Component
Selenophosphate
Independent chemical species record for Selenophosphate.
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
SEPHS2 supplies the activated selenium donor used for Sec-tRNA synthesis; mammalian loss/rescue experiments establish its biosynthetic requirement.
Experimental context and source evidence
- experimental_model
- Mammalian cell knockdown/rescue and selenoprotein synthesis assays.
- limitations
- Requirement for biosynthesis does not prove that SEPHS2 is always the last selenoprotein preserved during dietary restriction.
- organism
- Mammalian cultured cells
Selenium: literature corrections and mechanism additions · lines 1119–1128
Metabolic Ledger literature curation, 17 September 2026; primary papers linked individually · supports · Mammalian cell knockdown/rescue and selenoprotein synthesis assays. · secondary_verified · secondary_verified
## sephs2-selenium-donor-supply SEPHS2 prepares selenium for the machinery that builds selenoproteins. SEPHS2 supplies the activated selenium donor used for Sec-tRNA synthesis; mammalian loss/rescue experiments establish its biosynthetic requirement. Experimental model: Mammalian cell knockdown/rescue and selenoprotein synthesis assays. Organism: Mammalian cultured cells Limitations: Requirement for biosynthesis does not prove that SEPHS2 is always the last selenoprotein preserved during dietary restriction. Primary reference: [Selenophosphate synthetase 2 is essential for selenoprotein biosynthesis](https://pmc.ncbi.nlm.nih.gov/articles/PMC1868833/)
Complete structured claim and evidence
Where it participates (unsigned role)
PLP-dependent SEPSECS converts phosphoseryl-tRNA Sec to Sec-tRNA through phosphate elimination and selenium donation from selenophosphate, not incorporation of intact selenophosphate.
Experimental context and source evidence
- cell_type
- Purified enzyme/tRNA
- experimental_model
- Human enzyme/tRNA crystallography and biochemical assays
- limitations
- Not a measurement of dietary intake effects.
- organism
- Homo sapiens
Selenium: literature corrections and mechanism additions · lines 1154–1164
Metabolic Ledger literature curation, 17 September 2026; primary papers linked individually · supports · Human enzyme/tRNA crystallography and biochemical assays · secondary_verified · secondary_verified
## sepsecs-chemistry SEPSECS uses selenium from the donor to finish the tRNA-bound amino acid. PLP-dependent SEPSECS converts phosphoseryl-tRNA Sec to Sec-tRNA through phosphate elimination and selenium donation from selenophosphate, not incorporation of intact selenophosphate. Organism: Homo sapiens Cell type: Purified enzyme/tRNA Experimental model: Human enzyme/tRNA crystallography and biochemical assays Limitations: Not a measurement of dietary intake effects. Primary reference: [The human SepSecS–tRNASec complex reveals mechanism of selenocysteine formation](https://pubmed.ncbi.nlm.nih.gov/19608919/)
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.