Component

Human sideroflexin 1 / SFXN1

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. Purified SFXN1 transported serine in vitro, and human-cell genetic experiments identified it as an inner-mitochondrial-membrane serine transporter.

    Human sideroflexin 1 / SFXN1 → L-Serine source_derived_draftungraded
    Experimental context and source evidence
    evidence_access
    Primary abstract
    experimental_model
    Human CRISPR screens, localization and purified-protein transport experiments.
    limitations
    This does not imply SFXN1 is the only transporter or that all cellular serine is mitochondrial.
    nutrient_topic
    L-Serine collection; species, compartment, exposure, co-substrates and manipulation remain explicit. · L-Serine
    plain_language
    Serine must cross a compartment boundary before mitochondrial enzymes can use it.
    primary_references
    SFXN1 is a mitochondrial serine transporter required for one-carbon metabolism. · 2018 · https://pubmed.ncbi.nlm.nih.gov/30442778/ · DOI 10.1126/science.aat9528
    transport_effect
    raises Identified as an inner-mitochondrial-membrane serine importer.
    transport_pool
    the mitochondrial matrix Identified as an inner-mitochondrial-membrane serine importer.

    L-Serine: synthesis, one-carbon metabolism, lipids and cross-nutrient mechanisms (2026-09-19) · lines 142–148

    AI-assisted research curation; primary references, access levels and experimental limitations individually identified. Not publisher full text. · supports · Human CRISPR screens, localization and purified-protein transport experiments. · source_derived_draft · unverified_draft

    ## l-serine-sfxn1-import Serine must cross a compartment boundary before mitochondrial enzymes can use it. Purified SFXN1 transported serine in vitro, and human-cell genetic experiments identified it as an inner-mitochondrial-membrane serine transporter. Model: Human CRISPR screens, localization and purified-protein transport experiments. Limitations: This does not imply SFXN1 is the only transporter or that all cellular serine is mitochondrial. Evidence access: Primary abstract SFXN1 is a mitochondrial serine transporter required for one-carbon metabolism. · 2018 · https://pubmed.ncbi.nlm.nih.gov/30442778/ · DOI 10.1126/science.aat9528
    Complete structured claim and evidence

  2. SFXN1-null human cells had impaired glycine and purine synthesis; loss of both SFXN1 and SFXN3 caused stronger defects, including dependence on exogenous glycine.

    Human sideroflexin 1 / SFXN1 → Glycine and purine synthesis in human SFXN1-deficient cells source_derived_draftungraded
    Experimental context and source evidence
    availability_state
    machinery_impairment Imported condition classification; unverified.
    evidence_access
    Primary abstract
    experimental_model
    Human cell single and double knockout comparisons.
    limitations
    Related transporters provide redundancy; this is not a demonstrated dietary serine deficiency.
    nutrient_topic
    L-Serine collection; species, compartment, exposure, co-substrates and manipulation remain explicit. · L-Serine
    plain_language
    Transport capacity can limit another amino acid and nucleotide production.
    primary_references
    SFXN1 is a mitochondrial serine transporter required for one-carbon metabolism. · 2018 · https://pubmed.ncbi.nlm.nih.gov/30442778/ · DOI 10.1126/science.aat9528
    trigger_kind
    machinery_impairment Imported condition classification; unverified.

    L-Serine: synthesis, one-carbon metabolism, lipids and cross-nutrient mechanisms (2026-09-19) · lines 150–156

    AI-assisted research curation; primary references, access levels and experimental limitations individually identified. Not publisher full text. · supports · Human cell single and double knockout comparisons. · source_derived_draft · unverified_draft

    ## l-serine-sfxn1-loss Transport capacity can limit another amino acid and nucleotide production. SFXN1-null human cells had impaired glycine and purine synthesis; loss of both SFXN1 and SFXN3 caused stronger defects, including dependence on exogenous glycine. Model: Human cell single and double knockout comparisons. Limitations: Related transporters provide redundancy; this is not a demonstrated dietary serine deficiency. Evidence access: Primary abstract SFXN1 is a mitochondrial serine transporter required for one-carbon metabolism. · 2018 · https://pubmed.ncbi.nlm.nih.gov/30442778/ · DOI 10.1126/science.aat9528
    Complete structured claim and evidence

  3. The study attributed SFXN1-dependent complex III support to heme and 2-oxoglutarate metabolism rather than to its one-carbon-metabolism role alone.

    Human sideroflexin 1 / SFXN1 → Heme and 2-oxoglutarate support of SFXN1-dependent complex III function source_derived_draftungraded
    Experimental context and source evidence
    availability_state
    machinery_impairment Imported condition classification; unverified.
    evidence_access
    Primary abstract
    experimental_model
    Human cell metabolic and respiratory-chain experiments.
    limitations
    This does not reduce all SFXN1 phenotypes to one folate bottleneck.
    nutrient_topic
    L-Serine collection; species, compartment, exposure, co-substrates and manipulation remain explicit. · L-Serine
    plain_language
    Two effects of the same transporter can run through different downstream routes.
    primary_references
    The mitochondrial carrier SFXN1 is critical for complex III integrity and cellular metabolism. · 2021 · https://pubmed.ncbi.nlm.nih.gov/33730581/ · DOI 10.1016/j.celrep.2021.108869
    trigger_kind
    machinery_impairment Imported condition classification; unverified.

    L-Serine: synthesis, one-carbon metabolism, lipids and cross-nutrient mechanisms (2026-09-19) · lines 166–172

    AI-assisted research curation; primary references, access levels and experimental limitations individually identified. Not publisher full text. · supports · Human cell metabolic and respiratory-chain experiments. · source_derived_draft · unverified_draft

    ## l-serine-sfxn1-rescue-boundary Two effects of the same transporter can run through different downstream routes. The study attributed SFXN1-dependent complex III support to heme and 2-oxoglutarate metabolism rather than to its one-carbon-metabolism role alone. Model: Human cell metabolic and respiratory-chain experiments. Limitations: This does not reduce all SFXN1 phenotypes to one folate bottleneck. Evidence access: Primary abstract The mitochondrial carrier SFXN1 is critical for complex III integrity and cellular metabolism. · 2021 · https://pubmed.ncbi.nlm.nih.gov/33730581/ · DOI 10.1016/j.celrep.2021.108869
    Complete structured claim and evidence

  4. SFXN1 deficiency impaired complex III biogenesis, assembly and activity and compromised coenzyme Q levels.

    Human sideroflexin 1 / SFXN1 → Human mitochondrial complex III integrity source_derived_draftungraded
    Experimental context and source evidence
    availability_state
    machinery_impairment Imported condition classification; unverified.
    evidence_access
    Primary abstract
    experimental_model
    Human cultured-cell mitochondrial carrier characterization.
    limitations
    This is a transporter-loss experiment, not evidence that serine supplements raise CoQ.
    nutrient_topic
    L-Serine collection; species, compartment, exposure, co-substrates and manipulation remain explicit. · L-Serine
    plain_language
    A transport defect can affect the respiratory chain as well as one-carbon metabolism.
    primary_references
    The mitochondrial carrier SFXN1 is critical for complex III integrity and cellular metabolism. · 2021 · https://pubmed.ncbi.nlm.nih.gov/33730581/ · DOI 10.1016/j.celrep.2021.108869
    trigger_kind
    machinery_impairment Imported condition classification; unverified.

    L-Serine: synthesis, one-carbon metabolism, lipids and cross-nutrient mechanisms (2026-09-19) · lines 158–164

    AI-assisted research curation; primary references, access levels and experimental limitations individually identified. Not publisher full text. · supports · Human cultured-cell mitochondrial carrier characterization. · source_derived_draft · unverified_draft

    ## l-serine-sfxn1-respiration A transport defect can affect the respiratory chain as well as one-carbon metabolism. SFXN1 deficiency impaired complex III biogenesis, assembly and activity and compromised coenzyme Q levels. Model: Human cultured-cell mitochondrial carrier characterization. Limitations: This is a transporter-loss experiment, not evidence that serine supplements raise CoQ. Evidence access: Primary abstract The mitochondrial carrier SFXN1 is critical for complex III integrity and cellular metabolism. · 2021 · https://pubmed.ncbi.nlm.nih.gov/33730581/ · DOI 10.1016/j.celrep.2021.108869
    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