{"gene":"PF3D7_0611600","run_date":"2026-09-08T19:44:17","timeline":{"discoveries":[{"year":2016,"finding":"BTP1 (PF3D7_0611600) is a novel transmembrane protein that localizes to the basal complex of P. falciparum, colocalizing with the known basal complex marker MORN1. It shows distinct dynamics compared to other IMC proteins during schizogony, and live-imaging with a parasite plasma membrane marker demonstrated that basal complex dynamics (including BTP1 localization) are correlated with plasma membrane invagination during the final steps of cell division, suggesting BTP1 may be involved in interactions between the invaginating plasma membrane and the IMC.","method":"Fluorescence microscopy / live imaging, transgenic parasite lines with epitope-tagged BTP1, co-localization with MORN1 marker","journal":"Journal of cell science","confidence":"Medium","confidence_rationale":"Tier 3 / Moderate — direct localization experiment with functional correlation via plasma membrane marker, single lab, single paper with two orthogonal fluorescence approaches","pmids":["26763910"],"is_preprint":false,"attribution":[{"species":"Plasmodium falciparum","strain":""}]},{"year":2019,"finding":"BTP1 (PF3D7_0611600) colocalizes with MORN1 at the basal complex during segmentation in P. falciparum, and is recovered as part of the PfCINCH-containing basal complex by co-immunoprecipitation, establishing its membership in the basal complex protein complex.","method":"Immunofluorescence co-localization with MORN1; co-immunoprecipitation of PfCINCH-containing complexes followed by mass spectrometry","journal":"Nature communications","confidence":"Medium","confidence_rationale":"Tier 3 / Moderate — co-IP/MS identification plus co-localization, single lab, two orthogonal methods but no functional mutagenesis of BTP1 itself","pmids":["31097714"],"is_preprint":false,"attribution":[{"species":"Plasmodium falciparum","strain":"3D7"}]},{"year":2026,"finding":"BTP1 (PF3D7_0611600) is a transmembrane basal complex protein in P. falciparum whose localization was directly visualized by expansion microscopy (U-ExM) and DNA-PAINT nanoscopy. BTP1-mNeonGreen was also used as a basal complex marker to co-localize with PfVPS13L1-Halo, showing overlap during IMC formation, confirming BTP1's role as a bona fide basal complex transmembrane component during daughter cell formation.","method":"Expansion microscopy (U-ExM), DNA-PAINT (PAINT nanoscopy), fluorescence co-localization with tagged BTP1","journal":"Science advances","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — direct localization with two independent high-resolution imaging methods in a single study, but functional role of BTP1 itself not independently tested beyond its use as a marker","pmids":["41706859"],"is_preprint":false,"attribution":[{"species":"Plasmodium falciparum","strain":""}]},{"year":2025,"finding":"BTP1 (PF3D7_0611600) is among the differentially phosphorylated proteins detected in P. falciparum parasites depleted of PfPPM2 (a protein phosphatase), identifying BTP1 as a substrate (or indirect target) in a phosphorylation-regulated pathway governing IMC formation during parasite division.","method":"Phosphoproteomics on PfPPM2-depleted parasites","journal":"Nature communications","confidence":"Low","confidence_rationale":"Tier 4 / Weak — phosphoproteomics dataset; BTP1 phosphorylation detected but direct writer/eraser relationship not experimentally confirmed for BTP1 specifically","pmids":["40410154"],"is_preprint":false,"attribution":[{"species":"Plasmodium falciparum","strain":""}]},{"year":2026,"finding":"BTP1-mNeonGreen (BTP1-mNG) co-localizes with PfVPS13L1-Halo during IMC formation in P. falciparum schizonts, establishing that BTP1 marks the basal complex region where ER-IMC membrane contact sites (bridged by VPS13L1) are found, and confirming BTP1 as a spatial reference for the basal complex during IMC biogenesis.","method":"Fluorescence co-localization microscopy of episomally expressed BTP1-mNG with endogenously tagged PfVPS13L1-Halo","journal":"Nature communications","confidence":"Low","confidence_rationale":"Tier 3 / Weak — single co-localization experiment; BTP1 used as a marker rather than being functionally interrogated in this study","pmids":["41904125"],"is_preprint":false,"attribution":[{"species":"Plasmodium falciparum","strain":""}]}],"current_model":"BTP1 (PF3D7_0611600) is a Plasmodium-specific transmembrane protein that localizes to the basal complex—the contractile ring at the leading edge of the inner membrane complex—where it colocalizes with MORN1 and is part of the PfCINCH-containing basal complex, with its dynamics during schizogony correlated with plasma membrane invagination during daughter cell formation; its phosphorylation state is regulated downstream of PfPPM2, but no direct enzymatic activity or independent loss-of-function phenotype has been established for BTP1 itself."},"narrative":{"mechanistic_narrative":"BTP1 (PF3D7_0611600) is a Plasmodium falciparum transmembrane protein of the basal complex, the ring-shaped structure at the leading edge of the inner membrane complex (IMC) that drives daughter cell formation during schizogony [PMID:26763910]. It colocalizes with the basal complex marker MORN1 and is recovered biochemically as part of the PfCINCH-containing basal complex, establishing it as a bona fide component of this division machinery [PMID:26763910, PMID:31097714]. Live imaging showed that basal complex dynamics marked by BTP1 track plasma membrane invagination during the final steps of cell division, indicating a role at the interface between the invaginating plasma membrane and the IMC [PMID:26763910]. High-resolution imaging by expansion microscopy and DNA-PAINT confirmed its basal complex localization, and BTP1 has been used as a spatial reference to mark the region where ER-IMC membrane contact sites reside [PMID:41706859, PMID:41904125]. Its phosphorylation state is altered upon depletion of the phosphatase PfPPM2, placing BTP1 within a phosphoregulated pathway governing IMC formation [PMID:40410154]. Beyond its membership in the basal complex and correlation of its dynamics with membrane invagination, no direct enzymatic activity or independent loss-of-function phenotype has been established for BTP1 itself in the available corpus.","teleology":[{"year":2016,"claim":"Establishing whether a novel transmembrane protein participates in Plasmodium cell division required localizing it and correlating its behavior with the division machinery; this identified BTP1 as a basal complex protein whose dynamics track plasma membrane invagination.","evidence":"Fluorescence and live imaging of epitope-tagged BTP1 lines with MORN1 co-localization and a plasma membrane marker in P. falciparum","pmids":["26763910"],"confidence":"Medium","gaps":["No loss-of-function analysis of BTP1 itself","Correlation with membrane invagination does not demonstrate a causal or mechanical role","Molecular partners not yet defined"],"attribution":[{"species":"Plasmodium falciparum","strain":""}]},{"year":2019,"claim":"Whether BTP1's basal complex localization reflected physical membership in a defined protein complex was unresolved; biochemical recovery placed BTP1 within the PfCINCH-containing basal complex.","evidence":"Co-immunoprecipitation of PfCINCH complexes with mass spectrometry plus MORN1 co-localization in P. falciparum 3D7","pmids":["31097714"],"confidence":"Medium","gaps":["No mutagenesis of BTP1 to test complex assembly dependence","Direct binding partners of BTP1 within the complex not resolved","Functional contribution of BTP1 to complex activity untested"],"attribution":[{"species":"Plasmodium falciparum","strain":"3D7"}]},{"year":2025,"claim":"How basal complex/IMC formation is regulated post-translationally was unclear; phosphoproteomics identified BTP1 as a differentially phosphorylated target downstream of the phosphatase PfPPM2.","evidence":"Phosphoproteomics on PfPPM2-depleted P. falciparum parasites","pmids":["40410154"],"confidence":"Low","gaps":["Direct writer/eraser relationship for BTP1 phosphosites not experimentally confirmed","Functional consequence of BTP1 phosphorylation unknown","Distinction between direct and indirect PfPPM2 targeting not established"],"attribution":[{"species":"Plasmodium falciparum","strain":""}]},{"year":2026,"claim":"Confirming BTP1's precise localization and its spatial relationship to membrane biogenesis required higher resolution; nanoscopy and co-localization with VPS13L1 confirmed BTP1 as a transmembrane basal complex marker at ER-IMC membrane contact regions.","evidence":"Expansion microscopy (U-ExM), DNA-PAINT nanoscopy, and co-localization of BTP1-mNeonGreen with PfVPS13L1-Halo in P. falciparum","pmids":["41706859","41904125"],"confidence":"Low","gaps":["BTP1 used as a marker rather than functionally interrogated","No direct interaction between BTP1 and VPS13L1 demonstrated","Role of BTP1 in membrane contact site formation untested"],"attribution":[{"species":"Plasmodium falciparum","strain":""}]},{"year":null,"claim":"The direct molecular function of BTP1 and its independent contribution to basal complex biology remain unknown.","evidence":"No loss-of-function phenotype or reconstituted activity for BTP1 reported in the corpus","pmids":[],"confidence":"Low","gaps":["No BTP1 knockout/knockdown phenotype established","No direct enzymatic or mechanical activity assigned","Functional significance of its phosphorylation and membrane-invagination correlation undefined"],"attribution":[{"species":"Plasmodium falciparum","strain":""}]}],"mechanism_profile":{"molecular_activity":[],"localization":[],"pathway":[],"complexes":["PfCINCH-containing basal complex"],"partners":["MORN1 (CO-LOCALIZATION)","PFCINCH COMPLEX (CO-IP MEMBERSHIP)","PFVPS13L1 (CO-LOCALIZATION)"],"other_free_text":["BTP1 phosphorylation state is altered upon PfPPM2 depletion, placing it in a phosphoregulated pathway [#3]","BTP1 dynamics correlate with plasma membrane invagination during the final steps of cell division [#0]","Used as a basal complex spatial marker for ER-IMC membrane contact sites [#4]","No direct enzymatic activity or independent loss-of-function phenotype established for BTP1 itself"]}},"prefetch_data":{},"corpus_meta":[{"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":["BTP1"],"competing_organism_flag":false,"competing_organism_match":"","competing_organism_only":false},{"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":["BTP1"],"competing_organism_flag":false,"competing_organism_match":"","competing_organism_only":false},{"pmid":"41904125","id":"","title":"A bridge-like lipid transfer protein is critical for generation of invasive stages in malaria parasites.","date":"2026","source":"Nature communications","url":"https://pubmed.ncbi.nlm.nih.gov/41904125","citation_count":0,"is_preprint":false,"source_species":["Pf"],"role":"primary","match_terms":["BTP1"],"competing_organism_flag":false,"competing_organism_match":"","competing_organism_only":false},{"pmid":"40117352","id":"","title":"SIP2 is the master transcription factor of Plasmodium merozoite formation.","date":"2025","source":"Science advances","url":"https://pubmed.ncbi.nlm.nih.gov/40117352","citation_count":0,"is_preprint":false,"source_species":["Pf"],"role":"primary","match_terms":["BTP1"],"competing_organism_flag":false,"competing_organism_match":"","competing_organism_only":false},{"pmid":"40410154","id":"","title":"PfPPM2 signalling regulates asexual division and sexual conversion of human malaria parasite Plasmodium falciparum.","date":"2025","source":"Nature communications","url":"https://pubmed.ncbi.nlm.nih.gov/40410154","citation_count":0,"is_preprint":false,"source_species":["Pf"],"role":"primary","match_terms":["BTP1"],"competing_organism_flag":false,"competing_organism_match":"","competing_organism_only":false},{"pmid":"34878291","id":"","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":0,"is_preprint":false,"source_species":["Pf"],"role":"primary","match_terms":["BTP1"],"competing_organism_flag":false,"competing_organism_match":"","competing_organism_only":false},{"pmid":"39576115","id":"","title":"An inner membrane complex protein IMC1g in Plasmodium berghei is involved in asexual stage schizogony and parasite transmission.","date":"2024","source":"mBio","url":"https://pubmed.ncbi.nlm.nih.gov/39576115","citation_count":0,"is_preprint":false,"source_species":["Pf"],"role":"primary","match_terms":["BTP1"],"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":["BTP1"],"competing_organism_flag":false,"competing_organism_match":"","competing_organism_only":false},{"pmid":"31097714","id":"","title":"An essential contractile ring protein controls cell division in Plasmodium falciparum.","date":"2019","source":"Nature communications","url":"https://pubmed.ncbi.nlm.nih.gov/31097714","citation_count":0,"is_preprint":false,"source_species":["Pf"],"role":"primary","match_terms":["BTP1"],"competing_organism_flag":false,"competing_organism_match":"","competing_organism_only":false},{"pmid":"37400439","id":"","title":"A PPP-type pseudophosphatase is required for the maintenance of basal complex integrity in Plasmodium falciparum.","date":"2023","source":"Nature communications","url":"https://pubmed.ncbi.nlm.nih.gov/37400439","citation_count":0,"is_preprint":false,"source_species":["Pf"],"role":"primary","match_terms":["BTP1"],"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":["BTP1"],"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":["BTP1"],"competing_organism_flag":false,"competing_organism_match":"","competing_organism_only":false},{"pmid":"29138437","id":"","title":"Photosensitized INA-Labelled protein 1 (PhIL1) is novel component of the inner membrane complex and is required for Plasmodium parasite development.","date":"2017","source":"Scientific reports","url":"https://pubmed.ncbi.nlm.nih.gov/29138437","citation_count":0,"is_preprint":false,"source_species":["Pf"],"role":"primary","match_terms":["BTP1"],"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":["BTP1"],"competing_organism_flag":false,"competing_organism_match":"","competing_organism_only":false}],"cost":{"stage1":{"model":"claude-sonnet-4-6","input_tokens":15487,"output_tokens":1560,"usd":0.034931,"stage1_stop_reason":"end_turn"},"stage2":{"model":"claude-opus-4-8","input_tokens":6558,"output_tokens":2411,"usd":0.046532,"stage2_stop_reason":"end_turn"},"total_usd":0.081463,"stage1_batch_id":"msgbatch_01SRp5hyRc82zNjddxyCCXGk","stage2_batch_id":"msgbatch_01K3BTmBazRo3pRrMvyaPMTY","note":"batch pricing = 50% of standard"},"stage1_raw":"```json\n{\n  \"discoveries\": [\n    {\n      \"year\": 2016,\n      \"finding\": \"BTP1 (PF3D7_0611600) is a novel transmembrane protein that localizes to the basal complex of P. falciparum, colocalizing with the known basal complex marker MORN1. It shows distinct dynamics compared to other IMC proteins during schizogony, and live-imaging with a parasite plasma membrane marker demonstrated that basal complex dynamics (including BTP1 localization) are correlated with plasma membrane invagination during the final steps of cell division, suggesting BTP1 may be involved in interactions between the invaginating plasma membrane and the IMC.\",\n      \"method\": \"Fluorescence microscopy / live imaging, transgenic parasite lines with epitope-tagged BTP1, co-localization with MORN1 marker\",\n      \"journal\": \"Journal of cell science\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 3 / Moderate — direct localization experiment with functional correlation via plasma membrane marker, single lab, single paper with two orthogonal fluorescence approaches\",\n      \"pmids\": [\"26763910\"],\n      \"is_preprint\": false,\n      \"attribution\": [{\"species\": \"Plasmodium falciparum\", \"strain\": \"\"}]\n    },\n    {\n      \"year\": 2019,\n      \"finding\": \"BTP1 (PF3D7_0611600) colocalizes with MORN1 at the basal complex during segmentation in P. falciparum, and is recovered as part of the PfCINCH-containing basal complex by co-immunoprecipitation, establishing its membership in the basal complex protein complex.\",\n      \"method\": \"Immunofluorescence co-localization with MORN1; co-immunoprecipitation of PfCINCH-containing complexes followed by mass spectrometry\",\n      \"journal\": \"Nature communications\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 3 / Moderate — co-IP/MS identification plus co-localization, single lab, two orthogonal methods but no functional mutagenesis of BTP1 itself\",\n      \"pmids\": [\"31097714\"],\n      \"is_preprint\": false,\n      \"attribution\": [{\"species\": \"Plasmodium falciparum\", \"strain\": \"3D7\"}]\n    },\n    {\n      \"year\": 2026,\n      \"finding\": \"BTP1 (PF3D7_0611600) is a transmembrane basal complex protein in P. falciparum whose localization was directly visualized by expansion microscopy (U-ExM) and DNA-PAINT nanoscopy. BTP1-mNeonGreen was also used as a basal complex marker to co-localize with PfVPS13L1-Halo, showing overlap during IMC formation, confirming BTP1's role as a bona fide basal complex transmembrane component during daughter cell formation.\",\n      \"method\": \"Expansion microscopy (U-ExM), DNA-PAINT (PAINT nanoscopy), fluorescence co-localization with tagged BTP1\",\n      \"journal\": \"Science advances\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — direct localization with two independent high-resolution imaging methods in a single study, but functional role of BTP1 itself not independently tested beyond its use as a marker\",\n      \"pmids\": [\"41706859\"],\n      \"is_preprint\": false,\n      \"attribution\": [{\"species\": \"Plasmodium falciparum\", \"strain\": \"\"}]\n    },\n    {\n      \"year\": 2025,\n      \"finding\": \"BTP1 (PF3D7_0611600) is among the differentially phosphorylated proteins detected in P. falciparum parasites depleted of PfPPM2 (a protein phosphatase), identifying BTP1 as a substrate (or indirect target) in a phosphorylation-regulated pathway governing IMC formation during parasite division.\",\n      \"method\": \"Phosphoproteomics on PfPPM2-depleted parasites\",\n      \"journal\": \"Nature communications\",\n      \"confidence\": \"Low\",\n      \"confidence_rationale\": \"Tier 4 / Weak — phosphoproteomics dataset; BTP1 phosphorylation detected but direct writer/eraser relationship not experimentally confirmed for BTP1 specifically\",\n      \"pmids\": [\"40410154\"],\n      \"is_preprint\": false,\n      \"attribution\": [{\"species\": \"Plasmodium falciparum\", \"strain\": \"\"}]\n    },\n    {\n      \"year\": 2026,\n      \"finding\": \"BTP1-mNeonGreen (BTP1-mNG) co-localizes with PfVPS13L1-Halo during IMC formation in P. falciparum schizonts, establishing that BTP1 marks the basal complex region where ER-IMC membrane contact sites (bridged by VPS13L1) are found, and confirming BTP1 as a spatial reference for the basal complex during IMC biogenesis.\",\n      \"method\": \"Fluorescence co-localization microscopy of episomally expressed BTP1-mNG with endogenously tagged PfVPS13L1-Halo\",\n      \"journal\": \"Nature communications\",\n      \"confidence\": \"Low\",\n      \"confidence_rationale\": \"Tier 3 / Weak — single co-localization experiment; BTP1 used as a marker rather than being functionally interrogated in this study\",\n      \"pmids\": [\"41904125\"],\n      \"is_preprint\": false,\n      \"attribution\": [{\"species\": \"Plasmodium falciparum\", \"strain\": \"\"}]\n    }\n  ],\n  \"current_model\": \"BTP1 (PF3D7_0611600) is a Plasmodium-specific transmembrane protein that localizes to the basal complex—the contractile ring at the leading edge of the inner membrane complex—where it colocalizes with MORN1 and is part of the PfCINCH-containing basal complex, with its dynamics during schizogony correlated with plasma membrane invagination during daughter cell formation; its phosphorylation state is regulated downstream of PfPPM2, but no direct enzymatic activity or independent loss-of-function phenotype has been established for BTP1 itself.\"\n}\n```","stage2_raw":"```json\n{\n  \"mechanistic_narrative\": \"BTP1 (PF3D7_0611600) is a Plasmodium falciparum transmembrane protein of the basal complex, the ring-shaped structure at the leading edge of the inner membrane complex (IMC) that drives daughter cell formation during schizogony [#0]. It colocalizes with the basal complex marker MORN1 and is recovered biochemically as part of the PfCINCH-containing basal complex, establishing it as a bona fide component of this division machinery [#0, #1]. Live imaging showed that basal complex dynamics marked by BTP1 track plasma membrane invagination during the final steps of cell division, indicating a role at the interface between the invaginating plasma membrane and the IMC [#0]. High-resolution imaging by expansion microscopy and DNA-PAINT confirmed its basal complex localization, and BTP1 has been used as a spatial reference to mark the region where ER-IMC membrane contact sites reside [#2, #4]. Its phosphorylation state is altered upon depletion of the phosphatase PfPPM2, placing BTP1 within a phosphoregulated pathway governing IMC formation [#3]. Beyond its membership in the basal complex and correlation of its dynamics with membrane invagination, no direct enzymatic activity or independent loss-of-function phenotype has been established for BTP1 itself in the available corpus.\",\n  \"teleology\": [\n    {\n      \"year\": 2016,\n      \"claim\": \"Establishing whether a novel transmembrane protein participates in Plasmodium cell division required localizing it and correlating its behavior with the division machinery; this identified BTP1 as a basal complex protein whose dynamics track plasma membrane invagination.\",\n      \"evidence\": \"Fluorescence and live imaging of epitope-tagged BTP1 lines with MORN1 co-localization and a plasma membrane marker in P. falciparum\",\n      \"pmids\": [\"26763910\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"No loss-of-function analysis of BTP1 itself\", \"Correlation with membrane invagination does not demonstrate a causal or mechanical role\", \"Molecular partners not yet defined\"],\n      \"attribution\": [{\"species\": \"Plasmodium falciparum\", \"strain\": \"\"}]\n    },\n    {\n      \"year\": 2019,\n      \"claim\": \"Whether BTP1's basal complex localization reflected physical membership in a defined protein complex was unresolved; biochemical recovery placed BTP1 within the PfCINCH-containing basal complex.\",\n      \"evidence\": \"Co-immunoprecipitation of PfCINCH complexes with mass spectrometry plus MORN1 co-localization in P. falciparum 3D7\",\n      \"pmids\": [\"31097714\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"No mutagenesis of BTP1 to test complex assembly dependence\", \"Direct binding partners of BTP1 within the complex not resolved\", \"Functional contribution of BTP1 to complex activity untested\"],\n      \"attribution\": [{\"species\": \"Plasmodium falciparum\", \"strain\": \"3D7\"}]\n    },\n    {\n      \"year\": 2025,\n      \"claim\": \"How basal complex/IMC formation is regulated post-translationally was unclear; phosphoproteomics identified BTP1 as a differentially phosphorylated target downstream of the phosphatase PfPPM2.\",\n      \"evidence\": \"Phosphoproteomics on PfPPM2-depleted P. falciparum parasites\",\n      \"pmids\": [\"40410154\"],\n      \"confidence\": \"Low\",\n      \"gaps\": [\"Direct writer/eraser relationship for BTP1 phosphosites not experimentally confirmed\", \"Functional consequence of BTP1 phosphorylation unknown\", \"Distinction between direct and indirect PfPPM2 targeting not established\"],\n      \"attribution\": [{\"species\": \"Plasmodium falciparum\", \"strain\": \"\"}]\n    },\n    {\n      \"year\": 2026,\n      \"claim\": \"Confirming BTP1's precise localization and its spatial relationship to membrane biogenesis required higher resolution; nanoscopy and co-localization with VPS13L1 confirmed BTP1 as a transmembrane basal complex marker at ER-IMC membrane contact regions.\",\n      \"evidence\": \"Expansion microscopy (U-ExM), DNA-PAINT nanoscopy, and co-localization of BTP1-mNeonGreen with PfVPS13L1-Halo in P. falciparum\",\n      \"pmids\": [\"41706859\", \"41904125\"],\n      \"confidence\": \"Low\",\n      \"gaps\": [\"BTP1 used as a marker rather than functionally interrogated\", \"No direct interaction between BTP1 and VPS13L1 demonstrated\", \"Role of BTP1 in membrane contact site formation untested\"],\n      \"attribution\": [{\"species\": \"Plasmodium falciparum\", \"strain\": \"\"}]\n    },\n    {\n      \"year\": null,\n      \"claim\": \"The direct molecular function of BTP1 and its independent contribution to basal complex biology remain unknown.\",\n      \"evidence\": \"No loss-of-function phenotype or reconstituted activity for BTP1 reported in the corpus\",\n      \"pmids\": [],\n      \"confidence\": \"Low\",\n      \"gaps\": [\"No BTP1 knockout/knockdown phenotype established\", \"No direct enzymatic or mechanical activity assigned\", \"Functional significance of its phosphorylation and membrane-invagination correlation undefined\"],\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, 4]},\n      {\"term_id\": \"inner membrane complex\", \"supporting_discovery_ids\": [0, 2, 4]},\n      {\"term_id\": \"integral component of membrane\", \"supporting_discovery_ids\": [0, 2]}\n    ],\n    \"pathway\": [\n      {\"term_id\": \"cell division / schizogony\", \"supporting_discovery_ids\": [0, 1]},\n      {\"term_id\": \"IMC formation / daughter cell formation\", \"supporting_discovery_ids\": [2, 3, 4]}\n    ],\n    \"complexes\": [\"PfCINCH-containing basal complex\"],\n    \"partners\": [\"MORN1 (co-localization)\", \"PfCINCH complex (co-IP membership)\", \"PfVPS13L1 (co-localization)\"],\n    \"other_free_text\": [\n      \"BTP1 phosphorylation state is altered upon PfPPM2 depletion, placing it in a phosphoregulated pathway [#3]\",\n      \"BTP1 dynamics correlate with plasma membrane invagination during the final steps of cell division [#0]\",\n      \"Used as a basal complex spatial marker for ER-IMC membrane contact sites [#4]\",\n      \"No direct enzymatic activity or independent loss-of-function phenotype established for BTP1 itself\"\n    ]\n  }\n}\n```","audit_flag":null,"strains":[{"strain":"Pf3D7","gene_id":"PF3D7_0611600","name":null,"product":"basal complex transmembrane protein 1","uniprot_acc":null,"chromosome":null,"start_pos":null},{"strain":"PbANKA","gene_id":"PBANKA_0109900","name":null,"product":"basal complex transmembrane protein 1, putative","uniprot_acc":null,"chromosome":null,"start_pos":null},{"strain":"PkH","gene_id":"PKNH_1138500","name":null,"product":"basal complex transmembrane protein 1, putative","uniprot_acc":null,"chromosome":null,"start_pos":null}],"gene_symbol":"BTP1","evaluation":null}