{"gene":"PF3D7_1031200","run_date":"2026-09-08T12:51:28","timeline":{"discoveries":[{"year":2008,"finding":"MORN1 protein in P. falciparum localizes to the posterior ring of the inner membrane complex (IMC) of nascent daughter cells during erythrocytic schizogony, with protein expression peaking in late schizogony, consistent with a role in IMC assembly.","method":"Immunofluorescence/antibody localization across developmental stages","journal":"Eukaryotic cell","confidence":"Medium","confidence_rationale":"Tier 3 / Moderate — direct localization experiment with stage-specific expression data, single lab, single primary method","pmids":["18310354"],"is_preprint":false,"attribution":[{"species":"Plasmodium falciparum","strain":""}]},{"year":2016,"finding":"MORN1 serves as a marker for the basal complex in P. falciparum, colocalizing with the novel transmembrane protein BTP1 at the basal complex ring during schizogony; the basal complex dynamics correlate with plasma membrane invagination during cell division.","method":"Colocalization by fluorescence microscopy using tagged proteins","journal":"Journal of cell science","confidence":"Low","confidence_rationale":"Tier 3 / Weak — single lab, single colocalization method; MORN1 used as reference marker rather than subject of functional study","pmids":["26763910"],"is_preprint":false,"attribution":[{"species":"Plasmodium falciparum","strain":""}]},{"year":2020,"finding":"Crystal structure, SAXS, and EM structures of P. falciparum MORN1 protein were obtained, revealing that MORN repeats form a defined structural unit and that the protein dimerizes via its C-terminus in an antiparallel configuration, with dimers capable of forming extended or V-shaped quaternary structures depending on specific interface residues; no evidence was found for lipid membrane binding by the MORN repeat module.","method":"Macromolecular crystallography, small-angle X-ray scattering (SAXS), and electron microscopy; in vitro lipid-binding assays","journal":"PloS one","confidence":"High","confidence_rationale":"Tier 1 / Strong — multiple orthogonal structural methods (crystallography, SAXS, EM) combined with in vitro functional assays in a single rigorous study","pmids":["33296386"],"is_preprint":false,"attribution":[{"species":"Plasmodium falciparum","strain":""}]},{"year":2021,"finding":"Inducible knockout of MORN1 in P. falciparum blood stages causes no detectable defect in asexual parasite morphology or replicative fitness, demonstrating that MORN1 is dispensable for asexual replication in P. falciparum (in contrast to its essential role in Toxoplasma gondii).","method":"Inducible knockout (conditional gene disruption) with parasite morphology and growth fitness assays","journal":"mSphere","confidence":"High","confidence_rationale":"Tier 2 / Moderate — clean inducible knockout with morphological and fitness readouts, single lab but rigorous genetic approach with clear phenotypic outcome","pmids":["34878291"],"is_preprint":false,"attribution":[{"species":"Plasmodium falciparum","strain":""}]}],"current_model":"P. falciparum MORN1 (PF3D7_1031200) is a structural component of the basal complex/posterior IMC ring during schizogony whose MORN repeats mediate antiparallel C-terminal dimerization and higher-order oligomerization (not lipid binding), yet inducible knockout experiments show it is dispensable for asexual blood-stage replication and daughter-cell morphology."},"narrative":{"mechanistic_narrative":"MORN1 (PF3D7_1031200) is a structural component of the inner membrane complex (IMC) and basal complex of nascent daughter cells during Plasmodium falciparum erythrocytic schizogony, localizing to the posterior IMC ring with protein expression peaking in late schizogony [PMID:18310354]. It serves as a marker of the basal complex ring, where its dynamics track plasma membrane invagination during cell division [PMID:26763910]. Structurally, its MORN repeats form a defined module that drives C-terminal antiparallel dimerization and higher-order extended or V-shaped quaternary assemblies governed by specific interface residues, and this module does not bind lipid membranes [PMID:33296386]. Despite this structural role, inducible knockout of MORN1 produces no detectable defect in asexual parasite morphology or replicative fitness, establishing that it is dispensable for asexual blood-stage replication in P. falciparum, unlike the essential role of the ortholog in Toxoplasma gondii [PMID:34878291]. Beyond these findings, no substrate, catalytic activity, or direct functional partner of MORN1 has been characterized in the available corpus.","teleology":[{"year":2008,"claim":"Establishing where and when MORN1 acts was the first step in placing it within daughter-cell assembly; localization to the posterior IMC ring with late-schizont expression tied it to IMC formation during division.","evidence":"Immunofluorescence/antibody localization across erythrocytic developmental stages","pmids":["18310354"],"confidence":"Medium","gaps":["Localization alone does not establish function","No interacting partners identified","No test of whether MORN1 is required for IMC assembly"],"attribution":[{"species":"Plasmodium falciparum","strain":""}]},{"year":2016,"claim":"To refine the structure MORN1 marks, colocalization defined it as a basal complex marker alongside the transmembrane protein BTP1, linking the basal complex ring to plasma membrane invagination during cytokinesis.","evidence":"Colocalization by fluorescence microscopy using tagged proteins","pmids":["26763910"],"confidence":"Low","gaps":["MORN1 used as a reference marker rather than the subject of functional study, so its own contribution is not tested","Colocalization does not demonstrate physical interaction with BTP1","Single colocalization method from a single lab"],"attribution":[{"species":"Plasmodium falciparum","strain":""}]},{"year":2020,"claim":"How the MORN repeats build structure was resolved: rather than binding membrane lipids, the repeats mediate antiparallel C-terminal dimerization and tunable higher-order oligomerization, reframing MORN1 as a self-assembling scaffold module.","evidence":"Crystallography, SAXS and EM combined with in vitro lipid-binding assays on recombinant MORN1","pmids":["33296386"],"confidence":"High","gaps":["Structural behavior in vitro not linked to a specific in vivo assembly","Physiological binding partners at the interfaces not identified","Functional consequence of extended versus V-shaped conformations untested in the parasite"],"attribution":[{"species":"Plasmodium falciparum","strain":""}]},{"year":2021,"claim":"Whether the basal complex scaffold role of MORN1 is essential was tested directly: inducible knockout left asexual morphology and fitness intact, showing MORN1 is dispensable for blood-stage replication in P. falciparum and diverging from the essential Toxoplasma ortholog.","evidence":"Inducible conditional gene disruption with parasite morphology and growth fitness readouts","pmids":["34878291"],"confidence":"High","gaps":["Dispensability tested only in asexual blood stages, not sexual or other life-cycle stages","Possible functional redundancy with other basal complex components not resolved","Reason for divergence from the essential Toxoplasma ortholog not explained"],"attribution":[{"species":"Plasmodium falciparum","strain":""}]},{"year":null,"claim":"The in vivo function served by MORN1's self-assembling scaffold module at the basal complex, and why it is dispensable in P. falciparum asexual stages, remain unresolved.","evidence":"","pmids":[],"confidence":"Low","gaps":["No physiological binding partner of MORN1 identified","No stage other than asexual blood stage tested for a MORN1 requirement","No mechanistic link between the oligomerization behavior and basal complex function"],"attribution":[{"species":"Plasmodium falciparum","strain":""}]}],"mechanism_profile":{"molecular_activity":[],"localization":[],"pathway":[],"complexes":["basal complex","inner membrane complex (posterior ring)"],"partners":["BTP1 (COLOCALIZATION AT THE BASAL COMPLEX RING)"],"other_free_text":["MORN repeats form a defined structural unit mediating antiparallel C-terminal dimerization and extended or V-shaped higher-order oligomers [#2]","MORN repeat module shows no lipid membrane binding in vitro [#2]","Dispensable for asexual blood-stage replication in P. falciparum, in contrast to the essential Toxoplasma gondii ortholog [#3]"]}},"prefetch_data":{},"corpus_meta":[{"pmid":"18310354","id":"PMC_18310354","title":"MORN1 has a conserved role in asexual and sexual development across the apicomplexa.","date":"2008","source":"Eukaryotic cell","url":"https://pubmed.ncbi.nlm.nih.gov/18310354","citation_count":84,"is_preprint":false,"source_species":["Pf"],"role":"primary","match_terms":["MORN1"],"competing_organism_flag":false,"competing_organism_match":"","competing_organism_only":false},{"pmid":"26763910","id":"PMC_26763910","title":"Pellicle formation in the malaria parasite.","date":"2016","source":"Journal of cell science","url":"https://pubmed.ncbi.nlm.nih.gov/26763910","citation_count":30,"is_preprint":false,"source_species":["Pf"],"role":"primary","match_terms":["MORN1"],"competing_organism_flag":false,"competing_organism_match":"","competing_organism_only":false},{"pmid":"33296386","id":"PMC_33296386","title":"Structures of three MORN repeat proteins and a re-evaluation of the proposed lipid-binding properties of MORN repeats.","date":"2020","source":"PloS one","url":"https://pubmed.ncbi.nlm.nih.gov/33296386","citation_count":20,"is_preprint":false,"source_species":["Pf"],"role":"primary","match_terms":["MORN1","MORN"],"competing_organism_flag":false,"competing_organism_match":"","competing_organism_only":false},{"pmid":"34878291","id":"PMC_34878291","title":"The Basal Complex Protein PfMORN1 Is Not Required for Asexual Replication of Plasmodium falciparum.","date":"2021","source":"mSphere","url":"https://pubmed.ncbi.nlm.nih.gov/34878291","citation_count":9,"is_preprint":false,"source_species":["Pf"],"role":"primary","match_terms":["MORN1","PfMORN1"],"competing_organism_flag":false,"competing_organism_match":"","competing_organism_only":false}],"cost":{"stage1":{"model":"claude-sonnet-4-6","input_tokens":4721,"output_tokens":1064,"usd":0.015062,"stage1_stop_reason":"end_turn"},"stage2":{"model":"claude-opus-4-8","input_tokens":5850,"output_tokens":2124,"usd":0.041175,"stage2_stop_reason":"end_turn"},"total_usd":0.056237,"stage1_batch_id":"msgbatch_01DisAaTypwmC8QwdMBuePHo","stage2_batch_id":"msgbatch_0184zxZTqxiEfdYYfPMfkqjb","note":"batch pricing = 50% of standard"},"stage1_raw":"```json\n{\n  \"discoveries\": [\n    {\n      \"year\": 2008,\n      \"finding\": \"MORN1 protein in P. falciparum localizes to the posterior ring of the inner membrane complex (IMC) of nascent daughter cells during erythrocytic schizogony, with protein expression peaking in late schizogony, consistent with a role in IMC assembly.\",\n      \"method\": \"Immunofluorescence/antibody localization across developmental stages\",\n      \"journal\": \"Eukaryotic cell\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 3 / Moderate — direct localization experiment with stage-specific expression data, single lab, single primary method\",\n      \"pmids\": [\"18310354\"],\n      \"is_preprint\": false,\n      \"attribution\": [{\"species\": \"Plasmodium falciparum\", \"strain\": \"\"}]\n    },\n    {\n      \"year\": 2016,\n      \"finding\": \"MORN1 serves as a marker for the basal complex in P. falciparum, colocalizing with the novel transmembrane protein BTP1 at the basal complex ring during schizogony; the basal complex dynamics correlate with plasma membrane invagination during cell division.\",\n      \"method\": \"Colocalization by fluorescence microscopy using tagged proteins\",\n      \"journal\": \"Journal of cell science\",\n      \"confidence\": \"Low\",\n      \"confidence_rationale\": \"Tier 3 / Weak — single lab, single colocalization method; MORN1 used as reference marker rather than subject of functional study\",\n      \"pmids\": [\"26763910\"],\n      \"is_preprint\": false,\n      \"attribution\": [{\"species\": \"Plasmodium falciparum\", \"strain\": \"\"}]\n    },\n    {\n      \"year\": 2020,\n      \"finding\": \"Crystal structure, SAXS, and EM structures of P. falciparum MORN1 protein were obtained, revealing that MORN repeats form a defined structural unit and that the protein dimerizes via its C-terminus in an antiparallel configuration, with dimers capable of forming extended or V-shaped quaternary structures depending on specific interface residues; no evidence was found for lipid membrane binding by the MORN repeat module.\",\n      \"method\": \"Macromolecular crystallography, small-angle X-ray scattering (SAXS), and electron microscopy; in vitro lipid-binding assays\",\n      \"journal\": \"PloS one\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 / Strong — multiple orthogonal structural methods (crystallography, SAXS, EM) combined with in vitro functional assays in a single rigorous study\",\n      \"pmids\": [\"33296386\"],\n      \"is_preprint\": false,\n      \"attribution\": [{\"species\": \"Plasmodium falciparum\", \"strain\": \"\"}]\n    },\n    {\n      \"year\": 2021,\n      \"finding\": \"Inducible knockout of MORN1 in P. falciparum blood stages causes no detectable defect in asexual parasite morphology or replicative fitness, demonstrating that MORN1 is dispensable for asexual replication in P. falciparum (in contrast to its essential role in Toxoplasma gondii).\",\n      \"method\": \"Inducible knockout (conditional gene disruption) with parasite morphology and growth fitness assays\",\n      \"journal\": \"mSphere\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — clean inducible knockout with morphological and fitness readouts, single lab but rigorous genetic approach with clear phenotypic outcome\",\n      \"pmids\": [\"34878291\"],\n      \"is_preprint\": false,\n      \"attribution\": [{\"species\": \"Plasmodium falciparum\", \"strain\": \"\"}]\n    }\n  ],\n  \"current_model\": \"P. falciparum MORN1 (PF3D7_1031200) is a structural component of the basal complex/posterior IMC ring during schizogony whose MORN repeats mediate antiparallel C-terminal dimerization and higher-order oligomerization (not lipid binding), yet inducible knockout experiments show it is dispensable for asexual blood-stage replication and daughter-cell morphology.\"\n}\n```","stage2_raw":"{\n  \"mechanistic_narrative\": \"MORN1 (PF3D7_1031200) is a structural component of the inner membrane complex (IMC) and basal complex of nascent daughter cells during Plasmodium falciparum erythrocytic schizogony, localizing to the posterior IMC ring with protein expression peaking in late schizogony [#0]. It serves as a marker of the basal complex ring, where its dynamics track plasma membrane invagination during cell division [#1]. Structurally, its MORN repeats form a defined module that drives C-terminal antiparallel dimerization and higher-order extended or V-shaped quaternary assemblies governed by specific interface residues, and this module does not bind lipid membranes [#2]. Despite this structural role, inducible knockout of MORN1 produces no detectable defect in asexual parasite morphology or replicative fitness, establishing that it is dispensable for asexual blood-stage replication in P. falciparum, unlike the essential role of the ortholog in Toxoplasma gondii [#3]. Beyond these findings, no substrate, catalytic activity, or direct functional partner of MORN1 has been characterized in the available corpus.\",\n  \"teleology\": [\n    {\n      \"year\": 2008,\n      \"claim\": \"Establishing where and when MORN1 acts was the first step in placing it within daughter-cell assembly; localization to the posterior IMC ring with late-schizont expression tied it to IMC formation during division.\",\n      \"evidence\": \"Immunofluorescence/antibody localization across erythrocytic developmental stages\",\n      \"pmids\": [\"18310354\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\n        \"Localization alone does not establish function\",\n        \"No interacting partners identified\",\n        \"No test of whether MORN1 is required for IMC assembly\"\n      ],\n      \"attribution\": [{\"species\": \"Plasmodium falciparum\", \"strain\": \"\"}]\n    },\n    {\n      \"year\": 2016,\n      \"claim\": \"To refine the structure MORN1 marks, colocalization defined it as a basal complex marker alongside the transmembrane protein BTP1, linking the basal complex ring to plasma membrane invagination during cytokinesis.\",\n      \"evidence\": \"Colocalization by fluorescence microscopy using tagged proteins\",\n      \"pmids\": [\"26763910\"],\n      \"confidence\": \"Low\",\n      \"gaps\": [\n        \"MORN1 used as a reference marker rather than the subject of functional study, so its own contribution is not tested\",\n        \"Colocalization does not demonstrate physical interaction with BTP1\",\n        \"Single colocalization method from a single lab\"\n      ],\n      \"attribution\": [{\"species\": \"Plasmodium falciparum\", \"strain\": \"\"}]\n    },\n    {\n      \"year\": 2020,\n      \"claim\": \"How the MORN repeats build structure was resolved: rather than binding membrane lipids, the repeats mediate antiparallel C-terminal dimerization and tunable higher-order oligomerization, reframing MORN1 as a self-assembling scaffold module.\",\n      \"evidence\": \"Crystallography, SAXS and EM combined with in vitro lipid-binding assays on recombinant MORN1\",\n      \"pmids\": [\"33296386\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\n        \"Structural behavior in vitro not linked to a specific in vivo assembly\",\n        \"Physiological binding partners at the interfaces not identified\",\n        \"Functional consequence of extended versus V-shaped conformations untested in the parasite\"\n      ],\n      \"attribution\": [{\"species\": \"Plasmodium falciparum\", \"strain\": \"\"}]\n    },\n    {\n      \"year\": 2021,\n      \"claim\": \"Whether the basal complex scaffold role of MORN1 is essential was tested directly: inducible knockout left asexual morphology and fitness intact, showing MORN1 is dispensable for blood-stage replication in P. falciparum and diverging from the essential Toxoplasma ortholog.\",\n      \"evidence\": \"Inducible conditional gene disruption with parasite morphology and growth fitness readouts\",\n      \"pmids\": [\"34878291\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\n        \"Dispensability tested only in asexual blood stages, not sexual or other life-cycle stages\",\n        \"Possible functional redundancy with other basal complex components not resolved\",\n        \"Reason for divergence from the essential Toxoplasma ortholog not explained\"\n      ],\n      \"attribution\": [{\"species\": \"Plasmodium falciparum\", \"strain\": \"\"}]\n    },\n    {\n      \"year\": null,\n      \"claim\": \"The in vivo function served by MORN1's self-assembling scaffold module at the basal complex, and why it is dispensable in P. falciparum asexual stages, remain unresolved.\",\n      \"evidence\": \"\",\n      \"pmids\": [],\n      \"confidence\": \"Low\",\n      \"gaps\": [\n        \"No physiological binding partner of MORN1 identified\",\n        \"No stage other than asexual blood stage tested for a MORN1 requirement\",\n        \"No mechanistic link between the oligomerization behavior and basal complex function\"\n      ],\n      \"attribution\": [{\"species\": \"Plasmodium falciparum\", \"strain\": \"\"}]\n    }\n  ],\n  \"mechanism_profile\": {\n    \"molecular_activity\": [\n      {\"term_id\": \"GO:0042803\", \"supporting_discovery_ids\": [2]}\n    ],\n    \"localization\": [\n      {\"term_id\": \"GO:0070258\", \"supporting_discovery_ids\": [0]}\n    ],\n    \"pathway\": [\n      {\"term_id\": \"GO:0051301\", \"supporting_discovery_ids\": [1]}\n    ],\n    \"complexes\": [\"basal complex\", \"inner membrane complex (posterior ring)\"],\n    \"partners\": [\"BTP1 (colocalization at the basal complex ring)\"],\n    \"other_free_text\": [\n      \"MORN repeats form a defined structural unit mediating antiparallel C-terminal dimerization and extended or V-shaped higher-order oligomers [#2]\",\n      \"MORN repeat module shows no lipid membrane binding in vitro [#2]\",\n      \"Dispensable for asexual blood-stage replication in P. falciparum, in contrast to the essential Toxoplasma gondii ortholog [#3]\"\n    ]\n  }\n}","audit_flag":null,"strains":[{"strain":"Pf3D7","gene_id":"PF3D7_1031200","name":null,"product":"MORN repeat-containing protein 1","uniprot_acc":null,"chromosome":null,"start_pos":null},{"strain":"PbANKA","gene_id":"PBANKA_0515200","name":null,"product":"MORN repeat-containing protein 1, putative","uniprot_acc":null,"chromosome":null,"start_pos":null},{"strain":"PkH","gene_id":"PKNH_0615900","name":null,"product":"MORN repeat-containing protein 1, putative","uniprot_acc":null,"chromosome":null,"start_pos":null}],"gene_symbol":"MORN1","evaluation":null}