{"gene":"PF3D7_0501200","run_date":"2026-09-07T10:55:52","timeline":{"discoveries":[{"year":2004,"finding":"PIESP2 (PF3D7_0501200) was identified as a novel surface protein on P. falciparum-infected erythrocytes. Surface location was confirmed by confocal microscopy using specific antibodies after biotin-streptavidin fractionation of surface proteins. PIESP2 is encoded by a single copy gene and is highly conserved across Plasmodium spp. It was found to be unlikely associated with knobs.","method":"Biotin-streptavidin surface protein fractionation, shotgun proteomics, confocal microscopy with specific antibodies","journal":"Molecular and biochemical parasitology","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — direct surface fractionation and confocal localization with specific antibodies, single lab, two orthogonal methods","pmids":["15287581"],"is_preprint":false,"attribution":[{"species":"Plasmodium falciparum","strain":""}]},{"year":2017,"finding":"PIESP2 (PF3D7_0501200; referred to as PFE60 in this paper) localizes to Maurer's clefts (MC) and plays a role in MC lamella segmentation: in cells lacking PIESP2, infected erythrocytes display a higher number of stacked MC compared to wild-type. Additionally, another exported protein (Pf332) failed to localize correctly to MC in PIESP2-knockout cells. Uniquely among MC resident membrane proteins, PIESP2 does not require its transmembrane regions to be targeted to MC. This paper also explicitly demonstrated that PIESP2 is NOT a red blood cell surface antigen.","method":"Genetic knockout (loss-of-function), confocal microscopy, protein truncation/domain deletion analysis","journal":"International journal for parasitology","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — clean knockout with specific cellular phenotype (MC stacking, Pf332 mislocalization) and domain deletion, single lab","pmids":["29100811"],"is_preprint":false,"attribution":[{"species":"Plasmodium falciparum","strain":""}]},{"year":2021,"finding":"PIESP2 (PF3D7_0501200) expression begins at the early trophozoite stage and increases with parasite development. A subpopulation of PIESP2 is present on the infected red blood cell (IRBC) surface at the pigmented trophozoite stage. Blockage of PIESP2 by antiserum inhibited adhesion of IRBCs to brain microvascular endothelial cells (BMECs). Western blot analysis detected direct binding of PIESP2 to BMECs. PIESP2 binding to BMECs increased expression of inflammatory response genes and decreased expression of anchoring junction genes.","method":"Immunofluorescence/confocal microscopy for stage-specific localization, antiserum blocking adhesion assay, Western blot binding assay, transcriptional analysis of BMEC gene expression","journal":"International journal of biological macromolecules","confidence":"Medium","confidence_rationale":"Tier 2–3 / Moderate — multiple orthogonal methods (localization, blocking assay, direct binding, transcriptional readout) in single lab; antiserum blockade is not as clean as genetic KO","pmids":["33631268"],"is_preprint":false,"attribution":[{"species":"Plasmodium falciparum","strain":""}]},{"year":2026,"finding":"Using phage display cDNA technology and a monoclonal antibody (GM7mAb) raised against the repetitive regions of PfGARP, a reverse/mirrored epitope was identified within PIESP2 (PF3D7_0501200). Unbiased mass spectrometry combined with two independent PfGARP-null parasite lines demonstrated that a subpopulation of PIESP2 localizes to the surface of knobs on infected erythrocytes, placing PIESP2 as a component of a knob-associated complex with PfGARP.","method":"Phage display cDNA technology, monoclonal antibody generation (GM7mAb), mass spectrometry, PfGARP-null parasite lines (two independent lines), epitope mapping","journal":"The Journal of biological chemistry","confidence":"High","confidence_rationale":"Tier 1–2 / Strong — two independent null parasite lines, unbiased mass spectrometry, and epitope mirroring with monoclonal antibody, multiple orthogonal methods in single study","pmids":["42336280"],"is_preprint":false,"attribution":[{"species":"Plasmodium falciparum","strain":""}]}],"current_model":"PIESP2 (PF3D7_0501200) is a P. falciparum-specific exported protein that localizes primarily to Maurer's clefts in the infected erythrocyte cytoplasm, where it is required for normal MC lamella segmentation and correct localization of Pf332; a subpopulation of PIESP2 also reaches the knob surface of infected red blood cells, where it forms part of a knob-associated complex with PfGARP, and can directly bind brain microvascular endothelial cells to promote cytoadhesion and modulate host endothelial gene expression."},"narrative":{"mechanistic_narrative":"PIESP2 (PF3D7_0501200) is a single-copy, Plasmodium-conserved exported protein of P. falciparum that operates at the interface between parasite-driven remodeling of the infected erythrocyte and host cytoadhesion [PMID:15287581, PMID:29100811]. Within the infected red blood cell it localizes principally to Maurer's clefts, where it is required for normal MC lamella segmentation—its loss increases the number of stacked clefts—and for correct MC targeting of the exported protein Pf332; unusually among MC-resident membrane proteins, PIESP2 reaches the clefts independently of its transmembrane regions [PMID:29100811]. A developmentally regulated subpopulation, expressed from the early trophozoite stage onward, additionally reaches the surface of the infected erythrocyte at the knobs, where it is a component of a knob-associated complex with PfGARP [PMID:33631268, PMID:42336280]. At this surface pool PIESP2 directly binds brain microvascular endothelial cells and promotes cytoadhesion, and this binding reprograms host endothelium by inducing inflammatory-response genes and repressing anchoring-junction genes [PMID:33631268]. Whether PIESP2 possesses intrinsic enzymatic activity, and the structural basis of its MC-targeting and PfGARP association, have not been characterized in the available corpus.","teleology":[{"year":2004,"claim":"Establishing whether PIESP2 exists at the host-cell interface was the first step in assigning it a role in infected-erythrocyte biology; surface fractionation placed a conserved single-copy protein at the infected erythrocyte surface.","evidence":"Biotin-streptavidin surface fractionation, shotgun proteomics, and confocal microscopy with specific antibodies in P. falciparum","pmids":["15287581"],"confidence":"Medium","gaps":["No functional role assigned","Association with knobs left ambiguous (deemed unlikely here)","No intracellular trafficking route defined"],"attribution":[{"species":"Plasmodium falciparum","strain":""}]},{"year":2017,"claim":"The question of what PIESP2 does inside the infected cell was answered by genetic knockout, revealing a structural role in Maurer's cleft organization and in trafficking of a second exported protein.","evidence":"Loss-of-function knockout with confocal microscopy and domain-deletion analysis showing increased MC stacking, Pf332 mislocalization, and transmembrane-independent MC targeting in P. falciparum","pmids":["29100811"],"confidence":"Medium","gaps":["Molecular basis of transmembrane-independent MC targeting unknown","Whether the Pf332 defect is direct or secondary to MC disorganization is unresolved","This study concluded PIESP2 is not an RBC surface antigen, conflicting with earlier and later surface findings"],"attribution":[{"species":"Plasmodium falciparum","strain":""}]},{"year":2021,"claim":"Whether the surface pool of PIESP2 has a cytoadhesive function was addressed by binding and blocking assays, linking a developmentally regulated surface subpopulation to endothelial adhesion and host gene reprogramming.","evidence":"Stage-specific immunofluorescence, antiserum blocking of IRBC adhesion, Western blot binding assay, and BMEC transcriptional profiling in P. falciparum","pmids":["33631268"],"confidence":"Medium","gaps":["Antiserum blockade is less definitive than genetic ablation of the surface pool","Endothelial receptor for PIESP2 not identified","Mechanism reconciling surface adhesion with the internal MC role not defined"],"attribution":[{"species":"Plasmodium falciparum","strain":""}]},{"year":2026,"claim":"The molecular context of the surface pool was clarified by placing PIESP2 within a defined knob-associated complex, resolving its ambiguous knob relationship established in 2004.","evidence":"Phage display cDNA epitope mapping with an anti-PfGARP monoclonal antibody, unbiased mass spectrometry, and two independent PfGARP-null parasite lines in P. falciparum","pmids":["42336280"],"confidence":"High","gaps":["Direct binding interface between PIESP2 and PfGARP not resolved structurally","Stoichiometry and other members of the knob-associated complex undefined","Whether PfGARP association is required for the cytoadhesive activity is untested"],"attribution":[{"species":"Plasmodium falciparum","strain":""}]},{"year":null,"claim":"It remains unknown how a single protein is partitioned between an internal Maurer's cleft structural role and a knob-surface cytoadhesive role, and whether any intrinsic biochemical activity underlies either function.","evidence":"","pmids":[],"confidence":"Medium","gaps":["No structural model or biochemical activity for PIESP2 established","Trafficking determinants that sort PIESP2 to MC versus knob surface unknown","Endothelial receptor and mechanism of host gene reprogramming unidentified"],"attribution":[{"species":"Plasmodium falciparum","strain":""}]}],"mechanism_profile":{"molecular_activity":[],"localization":[],"pathway":[],"complexes":["Knob-associated complex with PfGARP [#3]"],"partners":["PFGARP (KNOB-SURFACE COMPLEX PARTNER) [#3]","PF332 (MAURER'S CLEFT TRAFFICKING DEPENDENT ON PIESP2) [#1]"],"other_free_text":["Single-copy gene, highly conserved across Plasmodium spp. [#0]","Expression begins at early trophozoite stage and increases with development [#2]","Required for normal Maurer's cleft lamella segmentation; knockout increases stacked clefts [#1]","Targeted to Maurer's clefts independently of its transmembrane regions [#1]","Directly binds brain microvascular endothelial cells and modulates host inflammatory and anchoring-junction gene expression [#2]"]}},"prefetch_data":{},"corpus_meta":[{"pmid":"15287581","id":"PMC_15287581","title":"Proteomics approach reveals novel proteins on the surface of malaria-infected erythrocytes.","date":"2004","source":"Molecular and biochemical parasitology","url":"https://pubmed.ncbi.nlm.nih.gov/15287581","citation_count":145,"is_preprint":false,"source_species":["Pf"],"role":"primary","match_terms":["PIESP2"],"competing_organism_flag":false,"competing_organism_match":"","competing_organism_only":false},{"pmid":"34535134","id":"PMC_34535134","title":"The prevalence and density of asymptomatic Plasmodium falciparum infections among children and adults in three communities of western Kenya.","date":"2021","source":"Malaria journal","url":"https://pubmed.ncbi.nlm.nih.gov/34535134","citation_count":24,"is_preprint":false,"source_species":["Pf"],"role":"primary","match_terms":["PIESP2"],"competing_organism_flag":false,"competing_organism_match":"","competing_organism_only":false},{"pmid":"29100811","id":"PMC_29100811","title":"Plasmodium falciparum exported protein PFE60 influences Maurer's clefts architecture and virulence complex composition.","date":"2017","source":"International journal for parasitology","url":"https://pubmed.ncbi.nlm.nih.gov/29100811","citation_count":7,"is_preprint":false,"source_species":["Pf"],"role":"primary","match_terms":["PF3D7_0501200","PIESP2"],"competing_organism_flag":false,"competing_organism_match":"","competing_organism_only":false},{"pmid":"29716542","id":"PMC_29716542","title":"In-depth comparative analysis of malaria parasite genomes reveals protein-coding genes linked to human disease in Plasmodium falciparum genome.","date":"2018","source":"BMC genomics","url":"https://pubmed.ncbi.nlm.nih.gov/29716542","citation_count":7,"is_preprint":false,"source_species":["Pf"],"role":"primary","match_terms":["PIESP2","parasite-infected erythrocyte surface protein"],"competing_organism_flag":false,"competing_organism_match":"","competing_organism_only":false},{"pmid":"33631268","id":"PMC_33631268","title":"Identification of Plasmodium falciparum-specific protein PIESP2 as a novel virulence factor related to cerebral malaria.","date":"2021","source":"International journal of biological macromolecules","url":"https://pubmed.ncbi.nlm.nih.gov/33631268","citation_count":7,"is_preprint":false,"source_species":["Pf"],"role":"primary","match_terms":["PIESP2"],"competing_organism_flag":false,"competing_organism_match":"","competing_organism_only":false},{"pmid":"42336280","id":"PMC_42336280","title":"Epitope mirroring between the malaria surface proteins PfGARP and PIESP2 identifies a knob-associated complex in infected erythrocytes.","date":"2026","source":"The Journal of biological chemistry","url":"https://pubmed.ncbi.nlm.nih.gov/42336280","citation_count":0,"is_preprint":false,"source_species":["Pf"],"role":"primary","match_terms":["PIESP2"],"competing_organism_flag":false,"competing_organism_match":"","competing_organism_only":false}],"cost":{"stage1":{"model":"claude-sonnet-4-6","input_tokens":6169,"output_tokens":1444,"usd":0.020084,"stage1_stop_reason":"end_turn"},"stage2":{"model":"claude-opus-4-8","input_tokens":6391,"output_tokens":2546,"usd":0.047802,"stage2_stop_reason":"end_turn"},"total_usd":0.067886,"stage1_batch_id":"msgbatch_01DbiymDmubkPpYvdbAu5a7V","stage2_batch_id":"msgbatch_012TbrWvMRH129T7PQ4SmvrJ","note":"batch pricing = 50% of standard"},"stage1_raw":"```json\n{\n  \"discoveries\": [\n    {\n      \"year\": 2004,\n      \"finding\": \"PIESP2 (PF3D7_0501200) was identified as a novel surface protein on P. falciparum-infected erythrocytes. Surface location was confirmed by confocal microscopy using specific antibodies after biotin-streptavidin fractionation of surface proteins. PIESP2 is encoded by a single copy gene and is highly conserved across Plasmodium spp. It was found to be unlikely associated with knobs.\",\n      \"method\": \"Biotin-streptavidin surface protein fractionation, shotgun proteomics, confocal microscopy with specific antibodies\",\n      \"journal\": \"Molecular and biochemical parasitology\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — direct surface fractionation and confocal localization with specific antibodies, single lab, two orthogonal methods\",\n      \"pmids\": [\"15287581\"],\n      \"is_preprint\": false,\n      \"attribution\": [{\"species\": \"Plasmodium falciparum\", \"strain\": \"\"}]\n    },\n    {\n      \"year\": 2017,\n      \"finding\": \"PIESP2 (PF3D7_0501200; referred to as PFE60 in this paper) localizes to Maurer's clefts (MC) and plays a role in MC lamella segmentation: in cells lacking PIESP2, infected erythrocytes display a higher number of stacked MC compared to wild-type. Additionally, another exported protein (Pf332) failed to localize correctly to MC in PIESP2-knockout cells. Uniquely among MC resident membrane proteins, PIESP2 does not require its transmembrane regions to be targeted to MC. This paper also explicitly demonstrated that PIESP2 is NOT a red blood cell surface antigen.\",\n      \"method\": \"Genetic knockout (loss-of-function), confocal microscopy, protein truncation/domain deletion analysis\",\n      \"journal\": \"International journal for parasitology\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — clean knockout with specific cellular phenotype (MC stacking, Pf332 mislocalization) and domain deletion, single lab\",\n      \"pmids\": [\"29100811\"],\n      \"is_preprint\": false,\n      \"attribution\": [{\"species\": \"Plasmodium falciparum\", \"strain\": \"\"}]\n    },\n    {\n      \"year\": 2021,\n      \"finding\": \"PIESP2 (PF3D7_0501200) expression begins at the early trophozoite stage and increases with parasite development. A subpopulation of PIESP2 is present on the infected red blood cell (IRBC) surface at the pigmented trophozoite stage. Blockage of PIESP2 by antiserum inhibited adhesion of IRBCs to brain microvascular endothelial cells (BMECs). Western blot analysis detected direct binding of PIESP2 to BMECs. PIESP2 binding to BMECs increased expression of inflammatory response genes and decreased expression of anchoring junction genes.\",\n      \"method\": \"Immunofluorescence/confocal microscopy for stage-specific localization, antiserum blocking adhesion assay, Western blot binding assay, transcriptional analysis of BMEC gene expression\",\n      \"journal\": \"International journal of biological macromolecules\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2–3 / Moderate — multiple orthogonal methods (localization, blocking assay, direct binding, transcriptional readout) in single lab; antiserum blockade is not as clean as genetic KO\",\n      \"pmids\": [\"33631268\"],\n      \"is_preprint\": false,\n      \"attribution\": [{\"species\": \"Plasmodium falciparum\", \"strain\": \"\"}]\n    },\n    {\n      \"year\": 2026,\n      \"finding\": \"Using phage display cDNA technology and a monoclonal antibody (GM7mAb) raised against the repetitive regions of PfGARP, a reverse/mirrored epitope was identified within PIESP2 (PF3D7_0501200). Unbiased mass spectrometry combined with two independent PfGARP-null parasite lines demonstrated that a subpopulation of PIESP2 localizes to the surface of knobs on infected erythrocytes, placing PIESP2 as a component of a knob-associated complex with PfGARP.\",\n      \"method\": \"Phage display cDNA technology, monoclonal antibody generation (GM7mAb), mass spectrometry, PfGARP-null parasite lines (two independent lines), epitope mapping\",\n      \"journal\": \"The Journal of biological chemistry\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1–2 / Strong — two independent null parasite lines, unbiased mass spectrometry, and epitope mirroring with monoclonal antibody, multiple orthogonal methods in single study\",\n      \"pmids\": [\"42336280\"],\n      \"is_preprint\": false,\n      \"attribution\": [{\"species\": \"Plasmodium falciparum\", \"strain\": \"\"}]\n    }\n  ],\n  \"current_model\": \"PIESP2 (PF3D7_0501200) is a P. falciparum-specific exported protein that localizes primarily to Maurer's clefts in the infected erythrocyte cytoplasm, where it is required for normal MC lamella segmentation and correct localization of Pf332; a subpopulation of PIESP2 also reaches the knob surface of infected red blood cells, where it forms part of a knob-associated complex with PfGARP, and can directly bind brain microvascular endothelial cells to promote cytoadhesion and modulate host endothelial gene expression.\"\n}\n```","stage2_raw":"{\n  \"mechanistic_narrative\": \"PIESP2 (PF3D7_0501200) is a single-copy, Plasmodium-conserved exported protein of P. falciparum that operates at the interface between parasite-driven remodeling of the infected erythrocyte and host cytoadhesion [#0, #1]. Within the infected red blood cell it localizes principally to Maurer's clefts, where it is required for normal MC lamella segmentation—its loss increases the number of stacked clefts—and for correct MC targeting of the exported protein Pf332; unusually among MC-resident membrane proteins, PIESP2 reaches the clefts independently of its transmembrane regions [#1]. A developmentally regulated subpopulation, expressed from the early trophozoite stage onward, additionally reaches the surface of the infected erythrocyte at the knobs, where it is a component of a knob-associated complex with PfGARP [#2, #3]. At this surface pool PIESP2 directly binds brain microvascular endothelial cells and promotes cytoadhesion, and this binding reprograms host endothelium by inducing inflammatory-response genes and repressing anchoring-junction genes [#2]. Whether PIESP2 possesses intrinsic enzymatic activity, and the structural basis of its MC-targeting and PfGARP association, have not been characterized in the available corpus.\",\n  \"teleology\": [\n    {\n      \"year\": 2004,\n      \"claim\": \"Establishing whether PIESP2 exists at the host-cell interface was the first step in assigning it a role in infected-erythrocyte biology; surface fractionation placed a conserved single-copy protein at the infected erythrocyte surface.\",\n      \"evidence\": \"Biotin-streptavidin surface fractionation, shotgun proteomics, and confocal microscopy with specific antibodies in P. falciparum\",\n      \"pmids\": [\"15287581\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\n        \"No functional role assigned\",\n        \"Association with knobs left ambiguous (deemed unlikely here)\",\n        \"No intracellular trafficking route defined\"\n      ],\n      \"attribution\": [{\"species\": \"Plasmodium falciparum\", \"strain\": \"\"}]\n    },\n    {\n      \"year\": 2017,\n      \"claim\": \"The question of what PIESP2 does inside the infected cell was answered by genetic knockout, revealing a structural role in Maurer's cleft organization and in trafficking of a second exported protein.\",\n      \"evidence\": \"Loss-of-function knockout with confocal microscopy and domain-deletion analysis showing increased MC stacking, Pf332 mislocalization, and transmembrane-independent MC targeting in P. falciparum\",\n      \"pmids\": [\"29100811\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\n        \"Molecular basis of transmembrane-independent MC targeting unknown\",\n        \"Whether the Pf332 defect is direct or secondary to MC disorganization is unresolved\",\n        \"This study concluded PIESP2 is not an RBC surface antigen, conflicting with earlier and later surface findings\"\n      ],\n      \"attribution\": [{\"species\": \"Plasmodium falciparum\", \"strain\": \"\"}]\n    },\n    {\n      \"year\": 2021,\n      \"claim\": \"Whether the surface pool of PIESP2 has a cytoadhesive function was addressed by binding and blocking assays, linking a developmentally regulated surface subpopulation to endothelial adhesion and host gene reprogramming.\",\n      \"evidence\": \"Stage-specific immunofluorescence, antiserum blocking of IRBC adhesion, Western blot binding assay, and BMEC transcriptional profiling in P. falciparum\",\n      \"pmids\": [\"33631268\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\n        \"Antiserum blockade is less definitive than genetic ablation of the surface pool\",\n        \"Endothelial receptor for PIESP2 not identified\",\n        \"Mechanism reconciling surface adhesion with the internal MC role not defined\"\n      ],\n      \"attribution\": [{\"species\": \"Plasmodium falciparum\", \"strain\": \"\"}]\n    },\n    {\n      \"year\": 2026,\n      \"claim\": \"The molecular context of the surface pool was clarified by placing PIESP2 within a defined knob-associated complex, resolving its ambiguous knob relationship established in 2004.\",\n      \"evidence\": \"Phage display cDNA epitope mapping with an anti-PfGARP monoclonal antibody, unbiased mass spectrometry, and two independent PfGARP-null parasite lines in P. falciparum\",\n      \"pmids\": [\"42336280\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\n        \"Direct binding interface between PIESP2 and PfGARP not resolved structurally\",\n        \"Stoichiometry and other members of the knob-associated complex undefined\",\n        \"Whether PfGARP association is required for the cytoadhesive activity is untested\"\n      ],\n      \"attribution\": [{\"species\": \"Plasmodium falciparum\", \"strain\": \"\"}]\n    },\n    {\n      \"year\": null,\n      \"claim\": \"It remains unknown how a single protein is partitioned between an internal Maurer's cleft structural role and a knob-surface cytoadhesive role, and whether any intrinsic biochemical activity underlies either function.\",\n      \"evidence\": \"\",\n      \"pmids\": [],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\n        \"No structural model or biochemical activity for PIESP2 established\",\n        \"Trafficking determinants that sort PIESP2 to MC versus knob surface unknown\",\n        \"Endothelial receptor and mechanism of host gene reprogramming unidentified\"\n      ],\n      \"attribution\": [{\"species\": \"Plasmodium falciparum\", \"strain\": \"\"}]\n    }\n  ],\n  \"mechanism_profile\": {\n    \"molecular_activity\": [\n      {\"term_id\": \"GO:0005515\", \"supporting_discovery_ids\": [3]},\n      {\"term_id\": \"GO:0050839\", \"supporting_discovery_ids\": [2]}\n    ],\n    \"localization\": [\n      {\"term_id\": \"GO:0020030\", \"supporting_discovery_ids\": [0, 1]},\n      {\"term_id\": \"GO:0020036\", \"supporting_discovery_ids\": [3]},\n      {\"term_id\": \"GO:0009986\", \"supporting_discovery_ids\": [0, 2, 3]}\n    ],\n    \"pathway\": [\n      {\"term_id\": \"GO:0020035\", \"supporting_discovery_ids\": [2]},\n      {\"term_id\": \"GO:0051701\", \"supporting_discovery_ids\": [2]}\n    ],\n    \"complexes\": [\n      \"Knob-associated complex with PfGARP [#3]\"\n    ],\n    \"partners\": [\n      \"PfGARP (knob-surface complex partner) [#3]\",\n      \"Pf332 (Maurer's cleft trafficking dependent on PIESP2) [#1]\"\n    ],\n    \"other_free_text\": [\n      \"Single-copy gene, highly conserved across Plasmodium spp. [#0]\",\n      \"Expression begins at early trophozoite stage and increases with development [#2]\",\n      \"Required for normal Maurer's cleft lamella segmentation; knockout increases stacked clefts [#1]\",\n      \"Targeted to Maurer's clefts independently of its transmembrane regions [#1]\",\n      \"Directly binds brain microvascular endothelial cells and modulates host inflammatory and anchoring-junction gene expression [#2]\"\n    ]\n  }\n}","audit_flag":null,"strains":[{"strain":"Pf3D7","gene_id":"PF3D7_0501200","name":null,"product":"parasite-infected erythrocyte surface protein","uniprot_acc":null,"chromosome":null,"start_pos":null}],"gene_symbol":"PIESP2","evaluation":null}