Component
Human MMADHC segment after Met116
N-terminally shortened MMADHC sequence examined using translation-reinitiation/expression constructs.
1 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
MMADHC expression/translation-reinitiation experiments in cblD patient fibroblasts indicated that sequence after Met116 was sufficient to support methylcobalamin synthesis.
Experimental context and source evidence
- availability_state
- machinery_impairment Imported condition classification; unverified.
- cross_nutrient
- false
- evidence_location
- Abstract
- experimental_model
- Human cblD fibroblast construct-rescue study
- exposure
- MMADHC constructs changing stop codons or downstream translation starts
- limitations
- Abstract-level domain inference; no claim of an independently purified physiological isoform.
- nutrient_topic
- Vitamin B12 research collection; topical membership is not evidence of a direct dietary effect. · Vitamin B12 (cobalamins)
- organism
- Homo sapiens
- plain_language
- The later portion of MMADHC could support the methyl-B12 branch in these cells.
- primary_references
- [stucki-2012-mmad-routing] Molecular mechanisms leading to three different phenotypes in the cblD defect of intracellular cobalamin metabolism (2012). https://pubmed.ncbi.nlm.nih.gov/22156578/ DOI: 10.1093/hmg/ddr579
- tissue_or_cell_type
- Patient fibroblasts
- trigger_kind
- machinery_impairment Imported condition classification; unverified.
Vitamin B12: mechanisms, deficiency and nutrient interactions (2026-09-17) · lines 851–863
AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Human cblD fibroblast construct-rescue study · source_derived_draft · unverified_draft
### b12-mmad-after116-methyl MMADHC expression/translation-reinitiation experiments in cblD patient fibroblasts indicated that sequence after Met116 was sufficient to support methylcobalamin synthesis. Condition category: machinery_impairment nutrient_topic: Vitamin B12 research collection; topical membership is not evidence of a direct dietary effect. plain_language: The later portion of MMADHC could support the methyl-B12 branch in these cells. organism: Homo sapiens tissue_or_cell_type: Patient fibroblasts experimental_model: Human cblD fibroblast construct-rescue study limitations: Abstract-level domain inference; no claim of an independently purified physiological isoform. exposure: MMADHC constructs changing stop codons or downstream translation starts cross_nutrient: false evidence_location: Abstract [stucki-2012-mmad-routing] Molecular mechanisms leading to three different phenotypes in the cblD defect of intracellular cobalamin metabolism (2012). https://pubmed.ncbi.nlm.nih.gov/22156578/ DOI: 10.1093/hmg/ddr579
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.