identifier: traitmech:000078
label: stress response
definition: A physiological program by which a cell senses and mounts a protective
  response to environmental or cellular stress, such as the RpoS-mediated general
  stress response of enteric bacteria.
definition_source: DOI:10.1146/annurev-micro-090110-102946
trait_category: PHYSIOLOGY
term_kind: CLASS
mapping_status: REVIEWED
parent_traits:
- METPO:1000059
synonyms:
- synonym_text: general stress response
  synonym_type: RELATED_SYNONYM
  source: DOI:10.1146/annurev-micro-090110-102946
evidence:
- reference: DOI:10.1146/annurev-micro-090110-102946
  notes: Battesti, Majdalani & Gottesman review the RpoS-mediated general stress response,
    a broad protective program induced by stress and stationary phase.
- reference: DOI:10.1038/nrmicro3032
  notes: Imlay reviews molecular stress-defense mechanisms, exemplifying inducible
    protective responses; parent of the oxidative-stress-response sub-variant.
canonical_examples:
- taxon_id: NCBITaxon:562
  taxon_label: Escherichia coli
  note: "general stress response (RpoS)"
  reference: PMID:38411096
- taxon_id: NCBITaxon:1299
  taxon_label: Deinococcus radiodurans
  note: "extreme stress resistance"
  reference: PMID:30339218
causal_graphs:
- graph_id: stress_response_induction
  title: Stress-induced protective response
  description: Evidence-backed causal sketch linking environmental stress to an induced,
    protective general stress response.
  nodes:
  - node_id: stress_response_trait
    label: stress response
    node_type: TRAIT
    grounding: traitmech:000078
    description: Capacity to mount a protective response to stress.
  - node_id: environmental_stress
    label: environmental stress
    node_type: ENVIRONMENTAL_FACTOR
    description: Disturbance of cellular homeostasis.
  - node_id: stress_response_process
    label: response to stress
    node_type: BIOLOGICAL_PROCESS
    grounding: GO:0006950
    description: Change in cell state triggered by a stressor.
  - node_id: ppgpp
    label: (p)ppGpp
    node_type: CHEMICAL
    description: Guanosine tetra/pentaphosphate alarmone of the stringent response.
  - node_id: rsh_enzymes
    label: RelA/SpoT homologue enzymes
    node_type: GENE_OR_PROTEIN
    description: RSH enzyme family that synthesizes and hydrolyzes (p)ppGpp.
  - node_id: nutrient_limitation
    label: nutrient limitation
    node_type: ENVIRONMENTAL_FACTOR
    description: Limiting availability of nutrients that triggers stress signaling.
  - node_id: ribosome_biosynthesis
    label: ribosome biosynthesis
    node_type: BIOLOGICAL_PROCESS
    description: Synthesis of ribosomes and translation-associated growth machinery.
  - node_id: stress_tolerance
    label: stress tolerance
    node_type: QUALITY
    description: Capacity to tolerate environmental stress.
  - node_id: rpos
    label: RpoS (sigma S)
    node_type: GENE_OR_PROTEIN
    description: General-stress-response sigma factor (sigma S / sigma 38).
    grounding: UniProtKB:A0A010TBV5
  - node_id: general_stress_resistance
    label: general stress resistance
    node_type: BIOLOGICAL_PROCESS
    description: Broad protective resistance to multiple stresses.
  - node_id: hfq
    label: Hfq
    node_type: GENE_OR_PROTEIN
    description: RNA chaperone enabling sRNA-dependent translational regulation.
    grounding: UniProtKB:A0A3B9B147
  edges:
  - subject: environmental_stress
    predicate: causes
    object: stress_response_process
    description: A stressor triggers the stress-response program.
    evidence:
    - reference: DOI:10.1146/annurev-micro-090110-102946
      notes: Battesti et al. review stress/stationary-phase induction of RpoS.
    predicate_id: biolink:causes
  - subject: stress_response_process
    predicate: enables
    object: stress_response_trait
    description: The induced program realizes the stress-response trait.
    evidence:
    - reference: DOI:10.1038/nrmicro3032
      notes: Imlay reviews inducible molecular stress defenses.
    predicate_id: RO:0002327
  - subject: rsh_enzymes
    predicate: synthesizes/hydrolyzes
    object: ppgpp
    description: RSH enzymes synthesize and hydrolyze the (p)ppGpp alarmone.
    evidence:
    - reference: DOI:10.1099/mic.0.001483
      notes: (p)ppGpp is synthesized and hydrolysed by RelA-SpoT homologue (RSH) enzymes;
        broadly conserved in bacteria.
  - subject: nutrient_limitation
    predicate: triggers
    object: ppgpp
    description: Nutrient-limiting conditions trigger a surge of (p)ppGpp.
    evidence:
    - reference: DOI:10.1099/mic.0.001483
      notes: Stringent response mediated by (p)ppGpp, whose intracellular surge is
        triggered by nutrient-limiting conditions.
  - subject: ppgpp
    predicate: inhibits
    object: ribosome_biosynthesis
    description: (p)ppGpp inhibits ribosome biosynthesis, slowing growth.
    evidence:
    - reference: DOI:10.1099/mic.0.001483
      notes: (p)ppGpp inhibits ribosome biosynthesis, inducing a slow-growth phenotype.
    predicate_id: RO:0002212
  - subject: ppgpp
    predicate: enhances
    object: stress_tolerance
    description: Moderate (p)ppGpp induction enhances stress tolerance.
    evidence:
    - reference: DOI:10.1016/j.isci.2024.108818
      notes: Moderate induction of (p)ppGpp reduces growth rate while enhancing stress
        tolerance.
  - subject: ppgpp
    predicate: positively regulates
    object: rpos
    description: (p)ppGpp positively regulates RpoS abundance/activity.
    evidence:
    - reference: DOI:10.1016/j.isci.2024.108818
      notes: (p)ppGpp positively regulates RpoS by transcriptional activation and
        by inhibiting RpoS proteolysis.
  - subject: rpos
    predicate: induces
    object: general_stress_resistance
    description: RpoS-dependent gene expression induces general stress resistance.
    evidence:
    - reference: DOI:10.1146/annurev-micro-090110-102946
      notes: RpoS-dependent gene expression leads to general stress resistance of
        cells.
  - subject: hfq
    predicate: enables
    object: rpos
    description: Hfq enables sRNA-dependent translation of RpoS.
    evidence:
    - reference: DOI:10.1128/mmbr.00151-22
      notes: Hfq is needed for sRNA-dependent RpoS translation.
    predicate_id: RO:0002327
  - subject: general_stress_resistance
    predicate: enables
    object: stress_response_trait
    description: General stress resistance realizes the stress-response trait.
    evidence:
    - reference: DOI:10.1146/annurev-micro-090110-102946
      notes: RpoS-mediated general stress resistance is the protective program defining
        the trait.
    predicate_id: RO:0002327
curation_history:
- timestamp: '2026-06-04T00:00:00Z'
  curator: claude
  action: PROPOSED_FROM_RESEARCH
  changes: Proposed candidate PHYSIOLOGY axis class (stress response) to parent specific
    stress-response sub-variants.
  llm_assisted: true
- timestamp: '2026-06-08T13:00:00Z'
  curator: claude
  action: CURATED_CAUSAL_GRAPH
  changes: Added evidence-backed causal graph (stress-induced protective response)
    with GO node grounding and biolink/RO predicate groundings; promoted PROPOSED
    to REVIEWED.
  llm_assisted: true
- timestamp: '2026-06-23T00:00:00Z'
  curator: claude
  action: ENRICH_CAUSAL_GRAPH
  changes: Added 8 evidence-backed generic edges (8 new nodes) from the deep-research
    report.
  llm_assisted: true
- timestamp: '2026-06-24T17:21:15Z'
  curator: claude
  action: GROUND_CAUSAL_PREDICATES
  changes: Grounded 3 causal-edge predicate_id field(s) via mappings/predicate_grounding.tsv
    (RO:0002327×2, RO:0002212×1).
  llm_assisted: true
- timestamp: '2026-06-26T07:15:20Z'
  curator: claude
  action: GROUND_CAUSAL_NODES
  changes: Grounded 2 causal-node grounding field(s) via mappings/node_grounding.tsv
    (UniProtKB:A0A010TBV5×1, UniProtKB:A0A3B9B147×1).
  llm_assisted: true