{"gene":"TG_293730","gene_symbol":"DHHC14","run_date":"2026-09-10T21:09:19","timeline":{"discoveries":[{"year":2020,"finding":"TgDHHC14 localizes to the inner membrane complex (IMC) of Toxoplasma gondii tachyzoites, and its disruption causes rapid collapse of the IMC in developing daughter cells with dramatic morphological defects, establishing TgDHHC14 as an IMC-resident palmitoyl acyltransferase essential for IMC biogenesis.","method":"Conditional disruption (loss-of-function), subcellular localization by imaging, morphological phenotype analysis","journal":"Cellular microbiology","confidence":"High","confidence_rationale":"Tier 2 / Moderate — clean conditional disruption with defined cellular phenotype (IMC collapse), direct localization by imaging, single lab but two orthogonal methods","pmids":["32329212"],"is_preprint":false,"attribution":[{"species":"Toxoplasma gondii","strain":""}]},{"year":2020,"finding":"TgDHHC14 and TgDHHC2 act sequentially in IMC sub-compartment formation: TgDHHC2 palmitoylates TgISP1/3 and TgIAP1/2 (which lose membrane association upon TgDHHC2 depletion but are unaffected by TgDHHC14 depletion), indicating that TgDHHC14 acts on a distinct set of IMC substrates at a different stage of IMC biogenesis.","method":"Conditional disruption of TgDHHC2 and TgDHHC14 individually, followed by localization assays for known palmitoylated IMC proteins (TgISP1/3, TgIAP1/2) as substrate readouts","journal":"Cellular microbiology","confidence":"High","confidence_rationale":"Tier 2 / Moderate — reciprocal loss-of-function epistasis with specific substrate readouts, two orthogonal genetic perturbations, single lab","pmids":["32329212"],"is_preprint":false,"attribution":[{"species":"Toxoplasma gondii","strain":""}]}],"current_model":"TgDHHC14 is an IMC-resident palmitoyl acyltransferase (PAT) in Toxoplasma gondii tachyzoites that is essential for parasite survival; its acyltransferase activity is required for the biogenesis of IMC sub-compartments during daughter-cell development, acting sequentially with TgDHHC2 on distinct palmitoylated IMC substrates, as disruption of TgDHHC14 causes collapse of the IMC in developing daughters without directly affecting the membrane association of TgISP1/3 or TgIAP1/2 (substrates of TgDHHC2)."},"narrative":{"mechanistic_narrative":"TgDHHC14 is an inner membrane complex (IMC)-resident member of the DHHC-CRD palmitoyl acyltransferase (PAT) family in Toxoplasma gondii. Conditional disruption of TgDHHC14 causes rapid collapse of the IMC in developing daughter cells, establishing its acyltransferase function as required for IMC biogenesis during daughter-cell formation [PMID:32329212]. TgDHHC14 acts sequentially with TgDHHC2 on distinct IMC substrates: TgDHHC2 palmitoylates TgISP1/3 and TgIAP1/2, whose membrane association is lost upon TgDHHC2 depletion but is unaffected by TgDHHC14 depletion, indicating that TgDHHC14 modifies a separate set of substrates at a different stage of IMC sub-compartment formation [PMID:32329212]. The direct palmitoylation substrates of TgDHHC14 have not been identified in the available corpus.","teleology":[{"year":2020,"claim":"It was unknown which cellular structure TgDHHC14 maintains; conditional disruption combined with imaging localized TgDHHC14 to the IMC and showed its loss causes rapid IMC collapse in developing daughters, establishing it as an IMC-resident PAT required for IMC biogenesis.","evidence":"Conditional loss-of-function, subcellular imaging, and morphological phenotype analysis in T. gondii tachyzoites","pmids":["32329212"],"confidence":"High","gaps":["Direct palmitoylation substrates of TgDHHC14 not identified","Enzymatic activity not reconstituted in vitro","Mechanism of IMC collapse downstream of substrate modification unresolved"],"attribution":[{"species":"Toxoplasma gondii","strain":""}]},{"year":2020,"claim":"To resolve whether TgDHHC14 and TgDHHC2 act on the same pathway, reciprocal depletion with substrate readouts showed TgDHHC2 (not TgDHHC14) controls membrane association of TgISP1/3 and TgIAP1/2, establishing that the two PATs act sequentially on distinct substrates during IMC sub-compartment formation.","evidence":"Individual conditional disruption of TgDHHC2 and TgDHHC14 with localization readouts of known palmitoylated IMC proteins as substrate proxies","pmids":["32329212"],"confidence":"High","gaps":["The specific substrates acted on by TgDHHC14 remain undefined","Stage/ordering of TgDHHC14 action within IMC biogenesis not molecularly mapped","No direct enzyme-substrate biochemistry"],"attribution":[{"species":"Toxoplasma gondii","strain":""}]}],"mechanism_profile":{"molecular_activity":[],"localization":[],"pathway":[],"complexes":[],"partners":["TGDHHC2 (FUNCTIONALLY SEQUENTIAL PAT ACTING ON DISTINCT IMC SUBSTRATES)"],"other_free_text":["Essential, non-redundant DHHC-CRD palmitoyl acyltransferase in Toxoplasma gondii tachyzoites","Required for IMC biogenesis during daughter-cell development; disruption causes IMC collapse in developing daughters","TgISP1/3 and TgIAP1/2 are substrates of TgDHHC2, not TgDHHC14; their membrane association is unaffected by TgDHHC14 depletion"]},"strain_conflicts":[]},"prefetch_data":{},"corpus_meta":[{"pmid":"32329212","id":"PMC_32329212","title":"Two palmitoyl acyltransferases involved sequentially in the biogenesis of the inner membrane complex of Toxoplasma gondii.","date":"2020","source":"Cellular microbiology","url":"https://pubmed.ncbi.nlm.nih.gov/32329212","citation_count":7,"is_preprint":false}],"cost":{"stage1":{"model":"claude-sonnet-4-6","input_tokens":4001,"output_tokens":1061,"usd":0.013959,"stage1_stop_reason":"end_turn"},"stage2":{"model":"claude-opus-4-8","input_tokens":5905,"output_tokens":2140,"usd":0.041513,"stage2_stop_reason":"end_turn"},"total_usd":0.05881,"stage1_batch_id":"msgbatch_015xmQKDRqnTh9anE4m7LiD6","stage2_batch_id":"msgbatch_01JLpkFTVhoQBNgqHCKFrVVU","note":"batch pricing = 50% of standard","corrective_rerun":"2026-09-10 wrong-gene rerun (round-4 rules)","corrective_reason":"summary amended"},"stage1_raw":"```json\n{\n  \"discoveries\": [\n    {\n      \"year\": 2013,\n      \"finding\": \"TgDHHC14 was identified as a member of the DHHC-CRD protein S-acyl transferase (PAT) family in Toxoplasma gondii; global functional analysis showed that some apicomplexan DHHCs, unlike in other eukaryotes, are essential for parasite growth with no functional redundancy.\",\n      \"method\": \"Comprehensive genomic survey combined with localization and essentiality assessment (reverse genetics) across Toxoplasma gondii and Plasmodium berghei\",\n      \"journal\": \"Traffic (Copenhagen, Denmark)\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Weak — clean essentiality assessment by reverse genetics in a large-scale study, but DHHC14-specific mechanistic detail is not resolved beyond essentiality and IMC localization\",\n      \"pmids\": [\"23638681\"],\n      \"is_preprint\": false,\n      \"attribution\": [\n        {\"species\": \"Toxoplasma gondii\", \"strain\": \"\"},\n        {\"species\": \"Plasmodium berghei\", \"strain\": \"\"}\n      ]\n    },\n    {\n      \"year\": 2020,\n      \"finding\": \"TgDHHC14 localizes to the inner membrane complex (IMC) of Toxoplasma gondii tachyzoites, and its disruption causes rapid collapse of the IMC in developing daughter cells with dramatic morphological defects, establishing TgDHHC14 as an IMC-resident palmitoyl acyltransferase essential for IMC biogenesis.\",\n      \"method\": \"Conditional disruption (loss-of-function), subcellular localization by imaging, morphological phenotype analysis\",\n      \"journal\": \"Cellular microbiology\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — clean conditional disruption with defined cellular phenotype (IMC collapse), direct localization by imaging, single lab but two orthogonal methods\",\n      \"pmids\": [\"32329212\"],\n      \"is_preprint\": false,\n      \"attribution\": [\n        {\"species\": \"Toxoplasma gondii\", \"strain\": \"\"}\n      ]\n    },\n    {\n      \"year\": 2020,\n      \"finding\": \"TgDHHC14 and TgDHHC2 act sequentially in IMC sub-compartment formation: TgDHHC2 palmitoylates TgISP1/3 and TgIAP1/2 (which lose membrane association upon TgDHHC2 depletion but are unaffected by TgDHHC14 depletion), indicating that TgDHHC14 acts on a distinct set of IMC substrates at a different stage of IMC biogenesis.\",\n      \"method\": \"Conditional disruption of TgDHHC2 and TgDHHC14 individually, followed by localization assays for known palmitoylated IMC proteins (TgISP1/3, TgIAP1/2) as substrate readouts\",\n      \"journal\": \"Cellular microbiology\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — reciprocal loss-of-function epistasis with specific substrate readouts, two orthogonal genetic perturbations, single lab\",\n      \"pmids\": [\"32329212\"],\n      \"is_preprint\": false,\n      \"attribution\": [\n        {\"species\": \"Toxoplasma gondii\", \"strain\": \"\"}\n      ]\n    }\n  ],\n  \"current_model\": \"TgDHHC14 is an IMC-resident palmitoyl acyltransferase (PAT) in Toxoplasma gondii tachyzoites that is essential for parasite survival; its acyltransferase activity is required for the biogenesis of IMC sub-compartments during daughter-cell development, acting sequentially with TgDHHC2 on distinct palmitoylated IMC substrates, as disruption of TgDHHC14 causes collapse of the IMC in developing daughters without directly affecting the membrane association of TgISP1/3 or TgIAP1/2 (substrates of TgDHHC2).\"\n}\n```","stage2_raw":"{\n  \"mechanistic_narrative\": \"TgDHHC14 is an inner membrane complex (IMC)-resident member of the DHHC-CRD palmitoyl acyltransferase (PAT) family in Toxoplasma gondii and is essential for tachyzoite survival, with no functional redundancy [#0, #1]. Conditional disruption of TgDHHC14 causes rapid collapse of the IMC in developing daughter cells, establishing its acyltransferase function as required for IMC biogenesis during daughter-cell formation [#1]. TgDHHC14 acts sequentially with TgDHHC2 on distinct IMC substrates: TgDHHC2 palmitoylates TgISP1/3 and TgIAP1/2, whose membrane association is lost upon TgDHHC2 depletion but is unaffected by TgDHHC14 depletion, indicating that TgDHHC14 modifies a separate set of substrates at a different stage of IMC sub-compartment formation [#2]. The direct palmitoylation substrates of TgDHHC14 have not been identified in the available corpus.\",\n  \"teleology\": [\n    {\n      \"year\": 2013,\n      \"claim\": \"Before this work it was unclear whether individual apicomplexan DHHC PATs were dispensable; genome-scale essentiality assessment established that TgDHHC14 is an essential, non-redundant member of the PAT family, distinguishing apicomplexan DHHCs from their functionally redundant eukaryotic counterparts.\",\n      \"evidence\": \"Comprehensive genomic survey with localization and reverse-genetics essentiality assessment across T. gondii and P. berghei\",\n      \"pmids\": [\"23638681\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\n        \"No DHHC14-specific substrate or mechanism resolved beyond essentiality\",\n        \"IMC localization noted but functional role in IMC not yet defined\",\n        \"No biochemical demonstration of acyltransferase activity\"\n      ],\n      \"attribution\": [\n        {\"species\": \"Toxoplasma gondii\", \"strain\": \"\"},\n        {\"species\": \"Plasmodium berghei\", \"strain\": \"\"}\n      ]\n    },\n    {\n      \"year\": 2020,\n      \"claim\": \"It was unknown which cellular structure TgDHHC14 maintains; conditional disruption combined with imaging localized TgDHHC14 to the IMC and showed its loss causes rapid IMC collapse in developing daughters, establishing it as an IMC-resident PAT required for IMC biogenesis.\",\n      \"evidence\": \"Conditional loss-of-function, subcellular imaging, and morphological phenotype analysis in T. gondii tachyzoites\",\n      \"pmids\": [\"32329212\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\n        \"Direct palmitoylation substrates of TgDHHC14 not identified\",\n        \"Enzymatic activity not reconstituted in vitro\",\n        \"Mechanism of IMC collapse downstream of substrate modification unresolved\"\n      ],\n      \"attribution\": [\n        {\"species\": \"Toxoplasma gondii\", \"strain\": \"\"}\n      ]\n    },\n    {\n      \"year\": 2020,\n      \"claim\": \"To resolve whether TgDHHC14 and TgDHHC2 act on the same pathway, reciprocal depletion with substrate readouts showed TgDHHC2 (not TgDHHC14) controls membrane association of TgISP1/3 and TgIAP1/2, establishing that the two PATs act sequentially on distinct substrates during IMC sub-compartment formation.\",\n      \"evidence\": \"Individual conditional disruption of TgDHHC2 and TgDHHC14 with localization readouts of known palmitoylated IMC proteins as substrate proxies\",\n      \"pmids\": [\"32329212\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\n        \"The specific substrates acted on by TgDHHC14 remain undefined\",\n        \"Stage/ordering of TgDHHC14 action within IMC biogenesis not molecularly mapped\",\n        \"No direct enzyme-substrate biochemistry\"\n      ],\n      \"attribution\": [\n        {\"species\": \"Toxoplasma gondii\", \"strain\": \"\"}\n      ]\n    },\n    {\n      \"year\": null,\n      \"claim\": \"The direct palmitoylation substrates of TgDHHC14 and the molecular pathway linking their modification to IMC integrity remain unidentified.\",\n      \"evidence\": \"\",\n      \"pmids\": [],\n      \"confidence\": \"High\",\n      \"gaps\": [\n        \"No TgDHHC14 substrate identified\",\n        \"No in vitro reconstitution of acyltransferase activity\",\n        \"Mechanism connecting substrate palmitoylation to IMC biogenesis unknown\"\n      ],\n      \"attribution\": [\n        {\"species\": \"Toxoplasma gondii\", \"strain\": \"\"}\n      ]\n    }\n  ],\n  \"mechanism_profile\": {\n    \"molecular_activity\": [\n      {\"term_id\": \"GO:0019706\", \"supporting_discovery_ids\": [0, 1], \"attribution\": [{\"species\": \"Toxoplasma gondii\", \"strain\": \"\"}]}\n    ],\n    \"localization\": [\n      {\"term_id\": \"GO:0033099\", \"supporting_discovery_ids\": [1, 2], \"attribution\": [{\"species\": \"Toxoplasma gondii\", \"strain\": \"\"}]}\n    ],\n    \"pathway\": [\n      {\"term_id\": \"GO:0018345\", \"supporting_discovery_ids\": [2], \"attribution\": [{\"species\": \"Toxoplasma gondii\", \"strain\": \"\"}]}\n    ],\n    \"complexes\": [],\n    \"partners\": [\n      \"TgDHHC2 (functionally sequential PAT acting on distinct IMC substrates)\"\n    ],\n    \"other_free_text\": [\n      \"Essential, non-redundant DHHC-CRD palmitoyl acyltransferase in Toxoplasma gondii tachyzoites\",\n      \"Required for IMC biogenesis during daughter-cell development; disruption causes IMC collapse in developing daughters\",\n      \"TgISP1/3 and TgIAP1/2 are substrates of TgDHHC2, not TgDHHC14; their membrane association is unaffected by TgDHHC14 depletion\"\n    ]\n  },\n  \"strain_conflicts\": []\n}","audit_flag":null,"strains":[{"strain":"ME49","gene_id":"TGME49_293730","name":"DHHC14","product":"palmitoyltransferase DHHC14","uniprot_acc":"A0A125YY95","chromosome":"TGME49_chrIa","start_pos":529625},{"strain":"GT1","gene_id":"TGGT1_293730","name":null,"product":"DHHC zinc finger domain-containing protein","uniprot_acc":null,"chromosome":"TGGT1_chrIa","start_pos":515727},{"strain":"RH88","gene_id":"TGRH88_019030","name":null,"product":"DHHC zinc finger domain-containing protein","uniprot_acc":null,"chromosome":"CM023081","start_pos":535893},{"strain":"VEG","gene_id":"TGVEG_293730","name":null,"product":"DHHC zinc finger domain-containing protein","uniprot_acc":"B9PY64","chromosome":"TGVEG_chrIa","start_pos":539349}]}