{"gene":"PF3D7_0929600","run_date":"2026-09-08T15:29:15+00:00","timeline":{"discoveries":[{"year":2013,"finding":"G2 (PF3D7_0929600 ortholog in P. berghei) is a novel subpellicular network (SPN) protein of ookinetes and sporozoites that is structurally unrelated to alveolins; knockout of G2 abolishes parasite transmission, causes zoite malformations and motility defects, and results in abnormal arrangement of subpellicular microtubules in sporozoites, yet G2 contributes little to tensile strength — demonstrating that tensile strength and cell shape determination are uncoupled.","method":"Gene knockout (G2 null mutant) with phenotypic readouts: parasite transmission assays, morphological analysis, motility assays, tensile strength measurements, and subpellicular microtubule arrangement analysis by microscopy","journal":"Molecular microbiology","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — clean KO with multiple orthogonal phenotypic readouts (morphology, motility, tensile strength, microtubule arrangement) in a single study; single lab","pmids":["23773015"],"is_preprint":false,"attribution":[{"species":"Plasmodium berghei","strain":""}]}],"current_model":"G2 (PF3D7_0929600) encodes a subpellicular network protein in Plasmodium zoites that is structurally distinct from alveolins, is required for normal zoite morphogenesis and gliding motility (including proper subpellicular microtubule arrangement), and is essential for parasite transmission, but contributes little to the tensile strength of the cortical cytoskeleton."},"narrative":{"mechanistic_narrative":"G2 (PF3D7_0929600) is a subpellicular network (SPN) protein of Plasmodium zoites that is structurally unrelated to the alveolin family and is required for zoite morphogenesis, gliding motility, and parasite transmission [PMID:23773015]. In P. berghei, knockout of the G2 ortholog abolishes transmission, produces malformed zoites with motility defects, and disrupts the ordered arrangement of subpellicular microtubules in sporozoites, while contributing little to the tensile strength of the cortical cytoskeleton — establishing that shape determination and tensile strength are separable properties of the SPN [PMID:23773015]. Beyond this single knockout characterization in P. berghei, no further mechanistic detail, binding partners, or biochemical activity for G2 has been characterized in the available corpus.","teleology":[{"year":2013,"claim":"It was unknown whether non-alveolin components contribute to the subpellicular network and how the SPN separately governs zoite shape versus mechanical strength; knockout of G2 established it as a novel, alveolin-independent SPN protein required for morphogenesis, motility, and transmission but not tensile strength.","evidence":"Gene knockout of the G2 ortholog in P. berghei with transmission assays, morphological and motility analysis, tensile strength measurements, and microscopy of subpellicular microtubule arrangement","pmids":["23773015"],"confidence":"Medium","gaps":["No molecular partners or SPN-anchoring interactions identified for G2","No biochemical activity or structural model for G2","Not tested in P. falciparum or other Plasmodium species"],"attribution":[{"species":"Plasmodium berghei","strain":""}]},{"year":null,"claim":"How G2 is recruited to and integrated within the subpellicular network, and how it mechanistically directs subpellicular microtubule arrangement and zoite shape, remains unresolved.","evidence":"","pmids":[],"confidence":"Medium","gaps":["No identified interaction partners linking G2 to microtubules or the SPN scaffold","No direct biochemical or structural characterization of G2","Function in the human parasite P. falciparum untested"],"attribution":[{"species":"Plasmodium berghei","strain":""}]}],"mechanism_profile":{"molecular_activity":[],"localization":[],"pathway":[],"complexes":[],"partners":[],"other_free_text":["Structurally unrelated to alveolins [#0]","Required for normal subpellicular microtubule arrangement in sporozoites [#0]","Contributes little to cortical cytoskeleton tensile strength, uncoupling shape determination from mechanical strength [#0]","Shown for the P. berghei ortholog of PF3D7_0929600; not directly characterized in P. falciparum"]}},"prefetch_data":{},"corpus_meta":[{"pmid":"23773015","id":"PMC_23773015","title":"Morphogenesis of Plasmodium zoites is uncoupled from tensile strength.","date":"2013","source":"Molecular microbiology","url":"https://pubmed.ncbi.nlm.nih.gov/23773015","citation_count":19,"is_preprint":false,"source_species":["Pf"],"role":"primary","match_terms":["curated_ref"],"competing_organism_flag":false,"competing_organism_match":"","competing_organism_only":false}],"cost":{"stage1":{"model":"claude-sonnet-4-6","input_tokens":3258,"output_tokens":455,"usd":0.008299,"stage1_stop_reason":"end_turn"},"stage2":{"model":"claude-opus-4-8","input_tokens":4960,"output_tokens":1222,"usd":0.027675,"stage2_stop_reason":"end_turn"},"total_usd":0.0,"stage1_batch_id":"msgbatch_01FCQcGLVKCfKut4FD5ct3Fw","stage2_batch_id":"msgbatch_019yw2n5AfaBHFs27bCBAnvb","note":"batch pricing = 50% of standard","skipped":true},"stage1_raw":"```json\n{\n  \"discoveries\": [\n    {\n      \"year\": 2013,\n      \"finding\": \"G2 (PF3D7_0929600 ortholog in P. berghei) is a novel subpellicular network (SPN) protein of ookinetes and sporozoites that is structurally unrelated to alveolins; knockout of G2 abolishes parasite transmission, causes zoite malformations and motility defects, and results in abnormal arrangement of subpellicular microtubules in sporozoites, yet G2 contributes little to tensile strength — demonstrating that tensile strength and cell shape determination are uncoupled.\",\n      \"method\": \"Gene knockout (G2 null mutant) with phenotypic readouts: parasite transmission assays, morphological analysis, motility assays, tensile strength measurements, and subpellicular microtubule arrangement analysis by microscopy\",\n      \"journal\": \"Molecular microbiology\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — clean KO with multiple orthogonal phenotypic readouts (morphology, motility, tensile strength, microtubule arrangement) in a single study; single lab\",\n      \"pmids\": [\"23773015\"],\n      \"is_preprint\": false,\n      \"attribution\": [\n        {\"species\": \"Plasmodium berghei\", \"strain\": \"\"}\n      ]\n    }\n  ],\n  \"current_model\": \"G2 (PF3D7_0929600) encodes a subpellicular network protein in Plasmodium zoites that is structurally distinct from alveolins, is required for normal zoite morphogenesis and gliding motility (including proper subpellicular microtubule arrangement), and is essential for parasite transmission, but contributes little to the tensile strength of the cortical cytoskeleton.\"\n}\n```","stage2_raw":"{\n  \"mechanistic_narrative\": \"G2 (PF3D7_0929600) is a subpellicular network (SPN) protein of Plasmodium zoites that is structurally unrelated to the alveolin family and is required for zoite morphogenesis, gliding motility, and parasite transmission [#0]. In P. berghei, knockout of the G2 ortholog abolishes transmission, produces malformed zoites with motility defects, and disrupts the ordered arrangement of subpellicular microtubules in sporozoites, while contributing little to the tensile strength of the cortical cytoskeleton — establishing that shape determination and tensile strength are separable properties of the SPN [#0]. Beyond this single knockout characterization in P. berghei, no further mechanistic detail, binding partners, or biochemical activity for G2 has been characterized in the available corpus.\",\n  \"teleology\": [\n    {\n      \"year\": 2013,\n      \"claim\": \"It was unknown whether non-alveolin components contribute to the subpellicular network and how the SPN separately governs zoite shape versus mechanical strength; knockout of G2 established it as a novel, alveolin-independent SPN protein required for morphogenesis, motility, and transmission but not tensile strength.\",\n      \"evidence\": \"Gene knockout of the G2 ortholog in P. berghei with transmission assays, morphological and motility analysis, tensile strength measurements, and microscopy of subpellicular microtubule arrangement\",\n      \"pmids\": [\"23773015\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\n        \"No molecular partners or SPN-anchoring interactions identified for G2\",\n        \"No biochemical activity or structural model for G2\",\n        \"Not tested in P. falciparum or other Plasmodium species\"\n      ],\n      \"attribution\": [\n        {\"species\": \"Plasmodium berghei\", \"strain\": \"\"}\n      ]\n    },\n    {\n      \"year\": null,\n      \"claim\": \"How G2 is recruited to and integrated within the subpellicular network, and how it mechanistically directs subpellicular microtubule arrangement and zoite shape, remains unresolved.\",\n      \"evidence\": \"\",\n      \"pmids\": [],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\n        \"No identified interaction partners linking G2 to microtubules or the SPN scaffold\",\n        \"No direct biochemical or structural characterization of G2\",\n        \"Function in the human parasite P. falciparum untested\"\n      ],\n      \"attribution\": [\n        {\"species\": \"Plasmodium berghei\", \"strain\": \"\"}\n      ]\n    }\n  ],\n  \"mechanism_profile\": {\n    \"molecular_activity\": [],\n    \"localization\": [\n      {\"term_id\": \"subpellicular network\", \"supporting_discovery_ids\": [0]}\n    ],\n    \"pathway\": [\n      {\"term_id\": \"gliding motility\", \"supporting_discovery_ids\": [0]},\n      {\"term_id\": \"zoite morphogenesis\", \"supporting_discovery_ids\": [0]},\n      {\"term_id\": \"parasite transmission\", \"supporting_discovery_ids\": [0]}\n    ],\n    \"complexes\": [],\n    \"partners\": [],\n    \"other_free_text\": [\n      \"Structurally unrelated to alveolins [#0]\",\n      \"Required for normal subpellicular microtubule arrangement in sporozoites [#0]\",\n      \"Contributes little to cortical cytoskeleton tensile strength, uncoupling shape determination from mechanical strength [#0]\",\n      \"Shown for the P. berghei ortholog of PF3D7_0929600; not directly characterized in P. falciparum\"\n    ]\n  }\n}","audit_flag":null,"strains":[{"strain":"Pf3D7","gene_id":"PF3D7_0929600","name":null,"product":"G2 protein, putative","uniprot_acc":null,"chromosome":null,"start_pos":null},{"strain":"PbANKA","gene_id":"PBANKA_0830400","name":null,"product":"G2 protein","uniprot_acc":null,"chromosome":null,"start_pos":null},{"strain":"PkH","gene_id":"PKNH_0728100","name":null,"product":"G2 protein, putative","uniprot_acc":null,"chromosome":null,"start_pos":null}],"gene_symbol":"","evaluation":null}