Component

Mitochondrial tRNA 5-taurinomethyluridine / tau-m5U34

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

10 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 acts on it

  1. Isotope tracing supported the beta-carbon of serine entering the methylene group of mitochondrial taurine-modified uridine through 5,10-methylene-THF.

    5,10-Methylenetetrahydrofolate → Mitochondrial tRNA 5-taurinomethyluridine / tau-m5U34 source_derived_draftungraded
    Experimental context and source evidence
    evidence_access
    Primary full text, Figure 1 and metabolic-labeling experiments
    experimental_model
    Human HeLa metabolic labeling plus biochemical reconstitution.
    limitations
    A folate connection is not evidence for a benefit from folic acid supplementation in replete people.
    nutrient_topic
    Taurine collection; molecular form, preparation, species, exposure and manipulation remain explicit. · Taurine
    plain_language
    Folate chemistry contributes part of the RNA mark; taurine supplies a different part.
    primary_references
    Metabolic and chemical regulation of tRNA modification associated with taurine deficiency and human disease. · 2018 · https://pubmed.ncbi.nlm.nih.gov/29390138/ · DOI 10.1093/nar/gky068

    Taurine: synthesis, transport, mitochondrial decoding and nutrient interactions (2026-09-19) · lines 209–215

    AI-assisted research curation; primary-abstract references and experimental limitations individually identified. Not publisher full text. · supports · Human HeLa metabolic labeling plus biochemical reconstitution. · source_derived_draft · unverified_draft

    ## taurine-folate-carbon-donor Folate chemistry contributes part of the RNA mark; taurine supplies a different part. Isotope tracing supported the beta-carbon of serine entering the methylene group of mitochondrial taurine-modified uridine through 5,10-methylene-THF. Model: Human HeLa metabolic labeling plus biochemical reconstitution. Limitations: A folate connection is not evidence for a benefit from folic acid supplementation in replete people. Evidence access: Primary full text, Figure 1 and metabolic-labeling experiments Metabolic and chemical regulation of tRNA modification associated with taurine deficiency and human disease. · 2018 · https://pubmed.ncbi.nlm.nih.gov/29390138/ · DOI 10.1093/nar/gky068
    Complete structured claim and evidence

  2. Mitochondrial folate-transporter-mutant CHO cells showed reduced taurine modification of mitochondrial tRNA.

    Chinese hamster mitochondrial folate transporter / Slc25a32 → Mitochondrial tRNA 5-taurinomethyluridine / tau-m5U34 source_derived_draftungraded
    Experimental context and source evidence
    availability_state
    machinery_impairment Imported condition classification; unverified.
    evidence_access
    Primary full text, Figure 1F
    experimental_model
    Chinese hamster ovary Mft mutant cells.
    limitations
    Compartment-specific transport failure is different from low total blood folate.
    nutrient_topic
    Taurine collection; molecular form, preparation, species, exposure and manipulation remain explicit. · Taurine
    plain_language
    Getting folate into the mitochondrial compartment matters.
    primary_references
    Metabolic and chemical regulation of tRNA modification associated with taurine deficiency and human disease. · 2018 · https://pubmed.ncbi.nlm.nih.gov/29390138/ · DOI 10.1093/nar/gky068
    trigger_kind
    machinery_impairment Imported condition classification; unverified.

    Taurine: synthesis, transport, mitochondrial decoding and nutrient interactions (2026-09-19) · lines 225–231

    AI-assisted research curation; primary-abstract references and experimental limitations individually identified. Not publisher full text. · supports · Chinese hamster ovary Mft mutant cells. · source_derived_draft · unverified_draft

    ## taurine-folate-carrier-mutation Getting folate into the mitochondrial compartment matters. Mitochondrial folate-transporter-mutant CHO cells showed reduced taurine modification of mitochondrial tRNA. Model: Chinese hamster ovary Mft mutant cells. Limitations: Compartment-specific transport failure is different from low total blood folate. Evidence access: Primary full text, Figure 1F Metabolic and chemical regulation of tRNA modification associated with taurine deficiency and human disease. · 2018 · https://pubmed.ncbi.nlm.nih.gov/29390138/ · DOI 10.1093/nar/gky068
    Complete structured claim and evidence

  3. Five patients in the ten-person MELAS trial showed a significant increase in leukocyte mitochondrial tRNA-Leu(UUR) taurine modification after high-dose taurine treatment.

    Taurine → Mitochondrial tRNA 5-taurinomethyluridine / tau-m5U34 source_derived_draftungraded
    Experimental context and source evidence
    availability_state
    machinery_impairment Imported condition classification; unverified.
    evidence_access
    Primary abstract
    experimental_model
    Open-label 52-week study; 9 or 12 g/day under clinical supervision.
    limitations
    Five molecular responders among ten patients; leukocyte measurements are not direct brain-tissue measurements.
    nutrient_topic
    Taurine collection; molecular form, preparation, species, exposure and manipulation remain explicit. · Taurine
    plain_language
    A molecular response was measurable in a specific mitochondrial disease.
    primary_references
    Taurine supplementation for prevention of stroke-like episodes in MELAS: a multicentre, open-label, 52-week phase III trial. · 2019 · https://pubmed.ncbi.nlm.nih.gov/29666206/ · DOI 10.1136/jnnp-2018-317964
    trigger_kind
    machinery_impairment Imported condition classification; unverified.

    Taurine: synthesis, transport, mitochondrial decoding and nutrient interactions (2026-09-19) · lines 281–287

    AI-assisted research curation; primary-abstract references and experimental limitations individually identified. Not publisher full text. · supports · Open-label 52-week study; 9 or 12 g/day under clinical supervision. · source_derived_draft · unverified_draft

    ## taurine-melas-rna-response A molecular response was measurable in a specific mitochondrial disease. Five patients in the ten-person MELAS trial showed a significant increase in leukocyte mitochondrial tRNA-Leu(UUR) taurine modification after high-dose taurine treatment. Model: Open-label 52-week study; 9 or 12 g/day under clinical supervision. Limitations: Five molecular responders among ten patients; leukocyte measurements are not direct brain-tissue measurements. Evidence access: Primary abstract Taurine supplementation for prevention of stroke-like episodes in MELAS: a multicentre, open-label, 52-week phase III trial. · 2019 · https://pubmed.ncbi.nlm.nih.gov/29666206/ · DOI 10.1136/jnnp-2018-317964
    Complete structured claim and evidence

  4. Reconstituting the human MTO1-GTPBP3 complex with hypomodified mitochondrial tRNA, taurine and 5,10-methylene-THF produced the taurine-containing U34 modification.

    Human mitochondrial tRNA modification protein / MTO1 → Mitochondrial tRNA 5-taurinomethyluridine / tau-m5U34 source_derived_draftungraded
    Experimental context and source evidence
    evidence_access
    Primary full text, in-vitro reconstitution methods and results
    experimental_model
    Human enzyme-complex reconstitution and mass spectrometry.
    limitations
    The reaction mixture also contained GTP, ATP, FAD, NADH, NADPH and magnesium; their presence alone does not demonstrate each is individually limiting.
    nutrient_topic
    Taurine collection; molecular form, preparation, species, exposure and manipulation remain explicit. · Taurine
    plain_language
    Two proteins join taurine and a folate-derived carbon unit onto mitochondrial tRNA.
    primary_references
    Metabolic and chemical regulation of tRNA modification associated with taurine deficiency and human disease. · 2018 · https://pubmed.ncbi.nlm.nih.gov/29390138/ · DOI 10.1093/nar/gky068

    Taurine: synthesis, transport, mitochondrial decoding and nutrient interactions (2026-09-19) · lines 201–207

    AI-assisted research curation; primary-abstract references and experimental limitations individually identified. Not publisher full text. · supports · Human enzyme-complex reconstitution and mass spectrometry. · source_derived_draft · unverified_draft

    ## taurine-mto1-gtpbp3 Two proteins join taurine and a folate-derived carbon unit onto mitochondrial tRNA. Reconstituting the human MTO1-GTPBP3 complex with hypomodified mitochondrial tRNA, taurine and 5,10-methylene-THF produced the taurine-containing U34 modification. Model: Human enzyme-complex reconstitution and mass spectrometry. Limitations: The reaction mixture also contained GTP, ATP, FAD, NADH, NADPH and magnesium; their presence alone does not demonstrate each is individually limiting. Evidence access: Primary full text, in-vitro reconstitution methods and results Metabolic and chemical regulation of tRNA modification associated with taurine deficiency and human disease. · 2018 · https://pubmed.ncbi.nlm.nih.gov/29390138/ · DOI 10.1093/nar/gky068
    Complete structured claim and evidence

  5. Shmt2-mutant Chinese hamster ovary cells showed reduced mitochondrial tRNA taurine modification compared with wild type.

    Chinese hamster mitochondrial serine hydroxymethyltransferase / Shmt2 → Mitochondrial tRNA 5-taurinomethyluridine / tau-m5U34 source_derived_draftungraded
    Experimental context and source evidence
    availability_state
    machinery_impairment Imported condition classification; unverified.
    evidence_access
    Primary full text, Figure 1F
    experimental_model
    CHO mutant-cell mass spectrometry.
    limitations
    This species-specific machinery defect is not a B6 or folate deprivation experiment.
    nutrient_topic
    Taurine collection; molecular form, preparation, species, exposure and manipulation remain explicit. · Taurine
    plain_language
    One-carbon supply can affect the same RNA mark even when the taurine molecule is present.
    primary_references
    Metabolic and chemical regulation of tRNA modification associated with taurine deficiency and human disease. · 2018 · https://pubmed.ncbi.nlm.nih.gov/29390138/ · DOI 10.1093/nar/gky068
    trigger_kind
    machinery_impairment Imported condition classification; unverified.

    Taurine: synthesis, transport, mitochondrial decoding and nutrient interactions (2026-09-19) · lines 217–223

    AI-assisted research curation; primary-abstract references and experimental limitations individually identified. Not publisher full text. · supports · CHO mutant-cell mass spectrometry. · source_derived_draft · unverified_draft

    ## taurine-shmt2-mutation One-carbon supply can affect the same RNA mark even when the taurine molecule is present. Shmt2-mutant Chinese hamster ovary cells showed reduced mitochondrial tRNA taurine modification compared with wild type. Model: CHO mutant-cell mass spectrometry. Limitations: This species-specific machinery defect is not a B6 or folate deprivation experiment. Evidence access: Primary full text, Figure 1F Metabolic and chemical regulation of tRNA modification associated with taurine deficiency and human disease. · 2018 · https://pubmed.ncbi.nlm.nih.gov/29390138/ · DOI 10.1093/nar/gky068
    Complete structured claim and evidence

  6. Taurine starvation reduced mitochondrial tRNA taurine modification in cultured cells, with corresponding dietary-depletion observations in cat liver and flatfish tissues.

    Taurine → Mitochondrial tRNA 5-taurinomethyluridine / tau-m5U34 source_derived_draftungraded
    Experimental context and source evidence
    availability_state
    nutrient_deficiency Imported condition classification; unverified.
    evidence_access
    Primary abstract
    experimental_model
    Cultured-cell and dietary animal experiments.
    limitations
    Cats and flatfish differ from adult humans in endogenous taurine synthesis; no universal human plasma threshold was determined.
    nutrient_topic
    Taurine collection; molecular form, preparation, species, exposure and manipulation remain explicit. · Taurine
    plain_language
    Insufficient taurine can leave fewer tRNAs carrying the normal mark.
    primary_references
    Metabolic and chemical regulation of tRNA modification associated with taurine deficiency and human disease. · 2018 · https://pubmed.ncbi.nlm.nih.gov/29390138/ · DOI 10.1093/nar/gky068
    trigger_kind
    nutrient_deficiency Imported condition classification; unverified.

    Taurine: synthesis, transport, mitochondrial decoding and nutrient interactions (2026-09-19) · lines 233–239

    AI-assisted research curation; primary-abstract references and experimental limitations individually identified. Not publisher full text. · supports · Cultured-cell and dietary animal experiments. · source_derived_draft · unverified_draft

    ## taurine-taurine-starvation-rna Insufficient taurine can leave fewer tRNAs carrying the normal mark. Taurine starvation reduced mitochondrial tRNA taurine modification in cultured cells, with corresponding dietary-depletion observations in cat liver and flatfish tissues. Model: Cultured-cell and dietary animal experiments. Limitations: Cats and flatfish differ from adult humans in endogenous taurine synthesis; no universal human plasma threshold was determined. Evidence access: Primary abstract Metabolic and chemical regulation of tRNA modification associated with taurine deficiency and human disease. · 2018 · https://pubmed.ncbi.nlm.nih.gov/29390138/ · DOI 10.1093/nar/gky068
    Complete structured claim and evidence

Where it participates (unsigned role)

  1. Taurine-depleted cultured cells accumulated mitochondrial tRNA cmnm5U, whose glycine-derived group replaces the taurine-derived group of tau-m5U.

    Glycine → Mitochondrial tRNA 5-carboxymethylaminomethyluridine / cmnm5U34 source_derived_draftungraded
    Experimental context and source evidence
    availability_state
    nutrient_deficiency Imported condition classification; unverified.
    evidence_access
    Primary abstract
    experimental_model
    Mass spectrometry of mitochondrial tRNAs from depleted cells.
    limitations
    Detection of an alternative mark does not establish complete functional rescue by glycine.
    nutrient_topic
    Taurine collection; molecular form, preparation, species, exposure and manipulation remain explicit. · Taurine
    plain_language
    Low taurine changed the chemical identity of the RNA modification.
    primary_references
    Metabolic and chemical regulation of tRNA modification associated with taurine deficiency and human disease. · 2018 · https://pubmed.ncbi.nlm.nih.gov/29390138/ · DOI 10.1093/nar/gky068
    trigger_kind
    nutrient_deficiency Imported condition classification; unverified.

    Taurine: synthesis, transport, mitochondrial decoding and nutrient interactions (2026-09-19) · lines 241–247

    AI-assisted research curation; primary-abstract references and experimental limitations individually identified. Not publisher full text. · supports · Mass spectrometry of mitochondrial tRNAs from depleted cells. · source_derived_draft · unverified_draft

    ## taurine-glycine-substitution Low taurine changed the chemical identity of the RNA modification. Taurine-depleted cultured cells accumulated mitochondrial tRNA cmnm5U, whose glycine-derived group replaces the taurine-derived group of tau-m5U. Model: Mass spectrometry of mitochondrial tRNAs from depleted cells. Limitations: Detection of an alternative mark does not establish complete functional rescue by glycine. Evidence access: Primary abstract Metabolic and chemical regulation of tRNA modification associated with taurine deficiency and human disease. · 2018 · https://pubmed.ncbi.nlm.nih.gov/29390138/ · DOI 10.1093/nar/gky068
    Complete structured claim and evidence

  2. Deleting GTPBP3 in human cells eliminated the normal taurine-containing wobble modification and reduced mitochondrial translation.

    Human mitochondrial GTP-binding protein 3 / GTPBP3 → Mitochondrial translation in human GTPBP3-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 GTPBP3-knockout cultured cells.
    limitations
    Adding substrate cannot be assumed to substitute for an absent enzyme.
    nutrient_topic
    Taurine collection; molecular form, preparation, species, exposure and manipulation remain explicit. · Taurine
    plain_language
    Removing the modifying machinery impaired mitochondrial protein production.
    primary_references
    Metabolic and chemical regulation of tRNA modification associated with taurine deficiency and human disease. · 2018 · https://pubmed.ncbi.nlm.nih.gov/29390138/ · DOI 10.1093/nar/gky068
    trigger_kind
    machinery_impairment Imported condition classification; unverified.

    Taurine: synthesis, transport, mitochondrial decoding and nutrient interactions (2026-09-19) · lines 249–255

    AI-assisted research curation; primary-abstract references and experimental limitations individually identified. Not publisher full text. · supports · Human GTPBP3-knockout cultured cells. · source_derived_draft · unverified_draft

    ## taurine-gtpbp3-translation Removing the modifying machinery impaired mitochondrial protein production. Deleting GTPBP3 in human cells eliminated the normal taurine-containing wobble modification and reduced mitochondrial translation. Model: Human GTPBP3-knockout cultured cells. Limitations: Adding substrate cannot be assumed to substitute for an absent enzyme. Evidence access: Primary abstract Metabolic and chemical regulation of tRNA modification associated with taurine deficiency and human disease. · 2018 · https://pubmed.ncbi.nlm.nih.gov/29390138/ · DOI 10.1093/nar/gky068
    Complete structured claim and evidence

  3. Mto1-deficient experimental cells and mice showed defective mitochondrial translation with mistargeting and aggregation of nuclear-encoded mitochondrial proteins; chemical chaperones reduced cytotoxicity.

    Mouse mitochondrial tRNA modification protein / Mto1 → Cytoplasmic proteostress following Mto1 loss in mouse models source_derived_draftungraded
    Experimental context and source evidence
    availability_state
    machinery_impairment Imported condition classification; unverified.
    evidence_access
    Primary abstract
    experimental_model
    Mto1 deficiency in experimental cells and mice.
    limitations
    The rescue used chemical chaperones, not proof that taurine treats absent Mto1.
    nutrient_topic
    Taurine collection; molecular form, preparation, species, exposure and manipulation remain explicit. · Taurine
    plain_language
    Failure of mitochondrial translation can disturb protein handling beyond mitochondria.
    primary_references
    Defective Mitochondrial tRNA Taurine Modification Activates Global Proteostress and Leads to Mitochondrial Disease. · 2018 · https://pubmed.ncbi.nlm.nih.gov/29320742/ · DOI 10.1016/j.celrep.2017.12.051
    trigger_kind
    machinery_impairment Imported condition classification; unverified.

    Taurine: synthesis, transport, mitochondrial decoding and nutrient interactions (2026-09-19) · lines 273–279

    AI-assisted research curation; primary-abstract references and experimental limitations individually identified. Not publisher full text. · supports · Mto1 deficiency in experimental cells and mice. · source_derived_draft · unverified_draft

    ## taurine-mto1-proteostress Failure of mitochondrial translation can disturb protein handling beyond mitochondria. Mto1-deficient experimental cells and mice showed defective mitochondrial translation with mistargeting and aggregation of nuclear-encoded mitochondrial proteins; chemical chaperones reduced cytotoxicity. Model: Mto1 deficiency in experimental cells and mice. Limitations: The rescue used chemical chaperones, not proof that taurine treats absent Mto1. Evidence access: Primary abstract Defective Mitochondrial tRNA Taurine Modification Activates Global Proteostress and Leads to Mitochondrial Disease. · 2018 · https://pubmed.ncbi.nlm.nih.gov/29320742/ · DOI 10.1016/j.celrep.2017.12.051
    Complete structured claim and evidence

  4. Catalytic SHMT2 loss in human cells impaired mitochondrial tRNA modification and caused preferential ribosome stalling at AAG lysine and UUG leucine codons.

    SHMT2 → Human mitochondrial translation at lysine and leucine codons source_derived_draftungraded
    Experimental context and source evidence
    availability_state
    machinery_impairment Imported condition classification; unverified.
    evidence_access
    Primary abstract
    experimental_model
    Human SHMT2 knockout and mitochondrial ribosome profiling.
    limitations
    The methyl-donor route was mechanistically inferred alongside measured modification and translation defects.
    nutrient_topic
    L-Serine collection; species, compartment, exposure, co-substrates and manipulation remain explicit. · L-Serine
    plain_language
    Serine-linked folate chemistry helps mitochondria read particular codons.
    primary_references
    Mitochondrial translation requires folate-dependent tRNA methylation. · 2018 · https://pubmed.ncbi.nlm.nih.gov/29364879/ · DOI 10.1038/nature25460
    trigger_kind
    machinery_impairment Imported condition classification; unverified.

    L-Serine: synthesis, one-carbon metabolism, lipids and cross-nutrient mechanisms (2026-09-19) · lines 174–180

    AI-assisted research curation; primary references, access levels and experimental limitations individually identified. Not publisher full text. · supports · Human SHMT2 knockout and mitochondrial ribosome profiling. · source_derived_draft · unverified_draft

    ## l-serine-shmt2-translation Serine-linked folate chemistry helps mitochondria read particular codons. Catalytic SHMT2 loss in human cells impaired mitochondrial tRNA modification and caused preferential ribosome stalling at AAG lysine and UUG leucine codons. Model: Human SHMT2 knockout and mitochondrial ribosome profiling. Limitations: The methyl-donor route was mechanistically inferred alongside measured modification and translation defects. Evidence access: Primary abstract Mitochondrial translation requires folate-dependent tRNA methylation. · 2018 · https://pubmed.ncbi.nlm.nih.gov/29364879/ · DOI 10.1038/nature25460
    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