identifier: traitmech:000014 label: zinc tolerant definition: A metal tolerance in which an organism grows in the presence of elevated zinc (Zn2+) concentrations, typically via cation-efflux resistance systems such as the czc determinant. definition_source: PMID:12829273 trait_category: ENVIRONMENT term_kind: CLASS mapping_status: REVIEWED parent_traits: - traitmech:000012 evidence: - reference: DOI:10.1111/j.1365-2958.2009.06792.x snippet: CzcP exports transition metals Zn(2+), Cd(2+) and Co(2+) notes: The cobalt-zinc-cadmium (czc) efflux system of Cupriavidus metallidurans confers zinc resistance. - reference: DOI:10.3389/fmicb.2020.00047 snippet: C. metallidurans BS1 conferred resistance to Zn2+ displaying a MIC of 20 mM, Cd2+ (2.5 mM), Co2+ (20mM), Ni2+ (8 mM), As3+ (3.5 mM), Cu2+ (5 mM), Au3+ (1 uM) and Pb2+ (1.7 mM) notes: 'Organism example: Cupriavidus metallidurans BS1 tolerates zinc to a MIC of 20 mM.' canonical_examples: - taxon_id: NCBITaxon:119219 taxon_label: Cupriavidus metallidurans note: "zinc-resistance determinants" reference: PMID:33540705 causal_graphs: - graph_id: zinc_tolerance_czc_efflux title: Zinc tolerance via czc cation-efflux system description: Evidence-backed causal sketch linking the cobalt-zinc-cadmium (czc) efflux determinant to cytoplasmic zinc detoxification. nodes: - node_id: zinc_tolerant_trait label: zinc tolerant node_type: TRAIT grounding: traitmech:000014 description: Capacity to grow at elevated Zn(2+) concentrations. - node_id: zinc_ion label: zinc(2+) ion node_type: CHEMICAL grounding: CHEBI:29105 description: Cytoplasmic Zn(2+) excess threatening protein mismetallation. - node_id: czc_efflux_system label: czc cation-efflux system node_type: GENE_OR_PROTEIN description: CzcCBA/CzcP machinery exporting Zn, Cd, and Co cations. grounding: UniProtKB:B0VPE1 - node_id: zinc_export label: zinc ion transmembrane transport node_type: BIOLOGICAL_PROCESS grounding: GO:0006829 description: Active export of Zn(2+) across the cytoplasmic membrane. - node_id: znta_atpase label: ZntA P-type ATPase node_type: GENE_OR_PROTEIN description: PIB2-type P-type ATPase mediating cytoplasmic zinc efflux. - node_id: zntr_regulator label: ZntR MerR-family regulator node_type: GENE_OR_PROTEIN description: MerR-family zinc-responsive transcriptional activator of zntA. - node_id: znta_expression label: zntA transcription node_type: BIOLOGICAL_PROCESS description: Transcription of the zntA zinc-efflux ATPase gene. - node_id: czccba_complex label: CzcCBA RND efflux complex node_type: GENE_OR_PROTEIN description: RND transenvelope pump exporting zinc from the periplasm. - node_id: polyphosphate label: polyphosphate node_type: CHEMICAL description: Cytoplasmic metal-binding polymer buffering zinc. grounding: CHEBI:16838 - node_id: glutathione label: glutathione node_type: CHEMICAL grounding: CHEBI:16856 description: Cytoplasmic thiol buffering intracellular zinc. - node_id: zinc_buffering label: zinc ion buffering node_type: BIOLOGICAL_PROCESS description: Intracellular sequestration maintaining zinc flow equilibrium. edges: - subject: zinc_ion predicate: challenges object: zinc_tolerant_trait description: Cytoplasmic zinc excess is the challenge the trait counters. evidence: - reference: DOI:10.3389/fmicb.2020.00047 notes: Cupriavidus metallidurans BS1 tolerates Zn(2+) to a MIC of 20 mM. predicate_id: METPO:2007406 - subject: czc_efflux_system predicate: enables object: zinc_export description: CzcP exports zinc together with cadmium and cobalt cations. evidence: - reference: DOI:10.1111/j.1365-2958.2009.06792.x notes: CzcP exports transition metals Zn(2+), Cd(2+), and Co(2+). predicate_id: RO:0002327 - subject: zinc_export predicate: mitigates object: zinc_ion description: Czc-mediated export depletes the cytoplasmic zinc pool. evidence: - reference: DOI:10.1111/j.1365-2958.2009.06792.x notes: The czc efflux system of C. metallidurans confers zinc resistance. predicate_id: METPO:2007407 - subject: znta_atpase predicate: exports object: zinc_ion description: ZntA PIB2-type ATPase effluxes cytoplasmic Zn(2+). evidence: - reference: DOI:10.1128/jb.00080-24 notes: Efflux of zinc ions is mediated by the PIB2-type ATPase, ZntA. predicate_id: METPO:2000209 - subject: znta_atpase predicate: promotes object: zinc_tolerant_trait description: ZntA-mediated efflux is causal for zinc resistance. evidence: - reference: DOI:10.1128/jb.00080-24 notes: Deletion of PIB2 ATPases sharply lowers IC50 (to 7.7 uM), showing their causal role in resistance. predicate_id: RO:0002213 - subject: zinc_ion predicate: upregulates object: znta_expression description: Elevated zinc induces transcription of the zntA efflux gene. evidence: - reference: DOI:10.1128/jb.00299-24 notes: At external zinc concentrations above 200 nM expression of the zntA gene is upregulated. - subject: zntr_regulator predicate: required for object: znta_expression description: ZntR is essential for zinc-responsive zntA expression. evidence: - reference: DOI:10.1128/jb.00299-24 notes: ZntR was essential for zntA expression. - subject: znta_expression predicate: results in object: czc_efflux_system description: zntA transcription yields the ZntA efflux machinery. evidence: - reference: DOI:10.1128/jb.00299-24 notes: Increased zntA expression provides ZntA exporter under zinc excess. - subject: czccba_complex predicate: exports object: zinc_ion description: CzcCBA RND pump exports Zn(2+) from the periplasm. evidence: - reference: DOI:10.1128/jb.00080-24 notes: The plasmid-encoded RND transenvelope pump CzcCBA exports Co(II), Zn(II), and Cd(II). predicate_id: METPO:2000209 - subject: polyphosphate predicate: contributes to object: zinc_buffering description: Polyphosphate buffers cytoplasmic zinc, shaping flow equilibrium. evidence: - reference: DOI:10.1128/jb.00080-24 notes: Metal-binding cytoplasmic components polyphosphate and glutathione influenced the flow equilibrium. predicate_id: RO:0002326 - subject: glutathione predicate: contributes to object: zinc_buffering description: Glutathione buffers cytoplasmic zinc, shaping flow equilibrium. evidence: - reference: DOI:10.1128/jb.00080-24 notes: Polyphosphate and glutathione influenced the flow equilibrium. predicate_id: RO:0002326 - subject: zinc_buffering predicate: mitigates object: zinc_ion description: Buffering lowers free cytoplasmic zinc. evidence: - reference: DOI:10.1128/jb.00080-24 notes: Cytoplasmic buffering components influence the zinc flow equilibrium. predicate_id: METPO:2007407 curation_history: - timestamp: '2026-05-28T00:00:00Z' curator: claude action: PROPOSED_FROM_RESEARCH changes: Proposed candidate ENVIRONMENT trait (zinc tolerance) from literature research; metal-specific sub-variant of metal tolerant. llm_assisted: true - timestamp: '2026-06-09T14:00:00Z' curator: claude action: CURATED_CAUSAL_GRAPH changes: Added evidence-backed causal graph (czc zinc efflux) with CHEBI/GO node groundings and RO/METPO predicate groundings; promoted PROPOSED to REVIEWED. llm_assisted: true - timestamp: '2026-06-14T06:38:14Z' curator: claude action: GROUND_CAUSAL_NODES changes: Grounded 1 causal-node grounding field(s) via mappings/node_grounding.tsv (UniProtKB:B0VPE1×1). llm_assisted: true - timestamp: '2026-06-23T00:00:00Z' curator: claude action: ENRICH_CAUSAL_GRAPH changes: Added 9 evidence-backed generic edges (7 new nodes) from the deep-research report. llm_assisted: true - timestamp: '2026-06-24T17:21:11Z' curator: claude action: GROUND_CAUSAL_PREDICATES changes: Grounded 6 causal-edge predicate_id field(s) via mappings/predicate_grounding.tsv (METPO:2000209×2, RO:0002326×2, RO:0002213×1, METPO:2007407×1). llm_assisted: true - timestamp: '2026-06-24T17:23:32Z' curator: claude action: GROUND_CAUSAL_NODES changes: Grounded 1 causal-node grounding field(s) via mappings/node_grounding.tsv (CHEBI:16838×1). llm_assisted: true