Component

Human phosphoserine phosphatase / PSPH

Context-specific entity; species, compartment and exposure are stated on each claim.

5 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. Human phosphoserine phosphatase catalyzes the final, effectively irreversible dephosphorylation step of the phosphorylated serine synthesis pathway.

    Human phosphoserine phosphatase / PSPH → L-Serine source_derived_draftungraded
    Experimental context and source evidence
    evidence_access
    Primary abstract
    experimental_model
    Recombinant human PSPH functional analysis.
    limitations
    Free phosphoserine is distinct from a phosphorylated serine residue in a protein.
    nutrient_topic
    L-Serine collection; species, compartment, exposure, co-substrates and manipulation remain explicit. · L-Serine
    plain_language
    The last enzyme releases free serine from its phosphorylated precursor.
    primary_references
    Effect of l-serine and magnesium ions on the functional properties of human phosphoserine phosphatase and its pathogenetic variants. · 2024 · https://pubmed.ncbi.nlm.nih.gov/38278334/ · DOI 10.1016/j.bbadis.2024.167034

    L-Serine: synthesis, one-carbon metabolism, lipids and cross-nutrient mechanisms (2026-09-19) · lines 46–52

    AI-assisted research curation; primary references, access levels and experimental limitations individually identified. Not publisher full text. · supports · Recombinant human PSPH functional analysis. · source_derived_draft · unverified_draft

    ## l-serine-psph-final-step The last enzyme releases free serine from its phosphorylated precursor. Human phosphoserine phosphatase catalyzes the final, effectively irreversible dephosphorylation step of the phosphorylated serine synthesis pathway. Model: Recombinant human PSPH functional analysis. Limitations: Free phosphoserine is distinct from a phosphorylated serine residue in a protein. Evidence access: Primary abstract Effect of l-serine and magnesium ions on the functional properties of human phosphoserine phosphatase and its pathogenetic variants. · 2024 · https://pubmed.ncbi.nlm.nih.gov/38278334/ · DOI 10.1016/j.bbadis.2024.167034
    Complete structured claim and evidence

  2. The 2024 human PSPH study found near-saturation with Mg2+ under physiological conditions and judged ordinary Mg2+/Ca2+ fluctuations unlikely to regulate activity substantially.

    Human phosphoserine phosphatase / PSPH → Mg2+ source_derived_draftungraded
    Experimental context and source evidence
    evidence_access
    Primary abstract
    experimental_model
    Purified human wild-type and variant PSPH; kinetic interpretation of physiological ion ranges.
    limitations
    This qualifies physiological extrapolation from binding assays; it does not deny the earlier calcium-bound structure.
    nutrient_topic
    L-Serine collection; species, compartment, exposure, co-substrates and manipulation remain explicit. · L-Serine
    plain_language
    A required mineral need not be the rate-limiting input when its binding site is already occupied.
    primary_references
    Effect of l-serine and magnesium ions on the functional properties of human phosphoserine phosphatase and its pathogenetic variants. · 2024 · https://pubmed.ncbi.nlm.nih.gov/38278334/ · DOI 10.1016/j.bbadis.2024.167034

    L-Serine: synthesis, one-carbon metabolism, lipids and cross-nutrient mechanisms (2026-09-19) · lines 62–68

    AI-assisted research curation; primary references, access levels and experimental limitations individually identified. Not publisher full text. · supports · Purified human wild-type and variant PSPH; kinetic interpretation of physiological ion ranges. · source_derived_draft · unverified_draft

    ## l-serine-psph-physiology A required mineral need not be the rate-limiting input when its binding site is already occupied. The 2024 human PSPH study found near-saturation with Mg2+ under physiological conditions and judged ordinary Mg2+/Ca2+ fluctuations unlikely to regulate activity substantially. Model: Purified human wild-type and variant PSPH; kinetic interpretation of physiological ion ranges. Limitations: This qualifies physiological extrapolation from binding assays; it does not deny the earlier calcium-bound structure. Evidence access: Primary abstract Effect of l-serine and magnesium ions on the functional properties of human phosphoserine phosphatase and its pathogenetic variants. · 2024 · https://pubmed.ncbi.nlm.nih.gov/38278334/ · DOI 10.1016/j.bbadis.2024.167034
    Complete structured claim and evidence

  3. The A35T PSPH substitution reduced catalytic efficiency about fiftyfold and lowered thermal stability; M52T had milder effects and D32N behaved like wild type in these assays.

    Human phosphoserine phosphatase / PSPH → Human PSPH A35T catalytic function source_derived_draftungraded
    Experimental context and source evidence
    availability_state
    machinery_impairment Imported condition classification; unverified.
    evidence_access
    Primary abstract
    experimental_model
    Recombinant human natural variants.
    limitations
    Assay behavior does not independently resolve the clinical pathogenicity of every variant.
    nutrient_topic
    L-Serine collection; species, compartment, exposure, co-substrates and manipulation remain explicit. · L-Serine
    plain_language
    Different variants in the same gene can have very different biochemical effects.
    primary_references
    Effect of l-serine and magnesium ions on the functional properties of human phosphoserine phosphatase and its pathogenetic variants. · 2024 · https://pubmed.ncbi.nlm.nih.gov/38278334/ · DOI 10.1016/j.bbadis.2024.167034
    trigger_kind
    machinery_impairment Imported condition classification; unverified.

    L-Serine: synthesis, one-carbon metabolism, lipids and cross-nutrient mechanisms (2026-09-19) · lines 78–84

    AI-assisted research curation; primary references, access levels and experimental limitations individually identified. Not publisher full text. · supports · Recombinant human natural variants. · source_derived_draft · unverified_draft

    ## l-serine-psph-variant Different variants in the same gene can have very different biochemical effects. The A35T PSPH substitution reduced catalytic efficiency about fiftyfold and lowered thermal stability; M52T had milder effects and D32N behaved like wild type in these assays. Model: Recombinant human natural variants. Limitations: Assay behavior does not independently resolve the clinical pathogenicity of every variant. Evidence access: Primary abstract Effect of l-serine and magnesium ions on the functional properties of human phosphoserine phosphatase and its pathogenetic variants. · 2024 · https://pubmed.ncbi.nlm.nih.gov/38278334/ · DOI 10.1016/j.bbadis.2024.167034
    Complete structured claim and evidence

What acts on it

  1. Serine inhibited isolated PSPH, but this inhibition did not control flux through the reconstructed phosphorylated pathway unless PSPH activity was severely impaired.

    L-Serine → Human phosphoserine phosphatase / PSPH source_derived_draftungraded
    Experimental context and source evidence
    evidence_access
    Primary abstract
    experimental_model
    Human enzyme assays and pathway-flux analysis.
    limitations
    Pathway reconstruction is not a measurement of all tissues in vivo.
    nutrient_topic
    L-Serine collection; species, compartment, exposure, co-substrates and manipulation remain explicit. · L-Serine
    plain_language
    Feedback measured on one enzyme need not control the whole pathway.
    primary_references
    Effect of l-serine and magnesium ions on the functional properties of human phosphoserine phosphatase and its pathogenetic variants. · 2024 · https://pubmed.ncbi.nlm.nih.gov/38278334/ · DOI 10.1016/j.bbadis.2024.167034

    L-Serine: synthesis, one-carbon metabolism, lipids and cross-nutrient mechanisms (2026-09-19) · lines 70–76

    AI-assisted research curation; primary references, access levels and experimental limitations individually identified. Not publisher full text. · supports · Human enzyme assays and pathway-flux analysis. · source_derived_draft · unverified_draft

    ## l-serine-psph-feedback Feedback measured on one enzyme need not control the whole pathway. Serine inhibited isolated PSPH, but this inhibition did not control flux through the reconstructed phosphorylated pathway unless PSPH activity was severely impaired. Model: Human enzyme assays and pathway-flux analysis. Limitations: Pathway reconstruction is not a measurement of all tissues in vivo. Evidence access: Primary abstract Effect of l-serine and magnesium ions on the functional properties of human phosphoserine phosphatase and its pathogenetic variants. · 2024 · https://pubmed.ncbi.nlm.nih.gov/38278334/ · DOI 10.1016/j.bbadis.2024.167034
    Complete structured claim and evidence

  2. Human PSPH uses an active-site Mg2+ ion; replacing it with Ca2+ changes coordination of catalytic Asp20 in a way that impedes nucleophilic attack.

    Mg2+ → Human phosphoserine phosphatase / PSPH source_derived_draftungraded
    Experimental context and source evidence
    evidence_access
    Primary abstract
    experimental_model
    Human enzyme crystallography; the calcium-bound structure used 0.7 M CaCl2 crystallization conditions.
    limitations
    The high-calcium structure does not establish inhibition by normal dietary calcium.
    nutrient_topic
    L-Serine collection; species, compartment, exposure, co-substrates and manipulation remain explicit. · L-Serine
    plain_language
    Two minerals can bind differently to the same enzyme.
    primary_references
    How calcium inhibits the magnesium-dependent enzyme human phosphoserine phosphatase. · 2004 · https://pubmed.ncbi.nlm.nih.gov/15291819/ · DOI 10.1111/j.0014-2956.2004.04277.x

    L-Serine: synthesis, one-carbon metabolism, lipids and cross-nutrient mechanisms (2026-09-19) · lines 54–60

    AI-assisted research curation; primary references, access levels and experimental limitations individually identified. Not publisher full text. · supports · Human enzyme crystallography; the calcium-bound structure used 0.7 M CaCl2 crystallization conditions. · source_derived_draft · unverified_draft

    ## l-serine-psph-metal Two minerals can bind differently to the same enzyme. Human PSPH uses an active-site Mg2+ ion; replacing it with Ca2+ changes coordination of catalytic Asp20 in a way that impedes nucleophilic attack. Model: Human enzyme crystallography; the calcium-bound structure used 0.7 M CaCl2 crystallization conditions. Limitations: The high-calcium structure does not establish inhibition by normal dietary calcium. Evidence access: Primary abstract How calcium inhibits the magnesium-dependent enzyme human phosphoserine phosphatase. · 2004 · https://pubmed.ncbi.nlm.nih.gov/15291819/ · DOI 10.1111/j.0014-2956.2004.04277.x
    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.

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