Component
Cubam-mediated IF-cobalamin endocytosis
Cubam-mediated IF-cobalamin endocytosis
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 acts on it
Disruption of both human AMN FXNPXF motifs impaired IF-B12 internalization and degradation in CHO-K1 cells despite preserved cubam surface expression.
Experimental context and source evidence
- availability_state
- machinery_impairment Imported condition classification; unverified.
- cross_nutrient
- false
- experimental_model
- Human AMN double-signal mutant plus rat cubilin 1-1389 in CHO-K1 cells
- exposure
- Both cytoplasmic motifs disrupted; wild-type and single-motif mutants as comparators
- limitations
- Engineered trafficking defect, not a patient genotype. Surface binding and intracellular entry are separate readouts.
- nutrient_topic
- Vitamin B12 research collection; topical membership is not evidence of a direct dietary effect. · Vitamin B12 (cobalamins)
- organism
- Human AMN; rat cubilin; Chinese hamster host cells; human/porcine IF reagents
- plain_language
- A receptor can reach the surface yet fail to internalize its cargo.
- primary_references
- [pedersen-2010-amn-endocytosis] AMN directs endocytosis of the intrinsic factor-vitamin B(12) receptor cubam by engaging ARH or Dab2. (2010). https://pubmed.ncbi.nlm.nih.gov/20088845/ DOI: 10.1111/j.1600-0854.2010.01042.x
- tissue_or_cell_type
- Engineered receptor internalization model
- trigger_kind
- machinery_impairment Imported condition classification; unverified.
Vitamin B12: mechanisms, deficiency and nutrient interactions (2026-09-17) · lines 491–502
AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Human AMN double-signal mutant plus rat cubilin 1-1389 in CHO-K1 cells · source_derived_draft · unverified_draft
### b12-abs-amn-endocytic-signal-loss Disruption of both human AMN FXNPXF motifs impaired IF-B12 internalization and degradation in CHO-K1 cells despite preserved cubam surface expression. Condition category: machinery_impairment nutrient_topic: Vitamin B12 research collection; topical membership is not evidence of a direct dietary effect. plain_language: A receptor can reach the surface yet fail to internalize its cargo. organism: Human AMN; rat cubilin; Chinese hamster host cells; human/porcine IF reagents tissue_or_cell_type: Engineered receptor internalization model experimental_model: Human AMN double-signal mutant plus rat cubilin 1-1389 in CHO-K1 cells limitations: Engineered trafficking defect, not a patient genotype. Surface binding and intracellular entry are separate readouts. exposure: Both cytoplasmic motifs disrupted; wild-type and single-motif mutants as comparators cross_nutrient: false [pedersen-2010-amn-endocytosis] AMN directs endocytosis of the intrinsic factor-vitamin B(12) receptor cubam by engaging ARH or Dab2. (2010). https://pubmed.ncbi.nlm.nih.gov/20088845/ DOI: 10.1111/j.1600-0854.2010.01042.x
Complete structured claim and evidenceHuman AMN coexpressed with rat cubilin 1-1389 enabled IF-B12 internalization in CHO-K1 cells; either intact FXNPXF cytoplasmic motif supported uptake.
Experimental context and source evidence
- cross_nutrient
- false
- experimental_model
- Human AMN plus rat cubilin minireceptor in CHO-K1 cells
- exposure
- Labeled human/porcine IF-B12 at 37 degrees C over 1-8 hours
- limitations
- Reconstituted mixed-species system. Cell-associated radiolabel includes surface-bound cargo and must not be equated with internalized ligand.
- nutrient_topic
- Vitamin B12 research collection; topical membership is not evidence of a direct dietary effect. · Vitamin B12 (cobalamins)
- organism
- Human AMN; rat cubilin; Chinese hamster host cells; human/porcine IF reagents
- plain_language
- Amnionless supplies signals that bring receptor-bound B12 into cells.
- primary_references
- [pedersen-2010-amn-endocytosis] AMN directs endocytosis of the intrinsic factor-vitamin B(12) receptor cubam by engaging ARH or Dab2. (2010). https://pubmed.ncbi.nlm.nih.gov/20088845/ DOI: 10.1111/j.1600-0854.2010.01042.x
- tissue_or_cell_type
- Engineered plasma-membrane endocytosis model
Vitamin B12: mechanisms, deficiency and nutrient interactions (2026-09-17) · lines 478–489
AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Human AMN plus rat cubilin minireceptor in CHO-K1 cells · source_derived_draft · unverified_draft
### b12-abs-amn-endocytosis Human AMN coexpressed with rat cubilin 1-1389 enabled IF-B12 internalization in CHO-K1 cells; either intact FXNPXF cytoplasmic motif supported uptake. Condition category: normal nutrient_topic: Vitamin B12 research collection; topical membership is not evidence of a direct dietary effect. plain_language: Amnionless supplies signals that bring receptor-bound B12 into cells. organism: Human AMN; rat cubilin; Chinese hamster host cells; human/porcine IF reagents tissue_or_cell_type: Engineered plasma-membrane endocytosis model experimental_model: Human AMN plus rat cubilin minireceptor in CHO-K1 cells limitations: Reconstituted mixed-species system. Cell-associated radiolabel includes surface-bound cargo and must not be equated with internalized ligand. exposure: Labeled human/porcine IF-B12 at 37 degrees C over 1-8 hours cross_nutrient: false [pedersen-2010-amn-endocytosis] AMN directs endocytosis of the intrinsic factor-vitamin B(12) receptor cubam by engaging ARH or Dab2. (2010). https://pubmed.ncbi.nlm.nih.gov/20088845/ DOI: 10.1111/j.1600-0854.2010.01042.x
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.