{"gene":"PF3D7_0515600","run_date":"2026-09-08T16:26:55","timeline":{"discoveries":[{"year":2020,"finding":"GEP (PBANKA_1115200) is expressed in gametocytes of both genders and partially localizes to osmiophilic bodies (OBs). Genetic deletion of GEP in P. berghei causes aberrant rupture of the parasitophorous vacuole membrane and erythrocyte membrane, delayed (but not aborted) OB discharge, and immotile axonemes in male flagellar gametes. Genetic crossing experiments confirmed that both male and female gep-null parasites are unable to establish mosquito infections, demonstrating pleiotropic roles in gamete egress and male exflagellation.","method":"Gene knockout (targeted deletion), fluorescence microscopy for OB localization, genetic crossing experiments, mosquito transmission assays","journal":"MicrobiologyOpen","confidence":"High","confidence_rationale":"Tier 2 / Strong — clean KO with defined cellular phenotypes across multiple orthogonal readouts (membrane rupture, OB discharge, axoneme motility, transmission), replicated via genetic crossing","pmids":["32352241"],"is_preprint":false,"attribution":[{"species":"Plasmodium berghei","strain":""}]},{"year":2021,"finding":"In P. falciparum, GEP (PF3D7_0515600) is hypophosphorylated in cdpk4-null gametocytes activated by xanthurenic acid, placing GEP downstream of PfCDPK4 in the calcium-signaling cascade that governs male gametogenesis. In vitro phosphorylation assays identified GEP as a putative direct or indirect substrate of PfCDPK4.","method":"Quantitative mass spectrometry-based phosphoproteomics of wild-type vs. Pfcdpk4-null gametocytes; in vitro kinase assay","journal":"mBio","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — phosphoproteomics plus in vitro kinase assay, single lab, GEP identified as hypophosphorylated substrate candidate but direct substrate relationship not fully reconstituted","pmids":["34724830"],"is_preprint":false,"attribution":[{"species":"Plasmodium falciparum","strain":""}]},{"year":2023,"finding":"GEP (PBANKA_1115200) is ubiquitinated in P. berghei gametocytes in a manner regulated by the SCFFBXO1 E3 ligase complex, and CDPK1 activity negatively regulates FBXO1-dependent ubiquitination of GEP, suggesting that phosphorylation and ubiquitination of GEP are antagonistically linked through CDPK1–FBXO1 crosstalk.","method":"Ubiquitinomic mass spectrometry of FBXO1-glucosylamine-depleted and CDPK1-KO parasites; comparative quantitative proteomics","journal":"Nature communications","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — ubiquitinomic survey identified GEP as a specific FBXO1-dependent ubiquitination target with CDPK1 crosstalk, single lab, no direct reconstitution of GEP ubiquitination","pmids":["36898988"],"is_preprint":false,"attribution":[{"species":"Plasmodium berghei","strain":""}]},{"year":2024,"finding":"In P. yoelii, GEP is detected as a proximal interactor of both DOZI and ALBA4 RNA-binding proteins within the condensed DOZI/CITH/ALBA mRNP complex in female gametocytes, indicating GEP mRNA (or GEP protein) is part of the translational repression machinery operating before fertilization.","method":"TurboID-based proximity proteomics (BioID) with DOZI and ALBA4 as baits in gametocytes and zygotes","journal":"PLoS pathogens","confidence":"Low","confidence_rationale":"Tier 3 / Weak — single proximity-labeling experiment, single lab; GEP listed among many proximal proteins with no functional follow-up specific to GEP","pmids":["39777415"],"is_preprint":false,"attribution":[{"species":"Plasmodium yoelii","strain":""}]},{"year":2024,"finding":"In P. yoelii, GEP expression is required for erythrocyte membrane rupture in both male and female gametocytes and for axoneme assembly in male gametocytes. Insertion of axonemal introns (kinesin8b intron1 or PF16 intron1) into the gep locus blocked GEP protein expression in the absence of the male-specific splicing activator RBPm1, confirming that GEP is a functional downstream target of the RBPm1-dependent axonemal intron splicing program in males.","method":"Gene deletion (Δgep), intron-insertion reporter lines, immunofluorescence (anti-TER-119, anti-α-Tubulin, Hoechst), quantitative phenotypic analysis across three independent experiments","journal":"Nature communications","confidence":"High","confidence_rationale":"Tier 2 / Strong — clean KO plus mechanistic intron-insertion experiments with functional rescue logic, multiple orthogonal readouts (EM rupture, genome replication, axoneme assembly), three independent replicates","pmids":["38824128"],"is_preprint":false,"attribution":[{"species":"Plasmodium yoelii","strain":"17XNL"}]},{"year":2022,"finding":"GEP (PBANKA_1115200) is detected in the interactome of the P. berghei PP1-LRR1 complex by co-immunoprecipitation/mass spectrometry, identifying GEP as a potential partner or regulated substrate within the PP1 phosphatase network during sexual development.","method":"Immunoprecipitation-mass spectrometry (interactome analysis) of PbLRR1","journal":"Open biology","confidence":"Low","confidence_rationale":"Tier 3 / Weak — single Co-IP/MS experiment, single lab, GEP listed among many interactome hits with no functional follow-up specific to GEP","pmids":["35920043"],"is_preprint":false,"attribution":[{"species":"Plasmodium berghei","strain":""}]}],"current_model":"GEP (PF3D7_0515600/PBANKA_1115200) is a Plasmodium-specific gametocyte protein that partially localizes to osmiophilic bodies, is required for rupture of both the parasitophorous vacuole membrane and erythrocyte membrane during gamete egress in both sexes, and is additionally required for axoneme motility in male gametes; its activity is regulated post-translationally by CDPK4-mediated phosphorylation and SCFFBXO1-mediated ubiquitination, and its expression in males depends on the RBPm1 axonemal intron splicing program."},"narrative":{"mechanistic_narrative":"GEP (PF3D7_0515600; ortholog PBANKA_1115200) is a Plasmodium gametocyte protein required for gamete egress and male exflagellation during the transition to mosquito-stage development [PMID:32352241]. It is expressed in gametocytes of both sexes and partially localizes to osmiophilic bodies; its genetic deletion in P. berghei causes aberrant rupture of the parasitophorous vacuole membrane and erythrocyte membrane, delayed osmiophilic body discharge, and immotile axonemes in male flagellar gametes, rendering both male and female null parasites unable to establish mosquito infection [PMID:32352241]. In P. yoelii, GEP is likewise required for erythrocyte membrane rupture in both sexes and for axoneme assembly in males, and its expression in males depends on the RBPm1-driven axonemal intron splicing program, established by intron-insertion experiments that abolished GEP expression in the absence of RBPm1 [PMID:38824128]. Post-translationally, GEP sits within the calcium-signaling machinery of gametogenesis: it is hypophosphorylated in P. falciparum cdpk4-null gametocytes and behaves as a PfCDPK4 substrate candidate in vitro [PMID:34724830], and in P. berghei it is ubiquitinated in an SCF-FBXO1-dependent manner that is negatively regulated by CDPK1 [PMID:36898988]. Beyond these regulatory links, the biochemical activity of the GEP protein itself is uncharacterized in the available corpus.","teleology":[{"year":2020,"claim":"Establishing whether GEP has a cellular function in sexual development, the first knockout defined it as a pleiotropic egress and exflagellation factor rather than a passive gametocyte marker.","evidence":"Targeted gene deletion in P. berghei with OB localization microscopy, genetic crossing, and mosquito transmission assays","pmids":["32352241"],"confidence":"High","gaps":["biochemical activity of GEP and how it drives membrane rupture is unknown","molecular basis of OB targeting not defined","how GEP contributes to axoneme motility is not resolved"],"attribution":[{"species":"Plasmodium berghei","strain":""}]},{"year":2021,"claim":"To place GEP within gametogenesis signaling, phosphoproteomics identified it as a CDPK4-dependent phosphoprotein, linking it to the calcium cascade that triggers male gametogenesis.","evidence":"Quantitative phosphoproteomics of wild-type vs. Pfcdpk4-null P. falciparum gametocytes plus in vitro kinase assay","pmids":["34724830"],"confidence":"Medium","gaps":["direct vs. indirect substrate relationship not fully reconstituted","phosphosites and their functional consequence for GEP not mapped"],"attribution":[{"species":"Plasmodium falciparum","strain":""}]},{"year":2022,"claim":"A PP1-LRR1 interactome survey raised the possibility that GEP is embedded in a phosphatase regulatory network during sexual development.","evidence":"Immunoprecipitation-mass spectrometry of PbLRR1 in P. berghei","pmids":["35920043"],"confidence":"Low","gaps":["single Co-IP/MS with no GEP-specific functional follow-up or reciprocal validation","whether GEP is a PP1 substrate or bystander is unknown"],"attribution":[{"species":"Plasmodium berghei","strain":""}]},{"year":2023,"claim":"Ubiquitinomics extended GEP regulation beyond phosphorylation, showing it is an SCF-FBXO1 ubiquitination target under antagonistic control by CDPK1.","evidence":"Ubiquitinomic and comparative proteomic mass spectrometry of FBXO1-depleted and CDPK1-KO P. berghei parasites","pmids":["36898988"],"confidence":"Medium","gaps":["GEP ubiquitination not directly reconstituted","consequence of ubiquitination for GEP stability or activity not established"],"attribution":[{"species":"Plasmodium berghei","strain":""}]},{"year":2024,"claim":"Cross-species knockout and intron-insertion experiments confirmed GEP's egress/axoneme role in P. yoelii and defined RBPm1-dependent intron splicing as the mechanism controlling its male-specific expression.","evidence":"Δgep deletion, axonemal-intron insertion reporter lines, and immunofluorescence phenotyping in P. yoelii 17XNL, across three independent experiments","pmids":["38824128"],"confidence":"High","gaps":["does not define GEP's biochemical role in membrane rupture or axoneme assembly","how RBPm1-dependent splicing intersects with the CDPK4/FBXO1 post-translational controls is unknown"],"attribution":[{"species":"Plasmodium yoelii","strain":"17XNL"}]},{"year":2024,"claim":"Proximity proteomics placed GEP near the DOZI/CITH/ALBA translational repression machinery, hinting that GEP transcript or protein is controlled by pre-fertilization mRNP storage in females.","evidence":"TurboID proximity proteomics with DOZI and ALBA4 baits in P. yoelii gametocytes and zygotes","pmids":["39777415"],"confidence":"Low","gaps":["single proximity-labeling dataset with no GEP-specific functional follow-up","whether GEP mRNA is a bona fide repressed transcript is untested"],"attribution":[{"species":"Plasmodium yoelii","strain":""}]},{"year":null,"claim":"The intrinsic biochemical activity of the GEP protein — how it mechanistically drives parasitophorous vacuole/erythrocyte membrane rupture and supports axoneme motility — remains unresolved.","evidence":"No timeline discovery assigns GEP an enzymatic activity, structural fold, or direct membrane-remodeling mechanism","pmids":[],"confidence":"Low","gaps":["no molecular activity assigned to GEP","no structural model","direct binding partners that execute egress not identified"],"attribution":[]}],"mechanism_profile":{"molecular_activity":[],"localization":[],"pathway":[],"complexes":["SCF(FBXO1) E3 ubiquitin ligase complex (GEP as regulated ubiquitination target) [#2]","PP1-LRR1 phosphatase complex (GEP as interactome hit) [#5]","DOZI/CITH/ALBA mRNP translational repression complex (GEP as proximal interactor) [#3]"],"partners":["PFCDPK4 (UPSTREAM KINASE; GEP HYPOPHOSPHORYLATED IN CDPK4-NULL) [#1]","FBXO1 (SCF E3 LIGASE MEDIATING GEP UBIQUITINATION) [#2]","CDPK1 (NEGATIVE REGULATOR OF FBXO1-DEPENDENT GEP UBIQUITINATION) [#2]","RBPM1 (MALE-SPECIFIC SPLICING ACTIVATOR REQUIRED FOR GEP EXPRESSION) [#4]","DOZI AND ALBA4 RNA-BINDING PROTEINS (PROXIMAL TO GEP) [#3]","PBLRR1 (PP1 REGULATORY SUBUNIT; GEP IN ITS INTERACTOME) [#5]"],"other_free_text":["GEP is required for rupture of both the parasitophorous vacuole membrane and erythrocyte membrane during gamete egress in both sexes [#0, #4].","GEP is additionally required for axoneme assembly and motility in male flagellar gametes; gep-null parasites of both sexes fail to establish mosquito infection [#0, #4].","Deletion of GEP causes delayed but not aborted osmiophilic body discharge [#0].","Male expression of GEP depends on RBPm1-mediated axonemal intron splicing [#4].","GEP function is documented in the P. berghei and P. yoelii orthologs; the P. falciparum ortholog PF3D7_0515600 is characterized only at the level of CDPK4-dependent phosphorylation [#1]."]}},"prefetch_data":{},"corpus_meta":[{"pmid":"32352241","id":"PMC_32352241","title":"Plasmodium berghei Gamete Egress Protein is required for fertility of both genders.","date":"2020","source":"MicrobiologyOpen","url":"https://pubmed.ncbi.nlm.nih.gov/32352241","citation_count":15,"is_preprint":false,"source_species":["Pf"],"role":"primary","match_terms":["GEP"],"competing_organism_flag":false,"competing_organism_match":"","competing_organism_only":false},{"pmid":"42001110","id":"","title":"Targeting protein-protein interactions in Plasmodium: from asexual replication to sexual development.","date":"2026","source":"Parasites & vectors","url":"https://pubmed.ncbi.nlm.nih.gov/42001110","citation_count":0,"is_preprint":false,"source_species":["Pf"],"role":"primary","match_terms":["GEP"],"competing_organism_flag":false,"competing_organism_match":"","competing_organism_only":false},{"pmid":"40623036","id":"","title":"Loss of serine/threonine protein phosphatase 6 severely impairs sexual stage development in malaria parasite Plasmodium berghei.","date":"2025","source":"PLoS pathogens","url":"https://pubmed.ncbi.nlm.nih.gov/40623036","citation_count":0,"is_preprint":false,"source_species":["Pf"],"role":"primary","match_terms":["GEP"],"competing_organism_flag":false,"competing_organism_match":"","competing_organism_only":false},{"pmid":"39777415","id":"","title":"Widespread release of translational repression across Plasmodium's host-to-vector transmission event.","date":"2025","source":"PLoS pathogens","url":"https://pubmed.ncbi.nlm.nih.gov/39777415","citation_count":0,"is_preprint":false,"source_species":["Pf"],"role":"primary","match_terms":["GEP"],"competing_organism_flag":false,"competing_organism_match":"","competing_organism_only":false},{"pmid":"34724830","id":"","title":"Plasmodium falciparum Calcium-Dependent Protein Kinase 4 is Critical for Male Gametogenesis and Transmission to the Mosquito Vector.","date":"2021","source":"mBio","url":"https://pubmed.ncbi.nlm.nih.gov/34724830","citation_count":0,"is_preprint":false,"source_species":["Pf"],"role":"primary","match_terms":["GEP"],"competing_organism_flag":false,"competing_organism_match":"","competing_organism_only":false},{"pmid":"38824128","id":"","title":"An axonemal intron splicing program sustains Plasmodium male development.","date":"2024","source":"Nature communications","url":"https://pubmed.ncbi.nlm.nih.gov/38824128","citation_count":0,"is_preprint":false,"source_species":["Pf"],"role":"primary","match_terms":["GEP"],"competing_organism_flag":false,"competing_organism_match":"","competing_organism_only":false},{"pmid":"35782151","id":"","title":"Gametogenesis in Plasmodium: Delving Deeper to Connect the Dots.","date":"2022","source":"Frontiers in cellular and infection microbiology","url":"https://pubmed.ncbi.nlm.nih.gov/35782151","citation_count":0,"is_preprint":false,"source_species":["Pf"],"role":"primary","match_terms":["GEP"],"competing_organism_flag":false,"competing_organism_match":"","competing_organism_only":false},{"pmid":"36898988","id":"","title":"The Skp1-Cullin1-FBXO1 complex is a pleiotropic regulator required for the formation of gametes and motile forms in Plasmodium berghei.","date":"2023","source":"Nature communications","url":"https://pubmed.ncbi.nlm.nih.gov/36898988","citation_count":0,"is_preprint":false,"source_species":["Pf"],"role":"primary","match_terms":["GEP"],"competing_organism_flag":false,"competing_organism_match":"","competing_organism_only":false},{"pmid":"33686010","id":"","title":"Malaria parasite egress at a glance.","date":"2021","source":"Journal of cell science","url":"https://pubmed.ncbi.nlm.nih.gov/33686010","citation_count":0,"is_preprint":false,"source_species":["Pf"],"role":"primary","match_terms":["GEP"],"competing_organism_flag":false,"competing_organism_match":"","competing_organism_only":false},{"pmid":"36094218","id":"","title":"PfSRPK1 Regulates Asexual Blood Stage Schizogony and Is Essential for Male Gamete Formation.","date":"2022","source":"Microbiology spectrum","url":"https://pubmed.ncbi.nlm.nih.gov/36094218","citation_count":0,"is_preprint":false,"source_species":["Pf"],"role":"primary","match_terms":["GEP"],"competing_organism_flag":false,"competing_organism_match":"","competing_organism_only":false},{"pmid":"35920043","id":"","title":"Plasmodium berghei leucine-rich repeat protein 1 downregulates protein phosphatase 1 activity and is required for efficient oocyst development.","date":"2022","source":"Open biology","url":"https://pubmed.ncbi.nlm.nih.gov/35920043","citation_count":0,"is_preprint":false,"source_species":["Pf"],"role":"primary","match_terms":["GEP"],"competing_organism_flag":false,"competing_organism_match":"","competing_organism_only":false},{"pmid":"34673764","id":"","title":"The Plasmodium NOT1-G paralogue is an essential regulator of sexual stage maturation and parasite transmission.","date":"2021","source":"PLoS biology","url":"https://pubmed.ncbi.nlm.nih.gov/34673764","citation_count":0,"is_preprint":false,"source_species":["Pf"],"role":"primary","match_terms":["GEP"],"competing_organism_flag":false,"competing_organism_match":"","competing_organism_only":false},{"pmid":"34268139","id":"","title":"Machine Learning Uses Chemo-Transcriptomic Profiles to Stratify Antimalarial Compounds With Similar Mode of Action.","date":"2021","source":"Frontiers in cellular and infection microbiology","url":"https://pubmed.ncbi.nlm.nih.gov/34268139","citation_count":0,"is_preprint":false,"source_species":["Pf"],"role":"primary","match_terms":["GEP"],"competing_organism_flag":false,"competing_organism_match":"","competing_organism_only":false}],"cost":{"stage1":{"model":"claude-sonnet-4-6","input_tokens":16040,"output_tokens":1957,"usd":0.038738,"stage1_stop_reason":"end_turn"},"stage2":{"model":"claude-opus-4-8","input_tokens":7080,"output_tokens":3241,"usd":0.058213,"stage2_stop_reason":"end_turn"},"total_usd":0.096951,"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\": 2020,\n      \"finding\": \"GEP (PBANKA_1115200) is expressed in gametocytes of both genders and partially localizes to osmiophilic bodies (OBs). Genetic deletion of GEP in P. berghei causes aberrant rupture of the parasitophorous vacuole membrane and erythrocyte membrane, delayed (but not aborted) OB discharge, and immotile axonemes in male flagellar gametes. Genetic crossing experiments confirmed that both male and female gep-null parasites are unable to establish mosquito infections, demonstrating pleiotropic roles in gamete egress and male exflagellation.\",\n      \"method\": \"Gene knockout (targeted deletion), fluorescence microscopy for OB localization, genetic crossing experiments, mosquito transmission assays\",\n      \"journal\": \"MicrobiologyOpen\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — clean KO with defined cellular phenotypes across multiple orthogonal readouts (membrane rupture, OB discharge, axoneme motility, transmission), replicated via genetic crossing\",\n      \"pmids\": [\"32352241\"],\n      \"is_preprint\": false,\n      \"attribution\": [{\"species\": \"Plasmodium berghei\", \"strain\": \"\"}]\n    },\n    {\n      \"year\": 2021,\n      \"finding\": \"In P. falciparum, GEP (PF3D7_0515600) is hypophosphorylated in cdpk4-null gametocytes activated by xanthurenic acid, placing GEP downstream of PfCDPK4 in the calcium-signaling cascade that governs male gametogenesis. In vitro phosphorylation assays identified GEP as a putative direct or indirect substrate of PfCDPK4.\",\n      \"method\": \"Quantitative mass spectrometry-based phosphoproteomics of wild-type vs. Pfcdpk4-null gametocytes; in vitro kinase assay\",\n      \"journal\": \"mBio\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — phosphoproteomics plus in vitro kinase assay, single lab, GEP identified as hypophosphorylated substrate candidate but direct substrate relationship not fully reconstituted\",\n      \"pmids\": [\"34724830\"],\n      \"is_preprint\": false,\n      \"attribution\": [{\"species\": \"Plasmodium falciparum\", \"strain\": \"\"}]\n    },\n    {\n      \"year\": 2023,\n      \"finding\": \"GEP (PBANKA_1115200) is ubiquitinated in P. berghei gametocytes in a manner regulated by the SCFFBXO1 E3 ligase complex, and CDPK1 activity negatively regulates FBXO1-dependent ubiquitination of GEP, suggesting that phosphorylation and ubiquitination of GEP are antagonistically linked through CDPK1–FBXO1 crosstalk.\",\n      \"method\": \"Ubiquitinomic mass spectrometry of FBXO1-glucosylamine-depleted and CDPK1-KO parasites; comparative quantitative proteomics\",\n      \"journal\": \"Nature communications\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — ubiquitinomic survey identified GEP as a specific FBXO1-dependent ubiquitination target with CDPK1 crosstalk, single lab, no direct reconstitution of GEP ubiquitination\",\n      \"pmids\": [\"36898988\"],\n      \"is_preprint\": false,\n      \"attribution\": [{\"species\": \"Plasmodium berghei\", \"strain\": \"\"}]\n    },\n    {\n      \"year\": 2024,\n      \"finding\": \"In P. yoelii, GEP is detected as a proximal interactor of both DOZI and ALBA4 RNA-binding proteins within the condensed DOZI/CITH/ALBA mRNP complex in female gametocytes, indicating GEP mRNA (or GEP protein) is part of the translational repression machinery operating before fertilization.\",\n      \"method\": \"TurboID-based proximity proteomics (BioID) with DOZI and ALBA4 as baits in gametocytes and zygotes\",\n      \"journal\": \"PLoS pathogens\",\n      \"confidence\": \"Low\",\n      \"confidence_rationale\": \"Tier 3 / Weak — single proximity-labeling experiment, single lab; GEP listed among many proximal proteins with no functional follow-up specific to GEP\",\n      \"pmids\": [\"39777415\"],\n      \"is_preprint\": false,\n      \"attribution\": [{\"species\": \"Plasmodium yoelii\", \"strain\": \"\"}]\n    },\n    {\n      \"year\": 2024,\n      \"finding\": \"In P. yoelii, GEP expression is required for erythrocyte membrane rupture in both male and female gametocytes and for axoneme assembly in male gametocytes. Insertion of axonemal introns (kinesin8b intron1 or PF16 intron1) into the gep locus blocked GEP protein expression in the absence of the male-specific splicing activator RBPm1, confirming that GEP is a functional downstream target of the RBPm1-dependent axonemal intron splicing program in males.\",\n      \"method\": \"Gene deletion (Δgep), intron-insertion reporter lines, immunofluorescence (anti-TER-119, anti-α-Tubulin, Hoechst), quantitative phenotypic analysis across three independent experiments\",\n      \"journal\": \"Nature communications\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — clean KO plus mechanistic intron-insertion experiments with functional rescue logic, multiple orthogonal readouts (EM rupture, genome replication, axoneme assembly), three independent replicates\",\n      \"pmids\": [\"38824128\"],\n      \"is_preprint\": false,\n      \"attribution\": [{\"species\": \"Plasmodium yoelii\", \"strain\": \"17XNL\"}]\n    },\n    {\n      \"year\": 2022,\n      \"finding\": \"GEP (PBANKA_1115200) is detected in the interactome of the P. berghei PP1-LRR1 complex by co-immunoprecipitation/mass spectrometry, identifying GEP as a potential partner or regulated substrate within the PP1 phosphatase network during sexual development.\",\n      \"method\": \"Immunoprecipitation-mass spectrometry (interactome analysis) of PbLRR1\",\n      \"journal\": \"Open biology\",\n      \"confidence\": \"Low\",\n      \"confidence_rationale\": \"Tier 3 / Weak — single Co-IP/MS experiment, single lab, GEP listed among many interactome hits with no functional follow-up specific to GEP\",\n      \"pmids\": [\"35920043\"],\n      \"is_preprint\": false,\n      \"attribution\": [{\"species\": \"Plasmodium berghei\", \"strain\": \"\"}]\n    }\n  ],\n  \"current_model\": \"GEP (PF3D7_0515600/PBANKA_1115200) is a Plasmodium-specific gametocyte protein that partially localizes to osmiophilic bodies, is required for rupture of both the parasitophorous vacuole membrane and erythrocyte membrane during gamete egress in both sexes, and is additionally required for axoneme motility in male gametes; its activity is regulated post-translationally by CDPK4-mediated phosphorylation and SCFFBXO1-mediated ubiquitination, and its expression in males depends on the RBPm1 axonemal intron splicing program.\"\n}\n```","stage2_raw":"{\n  \"mechanistic_narrative\": \"GEP (PF3D7_0515600; ortholog PBANKA_1115200) is a Plasmodium gametocyte protein required for gamete egress and male exflagellation during the transition to mosquito-stage development [#0]. It is expressed in gametocytes of both sexes and partially localizes to osmiophilic bodies; its genetic deletion in P. berghei causes aberrant rupture of the parasitophorous vacuole membrane and erythrocyte membrane, delayed osmiophilic body discharge, and immotile axonemes in male flagellar gametes, rendering both male and female null parasites unable to establish mosquito infection [#0]. In P. yoelii, GEP is likewise required for erythrocyte membrane rupture in both sexes and for axoneme assembly in males, and its expression in males depends on the RBPm1-driven axonemal intron splicing program, established by intron-insertion experiments that abolished GEP expression in the absence of RBPm1 [#4]. Post-translationally, GEP sits within the calcium-signaling machinery of gametogenesis: it is hypophosphorylated in P. falciparum cdpk4-null gametocytes and behaves as a PfCDPK4 substrate candidate in vitro [#1], and in P. berghei it is ubiquitinated in an SCF-FBXO1-dependent manner that is negatively regulated by CDPK1 [#2]. Beyond these regulatory links, the biochemical activity of the GEP protein itself is uncharacterized in the available corpus.\",\n  \"teleology\": [\n    {\n      \"year\": 2020,\n      \"claim\": \"Establishing whether GEP has a cellular function in sexual development, the first knockout defined it as a pleiotropic egress and exflagellation factor rather than a passive gametocyte marker.\",\n      \"evidence\": \"Targeted gene deletion in P. berghei with OB localization microscopy, genetic crossing, and mosquito transmission assays\",\n      \"pmids\": [\"32352241\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\n        \"biochemical activity of GEP and how it drives membrane rupture is unknown\",\n        \"molecular basis of OB targeting not defined\",\n        \"how GEP contributes to axoneme motility is not resolved\"\n      ],\n      \"attribution\": [{\"species\": \"Plasmodium berghei\", \"strain\": \"\"}]\n    },\n    {\n      \"year\": 2021,\n      \"claim\": \"To place GEP within gametogenesis signaling, phosphoproteomics identified it as a CDPK4-dependent phosphoprotein, linking it to the calcium cascade that triggers male gametogenesis.\",\n      \"evidence\": \"Quantitative phosphoproteomics of wild-type vs. Pfcdpk4-null P. falciparum gametocytes plus in vitro kinase assay\",\n      \"pmids\": [\"34724830\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\n        \"direct vs. indirect substrate relationship not fully reconstituted\",\n        \"phosphosites and their functional consequence for GEP not mapped\"\n      ],\n      \"attribution\": [{\"species\": \"Plasmodium falciparum\", \"strain\": \"\"}]\n    },\n    {\n      \"year\": 2022,\n      \"claim\": \"A PP1-LRR1 interactome survey raised the possibility that GEP is embedded in a phosphatase regulatory network during sexual development.\",\n      \"evidence\": \"Immunoprecipitation-mass spectrometry of PbLRR1 in P. berghei\",\n      \"pmids\": [\"35920043\"],\n      \"confidence\": \"Low\",\n      \"gaps\": [\n        \"single Co-IP/MS with no GEP-specific functional follow-up or reciprocal validation\",\n        \"whether GEP is a PP1 substrate or bystander is unknown\"\n      ],\n      \"attribution\": [{\"species\": \"Plasmodium berghei\", \"strain\": \"\"}]\n    },\n    {\n      \"year\": 2023,\n      \"claim\": \"Ubiquitinomics extended GEP regulation beyond phosphorylation, showing it is an SCF-FBXO1 ubiquitination target under antagonistic control by CDPK1.\",\n      \"evidence\": \"Ubiquitinomic and comparative proteomic mass spectrometry of FBXO1-depleted and CDPK1-KO P. berghei parasites\",\n      \"pmids\": [\"36898988\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\n        \"GEP ubiquitination not directly reconstituted\",\n        \"consequence of ubiquitination for GEP stability or activity not established\"\n      ],\n      \"attribution\": [{\"species\": \"Plasmodium berghei\", \"strain\": \"\"}]\n    },\n    {\n      \"year\": 2024,\n      \"claim\": \"Cross-species knockout and intron-insertion experiments confirmed GEP's egress/axoneme role in P. yoelii and defined RBPm1-dependent intron splicing as the mechanism controlling its male-specific expression.\",\n      \"evidence\": \"Δgep deletion, axonemal-intron insertion reporter lines, and immunofluorescence phenotyping in P. yoelii 17XNL, across three independent experiments\",\n      \"pmids\": [\"38824128\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\n        \"does not define GEP's biochemical role in membrane rupture or axoneme assembly\",\n        \"how RBPm1-dependent splicing intersects with the CDPK4/FBXO1 post-translational controls is unknown\"\n      ],\n      \"attribution\": [{\"species\": \"Plasmodium yoelii\", \"strain\": \"17XNL\"}]\n    },\n    {\n      \"year\": 2024,\n      \"claim\": \"Proximity proteomics placed GEP near the DOZI/CITH/ALBA translational repression machinery, hinting that GEP transcript or protein is controlled by pre-fertilization mRNP storage in females.\",\n      \"evidence\": \"TurboID proximity proteomics with DOZI and ALBA4 baits in P. yoelii gametocytes and zygotes\",\n      \"pmids\": [\"39777415\"],\n      \"confidence\": \"Low\",\n      \"gaps\": [\n        \"single proximity-labeling dataset with no GEP-specific functional follow-up\",\n        \"whether GEP mRNA is a bona fide repressed transcript is untested\"\n      ],\n      \"attribution\": [{\"species\": \"Plasmodium yoelii\", \"strain\": \"\"}]\n    },\n    {\n      \"year\": null,\n      \"claim\": \"The intrinsic biochemical activity of the GEP protein — how it mechanistically drives parasitophorous vacuole/erythrocyte membrane rupture and supports axoneme motility — remains unresolved.\",\n      \"evidence\": \"No timeline discovery assigns GEP an enzymatic activity, structural fold, or direct membrane-remodeling mechanism\",\n      \"pmids\": [],\n      \"confidence\": \"Low\",\n      \"gaps\": [\n        \"no molecular activity assigned to GEP\",\n        \"no structural model\",\n        \"direct binding partners that execute egress not identified\"\n      ],\n      \"attribution\": []\n    }\n  ],\n  \"mechanism_profile\": {\n    \"molecular_activity\": [\n      {\"term_id\": \"GO:0016567\", \"supporting_discovery_ids\": [2]}\n    ],\n    \"localization\": [\n      {\"term_id\": \"GO:0020005\", \"supporting_discovery_ids\": [0]}\n    ],\n    \"pathway\": [\n      {\"term_id\": \"GO:0007320\", \"supporting_discovery_ids\": [0, 4]},\n      {\"term_id\": \"GO:0035845\", \"supporting_discovery_ids\": [0, 4]}\n    ],\n    \"complexes\": [\n      \"SCF(FBXO1) E3 ubiquitin ligase complex (GEP as regulated ubiquitination target) [#2]\",\n      \"PP1-LRR1 phosphatase complex (GEP as interactome hit) [#5]\",\n      \"DOZI/CITH/ALBA mRNP translational repression complex (GEP as proximal interactor) [#3]\"\n    ],\n    \"partners\": [\n      \"PfCDPK4 (upstream kinase; GEP hypophosphorylated in cdpk4-null) [#1]\",\n      \"FBXO1 (SCF E3 ligase mediating GEP ubiquitination) [#2]\",\n      \"CDPK1 (negative regulator of FBXO1-dependent GEP ubiquitination) [#2]\",\n      \"RBPm1 (male-specific splicing activator required for GEP expression) [#4]\",\n      \"DOZI and ALBA4 RNA-binding proteins (proximal to GEP) [#3]\",\n      \"PbLRR1 (PP1 regulatory subunit; GEP in its interactome) [#5]\"\n    ],\n    \"other_free_text\": [\n      \"GEP is required for rupture of both the parasitophorous vacuole membrane and erythrocyte membrane during gamete egress in both sexes [#0, #4].\",\n      \"GEP is additionally required for axoneme assembly and motility in male flagellar gametes; gep-null parasites of both sexes fail to establish mosquito infection [#0, #4].\",\n      \"Deletion of GEP causes delayed but not aborted osmiophilic body discharge [#0].\",\n      \"Male expression of GEP depends on RBPm1-mediated axonemal intron splicing [#4].\",\n      \"GEP function is documented in the P. berghei and P. yoelii orthologs; the P. falciparum ortholog PF3D7_0515600 is characterized only at the level of CDPK4-dependent phosphorylation [#1].\"\n    ]\n  }\n}","audit_flag":null,"strains":[{"strain":"Pf3D7","gene_id":"PF3D7_0515600","name":null,"product":"gamete egress protein GEP, putative","uniprot_acc":null,"chromosome":null,"start_pos":null},{"strain":"PbANKA","gene_id":"PBANKA_1115200","name":null,"product":"gamete egress protein GEP","uniprot_acc":null,"chromosome":null,"start_pos":null},{"strain":"PkH","gene_id":"PKNH_1017600","name":null,"product":"gamete egress protein GEP, putative","uniprot_acc":null,"chromosome":null,"start_pos":null}],"gene_symbol":"GEP","evaluation":null}