Component
Mouse nicotinamide riboside kinase 2 / Nmrk2
Mouse NRK2 protein; distinct from human NMRK2.
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
Transient overexpression of active mouse NRK2 made NIH/3T3 fibroblasts responsive to nicotinamide riboside with increased cellular NAD+; the tested catalytically inactive kinase failed to support the response.
Experimental context and source evidence
- evidence_span
- {"source_cache": "artifacts/niacin-precursors-sources/nmrk2016.paragraphs.txt", "locator": "Normalized full-text paragraphs 7–7 (0-based)", "start_char": 5559, "end_char": 7104, "file_sha256": "fcbd5465aff51c9870d65fc9812edbad2cdf2af8bb16b6afb3170d7f0503178a", "text_sha256": "ffb453285526cec1670cc565f0b57f3893b48aba7e5014f693f09ea75079348f"}
- experimental_model
- Murine NRK gain/loss of function in fibroblasts and primary hepatocytes; separate human HepG2 stable-isotope experiments
- exposure
- Transient kinase overexpression with 4 micrograms plasmid; NR 0.5 mM for 6 h under the stated default protocol; mutant comparator NRK1-D36A or NRK2-D35A.
- limitations
- Forced expression in mouse fibroblasts; not a human supplementation study. Basal NAD was unchanged by active kinase overexpression without NR.
- nutrient_topic
- Niacin research collection; topical membership is not evidence of a direct dietary effect. · Niacin (vitamin B3)
- organism
- Mus musculus
- plain_language
- NR utilization depended on active riboside kinase in this cell model.
- primary_references
- [b3-pre-nmrk2016] NRK1 controls nicotinamide mononucleotide and nicotinamide riboside metabolism in mammalian cells. (2016). https://pubmed.ncbi.nlm.nih.gov/27725675/ DOI: 10.1038/ncomms13103
- supporting_evidence_spans
- [{"source_cache": "artifacts/niacin-precursors-sources/nmrk2016.paragraphs.txt", "locator": "Normalized full-text paragraphs 30–30 (0-based)", "start_char": 33613, "end_char": 35106, "file_sha256": "fcbd5465aff51c9870d65fc9812edbad2cdf2af8bb16b6afb3170d7f0503178a", "text_sha256": "e43865f05c251c7fbb357b31c7968056ae1b58fb1d0f4e61216e5013cb928a41"}, {"source_cache": "artifacts/niacin-precursors-sources/nmrk2016.paragraphs.txt", "locator": "Normalized full-text paragraphs 48–48 (0-based)", "start_char": 46035, "end_char": 46419, "file_sha256": "fcbd5465aff51c9870d65fc9812edbad2cdf2af8bb16b6afb3170d7f0503178a", "text_sha256": "4261a1ca6a50f8b37fd569171c8a9111b9a5ee53b2504811a46cfb40badcb90c"}]
- tissue_or_cell_type
- NIH/3T3 fibroblasts
Niacin: NAD metabolism, deficiency and nutrient interactions (2026-09-17) · lines 409–421
AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Murine NRK gain/loss of function in fibroblasts and primary hepatocytes; separate human HepG2 stable-isotope experiments · source_derived_draft · unverified_draft
### b3-pre-mouse-nrk2-nr Transient overexpression of active mouse NRK2 made NIH/3T3 fibroblasts responsive to nicotinamide riboside with increased cellular NAD+; the tested catalytically inactive kinase failed to support the response. Condition category: normal nutrient_topic: Niacin research collection; topical membership is not evidence of a direct dietary effect. plain_language: NR utilization depended on active riboside kinase in this cell model. organism: Mus musculus tissue_or_cell_type: NIH/3T3 fibroblasts experimental_model: Murine NRK gain/loss of function in fibroblasts and primary hepatocytes; separate human HepG2 stable-isotope experiments limitations: Forced expression in mouse fibroblasts; not a human supplementation study. Basal NAD was unchanged by active kinase overexpression without NR. exposure: Transient kinase overexpression with 4 micrograms plasmid; NR 0.5 mM for 6 h under the stated default protocol; mutant comparator NRK1-D36A or NRK2-D35A. evidence_span: {"source_cache": "artifacts/niacin-precursors-sources/nmrk2016.paragraphs.txt", "locator": "Normalized full-text paragraphs 7–7 (0-based)", "start_char": 5559, "end_char": 7104, "file_sha256": "fcbd5465aff51c9870d65fc9812edbad2cdf2af8bb16b6afb3170d7f0503178a", "text_sha256": "ffb453285526cec1670cc565f0b57f3893b48aba7e5014f693f09ea75079348f"} supporting_evidence_spans: [{"source_cache": "artifacts/niacin-precursors-sources/nmrk2016.paragraphs.txt", "locator": "Normalized full-text paragraphs 30–30 (0-based)", "start_char": 33613, "end_char": 35106, "file_sha256": "fcbd5465aff51c9870d65fc9812edbad2cdf2af8bb16b6afb3170d7f0503178a", "text_sha256": "e43865f05c251c7fbb357b31c7968056ae1b58fb1d0f4e61216e5013cb928a41"}, {"source_cache": "artifacts/niacin-precursors-sources/nmrk2016.paragraphs.txt", "locator": "Normalized full-text paragraphs 48–48 (0-based)", "start_char": 46035, "end_char": 46419, "file_sha256": "fcbd5465aff51c9870d65fc9812edbad2cdf2af8bb16b6afb3170d7f0503178a", "text_sha256": "4261a1ca6a50f8b37fd569171c8a9111b9a5ee53b2504811a46cfb40badcb90c"}] [b3-pre-nmrk2016] NRK1 controls nicotinamide mononucleotide and nicotinamide riboside metabolism in mammalian cells. (2016). https://pubmed.ncbi.nlm.nih.gov/27725675/ DOI: 10.1038/ncomms13103
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.