Component
Human HPF1 knockout genotype
Experimental HPF1-null U2OS genotype; distinct from protein and dietary deficiency.
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
HPF1-null U2OS cells showed near-loss of histone serine ADP-ribosylation after hydrogen-peroxide-induced DNA damage.
Experimental context and source evidence
- availability_state
- machinery_impairment Imported condition classification; unverified.
- cross_nutrient
- false
- evidence_span
- {"source_cache": "artifacts/niacin-consumption-sources/parp2017.txt", "locator": "Full text, normalized paragraph 36", "start_char": 12179, "end_char": 12883, "file_sha256": "8195abaa884a41856a21fb1d4e7ee376ce80424f11f4625ca4d597a717cef30e", "text_sha256": "a36d5aa7fb74cd3100332088b118c7c3d97951e35641dd7eed75ea4aa47ed9ee"}
- experimental_model
- SILAC proteomics comparing wild-type and HPF1-null U2OS cells
- exposure
- HPF1 gene deletion; H2O2 DNA damage
- limitations
- Some abundant H2B peptides retained very small signals; this is not literal proof of zero modification or dietary NAD deficiency.
- nutrient_topic
- Niacin research collection; topical membership is not evidence of a direct dietary effect. · Niacin (vitamin B3)
- organism
- Human
- plain_language
- Removing HPF1 largely eliminated this histone modification after experimental DNA damage.
- primary_references
- [b3-cons-parp2017] Serine ADP-Ribosylation Depends on HPF1. (2017). https://pubmed.ncbi.nlm.nih.gov/28190768/ DOI: 10.1016/j.molcel.2017.01.003
- tissue_or_cell_type
- U2OS osteosarcoma cells
- trigger_kind
- machinery_impairment Imported condition classification; unverified.
Niacin: NAD metabolism, deficiency and nutrient interactions (2026-09-17) · lines 663–675
AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · SILAC proteomics comparing wild-type and HPF1-null U2OS cells · source_derived_draft · unverified_draft
### b3-cons-hpf1-loss-histone-adpr HPF1-null U2OS cells showed near-loss of histone serine ADP-ribosylation after hydrogen-peroxide-induced DNA damage. Condition category: machinery_impairment nutrient_topic: Niacin research collection; topical membership is not evidence of a direct dietary effect. plain_language: Removing HPF1 largely eliminated this histone modification after experimental DNA damage. organism: Human tissue_or_cell_type: U2OS osteosarcoma cells experimental_model: SILAC proteomics comparing wild-type and HPF1-null U2OS cells limitations: Some abundant H2B peptides retained very small signals; this is not literal proof of zero modification or dietary NAD deficiency. exposure: HPF1 gene deletion; H2O2 DNA damage cross_nutrient: false evidence_span: {"source_cache": "artifacts/niacin-consumption-sources/parp2017.txt", "locator": "Full text, normalized paragraph 36", "start_char": 12179, "end_char": 12883, "file_sha256": "8195abaa884a41856a21fb1d4e7ee376ce80424f11f4625ca4d597a717cef30e", "text_sha256": "a36d5aa7fb74cd3100332088b118c7c3d97951e35641dd7eed75ea4aa47ed9ee"} [b3-cons-parp2017] Serine ADP-Ribosylation Depends on HPF1. (2017). https://pubmed.ncbi.nlm.nih.gov/28190768/ DOI: 10.1016/j.molcel.2017.01.003
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.