Component

Human cellular arginine sensor CASTOR1

Study-scoped entity; inspect species, exposure and experimental limitations on each claim.

4 recorded relationships. Experimental role, claim status and evidence remain attached to each record.

Read recorded mechanisms Open recursive mind map

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.

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.

Recorded relationships

What it acts on

  1. CASTOR1 was required for arginine deprivation to inhibit mTORC1.

    Human cellular arginine sensor CASTOR1 → Mechanistic target of rapamycin complex 1 source_derived_draftungraded
    Experimental context and source evidence
    availability_state
    nutrient_deficiency Imported condition classification; unverified.
    evidence_access
    Primary abstract
    experimental_model
    Mammalian-cell signaling experiments and biochemical CASTOR1 binding.
    limitations
    Experimental starvation response; no universal dietary cutoff.
    nutrient_topic
    L-Arginine collection; tissue, species, dose and formulation distinctions retained. · L-Arginine
    plain_language
    Low arginine is sensed through specific machinery.
    primary_references
    The CASTOR Proteins Are Arginine Sensors for the mTORC1 Pathway. · 2016 · https://pubmed.ncbi.nlm.nih.gov/26972053/ · DOI 10.1016/j.cell.2016.02.035
    trigger_kind
    nutrient_deficiency Imported condition classification; unverified.

    L-Arginine: transport, metabolic branches, nutrient interactions, availability and discovery questions (2026-09-18) · lines 190–196

    AI-assisted research curation; primary-abstract references and experimental limitations individually identified. Not publisher full text. · supports · Mammalian-cell signaling experiments and biochemical CASTOR1 binding. · source_derived_draft · unverified_draft

    ## arg-castor-starvation Low arginine is sensed through specific machinery. CASTOR1 was required for arginine deprivation to inhibit mTORC1. Model: Mammalian-cell signaling experiments and biochemical CASTOR1 binding. Limitations: Experimental starvation response; no universal dietary cutoff. Evidence access: Primary abstract The CASTOR Proteins Are Arginine Sensors for the mTORC1 Pathway. · 2016 · https://pubmed.ncbi.nlm.nih.gov/26972053/ · DOI 10.1016/j.cell.2016.02.035
    Complete structured claim and evidence

What acts on it

  1. Arginine bound CASTOR1 with an approximate dissociation constant of 30 micromolar.

    L-Arginine → Human cellular arginine sensor CASTOR1 source_derived_draftungraded
    Experimental context and source evidence
    evidence_access
    Primary abstract
    experimental_model
    Mammalian-cell signaling experiments and biochemical CASTOR1 binding.
    limitations
    Binding constant is not a human deficiency threshold.
    nutrient_topic
    L-Arginine collection; tissue, species, dose and formulation distinctions retained. · L-Arginine
    plain_language
    Arginine is a signal as well as a reaction substrate.
    primary_references
    The CASTOR Proteins Are Arginine Sensors for the mTORC1 Pathway. · 2016 · https://pubmed.ncbi.nlm.nih.gov/26972053/ · DOI 10.1016/j.cell.2016.02.035

    L-Arginine: transport, metabolic branches, nutrient interactions, availability and discovery questions (2026-09-18) · lines 174–180

    AI-assisted research curation; primary-abstract references and experimental limitations individually identified. Not publisher full text. · supports · Mammalian-cell signaling experiments and biochemical CASTOR1 binding. · source_derived_draft · unverified_draft

    ## arg-castor-binding Arginine is a signal as well as a reaction substrate. Arginine bound CASTOR1 with an approximate dissociation constant of 30 micromolar. Model: Mammalian-cell signaling experiments and biochemical CASTOR1 binding. Limitations: Binding constant is not a human deficiency threshold. Evidence access: Primary abstract The CASTOR Proteins Are Arginine Sensors for the mTORC1 Pathway. · 2016 · https://pubmed.ncbi.nlm.nih.gov/26972053/ · DOI 10.1016/j.cell.2016.02.035
    Complete structured claim and evidence

  2. Arginine binds between two ACT domains, controlling the neighboring GATOR2-binding site.

    L-Arginine → Human cellular arginine sensor CASTOR1 source_derived_draftungraded
    Experimental context and source evidence
    evidence_access
    Primary abstract
    experimental_model
    1.8-angstrom structure of arginine-bound CASTOR1 and functional analysis.
    limitations
    Structural homology to bacterial lysine sensors is not proof that lysine substitutes for arginine.
    nutrient_topic
    L-Arginine collection; tissue, species, dose and formulation distinctions retained. · L-Arginine
    plain_language
    The structure explains how binding can change signaling.
    primary_references
    Mechanism of arginine sensing by CASTOR1 upstream of mTORC1. · 2016 · https://pubmed.ncbi.nlm.nih.gov/27487210/ · DOI 10.1038/nature19079

    L-Arginine: transport, metabolic branches, nutrient interactions, availability and discovery questions (2026-09-18) · lines 198–204

    AI-assisted research curation; primary-abstract references and experimental limitations individually identified. Not publisher full text. · supports · 1.8-angstrom structure of arginine-bound CASTOR1 and functional analysis. · source_derived_draft · unverified_draft

    ## arg-castor-structure The structure explains how binding can change signaling. Arginine binds between two ACT domains, controlling the neighboring GATOR2-binding site. Model: 1.8-angstrom structure of arginine-bound CASTOR1 and functional analysis. Limitations: Structural homology to bacterial lysine sensors is not proof that lysine substitutes for arginine. Evidence access: Primary abstract Mechanism of arginine sensing by CASTOR1 upstream of mTORC1. · 2016 · https://pubmed.ncbi.nlm.nih.gov/27487210/ · DOI 10.1038/nature19079
    Complete structured claim and evidence

Where it participates (unsigned role)

  1. Arginine binding disrupted the CASTOR1–GATOR2 complex; arginine-binding capacity was needed for pathway activation.

    L-Arginine → Human CASTOR1–GATOR2 complex source_derived_draftungraded
    Experimental context and source evidence
    evidence_access
    Primary abstract
    experimental_model
    Mammalian-cell signaling experiments and biochemical CASTOR1 binding.
    limitations
    Do not equate pathway activation with guaranteed muscle growth.
    nutrient_topic
    L-Arginine collection; tissue, species, dose and formulation distinctions retained. · L-Arginine
    plain_language
    Binding releases a brake on nutrient signaling.
    primary_references
    The CASTOR Proteins Are Arginine Sensors for the mTORC1 Pathway. · 2016 · https://pubmed.ncbi.nlm.nih.gov/26972053/ · DOI 10.1016/j.cell.2016.02.035

    L-Arginine: transport, metabolic branches, nutrient interactions, availability and discovery questions (2026-09-18) · lines 182–188

    AI-assisted research curation; primary-abstract references and experimental limitations individually identified. Not publisher full text. · supports · Mammalian-cell signaling experiments and biochemical CASTOR1 binding. · source_derived_draft · unverified_draft

    ## arg-castor-release Binding releases a brake on nutrient signaling. Arginine binding disrupted the CASTOR1–GATOR2 complex; arginine-binding capacity was needed for pathway activation. Model: Mammalian-cell signaling experiments and biochemical CASTOR1 binding. Limitations: Do not equate pathway activation with guaranteed muscle growth. Evidence access: Primary abstract The CASTOR Proteins Are Arginine Sensors for the mTORC1 Pathway. · 2016 · https://pubmed.ncbi.nlm.nih.gov/26972053/ · DOI 10.1016/j.cell.2016.02.035
    Complete structured claim and evidence

In the sources

Preserved passages that mention this component, quoted exactly. Open one to read it in context.

    This is a research prototype built from draft material. It is not medical advice, and its statements still await verification against the original studies.

    Evidence, AI assistance and curation standards