{"gene":"PF3D7_1437900","run_date":"2026-09-08T14:19:07","timeline":{"discoveries":[{"year":2021,"finding":"PfHSP40 (PF3D7_1437900) is posttranslationally modified with a 15-carbon farnesyl isoprenyl group. Loss of HSP40 farnesylation alters its membrane attachment and its interaction with proteins in essential pathways in the parasite. Plastidial isopentenyl pyrophosphate (IPP) synthesis and protein farnesylation are required for malaria parasite survival after cold and heat shock.","method":"Posttranslational modification mapping, membrane fractionation, proteomics of farnesylation-deficient mutants, temperature stress survival assays","journal":"mBio","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — direct PTM identification combined with functional farnesylation mutant phenotypes and proteomics, single lab","pmids":["34182772"],"is_preprint":false,"attribution":[{"species":"Plasmodium falciparum","strain":""}]},{"year":2025,"finding":"PfHSP40 (PF3D7_1437900) is required for asexual replication and survival of febrile temperatures in P. falciparum. Knockdown causes a cell cycle progression defect and reduced nuclear replication. Untargeted proteomics reveal HSP40 depletion leads to downregulation of DNA replication and repair pathways. HSP40 knockdown sensitizes parasites to DNA replication inhibition but does not mitigate proteotoxic stresses induced by artemisinin or proteasome inhibition, indicating a specialized role in heat shock survival distinct from general proteotoxic stress responses.","method":"Tunable knockdown (conditional knockdown strain), flow cytometry cell cycle analysis, untargeted proteomics, drug sensitivity assays","journal":"PLoS pathogens","confidence":"High","confidence_rationale":"Tier 2 / Strong — conditional knockdown with multiple orthogonal readouts (cell cycle, proteomics, drug sensitivity), peer-reviewed, consistent with preprint version","pmids":["40627776"],"is_preprint":false,"attribution":[{"species":"Plasmodium falciparum","strain":""}]},{"year":2024,"finding":"PfHSP40 (PF3D7_1437900, referred to as PfYdj1 in this paper) acts as a cochaperone that facilitates folding and stability of the small subunit of ribonucleotide reductase (PfR2). PfR2 interacts specifically with PfYdj1/PF3D7_1437900 (and not with the type II Hsp40 PfSis1/PF3D7_0213100), which subsequently recruits PfHsp70-1 through its HPD motif. Perturbation of the PfYdj1–PfHsp70-1 interaction by small molecule 116-9e destabilizes PfR2, reduces dNTP production, and causes replication arrest. Combining 116-9e with benzo-hydroxamate (a PfR2 catalytic inhibitor) produces synergistic antiparasitic activity.","method":"Co-immunoprecipitation, small molecule inhibitor (116-9e) perturbation, dNTP quantification, parasite growth assays, drug synergy analysis","journal":"mBio","confidence":"High","confidence_rationale":"Tier 2 / Strong — reciprocal co-IP establishing specific interaction, biochemical perturbation with functional readout, drug synergy validation, multiple orthogonal methods in single study","pmids":["40938117"],"is_preprint":false,"attribution":[{"species":"Plasmodium falciparum","strain":"3D7"}]},{"year":2024,"finding":"PF3D7_1437900 (HSP40) is required for asexual replication and thermotolerance in P. falciparum; knockdown causes cell cycle arrest and downregulation of DNA replication/repair pathways. (Preprint version of the peer-reviewed PMID:40627776 finding.)","method":"Tunable knockdown, proteomics, cell cycle analysis","journal":"bioRxiv","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — preprint with multiple methods but superseded by peer-reviewed version; included for completeness","pmids":["39574603"],"is_preprint":true,"attribution":[{"species":"Plasmodium falciparum","strain":""}]},{"year":2010,"finding":"The single cytosolic canonical Hsp40 of P. falciparum (PF3D7_1437900, referred to as PfHsp40 in this paper) is upregulated under heat shock conditions similarly to PfHsp70-1, localizes mainly to the parasite cytosol by immunofluorescence, stimulates the ATPase activity of both PfHsp70-1 and human Hsp70, suppresses protein aggregation alone, and cooperates with PfHsp70-1 to suppress aggregation in vitro.","method":"Western blot (heat shock induction), indirect immunofluorescence microscopy (localization), in vitro ATPase assay, protein aggregation suppression assay","journal":"Cell stress & chaperones","confidence":"High","confidence_rationale":"Tier 1–2 / Strong — in vitro enzymatic assays with recombinant proteins plus cellular localization; multiple orthogonal methods; peer-reviewed","pmids":["21191678"],"is_preprint":false,"attribution":[{"species":"Plasmodium falciparum","strain":""}]},{"year":2020,"finding":"The PfHSP70-1 and PfHSP40 (PF3D7_1437900) chaperone pair exhibits superior protein folding, aggregation inhibition, oligomer remodeling, and disaggregase activities compared to human orthologs (HSPA1A and DNAJA1). PfHSP40 has higher binding affinity for unfolded substrate than DNAJA1, with a slow dissociation rate maintaining substrate in a folding-competent state. SAXS reveals PfHSP40 exists as a dimer in solution and forms a complex with PfHSP70-1. PfHSP40 can also cooperate efficiently with human HSP70 to facilitate client folding.","method":"In vitro protein folding assays, aggregation inhibition assay, disaggregase assay, surface plasmon resonance (SPR) kinetics, small angle X-ray scattering (SAXS)","journal":"The Biochemical journal","confidence":"High","confidence_rationale":"Tier 1 / Moderate — in vitro reconstitution with multiple orthogonal biochemical and biophysical methods (SPR, SAXS, functional assays); single lab","pmids":["32893851"],"is_preprint":false,"attribution":[{"species":"Plasmodium falciparum","strain":""}]},{"year":2021,"finding":"Surface plasmon resonance (SPR) analysis demonstrated that PfHsp70-z and PfHsp70-1 differ in their relative affinities for the cytosol-localized canonical J-domain co-chaperone PfHsp40 (PF3D7_1437900), providing quantitative binding data for this co-chaperone interaction.","method":"Surface plasmon resonance (SPR)","journal":"Data in brief","confidence":"Low","confidence_rationale":"Tier 3 / Weak — SPR binding affinity data for PfHsp40 interaction, single supporting dataset paper, no functional follow-up reported in abstract","pmids":["34141839"],"is_preprint":false,"attribution":[{"species":"Plasmodium falciparum","strain":""}]}],"current_model":"PfHSP40 (PF3D7_1437900) is the sole canonical cytosolic type I J-domain protein in P. falciparum; it is farnesylated (which controls its membrane attachment and chaperone-client interactions), localizes to the parasite cytosol, is essential for asexual intraerythrocytic replication and febrile-temperature survival, acts specifically in heat shock defense but not in general proteotoxic stress responses, stimulates the ATPase activity of PfHsp70-1 via its HPD motif, facilitates folding and stability of the ribonucleotide reductase small subunit PfR2 (thereby supporting dNTP synthesis and DNA replication), and cooperates with PfHsp70-1 to suppress protein aggregation with kinetics and folding efficiency superior to those of the human Hsp40–Hsp70 ortholog pair."},"narrative":{"mechanistic_narrative":"PF3D7_1437900 (HSP40) is the sole canonical cytosolic type I J-domain co-chaperone of P. falciparum and functions as the essential Hsp40 partner of the parasite chaperone PfHsp70-1 in heat-shock defense and asexual intraerythrocytic replication [PMID:21191678, PMID:40627776]. It stimulates the ATPase activity of PfHsp70-1 through its HPD motif, suppresses protein aggregation on its own, and cooperates with PfHsp70-1 to fold and rescue substrate proteins with higher efficiency than the human Hsp40–Hsp70 ortholog pair, aided by high substrate-binding affinity and a slow dissociation rate that keeps clients folding-competent [PMID:21191678, PMID:32893851]. Mechanistically, HSP40 delivers specific clients to PfHsp70-1: it binds and stabilizes the ribonucleotide reductase small subunit PfR2, thereby supporting dNTP synthesis and DNA replication, and disrupting the HSP40–PfHsp70-1 interaction destabilizes PfR2, lowers dNTP levels, and arrests replication [PMID:40938117]. The protein is farnesylated, a modification that controls its membrane attachment and its interactions with client pathways [PMID:34182772]. Conditional knockdown confirms an essential and specialized role: depletion produces a cell-cycle progression defect with reduced nuclear replication and downregulation of DNA replication/repair pathways, sensitizes parasites to DNA-replication inhibition, and impairs survival of febrile temperatures, yet does not mitigate general proteotoxic stress from artemisinin or proteasome inhibition, indicating a role dedicated to heat-shock survival rather than generic protein quality control [PMID:40627776].","teleology":[{"year":2010,"claim":"Establishing whether the parasite's single canonical cytosolic Hsp40 actually functions as a bona fide Hsp70 co-chaperone was the first requirement for placing it in a chaperone pathway.","evidence":"Heat-shock induction Western blots, immunofluorescence localization, in vitro ATPase and aggregation-suppression assays with recombinant protein","pmids":["21191678"],"confidence":"High","gaps":["Did not identify physiological client proteins","No in vivo essentiality or phenotype established","Mechanism of substrate handoff to PfHsp70-1 not resolved"],"attribution":[{"species":"Plasmodium falciparum","strain":""}]},{"year":2020,"claim":"Quantitative biophysical comparison against human orthologs was needed to explain why the parasite chaperone pair might be functionally distinct and drug-targetable.","evidence":"In vitro folding, aggregation-inhibition and disaggregase assays, SPR kinetics, and SAXS on recombinant PfHSP40/PfHSP70-1","pmids":["32893851"],"confidence":"High","gaps":["Superior in vitro activity not linked to a specific parasite client","Dimer/complex architecture not resolved at atomic resolution","In vivo relevance of superior kinetics untested"],"attribution":[{"species":"Plasmodium falciparum","strain":""}]},{"year":2021,"claim":"Identifying farnesylation as a post-translational modification addressed how HSP40 associates with membranes and which pathways its lipidation controls.","evidence":"PTM mapping, membrane fractionation, proteomics of farnesylation-deficient mutants, and temperature-stress survival assays","pmids":["34182772"],"confidence":"Medium","gaps":["Specific clients whose interaction depends on farnesylation not fully defined","Single lab","Enzymatic machinery adding the farnesyl group not characterized here"],"attribution":[{"species":"Plasmodium falciparum","strain":""}]},{"year":2021,"claim":"Measuring the relative affinities of HSP40 for different parasite Hsp70s refined which Hsp70 partner it preferentially engages.","evidence":"Surface plasmon resonance binding affinity measurements against PfHsp70-1 and PfHsp70-z","pmids":["34141839"],"confidence":"Low","gaps":["Single dataset paper with no functional follow-up reported","Biological consequence of affinity differences not tested","Not validated by an orthogonal binding method"],"attribution":[{"species":"Plasmodium falciparum","strain":""}]},{"year":2024,"claim":"Identifying PfR2 as a specific client linked the chaperone activity to a concrete essential process — dNTP synthesis for DNA replication — and validated the HSP40–Hsp70 interface as a drug target.","evidence":"Reciprocal co-immunoprecipitation, small-molecule (116-9e) perturbation, dNTP quantification, growth and drug-synergy assays in strain 3D7","pmids":["40938117"],"confidence":"High","gaps":["Structural basis of PfR2 recognition unresolved","Full client repertoire beyond PfR2 unknown","Whether farnesylation modulates PfR2 handling not tested"],"attribution":[{"species":"Plasmodium falciparum","strain":"3D7"}]},{"year":2025,"claim":"Conditional knockdown established essentiality and demonstrated that HSP40 acts specifically in heat-shock survival and DNA-replication support rather than in general proteotoxic stress responses.","evidence":"Tunable conditional knockdown, flow-cytometry cell-cycle analysis, untargeted proteomics, and drug-sensitivity assays","pmids":["40627776"],"confidence":"High","gaps":["Molecular link between chaperone loss and DNA-replication downregulation only correlative via proteomics","Client set responsible for thermotolerance beyond PfR2 not enumerated","Sexual-stage/transmission role not assessed"],"attribution":[{"species":"Plasmodium falciparum","strain":""}]},{"year":null,"claim":"The full client repertoire of HSP40 and the structural basis by which it selects and delivers substrates such as PfR2 to PfHsp70-1 remain to be defined.","evidence":"","pmids":[],"confidence":"Medium","gaps":["No atomic-resolution structure of the HSP40–PfHsp70-1 or HSP40–PfR2 complex","Clients other than PfR2 not systematically mapped","How farnesylation-dependent membrane targeting intersects with client selection is unresolved"],"attribution":[{"species":"Plasmodium falciparum","strain":""}]}],"mechanism_profile":{"molecular_activity":[],"localization":[],"pathway":[],"complexes":["PfHSP40 (PF3D7_1437900)–PfHsp70-1 chaperone complex"],"partners":["PFHSP70-1","PFR2 (RIBONUCLEOTIDE REDUCTASE SMALL SUBUNIT)","PFHSP70-Z (BINDING MEASURED)","HUMAN HSP70 (HETEROLOGOUS COOPERATION IN VITRO)"],"other_free_text":["Sole canonical cytosolic type I J-domain (Hsp40) protein of P. falciparum; also referred to as PfYdj1/PfHsp40 in the primary literature.","Stimulates Hsp70 ATPase activity via its HPD motif.","Exists as a dimer in solution (SAXS) and forms a complex with PfHsp70-1.","Post-translationally farnesylated; farnesylation controls membrane attachment and client interactions.","Disruption of the HSP40–PfHsp70-1 interaction by small molecule 116-9e destabilizes PfR2 and synergizes with the PfR2 inhibitor benzo-hydroxamate."]}},"prefetch_data":{},"corpus_meta":[{"pmid":"22925632","id":"PMC_22925632","title":"Plasmodium falciparum-encoded exported hsp70/hsp40 chaperone/co-chaperone complexes within the host erythrocyte.","date":"2012","source":"Cellular 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Loss of HSP40 farnesylation alters its membrane attachment and its interaction with proteins in essential pathways in the parasite. Plastidial isopentenyl pyrophosphate (IPP) synthesis and protein farnesylation are required for malaria parasite survival after cold and heat shock.\",\n      \"method\": \"Posttranslational modification mapping, membrane fractionation, proteomics of farnesylation-deficient mutants, temperature stress survival assays\",\n      \"journal\": \"mBio\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — direct PTM identification combined with functional farnesylation mutant phenotypes and proteomics, single lab\",\n      \"pmids\": [\"34182772\"],\n      \"is_preprint\": false,\n      \"attribution\": [{\"species\": \"Plasmodium falciparum\", \"strain\": \"\"}]\n    },\n    {\n      \"year\": 2025,\n      \"finding\": \"PfHSP40 (PF3D7_1437900) is required for asexual replication and survival of febrile temperatures in P. falciparum. Knockdown causes a cell cycle progression defect and reduced nuclear replication. Untargeted proteomics reveal HSP40 depletion leads to downregulation of DNA replication and repair pathways. HSP40 knockdown sensitizes parasites to DNA replication inhibition but does not mitigate proteotoxic stresses induced by artemisinin or proteasome inhibition, indicating a specialized role in heat shock survival distinct from general proteotoxic stress responses.\",\n      \"method\": \"Tunable knockdown (conditional knockdown strain), flow cytometry cell cycle analysis, untargeted proteomics, drug sensitivity assays\",\n      \"journal\": \"PLoS pathogens\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — conditional knockdown with multiple orthogonal readouts (cell cycle, proteomics, drug sensitivity), peer-reviewed, consistent with preprint version\",\n      \"pmids\": [\"40627776\"],\n      \"is_preprint\": false,\n      \"attribution\": [{\"species\": \"Plasmodium falciparum\", \"strain\": \"\"}]\n    },\n    {\n      \"year\": 2024,\n      \"finding\": \"PfHSP40 (PF3D7_1437900, referred to as PfYdj1 in this paper) acts as a cochaperone that facilitates folding and stability of the small subunit of ribonucleotide reductase (PfR2). PfR2 interacts specifically with PfYdj1/PF3D7_1437900 (and not with the type II Hsp40 PfSis1/PF3D7_0213100), which subsequently recruits PfHsp70-1 through its HPD motif. Perturbation of the PfYdj1–PfHsp70-1 interaction by small molecule 116-9e destabilizes PfR2, reduces dNTP production, and causes replication arrest. Combining 116-9e with benzo-hydroxamate (a PfR2 catalytic inhibitor) produces synergistic antiparasitic activity.\",\n      \"method\": \"Co-immunoprecipitation, small molecule inhibitor (116-9e) perturbation, dNTP quantification, parasite growth assays, drug synergy analysis\",\n      \"journal\": \"mBio\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — reciprocal co-IP establishing specific interaction, biochemical perturbation with functional readout, drug synergy validation, multiple orthogonal methods in single study\",\n      \"pmids\": [\"40938117\"],\n      \"is_preprint\": false,\n      \"attribution\": [{\"species\": \"Plasmodium falciparum\", \"strain\": \"3D7\"}]\n    },\n    {\n      \"year\": 2024,\n      \"finding\": \"PF3D7_1437900 (HSP40) is required for asexual replication and thermotolerance in P. falciparum; knockdown causes cell cycle arrest and downregulation of DNA replication/repair pathways. (Preprint version of the peer-reviewed PMID:40627776 finding.)\",\n      \"method\": \"Tunable knockdown, proteomics, cell cycle analysis\",\n      \"journal\": \"bioRxiv\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — preprint with multiple methods but superseded by peer-reviewed version; included for completeness\",\n      \"pmids\": [\"39574603\"],\n      \"is_preprint\": true,\n      \"attribution\": [{\"species\": \"Plasmodium falciparum\", \"strain\": \"\"}]\n    },\n    {\n      \"year\": 2010,\n      \"finding\": \"The single cytosolic canonical Hsp40 of P. falciparum (PF3D7_1437900, referred to as PfHsp40 in this paper) is upregulated under heat shock conditions similarly to PfHsp70-1, localizes mainly to the parasite cytosol by immunofluorescence, stimulates the ATPase activity of both PfHsp70-1 and human Hsp70, suppresses protein aggregation alone, and cooperates with PfHsp70-1 to suppress aggregation in vitro.\",\n      \"method\": \"Western blot (heat shock induction), indirect immunofluorescence microscopy (localization), in vitro ATPase assay, protein aggregation suppression assay\",\n      \"journal\": \"Cell stress & chaperones\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1–2 / Strong — in vitro enzymatic assays with recombinant proteins plus cellular localization; multiple orthogonal methods; peer-reviewed\",\n      \"pmids\": [\"21191678\"],\n      \"is_preprint\": false,\n      \"attribution\": [{\"species\": \"Plasmodium falciparum\", \"strain\": \"\"}]\n    },\n    {\n      \"year\": 2020,\n      \"finding\": \"The PfHSP70-1 and PfHSP40 (PF3D7_1437900) chaperone pair exhibits superior protein folding, aggregation inhibition, oligomer remodeling, and disaggregase activities compared to human orthologs (HSPA1A and DNAJA1). PfHSP40 has higher binding affinity for unfolded substrate than DNAJA1, with a slow dissociation rate maintaining substrate in a folding-competent state. SAXS reveals PfHSP40 exists as a dimer in solution and forms a complex with PfHSP70-1. PfHSP40 can also cooperate efficiently with human HSP70 to facilitate client folding.\",\n      \"method\": \"In vitro protein folding assays, aggregation inhibition assay, disaggregase assay, surface plasmon resonance (SPR) kinetics, small angle X-ray scattering (SAXS)\",\n      \"journal\": \"The Biochemical journal\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 / Moderate — in vitro reconstitution with multiple orthogonal biochemical and biophysical methods (SPR, SAXS, functional assays); single lab\",\n      \"pmids\": [\"32893851\"],\n      \"is_preprint\": false,\n      \"attribution\": [{\"species\": \"Plasmodium falciparum\", \"strain\": \"\"}]\n    },\n    {\n      \"year\": 2021,\n      \"finding\": \"Surface plasmon resonance (SPR) analysis demonstrated that PfHsp70-z and PfHsp70-1 differ in their relative affinities for the cytosol-localized canonical J-domain co-chaperone PfHsp40 (PF3D7_1437900), providing quantitative binding data for this co-chaperone interaction.\",\n      \"method\": \"Surface plasmon resonance (SPR)\",\n      \"journal\": \"Data in brief\",\n      \"confidence\": \"Low\",\n      \"confidence_rationale\": \"Tier 3 / Weak — SPR binding affinity data for PfHsp40 interaction, single supporting dataset paper, no functional follow-up reported in abstract\",\n      \"pmids\": [\"34141839\"],\n      \"is_preprint\": false,\n      \"attribution\": [{\"species\": \"Plasmodium falciparum\", \"strain\": \"\"}]\n    }\n  ],\n  \"current_model\": \"PfHSP40 (PF3D7_1437900) is the sole canonical cytosolic type I J-domain protein in P. falciparum; it is farnesylated (which controls its membrane attachment and chaperone-client interactions), localizes to the parasite cytosol, is essential for asexual intraerythrocytic replication and febrile-temperature survival, acts specifically in heat shock defense but not in general proteotoxic stress responses, stimulates the ATPase activity of PfHsp70-1 via its HPD motif, facilitates folding and stability of the ribonucleotide reductase small subunit PfR2 (thereby supporting dNTP synthesis and DNA replication), and cooperates with PfHsp70-1 to suppress protein aggregation with kinetics and folding efficiency superior to those of the human Hsp40–Hsp70 ortholog pair.\"\n}\n```","stage2_raw":"{\n  \"mechanistic_narrative\": \"PF3D7_1437900 (HSP40) is the sole canonical cytosolic type I J-domain co-chaperone of P. falciparum and functions as the essential Hsp40 partner of the parasite chaperone PfHsp70-1 in heat-shock defense and asexual intraerythrocytic replication [#4, #1]. It stimulates the ATPase activity of PfHsp70-1 through its HPD motif, suppresses protein aggregation on its own, and cooperates with PfHsp70-1 to fold and rescue substrate proteins with higher efficiency than the human Hsp40–Hsp70 ortholog pair, aided by high substrate-binding affinity and a slow dissociation rate that keeps clients folding-competent [#4, #5]. Mechanistically, HSP40 delivers specific clients to PfHsp70-1: it binds and stabilizes the ribonucleotide reductase small subunit PfR2, thereby supporting dNTP synthesis and DNA replication, and disrupting the HSP40–PfHsp70-1 interaction destabilizes PfR2, lowers dNTP levels, and arrests replication [#2]. The protein is farnesylated, a modification that controls its membrane attachment and its interactions with client pathways [#0]. Conditional knockdown confirms an essential and specialized role: depletion produces a cell-cycle progression defect with reduced nuclear replication and downregulation of DNA replication/repair pathways, sensitizes parasites to DNA-replication inhibition, and impairs survival of febrile temperatures, yet does not mitigate general proteotoxic stress from artemisinin or proteasome inhibition, indicating a role dedicated to heat-shock survival rather than generic protein quality control [#1].\"\n,\n  \"teleology\": [\n    {\n      \"year\": 2010,\n      \"claim\": \"Establishing whether the parasite's single canonical cytosolic Hsp40 actually functions as a bona fide Hsp70 co-chaperone was the first requirement for placing it in a chaperone pathway.\",\n      \"evidence\": \"Heat-shock induction Western blots, immunofluorescence localization, in vitro ATPase and aggregation-suppression assays with recombinant protein\",\n      \"pmids\": [\"21191678\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Did not identify physiological client proteins\", \"No in vivo essentiality or phenotype established\", \"Mechanism of substrate handoff to PfHsp70-1 not resolved\"],\n      \"attribution\": [{\"species\": \"Plasmodium falciparum\", \"strain\": \"\"}]\n    },\n    {\n      \"year\": 2020,\n      \"claim\": \"Quantitative biophysical comparison against human orthologs was needed to explain why the parasite chaperone pair might be functionally distinct and drug-targetable.\",\n      \"evidence\": \"In vitro folding, aggregation-inhibition and disaggregase assays, SPR kinetics, and SAXS on recombinant PfHSP40/PfHSP70-1\",\n      \"pmids\": [\"32893851\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Superior in vitro activity not linked to a specific parasite client\", \"Dimer/complex architecture not resolved at atomic resolution\", \"In vivo relevance of superior kinetics untested\"],\n      \"attribution\": [{\"species\": \"Plasmodium falciparum\", \"strain\": \"\"}]\n    },\n    {\n      \"year\": 2021,\n      \"claim\": \"Identifying farnesylation as a post-translational modification addressed how HSP40 associates with membranes and which pathways its lipidation controls.\",\n      \"evidence\": \"PTM mapping, membrane fractionation, proteomics of farnesylation-deficient mutants, and temperature-stress survival assays\",\n      \"pmids\": [\"34182772\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Specific clients whose interaction depends on farnesylation not fully defined\", \"Single lab\", \"Enzymatic machinery adding the farnesyl group not characterized here\"],\n      \"attribution\": [{\"species\": \"Plasmodium falciparum\", \"strain\": \"\"}]\n    },\n    {\n      \"year\": 2021,\n      \"claim\": \"Measuring the relative affinities of HSP40 for different parasite Hsp70s refined which Hsp70 partner it preferentially engages.\",\n      \"evidence\": \"Surface plasmon resonance binding affinity measurements against PfHsp70-1 and PfHsp70-z\",\n      \"pmids\": [\"34141839\"],\n      \"confidence\": \"Low\",\n      \"gaps\": [\"Single dataset paper with no functional follow-up reported\", \"Biological consequence of affinity differences not tested\", \"Not validated by an orthogonal binding method\"],\n      \"attribution\": [{\"species\": \"Plasmodium falciparum\", \"strain\": \"\"}]\n    },\n    {\n      \"year\": 2024,\n      \"claim\": \"Identifying PfR2 as a specific client linked the chaperone activity to a concrete essential process — dNTP synthesis for DNA replication — and validated the HSP40–Hsp70 interface as a drug target.\",\n      \"evidence\": \"Reciprocal co-immunoprecipitation, small-molecule (116-9e) perturbation, dNTP quantification, growth and drug-synergy assays in strain 3D7\",\n      \"pmids\": [\"40938117\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Structural basis of PfR2 recognition unresolved\", \"Full client repertoire beyond PfR2 unknown\", \"Whether farnesylation modulates PfR2 handling not tested\"],\n      \"attribution\": [{\"species\": \"Plasmodium falciparum\", \"strain\": \"3D7\"}]\n    },\n    {\n      \"year\": 2025,\n      \"claim\": \"Conditional knockdown established essentiality and demonstrated that HSP40 acts specifically in heat-shock survival and DNA-replication support rather than in general proteotoxic stress responses.\",\n      \"evidence\": \"Tunable conditional knockdown, flow-cytometry cell-cycle analysis, untargeted proteomics, and drug-sensitivity assays\",\n      \"pmids\": [\"40627776\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Molecular link between chaperone loss and DNA-replication downregulation only correlative via proteomics\", \"Client set responsible for thermotolerance beyond PfR2 not enumerated\", \"Sexual-stage/transmission role not assessed\"],\n      \"attribution\": [{\"species\": \"Plasmodium falciparum\", \"strain\": \"\"}]\n    },\n    {\n      \"year\": null,\n      \"claim\": \"The full client repertoire of HSP40 and the structural basis by which it selects and delivers substrates such as PfR2 to PfHsp70-1 remain to be defined.\",\n      \"evidence\": \"\",\n      \"pmids\": [],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"No atomic-resolution structure of the HSP40–PfHsp70-1 or HSP40–PfR2 complex\", \"Clients other than PfR2 not systematically mapped\", \"How farnesylation-dependent membrane targeting intersects with client selection is unresolved\"],\n      \"attribution\": [{\"species\": \"Plasmodium falciparum\", \"strain\": \"\"}]\n    }\n  ],\n  \"mechanism_profile\": {\n    \"molecular_activity\": [\n      {\"term_id\": \"GO:0001671\", \"supporting_discovery_ids\": [2, 4]},\n      {\"term_id\": \"GO:0051087\", \"supporting_discovery_ids\": [4, 5]},\n      {\"term_id\": \"GO:0051082\", \"supporting_discovery_ids\": [4, 5]},\n      {\"term_id\": \"GO:0030544\", \"supporting_discovery_ids\": [6]}\n    ],\n    \"localization\": [\n      {\"term_id\": \"GO:0005829\", \"supporting_discovery_ids\": [4]},\n      {\"term_id\": \"GO:0016020\", \"supporting_discovery_ids\": [0]}\n    ],\n    \"pathway\": [\n      {\"term_id\": \"GO:0034605\", \"supporting_discovery_ids\": [1, 4]},\n      {\"term_id\": \"GO:0006260\", \"supporting_discovery_ids\": [1, 2]},\n      {\"term_id\": \"GO:0006281\", \"supporting_discovery_ids\": [1]},\n      {\"term_id\": \"GO:0009263\", \"supporting_discovery_ids\": [2]},\n      {\"term_id\": \"GO:0018343\", \"supporting_discovery_ids\": [0]}\n    ],\n    \"complexes\": [\n      \"PfHSP40 (PF3D7_1437900)–PfHsp70-1 chaperone complex\"\n    ],\n    \"partners\": [\n      \"PfHsp70-1\",\n      \"PfR2 (ribonucleotide reductase small subunit)\",\n      \"PfHsp70-z (binding measured)\",\n      \"human Hsp70 (heterologous cooperation in vitro)\"\n    ],\n    \"other_free_text\": [\n      \"Sole canonical cytosolic type I J-domain (Hsp40) protein of P. falciparum; also referred to as PfYdj1/PfHsp40 in the primary literature.\",\n      \"Stimulates Hsp70 ATPase activity via its HPD motif.\",\n      \"Exists as a dimer in solution (SAXS) and forms a complex with PfHsp70-1.\",\n      \"Post-translationally farnesylated; farnesylation controls membrane attachment and client interactions.\",\n      \"Disruption of the HSP40–PfHsp70-1 interaction by small molecule 116-9e destabilizes PfR2 and synergizes with the PfR2 inhibitor benzo-hydroxamate.\"\n    ]\n  }\n}","audit_flag":null,"strains":[{"strain":"Pf3D7","gene_id":"PF3D7_1437900","name":null,"product":"HSP40, subfamily A","uniprot_acc":null,"chromosome":null,"start_pos":null},{"strain":"PbANKA","gene_id":"PBANKA_0610900","name":null,"product":"HSP40, subfamily A, putative","uniprot_acc":null,"chromosome":null,"start_pos":null},{"strain":"PkH","gene_id":"PKNH_0424600","name":null,"product":"HSP40, subfamily A, putative","uniprot_acc":null,"chromosome":null,"start_pos":null}],"gene_symbol":"HSP40","evaluation":null}