Component
Human urocanate hydratase / UROC1
Context-specific entity; species, compartment and exposure are stated on each claim.
2 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
A girl with urocanic aciduria carried UROC1 L70P/R450C variants; expression and activity studies supported impaired enzyme function.
Experimental context and source evidence
- availability_state
- machinery_impairment Imported condition classification; unverified.
- evidence_access
- Primary abstract
- experimental_model
- Single human case plus variant expression, enzyme assays and computational interpretation.
- limitations
- The biochemical association is stronger than attribution of every neurological feature in a single patient.
- nutrient_topic
- L-Histidine collection; species, compartment, exposure, co-substrates and manipulation remain explicit. · L-Histidine
- plain_language
- A block at the second enzyme allowed an upstream metabolite to accumulate.
- primary_references
- Mutations in the urocanase gene UROC1 are associated with urocanic aciduria. · 2009 · https://pubmed.ncbi.nlm.nih.gov/19304569/ · DOI 10.1136/jmg.2008.060632
- trigger_kind
- machinery_impairment Imported condition classification; unverified.
L-Histidine: supply, catabolism, histamine, receptors and cross-nutrient mechanisms (2026-09-19) · lines 186–192
AI-assisted research curation; primary references, access levels and experimental limitations individually identified. Not publisher full text. · supports · Single human case plus variant expression, enzyme assays and computational interpretation. · source_derived_draft · unverified_draft
## histidine-uroc-human-loss A block at the second enzyme allowed an upstream metabolite to accumulate. A girl with urocanic aciduria carried UROC1 L70P/R450C variants; expression and activity studies supported impaired enzyme function. Model: Single human case plus variant expression, enzyme assays and computational interpretation. Limitations: The biochemical association is stronger than attribution of every neurological feature in a single patient. Evidence access: Primary abstract Mutations in the urocanase gene UROC1 are associated with urocanic aciduria. · 2009 · https://pubmed.ncbi.nlm.nih.gov/19304569/ · DOI 10.1136/jmg.2008.060632
Complete structured claim and evidenceUROC1 hydrates urocanate to imidazolonepropionate in the histidine degradation pathway.
Experimental context and source evidence
- evidence_access
- Primary full text; pathway background
- experimental_model
- Established reaction in the pathway map of a primary human cancer-cell study; genetic perturbation and metabolomics investigate pathway flux rather than purified kinetics of every individual enzyme.
- limitations
- Not a claim that added histidine can bypass UROC1 loss. Correction record: A 2022 author correction is indexed (PMID 35017686). The publisher-accessible record identifies corrected Fig. 1f, Extended Data Fig. 11, Supplementary Fig. 3 and source data for Figs. 1/2, including an erroneous doxorubicin replicate. Complete correction narrative was not accessible; its full impact is not independently cleared. The original study remains flagged corrected, and no comprehensive safety claim is made. https://www.nature.com/articles/s41586-021-03487-2
- nutrient_topic
- L-Histidine collection; species, compartment, exposure, co-substrates and manipulation remain explicit. · L-Histidine
- plain_language
- A second enzyme changes urocanate into the next intermediate.
- primary_references
- Histidine catabolism is a major determinant of methotrexate sensitivity. · 2018 · https://pubmed.ncbi.nlm.nih.gov/29995852/ · DOI 10.1038/s41586-018-0316-7
L-Histidine: supply, catabolism, histamine, receptors and cross-nutrient mechanisms (2026-09-19) · lines 114–120
AI-assisted research curation; primary references, access levels and experimental limitations individually identified. Not publisher full text. · supports · Established reaction in the pathway map of a primary human cancer-cell study; genetic perturbation and metabolomics investigate pathway flux rather than purified kinetics of every individual enzyme. · source_derived_draft · unverified_draft
## histidine-uroc-reaction A second enzyme changes urocanate into the next intermediate. UROC1 hydrates urocanate to imidazolonepropionate in the histidine degradation pathway. Model: Established reaction in the pathway map of a primary human cancer-cell study; genetic perturbation and metabolomics investigate pathway flux rather than purified kinetics of every individual enzyme. Limitations: Not a claim that added histidine can bypass UROC1 loss. Correction record: A 2022 author correction is indexed (PMID 35017686). The publisher-accessible record identifies corrected Fig. 1f, Extended Data Fig. 11, Supplementary Fig. 3 and source data for Figs. 1/2, including an erroneous doxorubicin replicate. Complete correction narrative was not accessible; its full impact is not independently cleared. The original study remains flagged corrected, and no comprehensive safety claim is made. https://www.nature.com/articles/s41586-021-03487-2 Evidence access: Primary full text; pathway background Histidine catabolism is a major determinant of methotrexate sensitivity. · 2018 · https://pubmed.ncbi.nlm.nih.gov/29995852/ · DOI 10.1038/s41586-018-0316-7
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.