{"gene":"PF3D7_0704100","run_date":"2026-09-08T16:26:55","timeline":{"discoveries":[{"year":2026,"finding":"BTP2 (PF3D7_0704100) is required for individual daughter cell separation during asexual replication in P. falciparum. Parasites lacking BTP2 are still enveloped by membranes but fail to separate from each other, resulting in multiorganellar mutants. The defect was isolated to a specific step during basal complex development, and the contractile ability of the basal complex remains intact in BTP2-null parasites. Expansion microscopy and DNA-PAINT imaging established that BTP2 is a transmembrane basal complex protein whose loss disrupts daughter cell individualization without abolishing contractile ring function.","method":"Conditional/genetic knockout with expansion microscopy (ExM) and DNA points accumulation for imaging in nanoscale topography (DNA-PAINT); phenotypic characterization of BTP2-null parasites","journal":"Science advances","confidence":"High","confidence_rationale":"Tier 2 / Moderate — clean genetic knockout with defined cellular phenotype, two orthogonal high-resolution imaging methods (expansion microscopy + DNA-PAINT), and functional dissection isolating the specific step disrupted","pmids":["41706859"],"is_preprint":false,"attribution":[{"species":"Plasmodium falciparum","strain":""}]},{"year":2019,"finding":"BTP2 (PF3D7_0704100) localizes to the basal complex of P. falciparum during schizogony and was identified as an interaction partner of PfCINCH (the coordinator of nascent cell detachment) along with PfBCP1, based on co-localization and interaction studies reported in Rudlaff et al., 2019.","method":"Immunofluorescence localization; protein interaction/co-localization with PfCINCH and PfBCP1 (cited as established in Rudlaff et al., 2019)","journal":"Frontiers in cellular and infection microbiology","confidence":"Low","confidence_rationale":"Tier 3 / Weak — interaction and localization reported only as a citation summary in a review abstract body mention, single indirect reference with no primary experimental detail provided in this corpus entry","pmids":["31824870"],"is_preprint":false,"attribution":[{"species":"Plasmodium falciparum","strain":""}]},{"year":2022,"finding":"BTP2 (PF3D7_0704100) localizes to the leading edge of the emerging inner membrane complex (basal complex) in P. falciparum schizonts, but is not detected by immunofluorescence during gametocytogenesis, in contrast to PfBLEB and PfCINCH. This indicates that BTP2 is not recruited to the basal complex equivalent structure during transmission-stage development.","method":"Immunofluorescence assay using PfBTP2-3xHA parasite strains; comparison across asexual and gametocyte stages","journal":"Proceedings of the National Academy of Sciences of the United States of America","confidence":"Medium","confidence_rationale":"Tier 3 / Moderate — direct localization experiment using epitope-tagged endogenous protein across multiple life-cycle stages, single lab but specific parasite strain used","pmids":["35972967"],"is_preprint":false,"attribution":[{"species":"Plasmodium falciparum","strain":""}]}],"current_model":"BTP2 (PF3D7_0704100) is a transmembrane protein of the P. falciparum basal complex that localizes to the leading edge of the inner membrane complex during schizogony and is specifically required for the separation of individual daughter merozoites from each other—a step distinct from basal complex contractile function itself—while playing no detectable role during gametocytogenesis."},"narrative":{"mechanistic_narrative":"BTP2 (PF3D7_0704100) is a transmembrane component of the Plasmodium falciparum basal complex that is specifically required for the separation of individual daughter merozoites during asexual schizogony [PMID:41706859]. During schizont development BTP2 localizes to the basal complex, concentrating at the leading edge of the emerging inner membrane complex [PMID:35972967]. Genetic ablation of BTP2 yields daughter cells that remain enveloped by membranes but fail to individualize, producing multiorganellar mutants; notably, the contractile function of the basal complex ring stays intact in BTP2-null parasites, isolating BTP2's role to daughter cell separation rather than to constriction itself [PMID:41706859]. BTP2's contribution is stage-restricted: it is not detected during gametocytogenesis, in contrast to other basal complex proteins, indicating it is not deployed during transmission-stage development [PMID:35972967]. Beyond its transmembrane basal complex localization and its role in merozoite individualization, no further biochemical mechanism—such as how BTP2 is recruited or what it binds within the complex—has been characterized in the available corpus.","teleology":[{"year":2019,"claim":"The first question was whether BTP2 is a genuine basal complex resident, addressed by placing it within the known contractile machinery of the complex.","evidence":"Immunofluorescence localization and reported interaction/co-localization with PfCINCH and PfBCP1 during schizogony","pmids":["31824870"],"confidence":"Low","gaps":["Interaction reported only as a citation summary with no primary experimental detail in this corpus entry","No reciprocal validation or direct binding assay for the PfCINCH/PfBCP1 association","Functional role of BTP2 not addressed"],"attribution":[{"species":"Plasmodium falciparum","strain":""}]},{"year":2022,"claim":"Establishing where and when BTP2 acts, endogenous tagging showed it localizes to the leading edge of the emerging inner membrane complex in schizonts but is absent from the gametocyte basal complex equivalent, defining its role as stage-restricted to asexual replication.","evidence":"Immunofluorescence of PfBTP2-3xHA endogenously tagged parasites compared across asexual and gametocyte stages","pmids":["35972967"],"confidence":"Medium","gaps":["Does not define BTP2's molecular function at the basal complex","Recruitment mechanism to the leading edge unknown","Single lab and single strain"],"attribution":[{"species":"Plasmodium falciparum","strain":""}]},{"year":2026,"claim":"The functional question—what BTP2 actually does—was resolved by knockout, showing it is specifically required for individual daughter cell separation, a step distinct from basal complex contraction.","evidence":"Conditional/genetic knockout with expansion microscopy and DNA-PAINT imaging; phenotypic characterization of BTP2-null parasites","pmids":["41706859"],"confidence":"High","gaps":["Molecular mechanism by which BTP2 drives individualization is undefined","How the transmembrane topology relates to its separation function is unresolved","Direct binding partners within the basal complex not biochemically mapped"],"attribution":[{"species":"Plasmodium falciparum","strain":""}]},{"year":null,"claim":"It remains unknown how BTP2 mechanistically mediates daughter cell separation and what molecular interactions or membrane activities underlie its transmembrane function at the basal complex leading edge.","evidence":"","pmids":[],"confidence":"High","gaps":["No defined biochemical activity or direct interactor set for BTP2","No structural model of BTP2 within the basal complex","Recruitment pathway to the inner membrane complex leading edge uncharacterized"],"attribution":[{"species":"Plasmodium falciparum","strain":""}]}],"mechanism_profile":{"molecular_activity":[],"localization":[],"pathway":[],"complexes":["basal complex"],"partners":["PFCINCH","PFBCP1"],"other_free_text":["Transmembrane basal complex protein required for merozoite separation but dispensable for basal complex contractile function [#0]","Not detected during gametocytogenesis, unlike PfBLEB and PfCINCH [#2]"]}},"prefetch_data":{},"corpus_meta":[{"pmid":"41706859","id":"PMC_41706859","title":"Transmembrane proteins mediate basal complex assembly and individual daughter cell formation in malaria parasites.","date":"2026","source":"Science advances","url":"https://pubmed.ncbi.nlm.nih.gov/41706859","citation_count":1,"is_preprint":false,"source_species":["Pf"],"role":"primary","match_terms":["BTP2"],"competing_organism_flag":false,"competing_organism_match":"","competing_organism_only":false},{"pmid":"35972967","id":"","title":"Identification of basal complex protein that is essential for maturation of transmission-stage malaria parasites.","date":"2022","source":"Proceedings of the National Academy of Sciences of the United States of America","url":"https://pubmed.ncbi.nlm.nih.gov/35972967","citation_count":0,"is_preprint":false,"source_species":["Pf"],"role":"primary","match_terms":["BTP2"],"competing_organism_flag":false,"competing_organism_match":"","competing_organism_only":false},{"pmid":"33489940","id":"","title":"The Dynamic Roles of the Inner Membrane Complex in the Multiple Stages of the Malaria Parasite.","date":"2021","source":"Frontiers in cellular and infection microbiology","url":"https://pubmed.ncbi.nlm.nih.gov/33489940","citation_count":0,"is_preprint":false,"source_species":["Pf"],"role":"primary","match_terms":["BTP2"],"competing_organism_flag":false,"competing_organism_match":"","competing_organism_only":false},{"pmid":"33954122","id":"","title":"The Ringleaders: Understanding the Apicomplexan Basal Complex Through Comparison to Established Contractile Ring Systems.","date":"2021","source":"Frontiers in cellular and infection microbiology","url":"https://pubmed.ncbi.nlm.nih.gov/33954122","citation_count":0,"is_preprint":false,"source_species":["Pf"],"role":"primary","match_terms":["BTP2"],"competing_organism_flag":false,"competing_organism_match":"","competing_organism_only":false},{"pmid":"31824870","id":"","title":"Who Needs a Contractile Actomyosin Ring? The Plethora of Alternative Ways to Divide a Protozoan Parasite.","date":"2019","source":"Frontiers in cellular and infection microbiology","url":"https://pubmed.ncbi.nlm.nih.gov/31824870","citation_count":0,"is_preprint":false,"source_species":["Pf"],"role":"primary","match_terms":["BTP2"],"competing_organism_flag":false,"competing_organism_match":"","competing_organism_only":false}],"cost":{"stage1":{"model":"claude-sonnet-4-6","input_tokens":6744,"output_tokens":1027,"usd":0.017819,"stage1_stop_reason":"end_turn"},"stage2":{"model":"claude-opus-4-8","input_tokens":5802,"output_tokens":1781,"usd":0.036768,"stage2_stop_reason":"end_turn"},"total_usd":0.054587,"stage1_batch_id":"msgbatch_01NE1MTa8x1hW7Lo4tAaNzY1","stage2_batch_id":"msgbatch_0141vaQdeFvbo2q39AinvXM9","note":"batch pricing = 50% of standard"},"stage1_raw":"```json\n{\n  \"discoveries\": [\n    {\n      \"year\": 2026,\n      \"finding\": \"BTP2 (PF3D7_0704100) is required for individual daughter cell separation during asexual replication in P. falciparum. Parasites lacking BTP2 are still enveloped by membranes but fail to separate from each other, resulting in multiorganellar mutants. The defect was isolated to a specific step during basal complex development, and the contractile ability of the basal complex remains intact in BTP2-null parasites. Expansion microscopy and DNA-PAINT imaging established that BTP2 is a transmembrane basal complex protein whose loss disrupts daughter cell individualization without abolishing contractile ring function.\",\n      \"method\": \"Conditional/genetic knockout with expansion microscopy (ExM) and DNA points accumulation for imaging in nanoscale topography (DNA-PAINT); phenotypic characterization of BTP2-null parasites\",\n      \"journal\": \"Science advances\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — clean genetic knockout with defined cellular phenotype, two orthogonal high-resolution imaging methods (expansion microscopy + DNA-PAINT), and functional dissection isolating the specific step disrupted\",\n      \"pmids\": [\"41706859\"],\n      \"is_preprint\": false,\n      \"attribution\": [{\"species\": \"Plasmodium falciparum\", \"strain\": \"\"}]\n    },\n    {\n      \"year\": 2019,\n      \"finding\": \"BTP2 (PF3D7_0704100) localizes to the basal complex of P. falciparum during schizogony and was identified as an interaction partner of PfCINCH (the coordinator of nascent cell detachment) along with PfBCP1, based on co-localization and interaction studies reported in Rudlaff et al., 2019.\",\n      \"method\": \"Immunofluorescence localization; protein interaction/co-localization with PfCINCH and PfBCP1 (cited as established in Rudlaff et al., 2019)\",\n      \"journal\": \"Frontiers in cellular and infection microbiology\",\n      \"confidence\": \"Low\",\n      \"confidence_rationale\": \"Tier 3 / Weak — interaction and localization reported only as a citation summary in a review abstract body mention, single indirect reference with no primary experimental detail provided in this corpus entry\",\n      \"pmids\": [\"31824870\"],\n      \"is_preprint\": false,\n      \"attribution\": [{\"species\": \"Plasmodium falciparum\", \"strain\": \"\"}]\n    },\n    {\n      \"year\": 2022,\n      \"finding\": \"BTP2 (PF3D7_0704100) localizes to the leading edge of the emerging inner membrane complex (basal complex) in P. falciparum schizonts, but is not detected by immunofluorescence during gametocytogenesis, in contrast to PfBLEB and PfCINCH. This indicates that BTP2 is not recruited to the basal complex equivalent structure during transmission-stage development.\",\n      \"method\": \"Immunofluorescence assay using PfBTP2-3xHA parasite strains; comparison across asexual and gametocyte stages\",\n      \"journal\": \"Proceedings of the National Academy of Sciences of the United States of America\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 3 / Moderate — direct localization experiment using epitope-tagged endogenous protein across multiple life-cycle stages, single lab but specific parasite strain used\",\n      \"pmids\": [\"35972967\"],\n      \"is_preprint\": false,\n      \"attribution\": [{\"species\": \"Plasmodium falciparum\", \"strain\": \"\"}]\n    }\n  ],\n  \"current_model\": \"BTP2 (PF3D7_0704100) is a transmembrane protein of the P. falciparum basal complex that localizes to the leading edge of the inner membrane complex during schizogony and is specifically required for the separation of individual daughter merozoites from each other—a step distinct from basal complex contractile function itself—while playing no detectable role during gametocytogenesis.\"\n}\n```","stage2_raw":"{\n  \"mechanistic_narrative\": \"BTP2 (PF3D7_0704100) is a transmembrane component of the Plasmodium falciparum basal complex that is specifically required for the separation of individual daughter merozoites during asexual schizogony [#0]. During schizont development BTP2 localizes to the basal complex, concentrating at the leading edge of the emerging inner membrane complex [#2]. Genetic ablation of BTP2 yields daughter cells that remain enveloped by membranes but fail to individualize, producing multiorganellar mutants; notably, the contractile function of the basal complex ring stays intact in BTP2-null parasites, isolating BTP2's role to daughter cell separation rather than to constriction itself [#0]. BTP2's contribution is stage-restricted: it is not detected during gametocytogenesis, in contrast to other basal complex proteins, indicating it is not deployed during transmission-stage development [#2]. Beyond its transmembrane basal complex localization and its role in merozoite individualization, no further biochemical mechanism—such as how BTP2 is recruited or what it binds within the complex—has been characterized in the available corpus.\",\n  \"teleology\": [\n    {\n      \"year\": 2019,\n      \"claim\": \"The first question was whether BTP2 is a genuine basal complex resident, addressed by placing it within the known contractile machinery of the complex.\",\n      \"evidence\": \"Immunofluorescence localization and reported interaction/co-localization with PfCINCH and PfBCP1 during schizogony\",\n      \"pmids\": [\"31824870\"],\n      \"confidence\": \"Low\",\n      \"gaps\": [\n        \"Interaction reported only as a citation summary with no primary experimental detail in this corpus entry\",\n        \"No reciprocal validation or direct binding assay for the PfCINCH/PfBCP1 association\",\n        \"Functional role of BTP2 not addressed\"\n      ],\n      \"attribution\": [{\"species\": \"Plasmodium falciparum\", \"strain\": \"\"}]\n    },\n    {\n      \"year\": 2022,\n      \"claim\": \"Establishing where and when BTP2 acts, endogenous tagging showed it localizes to the leading edge of the emerging inner membrane complex in schizonts but is absent from the gametocyte basal complex equivalent, defining its role as stage-restricted to asexual replication.\",\n      \"evidence\": \"Immunofluorescence of PfBTP2-3xHA endogenously tagged parasites compared across asexual and gametocyte stages\",\n      \"pmids\": [\"35972967\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\n        \"Does not define BTP2's molecular function at the basal complex\",\n        \"Recruitment mechanism to the leading edge unknown\",\n        \"Single lab and single strain\"\n      ],\n      \"attribution\": [{\"species\": \"Plasmodium falciparum\", \"strain\": \"\"}]\n    },\n    {\n      \"year\": 2026,\n      \"claim\": \"The functional question—what BTP2 actually does—was resolved by knockout, showing it is specifically required for individual daughter cell separation, a step distinct from basal complex contraction.\",\n      \"evidence\": \"Conditional/genetic knockout with expansion microscopy and DNA-PAINT imaging; phenotypic characterization of BTP2-null parasites\",\n      \"pmids\": [\"41706859\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\n        \"Molecular mechanism by which BTP2 drives individualization is undefined\",\n        \"How the transmembrane topology relates to its separation function is unresolved\",\n        \"Direct binding partners within the basal complex not biochemically mapped\"\n      ],\n      \"attribution\": [{\"species\": \"Plasmodium falciparum\", \"strain\": \"\"}]\n    },\n    {\n      \"year\": null,\n      \"claim\": \"It remains unknown how BTP2 mechanistically mediates daughter cell separation and what molecular interactions or membrane activities underlie its transmembrane function at the basal complex leading edge.\",\n      \"evidence\": \"\",\n      \"pmids\": [],\n      \"confidence\": \"High\",\n      \"gaps\": [\n        \"No defined biochemical activity or direct interactor set for BTP2\",\n        \"No structural model of BTP2 within the basal complex\",\n        \"Recruitment pathway to the inner membrane complex leading edge uncharacterized\"\n      ],\n      \"attribution\": [{\"species\": \"Plasmodium falciparum\", \"strain\": \"\"}]\n    }\n  ],\n  \"mechanism_profile\": {\n    \"molecular_activity\": [],\n    \"localization\": [\n      {\"term_id\": \"basal complex\", \"supporting_discovery_ids\": [0, 1, 2]},\n      {\"term_id\": \"inner membrane complex leading edge\", \"supporting_discovery_ids\": [2]}\n    ],\n    \"pathway\": [\n      {\"term_id\": \"schizogony / daughter cell individualization\", \"supporting_discovery_ids\": [0]}\n    ],\n    \"complexes\": [\"basal complex\"],\n    \"partners\": [\"PfCINCH\", \"PfBCP1\"],\n    \"other_free_text\": [\n      \"Transmembrane basal complex protein required for merozoite separation but dispensable for basal complex contractile function [#0]\",\n      \"Not detected during gametocytogenesis, unlike PfBLEB and PfCINCH [#2]\"\n    ]\n  }\n}","audit_flag":null,"strains":[{"strain":"Pf3D7","gene_id":"PF3D7_0704100","name":null,"product":"basal complex transmembrane protein 2","uniprot_acc":null,"chromosome":null,"start_pos":null},{"strain":"PbANKA","gene_id":"PBANKA_0801800","name":null,"product":"basal complex transmembrane protein 2, putative","uniprot_acc":null,"chromosome":null,"start_pos":null},{"strain":"PkH","gene_id":"PKNH_0102300","name":null,"product":"basal complex transmembrane protein 2, putative","uniprot_acc":null,"chromosome":null,"start_pos":null}],"gene_symbol":"BTP2","evaluation":null}