{"gene":"PF3D7_0823000","run_date":"2026-09-08T16:26:55","timeline":{"discoveries":[{"year":2026,"finding":"PfVps15 (PF3D7_0823000) physically interacts with PfPI3K (PfVps34), as demonstrated by co-immunoprecipitation, establishing it as a binding partner of the parasite's PI3-kinase.","method":"Co-immunoprecipitation (Co-IP) pulldown","journal":"PLoS Pathogens","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — reciprocal Co-IP demonstrating physical interaction, single lab with two supporting lines of evidence (interaction + functional consequence)","pmids":["42611934"],"is_preprint":false,"attribution":[{"species":"Plasmodium falciparum","strain":""}]},{"year":2026,"finding":"Unlike its yeast and mammalian orthologues, PfVps15 is potentially not part of a heterotetrameric complex, suggesting a divergent complex architecture in P. falciparum.","method":"Bioinformatics analysis combined with co-immunoprecipitation (absence of other canonical complex partners)","journal":"PLoS Pathogens","confidence":"Low","confidence_rationale":"Tier 3 / Weak — single lab, negative/absence result inferred from bioinformatics and partial Co-IP data; abstract does not detail full reconstitution","pmids":["42611934"],"is_preprint":false,"attribution":[{"species":"Plasmodium falciparum","strain":""}]},{"year":2026,"finding":"PfVps15 is constitutively expressed throughout the asexual erythrocytic cycle, as shown by expression analysis across parasite stages.","method":"Stage-specific expression analysis (protein level)","journal":"PLoS Pathogens","confidence":"Medium","confidence_rationale":"Tier 3 / Moderate — direct detection of protein expression across multiple stages, single lab","pmids":["42611934"],"is_preprint":false,"attribution":[{"species":"Plasmodium falciparum","strain":""}]},{"year":2026,"finding":"Removal of PfVps15 from its site of action by knock-sideways leads to rapid parasite death, establishing it as essential for asexual intraerythrocytic parasite survival.","method":"Knock-sideways (conditional mislocalization) with cell viability readout","journal":"PLoS Pathogens","confidence":"High","confidence_rationale":"Tier 2 / Moderate — clean conditional loss-of-function with defined lethal phenotype, single lab with multiple orthogonal downstream phenotypic readouts","pmids":["42611934"],"is_preprint":false,"attribution":[{"species":"Plasmodium falciparum","strain":""}]},{"year":2026,"finding":"Knock-sideways removal of PfVps15 results in a decrease in cellular PI3P levels, placing PfVps15 upstream of or co-regulatory with PI3P production by PfPI3K.","method":"Knock-sideways followed by PI3P level measurement (fluorescent PI3P biosensor or equivalent)","journal":"PLoS Pathogens","confidence":"High","confidence_rationale":"Tier 2 / Moderate — conditional loss-of-function with direct biochemical readout (PI3P levels), single lab, multiple phenotypic endpoints","pmids":["42611934"],"is_preprint":false,"attribution":[{"species":"Plasmodium falciparum","strain":""}]},{"year":2026,"finding":"Knock-sideways removal of PfVps15 abrogates delivery of host-cell cytosol-containing vesicles to the food vacuole, demonstrating a role for PfVps15 in the vesicular trafficking pathway of host-cell cytosol.","method":"Knock-sideways combined with fluorescence microscopy tracking of host-cell cytosol delivery","journal":"PLoS Pathogens","confidence":"High","confidence_rationale":"Tier 2 / Moderate — conditional loss-of-function with defined cellular trafficking phenotype, single lab, multiple orthogonal readouts","pmids":["42611934"],"is_preprint":false,"attribution":[{"species":"Plasmodium falciparum","strain":""}]},{"year":2026,"finding":"Knock-sideways removal of PfVps15 causes defects in apicoplast biogenesis, establishing a role for PfVps15 in apicoplast maintenance.","method":"Knock-sideways combined with fluorescence microscopy of apicoplast markers","journal":"PLoS Pathogens","confidence":"High","confidence_rationale":"Tier 2 / Moderate — conditional loss-of-function with specific organelle phenotype readout, single lab","pmids":["42611934"],"is_preprint":false,"attribution":[{"species":"Plasmodium falciparum","strain":""}]},{"year":2026,"finding":"Knock-sideways removal of PfVps15 causes defects in mitochondrial fission, establishing a role for PfVps15 in mitochondrion dynamics.","method":"Knock-sideways combined with fluorescence microscopy of mitochondrial morphology","journal":"PLoS Pathogens","confidence":"High","confidence_rationale":"Tier 2 / Moderate — conditional loss-of-function with specific organelle morphology phenotype, single lab","pmids":["42611934"],"is_preprint":false,"attribution":[{"species":"Plasmodium falciparum","strain":""}]},{"year":2017,"finding":"PfVps15 (encoded by PF14_0294) is phosphorylated in vivo at serine 250, a site consistent with cAMP-dependent protein kinase A (PKA) phosphorylation, suggesting post-translational regulation by PKA during intraerythrocytic stages.","method":"In vivo phosphoproteomics (phosphosite data from PlasmoDB, attributed to PKA consensus site analysis)","journal":"Biomedical Journal","confidence":"Low","confidence_rationale":"Tier 3 / Weak — single phosphosite detection from database-aggregated phosphoproteomics; PKA identity of the writer is inferred from consensus sequence, not experimentally confirmed","pmids":["28411879"],"is_preprint":false,"attribution":[{"species":"Plasmodium falciparum","strain":""}]}],"current_model":"PF3D7_0823000 (PfVps15) is a constitutively expressed pseudokinase that physically interacts with PfPI3K (PfVps34) — though apparently not as part of a canonical heterotetrameric complex — and is essential for asexual parasite survival; its conditional removal reduces cellular PI3P levels, blocks delivery of host-cell cytosol-containing vesicles to the food vacuole, and disrupts apicoplast biogenesis and mitochondrial fission, placing it as a critical regulator of PI3P production and downstream organelle/vesicular trafficking in P. falciparum."},"narrative":{"mechanistic_narrative":"PF3D7_0823000 (VPS15) is a constitutively expressed putative serine/threonine protein kinase that functions as a physical partner of the parasite PI3-kinase PfPI3K (PfVps34) and acts as a critical regulator of PI3P production and downstream organelle and vesicular homeostasis in Plasmodium falciparum [PMID:42611934]. Reciprocal co-immunoprecipitation establishes the direct PfVps15–PfPI3K interaction, but unlike its yeast and mammalian orthologues PfVps15 appears not to assemble into a canonical heterotetrameric complex, indicating a divergent complex architecture in P. falciparum [PMID:42611934]. Conditional removal of PfVps15 from its site of action by knock-sideways is rapidly lethal to asexual intraerythrocytic parasites and lowers cellular PI3P levels, placing PfVps15 upstream of or co-regulatory with PfPI3K-dependent PI3P synthesis [PMID:42611934]. Loss of PfVps15 blocks delivery of host-cell cytosol-containing vesicles to the food vacuole and disrupts apicoplast biogenesis and mitochondrial fission, linking its PI3P-regulatory role to endomembrane trafficking and organelle maintenance [PMID:42611934]. Beyond these functional and interaction data, no catalytic activity, structural model, or full complex composition has been characterized in the available corpus.","teleology":[{"year":2017,"claim":"Before functional dissection, the question was whether PfVps15 is post-translationally regulated during blood-stage growth; in vivo detection of a phosphosite established that it is a phosphoprotein subject to potential kinase-mediated control.","evidence":"In vivo phosphoproteomics identifying phosphorylation at serine 250 consistent with a PKA consensus site","pmids":["28411879"],"confidence":"Low","gaps":["PKA as the responsible kinase is inferred from consensus sequence, not experimentally confirmed","Functional consequence of S250 phosphorylation unknown","Single database-aggregated phosphosite without validation"],"attribution":[{"species":"Plasmodium falciparum","strain":""}]},{"year":2026,"claim":"To place PfVps15 in a pathway, the key question was which enzyme it partners with; co-immunoprecipitation showed it physically binds PfPI3K (PfVps34), identifying it as a component of the parasite PI3-kinase machinery.","evidence":"Reciprocal co-immunoprecipitation pulldown in P. falciparum","pmids":["42611934"],"confidence":"Medium","gaps":["Interaction interface and stoichiometry undefined","Whether binding modulates PfPI3K catalytic activity not shown directly"],"attribution":[{"species":"Plasmodium falciparum","strain":""}]},{"year":2026,"claim":"Whether PfVps15 assembles into the canonical Vps15/Vps34 heterotetramer seen in yeast and mammals was open; bioinformatics plus Co-IP data indicated absence of the other canonical partners, arguing for a divergent complex architecture in P. falciparum.","evidence":"Bioinformatics analysis combined with co-immunoprecipitation (absence of canonical complex partners)","pmids":["42611934"],"confidence":"Low","gaps":["Negative/absence result not confirmed by full complex reconstitution","Alternative complex partners not identified","Does not rule out transient or substoichiometric associations"],"attribution":[{"species":"Plasmodium falciparum","strain":""}]},{"year":2026,"claim":"The expression pattern that would constrain when PfVps15 acts was unknown; stage-resolved protein analysis showed constitutive expression across the asexual erythrocytic cycle, consistent with a housekeeping regulatory role.","evidence":"Stage-specific protein-level expression analysis","pmids":["42611934"],"confidence":"Medium","gaps":["Subcellular localization not defined by this readout","Expression in sexual/other life-cycle stages not addressed"],"attribution":[{"species":"Plasmodium falciparum","strain":""}]},{"year":2026,"claim":"Whether PfVps15 is required for parasite viability was untested; conditional mislocalization by knock-sideways caused rapid parasite death, establishing it as essential for asexual intraerythrocytic survival.","evidence":"Knock-sideways conditional mislocalization with viability readout in P. falciparum","pmids":["42611934"],"confidence":"High","gaps":["Molecular cause of lethality not resolved to a single downstream event","Requirement in non-asexual stages not tested"],"attribution":[{"species":"Plasmodium falciparum","strain":""}]},{"year":2026,"claim":"To connect PfVps15 to lipid signaling, the question was whether it influences PI3P production; knock-sideways removal decreased cellular PI3P, positioning PfVps15 upstream of or co-regulatory with PfPI3K activity.","evidence":"Knock-sideways followed by cellular PI3P level measurement in P. falciparum","pmids":["42611934"],"confidence":"High","gaps":["Direct effect on PfPI3K catalytic rate vs. indirect stabilization not distinguished","Whether PfVps15 itself has catalytic activity toward PI3P production untested"],"attribution":[{"species":"Plasmodium falciparum","strain":""}]},{"year":2026,"claim":"The cellular processes downstream of PfVps15/PI3P were undefined; knock-sideways revealed loss of host-cell cytosol vesicle delivery to the food vacuole and defects in apicoplast biogenesis and mitochondrial fission, linking PfVps15 to endomembrane trafficking and organelle maintenance.","evidence":"Knock-sideways combined with fluorescence microscopy of host-cell cytosol delivery, apicoplast markers, and mitochondrial morphology in P. falciparum","pmids":["42611934"],"confidence":"High","gaps":["Whether the trafficking, apicoplast, and mitochondrial defects are all direct consequences of reduced PI3P or independent roles is unresolved","Effector proteins reading out the PI3P signal not identified"],"attribution":[{"species":"Plasmodium falciparum","strain":""}]},{"year":null,"claim":"It remains unknown whether PfVps15 possesses genuine catalytic (pseudo)kinase activity, what its non-canonical complex composition is, and how it mechanistically stimulates PfPI3K-dependent PI3P synthesis.","evidence":"","pmids":[],"confidence":"Low","gaps":["No enzymatic activity assay for PfVps15","Full complex composition unresolved","No structural model of the PfVps15–PfPI3K interaction"],"attribution":[{"species":"Plasmodium falciparum","strain":""}]}],"mechanism_profile":{"molecular_activity":[],"localization":[],"pathway":[],"complexes":["PfVps15–PfPI3K (PfVps34) interaction; not a canonical heterotetrameric complex"],"partners":["PFPI3K / PFVPS34"],"other_free_text":["Constitutively expressed across the asexual erythrocytic cycle [#2]","Essential for asexual intraerythrocytic survival; conditional removal is rapidly lethal [#3]","Conditional loss reduces cellular PI3P levels [#4]","Required for delivery of host-cell cytosol-containing vesicles to the food vacuole [#5]","Required for apicoplast biogenesis and mitochondrial fission [#6, #7]","Phosphorylated in vivo at Ser250, a PKA consensus site (writer inferred, not confirmed) [#8]"]}},"prefetch_data":{},"corpus_meta":[{"pmid":"42611934","id":"PMC_42611934","title":"The malaria parasite Plasmodium falciparum Vps15 is a Phosphatidylinositol 3-kinase interactor important for host-cell cytosol delivery to the food vacuole and apicoplast and mitochondrion dynamics.","date":"2026","source":"PLoS pathogens","url":"https://pubmed.ncbi.nlm.nih.gov/42611934","citation_count":0,"is_preprint":false,"source_species":["Pf"],"role":"primary","match_terms":["VPS15","PfVPS15"],"competing_organism_flag":false,"competing_organism_match":"","competing_organism_only":false},{"pmid":"42518850","id":"","title":"The role of autophagy in protozoan infections.","date":"2026","source":"Frontiers in cellular and infection microbiology","url":"https://pubmed.ncbi.nlm.nih.gov/42518850","citation_count":0,"is_preprint":false,"source_species":["Pf"],"role":"primary","match_terms":["VPS15"],"competing_organism_flag":false,"competing_organism_match":"","competing_organism_only":false},{"pmid":"41390482","id":"","title":"An ER-resident lipid scramblase is crucial for biogenesis and function of apicomplexan parasite secretory organelles.","date":"2025","source":"Nature communications","url":"https://pubmed.ncbi.nlm.nih.gov/41390482","citation_count":0,"is_preprint":false,"source_species":["Pf"],"role":"primary","match_terms":["VPS15"],"competing_organism_flag":false,"competing_organism_match":"","competing_organism_only":false},{"pmid":"40243121","id":"","title":"Effects of chloroquine and hydroxychloroquine on bone health (Review).","date":"2025","source":"Molecular medicine reports","url":"https://pubmed.ncbi.nlm.nih.gov/40243121","citation_count":0,"is_preprint":false,"source_species":["Pf"],"role":"primary","match_terms":["VPS15"],"competing_organism_flag":false,"competing_organism_match":"","competing_organism_only":false},{"pmid":"33879496","id":"","title":"Dual RNA Sequencing Meta-analysis in Plasmodium Infection Identifies Host-Parasite Interactions.","date":"2021","source":"mSystems","url":"https://pubmed.ncbi.nlm.nih.gov/33879496","citation_count":0,"is_preprint":false,"source_species":["Pf"],"role":"primary","match_terms":["VPS15"],"competing_organism_flag":false,"competing_organism_match":"","competing_organism_only":false},{"pmid":"33672278","id":"","title":"Unraveling Cell Death Pathways during Malaria Infection: What Do We Know So Far?","date":"2021","source":"Cells","url":"https://pubmed.ncbi.nlm.nih.gov/33672278","citation_count":0,"is_preprint":false,"source_species":["Pf"],"role":"primary","match_terms":["VPS15"],"competing_organism_flag":false,"competing_organism_match":"","competing_organism_only":false},{"pmid":"37791074","id":"","title":"Regulation of phosphoinositide metabolism in Apicomplexan parasites.","date":"2023","source":"Frontiers in cell and developmental biology","url":"https://pubmed.ncbi.nlm.nih.gov/37791074","citation_count":0,"is_preprint":false,"source_species":["Pf"],"role":"primary","match_terms":["VPS15"],"competing_organism_flag":false,"competing_organism_match":"","competing_organism_only":false},{"pmid":"36376561","id":"","title":"Beyond PI3Ks: targeting phosphoinositide kinases in disease.","date":"2022","source":"Nature reviews. 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biology","url":"https://pubmed.ncbi.nlm.nih.gov/30271774","citation_count":0,"is_preprint":false,"source_species":["Pf"],"role":"primary","match_terms":["VPS15"],"competing_organism_flag":false,"competing_organism_match":"","competing_organism_only":false},{"pmid":"24278114","id":"","title":"A process similar to autophagy is associated with cytocidal chloroquine resistance in Plasmodium falciparum.","date":"2013","source":"PloS one","url":"https://pubmed.ncbi.nlm.nih.gov/24278114","citation_count":0,"is_preprint":false,"source_species":["Pf"],"role":"primary","match_terms":["VPS15"],"competing_organism_flag":false,"competing_organism_match":"","competing_organism_only":false}],"cost":{"stage1":{"model":"claude-sonnet-4-6","input_tokens":18850,"output_tokens":2021,"usd":0.043432,"stage1_stop_reason":"end_turn"},"stage2":{"model":"claude-opus-4-8","input_tokens":7314,"output_tokens":3221,"usd":0.058548,"stage2_stop_reason":"end_turn"},"total_usd":0.10198,"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\": \"PfVps15 (PF3D7_0823000) physically interacts with PfPI3K (PfVps34), as demonstrated by co-immunoprecipitation, establishing it as a binding partner of the parasite's PI3-kinase.\",\n      \"method\": \"Co-immunoprecipitation (Co-IP) pulldown\",\n      \"journal\": \"PLoS Pathogens\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — reciprocal Co-IP demonstrating physical interaction, single lab with two supporting lines of evidence (interaction + functional consequence)\",\n      \"pmids\": [\"42611934\"],\n      \"is_preprint\": false,\n      \"attribution\": [{\"species\": \"Plasmodium falciparum\", \"strain\": \"\"}]\n    },\n    {\n      \"year\": 2026,\n      \"finding\": \"Unlike its yeast and mammalian orthologues, PfVps15 is potentially not part of a heterotetrameric complex, suggesting a divergent complex architecture in P. falciparum.\",\n      \"method\": \"Bioinformatics analysis combined with co-immunoprecipitation (absence of other canonical complex partners)\",\n      \"journal\": \"PLoS Pathogens\",\n      \"confidence\": \"Low\",\n      \"confidence_rationale\": \"Tier 3 / Weak — single lab, negative/absence result inferred from bioinformatics and partial Co-IP data; abstract does not detail full reconstitution\",\n      \"pmids\": [\"42611934\"],\n      \"is_preprint\": false,\n      \"attribution\": [{\"species\": \"Plasmodium falciparum\", \"strain\": \"\"}]\n    },\n    {\n      \"year\": 2026,\n      \"finding\": \"PfVps15 is constitutively expressed throughout the asexual erythrocytic cycle, as shown by expression analysis across parasite stages.\",\n      \"method\": \"Stage-specific expression analysis (protein level)\",\n      \"journal\": \"PLoS Pathogens\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 3 / Moderate — direct detection of protein expression across multiple stages, single lab\",\n      \"pmids\": [\"42611934\"],\n      \"is_preprint\": false,\n      \"attribution\": [{\"species\": \"Plasmodium falciparum\", \"strain\": \"\"}]\n    },\n    {\n      \"year\": 2026,\n      \"finding\": \"Removal of PfVps15 from its site of action by knock-sideways leads to rapid parasite death, establishing it as essential for asexual intraerythrocytic parasite survival.\",\n      \"method\": \"Knock-sideways (conditional mislocalization) with cell viability readout\",\n      \"journal\": \"PLoS Pathogens\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — clean conditional loss-of-function with defined lethal phenotype, single lab with multiple orthogonal downstream phenotypic readouts\",\n      \"pmids\": [\"42611934\"],\n      \"is_preprint\": false,\n      \"attribution\": [{\"species\": \"Plasmodium falciparum\", \"strain\": \"\"}]\n    },\n    {\n      \"year\": 2026,\n      \"finding\": \"Knock-sideways removal of PfVps15 results in a decrease in cellular PI3P levels, placing PfVps15 upstream of or co-regulatory with PI3P production by PfPI3K.\",\n      \"method\": \"Knock-sideways followed by PI3P level measurement (fluorescent PI3P biosensor or equivalent)\",\n      \"journal\": \"PLoS Pathogens\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — conditional loss-of-function with direct biochemical readout (PI3P levels), single lab, multiple phenotypic endpoints\",\n      \"pmids\": [\"42611934\"],\n      \"is_preprint\": false,\n      \"attribution\": [{\"species\": \"Plasmodium falciparum\", \"strain\": \"\"}]\n    },\n    {\n      \"year\": 2026,\n      \"finding\": \"Knock-sideways removal of PfVps15 abrogates delivery of host-cell cytosol-containing vesicles to the food vacuole, demonstrating a role for PfVps15 in the vesicular trafficking pathway of host-cell cytosol.\",\n      \"method\": \"Knock-sideways combined with fluorescence microscopy tracking of host-cell cytosol delivery\",\n      \"journal\": \"PLoS Pathogens\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — conditional loss-of-function with defined cellular trafficking phenotype, single lab, multiple orthogonal readouts\",\n      \"pmids\": [\"42611934\"],\n      \"is_preprint\": false,\n      \"attribution\": [{\"species\": \"Plasmodium falciparum\", \"strain\": \"\"}]\n    },\n    {\n      \"year\": 2026,\n      \"finding\": \"Knock-sideways removal of PfVps15 causes defects in apicoplast biogenesis, establishing a role for PfVps15 in apicoplast maintenance.\",\n      \"method\": \"Knock-sideways combined with fluorescence microscopy of apicoplast markers\",\n      \"journal\": \"PLoS Pathogens\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — conditional loss-of-function with specific organelle phenotype readout, single lab\",\n      \"pmids\": [\"42611934\"],\n      \"is_preprint\": false,\n      \"attribution\": [{\"species\": \"Plasmodium falciparum\", \"strain\": \"\"}]\n    },\n    {\n      \"year\": 2026,\n      \"finding\": \"Knock-sideways removal of PfVps15 causes defects in mitochondrial fission, establishing a role for PfVps15 in mitochondrion dynamics.\",\n      \"method\": \"Knock-sideways combined with fluorescence microscopy of mitochondrial morphology\",\n      \"journal\": \"PLoS Pathogens\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — conditional loss-of-function with specific organelle morphology phenotype, single lab\",\n      \"pmids\": [\"42611934\"],\n      \"is_preprint\": false,\n      \"attribution\": [{\"species\": \"Plasmodium falciparum\", \"strain\": \"\"}]\n    },\n    {\n      \"year\": 2017,\n      \"finding\": \"PfVps15 (encoded by PF14_0294) is phosphorylated in vivo at serine 250, a site consistent with cAMP-dependent protein kinase A (PKA) phosphorylation, suggesting post-translational regulation by PKA during intraerythrocytic stages.\",\n      \"method\": \"In vivo phosphoproteomics (phosphosite data from PlasmoDB, attributed to PKA consensus site analysis)\",\n      \"journal\": \"Biomedical Journal\",\n      \"confidence\": \"Low\",\n      \"confidence_rationale\": \"Tier 3 / Weak — single phosphosite detection from database-aggregated phosphoproteomics; PKA identity of the writer is inferred from consensus sequence, not experimentally confirmed\",\n      \"pmids\": [\"28411879\"],\n      \"is_preprint\": false,\n      \"attribution\": [{\"species\": \"Plasmodium falciparum\", \"strain\": \"\"}]\n    }\n  ],\n  \"current_model\": \"PF3D7_0823000 (PfVps15) is a constitutively expressed pseudokinase that physically interacts with PfPI3K (PfVps34) — though apparently not as part of a canonical heterotetrameric complex — and is essential for asexual parasite survival; its conditional removal reduces cellular PI3P levels, blocks delivery of host-cell cytosol-containing vesicles to the food vacuole, and disrupts apicoplast biogenesis and mitochondrial fission, placing it as a critical regulator of PI3P production and downstream organelle/vesicular trafficking in P. falciparum.\"\n}\n```","stage2_raw":"{\n  \"mechanistic_narrative\": \"PF3D7_0823000 (VPS15) is a constitutively expressed putative serine/threonine protein kinase that functions as a physical partner of the parasite PI3-kinase PfPI3K (PfVps34) and acts as a critical regulator of PI3P production and downstream organelle and vesicular homeostasis in Plasmodium falciparum [#0, #2, #4]. Reciprocal co-immunoprecipitation establishes the direct PfVps15\\u2013PfPI3K interaction, but unlike its yeast and mammalian orthologues PfVps15 appears not to assemble into a canonical heterotetrameric complex, indicating a divergent complex architecture in P. falciparum [#0, #1]. Conditional removal of PfVps15 from its site of action by knock-sideways is rapidly lethal to asexual intraerythrocytic parasites and lowers cellular PI3P levels, placing PfVps15 upstream of or co-regulatory with PfPI3K-dependent PI3P synthesis [#3, #4]. Loss of PfVps15 blocks delivery of host-cell cytosol-containing vesicles to the food vacuole and disrupts apicoplast biogenesis and mitochondrial fission, linking its PI3P-regulatory role to endomembrane trafficking and organelle maintenance [#5, #6, #7]. Beyond these functional and interaction data, no catalytic activity, structural model, or full complex composition has been characterized in the available corpus.\",\n  \"teleology\": [\n    {\n      \"year\": 2017,\n      \"claim\": \"Before functional dissection, the question was whether PfVps15 is post-translationally regulated during blood-stage growth; in vivo detection of a phosphosite established that it is a phosphoprotein subject to potential kinase-mediated control.\",\n      \"evidence\": \"In vivo phosphoproteomics identifying phosphorylation at serine 250 consistent with a PKA consensus site\",\n      \"pmids\": [\"28411879\"],\n      \"confidence\": \"Low\",\n      \"gaps\": [\n        \"PKA as the responsible kinase is inferred from consensus sequence, not experimentally confirmed\",\n        \"Functional consequence of S250 phosphorylation unknown\",\n        \"Single database-aggregated phosphosite without validation\"\n      ],\n      \"attribution\": [{\"species\": \"Plasmodium falciparum\", \"strain\": \"\"}]\n    },\n    {\n      \"year\": 2026,\n      \"claim\": \"To place PfVps15 in a pathway, the key question was which enzyme it partners with; co-immunoprecipitation showed it physically binds PfPI3K (PfVps34), identifying it as a component of the parasite PI3-kinase machinery.\",\n      \"evidence\": \"Reciprocal co-immunoprecipitation pulldown in P. falciparum\",\n      \"pmids\": [\"42611934\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\n        \"Interaction interface and stoichiometry undefined\",\n        \"Whether binding modulates PfPI3K catalytic activity not shown directly\"\n      ],\n      \"attribution\": [{\"species\": \"Plasmodium falciparum\", \"strain\": \"\"}]\n    },\n    {\n      \"year\": 2026,\n      \"claim\": \"Whether PfVps15 assembles into the canonical Vps15/Vps34 heterotetramer seen in yeast and mammals was open; bioinformatics plus Co-IP data indicated absence of the other canonical partners, arguing for a divergent complex architecture in P. falciparum.\",\n      \"evidence\": \"Bioinformatics analysis combined with co-immunoprecipitation (absence of canonical complex partners)\",\n      \"pmids\": [\"42611934\"],\n      \"confidence\": \"Low\",\n      \"gaps\": [\n        \"Negative/absence result not confirmed by full complex reconstitution\",\n        \"Alternative complex partners not identified\",\n        \"Does not rule out transient or substoichiometric associations\"\n      ],\n      \"attribution\": [{\"species\": \"Plasmodium falciparum\", \"strain\": \"\"}]\n    },\n    {\n      \"year\": 2026,\n      \"claim\": \"The expression pattern that would constrain when PfVps15 acts was unknown; stage-resolved protein analysis showed constitutive expression across the asexual erythrocytic cycle, consistent with a housekeeping regulatory role.\",\n      \"evidence\": \"Stage-specific protein-level expression analysis\",\n      \"pmids\": [\"42611934\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\n        \"Subcellular localization not defined by this readout\",\n        \"Expression in sexual/other life-cycle stages not addressed\"\n      ],\n      \"attribution\": [{\"species\": \"Plasmodium falciparum\", \"strain\": \"\"}]\n    },\n    {\n      \"year\": 2026,\n      \"claim\": \"Whether PfVps15 is required for parasite viability was untested; conditional mislocalization by knock-sideways caused rapid parasite death, establishing it as essential for asexual intraerythrocytic survival.\",\n      \"evidence\": \"Knock-sideways conditional mislocalization with viability readout in P. falciparum\",\n      \"pmids\": [\"42611934\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\n        \"Molecular cause of lethality not resolved to a single downstream event\",\n        \"Requirement in non-asexual stages not tested\"\n      ],\n      \"attribution\": [{\"species\": \"Plasmodium falciparum\", \"strain\": \"\"}]\n    },\n    {\n      \"year\": 2026,\n      \"claim\": \"To connect PfVps15 to lipid signaling, the question was whether it influences PI3P production; knock-sideways removal decreased cellular PI3P, positioning PfVps15 upstream of or co-regulatory with PfPI3K activity.\",\n      \"evidence\": \"Knock-sideways followed by cellular PI3P level measurement in P. falciparum\",\n      \"pmids\": [\"42611934\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\n        \"Direct effect on PfPI3K catalytic rate vs. indirect stabilization not distinguished\",\n        \"Whether PfVps15 itself has catalytic activity toward PI3P production untested\"\n      ],\n      \"attribution\": [{\"species\": \"Plasmodium falciparum\", \"strain\": \"\"}]\n    },\n    {\n      \"year\": 2026,\n      \"claim\": \"The cellular processes downstream of PfVps15/PI3P were undefined; knock-sideways revealed loss of host-cell cytosol vesicle delivery to the food vacuole and defects in apicoplast biogenesis and mitochondrial fission, linking PfVps15 to endomembrane trafficking and organelle maintenance.\",\n      \"evidence\": \"Knock-sideways combined with fluorescence microscopy of host-cell cytosol delivery, apicoplast markers, and mitochondrial morphology in P. falciparum\",\n      \"pmids\": [\"42611934\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\n        \"Whether the trafficking, apicoplast, and mitochondrial defects are all direct consequences of reduced PI3P or independent roles is unresolved\",\n        \"Effector proteins reading out the PI3P signal not identified\"\n      ],\n      \"attribution\": [{\"species\": \"Plasmodium falciparum\", \"strain\": \"\"}]\n    },\n    {\n      \"year\": null,\n      \"claim\": \"It remains unknown whether PfVps15 possesses genuine catalytic (pseudo)kinase activity, what its non-canonical complex composition is, and how it mechanistically stimulates PfPI3K-dependent PI3P synthesis.\",\n      \"evidence\": \"\",\n      \"pmids\": [],\n      \"confidence\": \"Low\",\n      \"gaps\": [\n        \"No enzymatic activity assay for PfVps15\",\n        \"Full complex composition unresolved\",\n        \"No structural model of the PfVps15\\u2013PfPI3K interaction\"\n      ],\n      \"attribution\": [{\"species\": \"Plasmodium falciparum\", \"strain\": \"\"}]\n    }\n  ],\n  \"mechanism_profile\": {\n    \"molecular_activity\": [\n      {\"term_id\": \"GO:0004672\", \"supporting_discovery_ids\": [8]},\n      {\"term_id\": \"GO:0035004\", \"supporting_discovery_ids\": [4]},\n      {\"term_id\": \"GO:0019901\", \"supporting_discovery_ids\": [0]}\n    ],\n    \"localization\": [],\n    \"pathway\": [\n      {\"term_id\": \"GO:0016192\", \"supporting_discovery_ids\": [5]},\n      {\"term_id\": \"GO:0036258\", \"supporting_discovery_ids\": [7]}\n    ],\n    \"complexes\": [\n      \"PfVps15\\u2013PfPI3K (PfVps34) interaction; not a canonical heterotetrameric complex\"\n    ],\n    \"partners\": [\n      \"PfPI3K / PfVps34\"\n    ],\n    \"other_free_text\": [\n      \"Constitutively expressed across the asexual erythrocytic cycle [#2]\",\n      \"Essential for asexual intraerythrocytic survival; conditional removal is rapidly lethal [#3]\",\n      \"Conditional loss reduces cellular PI3P levels [#4]\",\n      \"Required for delivery of host-cell cytosol-containing vesicles to the food vacuole [#5]\",\n      \"Required for apicoplast biogenesis and mitochondrial fission [#6, #7]\",\n      \"Phosphorylated in vivo at Ser250, a PKA consensus site (writer inferred, not confirmed) [#8]\"\n    ]\n  }\n}","audit_flag":null,"strains":[{"strain":"Pf3D7","gene_id":"PF3D7_0823000","name":null,"product":"serine/threonine protein kinase VPS15, putative","uniprot_acc":null,"chromosome":null,"start_pos":null},{"strain":"PbANKA","gene_id":"PBANKA_0707600","name":null,"product":"serine/threonine protein kinase VPS15, putative","uniprot_acc":null,"chromosome":null,"start_pos":null},{"strain":"PkH","gene_id":"PKNH_1317000","name":null,"product":"serine/threonine protein kinase VPS15, putative","uniprot_acc":null,"chromosome":null,"start_pos":null}],"gene_symbol":"VPS15","evaluation":null}