Component
Human methenyltetrahydrofolate synthetase / MTHFS
Human ATP-dependent 5-formyltetrahydrofolate cyclo-ligase.
3 recorded relationships. Experimental role, claim status and evidence remain attached to each record.
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.
Other things that act on it
Enzymes, hormones, genes, and other components with a recorded effect. These are not nutrients, so they do not count toward the arrows above. Each finding names the chapter that recorded it.
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.
What it acts on
Purified human liver MTHFS converts 5-formyl-THF into 5,10-methenyl-THF.
Experimental context and source evidence
- experimental_model
- Purified liver enzyme
- exposure
- Purified human liver enzyme and folate substrates; initial-velocity measurements.
- limitations
- An enzyme assay does not establish clinical benefit from folinic acid.
- nutrient_topic
- Folate and folic acid research collection; topical membership is not evidence of a direct dietary effect. · Folate (vitamin B9)
- organism
- Homo sapiens
- plain_language
- This enzyme moves folinic acid into the methenyl-folate pool.
- primary_references
- [bertrand-1987] Human liver methenyltetrahydrofolate synthetase: improved purification and increased affinity for folate polyglutamate substrates (1987). https://pubmed.ncbi.nlm.nih.gov/3801490/ DOI: 10.1016/0167-4838(87)90004-5
- tissue_or_cell_type
- Liver-derived, cell-free
Folate and folic acid: mechanisms, deficiency and nutrient interactions (2026-09-17) · lines 1243–1253
AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Purified liver enzyme · source_derived_draft · unverified_draft
### mthfs-folinic-acid-conversion Purified human liver MTHFS converts 5-formyl-THF into 5,10-methenyl-THF. Condition category: normal nutrient_topic: Folate and folic acid research collection; topical membership is not evidence of a direct dietary effect. plain_language: This enzyme moves folinic acid into the methenyl-folate pool. organism: Homo sapiens tissue_or_cell_type: Liver-derived, cell-free experimental_model: Purified liver enzyme limitations: An enzyme assay does not establish clinical benefit from folinic acid. exposure: Purified human liver enzyme and folate substrates; initial-velocity measurements. [bertrand-1987] Human liver methenyltetrahydrofolate synthetase: improved purification and increased affinity for folate polyglutamate substrates (1987). https://pubmed.ncbi.nlm.nih.gov/3801490/ DOI: 10.1016/0167-4838(87)90004-5
Complete structured claim and evidence
What acts on it
The purified human liver MTHFS reaction requires ATP and Mg2+ and is an ADP-forming cyclo-ligase reaction.
Experimental context and source evidence
- cross_nutrient
- Magnesium and ATP support folate interconversion.
- experimental_model
- Purified liver enzyme
- exposure
- Controlled enzyme assay with ATP and magnesium.
- limitations
- Cofactor dependence does not establish a dietary magnesium threshold.
- nutrient_topic
- Folate and folic acid research collection; topical membership is not evidence of a direct dietary effect. · Folate (vitamin B9)
- organism
- Homo sapiens
- plain_language
- ATP supplies energy for this magnesium-dependent folate conversion.
- primary_references
- [bertrand-1987] Human liver methenyltetrahydrofolate synthetase: improved purification and increased affinity for folate polyglutamate substrates (1987). https://pubmed.ncbi.nlm.nih.gov/3801490/ DOI: 10.1016/0167-4838(87)90004-5
- tissue_or_cell_type
- Liver-derived, cell-free
Folate and folic acid: mechanisms, deficiency and nutrient interactions (2026-09-17) · lines 1255–1266
AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Purified liver enzyme · source_derived_draft · unverified_draft
### mthfs-atp-magnesium-dependence The purified human liver MTHFS reaction requires ATP and Mg2+ and is an ADP-forming cyclo-ligase reaction. Condition category: normal nutrient_topic: Folate and folic acid research collection; topical membership is not evidence of a direct dietary effect. plain_language: ATP supplies energy for this magnesium-dependent folate conversion. organism: Homo sapiens tissue_or_cell_type: Liver-derived, cell-free experimental_model: Purified liver enzyme limitations: Cofactor dependence does not establish a dietary magnesium threshold. exposure: Controlled enzyme assay with ATP and magnesium. cross_nutrient: Magnesium and ATP support folate interconversion. [bertrand-1987] Human liver methenyltetrahydrofolate synthetase: improved purification and increased affinity for folate polyglutamate substrates (1987). https://pubmed.ncbi.nlm.nih.gov/3801490/ DOI: 10.1016/0167-4838(87)90004-5
Complete structured claim and evidencePatient 1 fibroblast lysate had no detectable MTHFS activity in the reported product-formation assay.
Experimental context and source evidence
- availability_state
- machinery_impairment Imported condition classification; unverified.
- evidence_location
- Results 3.3 and Figure 4.
- experimental_model
- Fibroblast lysate enzyme assay
- exposure
- Lysate enzyme assay versus control; Figure 4.
- limitations
- Assay-specific nondetection does not prove zero activity in every tissue or separate the two alleles.
- nutrient_topic
- Folate and folic acid research collection; topical membership is not evidence of a direct dietary effect. · Folate (vitamin B9)
- organism
- Homo sapiens
- plain_language
- These patient cells could not measurably perform the tested folate conversion.
- primary_references
- [rodan-2018] 5,10-methenyltetrahydrofolate synthetase deficiency causes a neurometabolic disorder associated with microcephaly, epilepsy, and cerebral hypomyelination (2018). https://pubmed.ncbi.nlm.nih.gov/30031689/ DOI: 10.1016/j.ymgme.2018.06.006
- tissue_or_cell_type
- Patient 1 skin fibroblasts
- trigger_kind
- machinery_impairment Imported condition classification; unverified.
Folate and folic acid: mechanisms, deficiency and nutrient interactions (2026-09-17) · lines 1268–1279
AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Fibroblast lysate enzyme assay · source_derived_draft · unverified_draft
### mthfs-patient1-enzyme-activity Patient 1 fibroblast lysate had no detectable MTHFS activity in the reported product-formation assay. Condition category: machinery_impairment nutrient_topic: Folate and folic acid research collection; topical membership is not evidence of a direct dietary effect. plain_language: These patient cells could not measurably perform the tested folate conversion. organism: Homo sapiens tissue_or_cell_type: Patient 1 skin fibroblasts experimental_model: Fibroblast lysate enzyme assay limitations: Assay-specific nondetection does not prove zero activity in every tissue or separate the two alleles. exposure: Lysate enzyme assay versus control; Figure 4. evidence_location: Results 3.3 and Figure 4. [rodan-2018] 5,10-methenyltetrahydrofolate synthetase deficiency causes a neurometabolic disorder associated with microcephaly, epilepsy, and cerebral hypomyelination (2018). https://pubmed.ncbi.nlm.nih.gov/30031689/ DOI: 10.1016/j.ymgme.2018.06.006
Complete structured claim and evidence
The events it takes part in
A mechanism often involves more than two components. These are the full events, with every participant and its role.
Situations it appears in
Low-supply and faulty-machinery situations recorded in the chapters where this component plays a part.
In the sources
Preserved passages that mention this component, quoted exactly. Open one to read it in context.
Open hypotheses
Proposed ideas that involve this component. They are labeled as hypotheses and do not change any recorded statement.
This is a research prototype built from draft material. It is not medical advice, and its statements still await verification against the original studies.