redox supply and cross-nutrient mechanisms (2026-09-19) · lines 28–34

    AI-assisted research curation; primary references, access levels and experimental limitations individually identified. Not publisher full text. · supports · Human CTNS crystallography, cryo-EM, transport and spectroscopic assays. · source_derived_draft · unverified_draft

    ## l-cysteine-lysosomal-export Protein recycling supplies sulfur only if its breakdown products can leave the lysosome. Human cystinosin structures and functional assays support proton-coupled cystine export from the lysosomal lumen toward the cytosol. Model: Human CTNS crystallography, cryo-EM, transport and spectroscopic assays. Limitations: Transport was assayed with engineered constructs; normal dietary intake does not bypass a defective lysosomal exporter. Evidence access: Primary full text Structure and mechanism of human cystine exporter cystinosin. · 2022 · https://pubmed.ncbi.nlm.nih.gov/36113465/ · DOI 10.1016/j.cell.2022.08.020
    Complete structured claim and evidence

What acts on it

  1. Mutating human cystinosin K273, K280, D305, W138, N166 or F142 abolished cystine transport in the reported assays.

    Human CTNS substrate-binding mutations → Human lysosomal cystine transporter / CTNS source_derived_draftungraded
    Experimental context and source evidence
    availability_state
    machinery_impairment Imported condition classification; unverified.
    evidence_access
    Primary full text
    experimental_model
    Human CTNS site-directed mutagenesis and transport measurements.
    limitations
    Experimental mutations and disease-associated variants are not a dietary deficiency.
    nutrient_topic
    L-Cysteine collection; species, compartment, exposure, co-substrates and manipulation remain explicit. · L-Cysteine
    plain_language
    A correctly located transporter may still fail to recognize or move its substrate.
    primary_references
    Structure and mechanism of human cystine exporter cystinosin. · 2022 · https://pubmed.ncbi.nlm.nih.gov/36113465/ · DOI 10.1016/j.cell.2022.08.020
    trigger_kind
    machinery_impairment Imported condition classification; unverified.

    L-Cysteine: sulfur allocation, redox supply and cross-nutrient mechanisms (2026-09-19) · lines 36–42

    AI-assisted research curation; primary references, access levels and experimental limitations individually identified. Not publisher full text. · supports · Human CTNS site-directed mutagenesis and transport measurements. · source_derived_draft · unverified_draft

    ## l-cysteine-ctns-binding-residues A correctly located transporter may still fail to recognize or move its substrate. Mutating human cystinosin K273, K280, D305, W138, N166 or F142 abolished cystine transport in the reported assays. Model: Human CTNS site-directed mutagenesis and transport measurements. Limitations: Experimental mutations and disease-associated variants are not a dietary deficiency. Evidence access: Primary full text Structure and mechanism of human cystine exporter cystinosin. · 2022 · https://pubmed.ncbi.nlm.nih.gov/36113465/ · DOI 10.1016/j.cell.2022.08.020
    Complete structured claim and evidence

  2. D346N substitution abolished the pH-dependent conformational switch; the authors proposed D346 as a key protonation site controlling human cystinosin transitions.

    Proposed human CTNS D346 protonation switch → Human lysosomal cystine transporter / CTNS source_derived_draftungraded
    Experimental context and source evidence
    evidence_access
    Primary full text
    experimental_model
    Human CTNS mutagenesis and double electron–electron resonance spectroscopy at pH 5.2 and 7.4.
    limitations
    A structure-supported protonation model is not a demonstrated effect of changing dietary acid or mineral intake.
    nutrient_topic
    L-Cysteine collection; species, compartment, exposure, co-substrates and manipulation remain explicit. · L-Cysteine
    plain_language
    The transporter couples substrate movement to an acidic compartment.
    primary_references
    Structure and mechanism of human cystine exporter cystinosin. · 2022 · https://pubmed.ncbi.nlm.nih.gov/36113465/ · DOI 10.1016/j.cell.2022.08.020

    L-Cysteine: sulfur allocation, redox supply and cross-nutrient mechanisms (2026-09-19) · lines 44–50

    AI-assisted research curation; primary references, access levels and experimental limitations individually identified. Not publisher full text. · supports · Human CTNS mutagenesis and double electron–electron resonance spectroscopy at pH 5.2 and 7.4. · source_derived_draft · unverified_draft

    ## l-cysteine-ctns-proton-switch The transporter couples substrate movement to an acidic compartment. D346N substitution abolished the pH-dependent conformational switch; the authors proposed D346 as a key protonation site controlling human cystinosin transitions. Model: Human CTNS mutagenesis and double electron–electron resonance spectroscopy at pH 5.2 and 7.4. Limitations: A structure-supported protonation model is not a demonstrated effect of changing dietary acid or mineral intake. Evidence access: Primary full text Structure and mechanism of human cystine exporter cystinosin. · 2022 · https://pubmed.ncbi.nlm.nih.gov/36113465/ · DOI 10.1016/j.cell.2022.08.020
    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.

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