Component
Lysosome
Lysosome
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.
Where it participates (unsigned role)
Reconstituted human ABCD4 moved cobalamin from liposome interior to exterior with external ATP; the ATPase-defective K427A control lacked this activity.
Experimental context and source evidence
- cross_nutrient
- false
- evidence_location
- Results: Figures 3, 4, 5; Experimental procedures: liposomes and transport assays
- experimental_model
- Purified human ABCD4/LMBD1 in synthetic liposomes after yeast expression
- exposure
- 100 micromolar lumenal cobalamin, external ATP, 37 C
- limitations
- Artificial membrane orientation models lysosomal export; exact cobalamin upper ligand was not specified in retrieved methods.
- nutrient_topic
- Vitamin B12 research collection; topical membership is not evidence of a direct dietary effect. · Vitamin B12 (cobalamins)
- organism
- Homo sapiens
- plain_language
- ABCD4 used ATP-dependent machinery to move B12 across a membrane.
- primary_references
- [kitai-2021-abcd4-transport] The lysosomal protein ABCD4 can transport vitamin B12 across liposomal membranes in vitro (2021). https://pubmed.ncbi.nlm.nih.gov/33845046/ DOI: 10.1016/j.jbc.2021.100654
- tissue_or_cell_type
- Cell-free membrane system
Vitamin B12: mechanisms, deficiency and nutrient interactions (2026-09-17) · lines 613–625
AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Purified human ABCD4/LMBD1 in synthetic liposomes after yeast expression · source_derived_draft · unverified_draft
### b12-abcd4-atp-export Reconstituted human ABCD4 moved cobalamin from liposome interior to exterior with external ATP; the ATPase-defective K427A control lacked this activity. Condition category: normal nutrient_topic: Vitamin B12 research collection; topical membership is not evidence of a direct dietary effect. plain_language: ABCD4 used ATP-dependent machinery to move B12 across a membrane. organism: Homo sapiens tissue_or_cell_type: Cell-free membrane system experimental_model: Purified human ABCD4/LMBD1 in synthetic liposomes after yeast expression limitations: Artificial membrane orientation models lysosomal export; exact cobalamin upper ligand was not specified in retrieved methods. exposure: 100 micromolar lumenal cobalamin, external ATP, 37 C cross_nutrient: false evidence_location: Results: Figures 3, 4, 5; Experimental procedures: liposomes and transport assays [kitai-2021-abcd4-transport] The lysosomal protein ABCD4 can transport vitamin B12 across liposomal membranes in vitro (2021). https://pubmed.ncbi.nlm.nih.gov/33845046/ DOI: 10.1016/j.jbc.2021.100654
Complete structured claim and evidenceIn HuH7 cells expressing human ABCD4-HA, adding LMBD1-GFP shifted ABCD4 from an ER-like distribution toward LAMP1-positive lysosomes.
Experimental context and source evidence
- cross_nutrient
- false
- evidence_location
- Results: Figures 1, 6, 7; Methods: cell lines and CRISPR
- experimental_model
- Human HuH7 tagged-protein localization
- exposure
- ABCD4-HA stable expression and transient LMBD1-GFP
- limitations
- Tagged overexpression; colocalization does not measure cobalamin flux.
- nutrient_topic
- Vitamin B12 research collection; topical membership is not evidence of a direct dietary effect. · Vitamin B12 (cobalamins)
- organism
- Homo sapiens
- plain_language
- LMBD1 helped the B12 transporter reach lysosomes.
- primary_references
- [kawaguchi-2016-lmbd1-escort] Translocation of the ABC transporter ABCD4 from the endoplasmic reticulum to lysosomes requires the escort protein LMBD1 (2016). https://pubmed.ncbi.nlm.nih.gov/27456980/ DOI: 10.1038/srep30183
- tissue_or_cell_type
- Hepatoma cell line
Vitamin B12: mechanisms, deficiency and nutrient interactions (2026-09-17) · lines 571–583
AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Human HuH7 tagged-protein localization · source_derived_draft · unverified_draft
### b12-lmbrd1-escort-huh7 In HuH7 cells expressing human ABCD4-HA, adding LMBD1-GFP shifted ABCD4 from an ER-like distribution toward LAMP1-positive lysosomes. Condition category: normal nutrient_topic: Vitamin B12 research collection; topical membership is not evidence of a direct dietary effect. plain_language: LMBD1 helped the B12 transporter reach lysosomes. organism: Homo sapiens tissue_or_cell_type: Hepatoma cell line experimental_model: Human HuH7 tagged-protein localization limitations: Tagged overexpression; colocalization does not measure cobalamin flux. exposure: ABCD4-HA stable expression and transient LMBD1-GFP cross_nutrient: false evidence_location: Results: Figures 1, 6, 7; Methods: cell lines and CRISPR [kawaguchi-2016-lmbd1-escort] Translocation of the ABC transporter ABCD4 from the endoplasmic reticulum to lysosomes requires the escort protein LMBD1 (2016). https://pubmed.ncbi.nlm.nih.gov/27456980/ DOI: 10.1038/srep30183
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.