{"gene":"PF3D7_0207800","run_date":"2026-09-07T10:55:51","timeline":{"discoveries":[{"year":2002,"finding":"SERA3 (PF3D7_0207800) gene could be disrupted in P. falciparum blood-stage parasites without loss of viability, demonstrating it is dispensable for erythrocytic cycle maintenance. Additionally, antibodies from malaria-immune individuals reacted with SERA3 recombinant protein, suggesting expression in at least some parasite populations.","method":"Gene disruption (knockout) by targeted homologous recombination; reactivity with immune sera","journal":"The Journal of biological chemistry","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — targeted gene disruption with clear phenotypic readout, single lab, two methods (disruption + immune serology)","pmids":["12228245"],"is_preprint":false,"attribution":[{"species":"Plasmodium falciparum","strain":""}]},{"year":2002,"finding":"Polyclonal antibodies against the N-terminal recombinant domain of SERA3 detected SERA3 protein expression by indirect immunofluorescence microscopy in trophozoite- and schizont-infected erythrocytes, with localization similar to other SERA family members (SERA4–6).","method":"Indirect immunofluorescence microscopy with specific polyclonal antibodies against SERA3 N-terminal recombinant protein","journal":"The Journal of biological chemistry","confidence":"Medium","confidence_rationale":"Tier 3 / Moderate — direct localization experiment, single lab, replicated across multiple parasite strains","pmids":["12244052"],"is_preprint":false,"attribution":[{"species":"Plasmodium falciparum","strain":""}]},{"year":1994,"finding":"SERA3 was identified as a distinct gene located 1.8 kb upstream of the SERA (SERA5) gene on chromosome 2, transcribed in the same orientation. SERA3 mRNA is expressed in a stage-specific manner, exclusively in trophozoite and schizont stages, as part of a coordinately regulated transcription cluster with SERA and SERA2.","method":"RT-PCR, transcript mapping, RNA sequencing, Northern analysis","journal":"Molecular and biochemical parasitology","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — direct transcript mapping and stage-specific expression characterization, single lab, multiple RNA methods","pmids":["7891737"],"is_preprint":false,"attribution":[{"species":"Plasmodium falciparum","strain":""}]},{"year":2007,"finding":"SERA3 (PF3D7_0207800) belongs to the serine-type SERA subgroup in P. falciparum, possessing an atypical active-site serine residue instead of the canonical cysteine in its papain-like protease domain. Knockout of SERA3 (along with SERA1, SERA4, SERA9) was achievable, confirming it is non-essential for blood-stage survival, in contrast to SERA5 which could not be disrupted.","method":"Targeted gene knockout by homologous recombination; phylogenetic analysis of active-site residues","journal":"Infection and immunity","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — targeted gene disruption with phenotypic readout, single lab, supported by sequence/phylogenetic analysis","pmids":["17893128"],"is_preprint":false,"attribution":[{"species":"Plasmodium falciparum","strain":""}]},{"year":2008,"finding":"P. berghei SERA3 (PbSERA3), the ortholog studied in a rodent malaria model, is transcribed in late liver stages and its protein is processed and detected by Western blot in schizont-infected cells and merozoite-infected detached hepatic cells. Immunofluorescence assays showed PbSERA3 leaks into the host cell cytoplasm during merozoite development in hepatocytes, potentially contributing to host cell death or activating host cell proteases.","method":"RT-PCR, transgenic P. berghei expressing TAP-tagged PbSERA3 under endogenous promoter, immunofluorescence assay, Western blot","journal":"Cellular microbiology","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — multiple orthogonal methods (transgenic tagging, IFA, Western blot), single lab","pmids":["18419771"],"is_preprint":false,"attribution":[{"species":"Plasmodium berghei","strain":""}]},{"year":2009,"finding":"In P. berghei, deletion of the serine-type SERAs (PbSERA1 and PbSERA2, the serine-type subfamily members) resulted in increased expression of the cysteine-type PbSERA3, indicating compensatory upregulation between SERA subfamilies. P. berghei serine-type SERA knockouts progressed normally through the parasite life cycle, further supporting non-essential roles for serine-type SERAs when cysteine-type members can compensate.","method":"Single and double gene knockouts by targeted gene replacement; fluorescent tagging with mCherry for localization; antibody localization; expression analysis","journal":"Cellular microbiology","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — genetic epistasis via double knockout with compensatory expression readout, single lab, multiple methods","pmids":["20039882"],"is_preprint":false,"attribution":[{"species":"Plasmodium berghei","strain":""}]},{"year":2019,"finding":"PbSERA3 (the P. berghei ortholog) is expressed in gametocytes and is processed by the subtilisin-like serine protease PbSUB1 upon gametocyte activation, establishing PbSERA3 as a substrate of PbSUB1 in sexual stages.","method":"Transgenic P. berghei lines deficient in PbSUB1 expression or enzyme activity; Western blot detection of PbSERA3 processing products","journal":"Cellular microbiology","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — substrate-protease relationship established by genetic loss-of-function of the protease with direct detection of processing, single lab","pmids":["30941868"],"is_preprint":false,"attribution":[{"species":"Plasmodium berghei","strain":""}]},{"year":2026,"finding":"PbSERA3 is required for hepatic merozoite egress in P. berghei. Conditional mutants (Flp/FRT system) developed normally through late liver stages but failed to initiate blood-stage infection, demonstrating a specific role in egress from hepatocytes. PbSERA3 was also found on the surface of ookinetes and sporozoites under non-permeabilized conditions (extracellular localization), and is processed in these stages into two products as in blood stages. PbSERA3 is identified as a substrate of SUB1, and its proteolytic maturation by SUB1 is implicated as a conserved and critical event for hepatic egress.","method":"Yeast-based Flp/FRT conditional mutagenesis; surface labeling under non-permeabilized conditions; Western blot for processing products; transgenic parasite lines","journal":"mBio","confidence":"High","confidence_rationale":"Tier 2 / Strong — conditional genetic system with clear stage-specific phenotype, multiple orthogonal methods (conditional KO, surface localization, processing analysis), single rigorous study","pmids":["41616267"],"is_preprint":false,"attribution":[{"species":"Plasmodium berghei","strain":""}]}],"current_model":"SERA3 (PF3D7_0207800) is a serine-type SERA family member with a papain-like protease domain bearing an atypical active-site serine residue; it is expressed in trophozoite and schizont stages, is dispensable for P. falciparum blood-stage survival (can be genetically disrupted), and its P. berghei ortholog (PbSERA3, which belongs to the cysteine-type subfamily) is an essential protease substrate of SUB1 that is processed at multiple life cycle stages and is specifically required for hepatic merozoite egress, with compensatory upregulation occurring when serine-type SERA family members are deleted."},"narrative":{"mechanistic_narrative":"SERA3 (PF3D7_0207800) is a stage-specifically expressed member of the SERA family of papain-like proteins in Plasmodium, transcribed exclusively in trophozoite and schizont stages as part of a coordinately regulated cluster with SERA and SERA2 on chromosome 2 [PMID:7891737]. In P. falciparum it belongs to the serine-type SERA subgroup, bearing an atypical active-site serine in place of the canonical papain-family cysteine [PMID:17893128], and its protein is detectable in trophozoite- and schizont-infected erythrocytes with a distribution resembling other SERA members [PMID:12244052]. SERA3 is dispensable for the P. falciparum erythrocytic cycle: it can be genetically disrupted without loss of viability, in contrast to the non-disruptable SERA5 [PMID:12228245, PMID:17893128]. Functional characterization of the gene itself comes largely from the rodent-malaria ortholog PbSERA3, which is a substrate of the subtilisin-like protease SUB1 processed at multiple life-cycle stages, localizes to the surface of ookinetes and sporozoites, and is specifically required for hepatic merozoite egress [PMID:30941868, PMID:41616267]; deletion of serine-type SERAs in P. berghei triggers compensatory upregulation of the cysteine-type PbSERA3 [PMID:20039882]. Beyond this stage-specific expression, dispensability in blood stages, and the SUB1-substrate/egress role defined in P. berghei, no enzymatic activity or direct substrate of the P. falciparum protein has been characterized in the available corpus.","teleology":[{"year":1994,"claim":"Establishing that SERA3 is a discrete, stage-restricted gene distinguished it from the neighboring SERA5 locus and placed it within a coordinately regulated transcriptional program, framing when in the cycle it could act.","evidence":"RT-PCR, transcript mapping, and Northern analysis in P. falciparum","pmids":["7891737"],"confidence":"Medium","gaps":["Transcript timing does not reveal protein function","No protease activity or substrate defined"],"attribution":[{"species":"Plasmodium falciparum","strain":""}]},{"year":2002,"claim":"Whether SERA3 was individually required for the blood-stage cycle was unknown; targeted disruption showed it is dispensable, while immune-serum reactivity confirmed it is expressed in infected individuals.","evidence":"Targeted homologous-recombination knockout plus immune-serum reactivity in P. falciparum","pmids":["12228245"],"confidence":"Medium","gaps":["Dispensability does not identify a positive function","Possible redundancy with other SERA members untested here"],"attribution":[{"species":"Plasmodium falciparum","strain":""}]},{"year":2002,"claim":"The spatial context of SERA3 was undefined; immunofluorescence localized the protein in trophozoite- and schizont-infected erythrocytes similarly to SERA4-6, tying it to the same subcellular niche as other family members.","evidence":"Indirect immunofluorescence with anti-SERA3 N-terminal antibodies in P. falciparum","pmids":["12244052"],"confidence":"Medium","gaps":["Precise organellar compartment not resolved","Function within that compartment unknown"],"attribution":[{"species":"Plasmodium falciparum","strain":""}]},{"year":2007,"claim":"The catalytic classification of SERA3 was open; phylogenetic and active-site analysis assigned it to the serine-type SERA subgroup with an atypical serine, and knockout confirmed non-essentiality versus the essential SERA5.","evidence":"Targeted knockout and active-site phylogenetic analysis in P. falciparum","pmids":["17893128"],"confidence":"Medium","gaps":["Whether the atypical serine confers catalytic activity untested","No substrate identified"],"attribution":[{"species":"Plasmodium falciparum","strain":""}]},{"year":2008,"claim":"Whether the ortholog had a role beyond blood stages was unknown; PbSERA3 was shown to be expressed and processed in late liver stages and to leak into the hepatocyte cytoplasm during merozoite development.","evidence":"Transgenic TAP-tagged PbSERA3, RT-PCR, IFA, and Western blot in P. berghei","pmids":["18419771"],"confidence":"Medium","gaps":["Causal role in host-cell death not demonstrated","Findings are ortholog-specific and may not transfer to P. falciparum"],"attribution":[{"species":"Plasmodium berghei","strain":""}]},{"year":2009,"claim":"Redundancy among SERA subfamilies was untested; deleting serine-type PbSERAs raised cysteine-type PbSERA3 expression, revealing compensatory regulation that explains blood-stage dispensability.","evidence":"Single and double gene knockouts with expression and localization analysis in P. berghei","pmids":["20039882"],"confidence":"Medium","gaps":["Mechanism of compensatory upregulation unknown","Functional interchangeability of subfamilies not directly demonstrated"],"attribution":[{"species":"Plasmodium berghei","strain":""}]},{"year":2019,"claim":"The upstream protease acting on SERA3 was unidentified; loss of PbSUB1 activity abolished PbSERA3 processing in activated gametocytes, defining it as a SUB1 substrate in sexual stages.","evidence":"PbSUB1-deficient transgenic lines with Western blot of PbSERA3 processing in P. berghei","pmids":["30941868"],"confidence":"Medium","gaps":["Functional consequence of processing in gametocytes not established","Direct cleavage-site mapping not shown"],"attribution":[{"species":"Plasmodium berghei","strain":""}]},{"year":2026,"claim":"A definitive essential function had not been assigned; conditional deletion showed PbSERA3 is specifically required for hepatic merozoite egress and is a SUB1 substrate processed across multiple stages with surface exposure on ookinetes and sporozoites.","evidence":"Flp/FRT conditional mutagenesis, surface labeling under non-permeabilized conditions, and processing analysis in P. berghei","pmids":["41616267"],"confidence":"High","gaps":["Molecular mechanism of egress action undefined","Whether the P. falciparum protein performs the analogous liver-stage role untested"],"attribution":[{"species":"Plasmodium berghei","strain":""}]},{"year":null,"claim":"It remains unknown whether the P. falciparum SERA3 protein is catalytically active, what its substrates or physiological cleavage products are, and whether it shares the liver-stage egress role defined for its P. berghei ortholog.","evidence":"No direct enzymatic or P. falciparum liver-stage functional evidence in the corpus","pmids":[],"confidence":"Low","gaps":["No demonstrated protease activity for the P. falciparum protein","No substrate identified","Cross-species functional conservation untested in P. falciparum"],"attribution":[]}],"mechanism_profile":{"molecular_activity":[],"localization":[],"pathway":[],"complexes":[],"partners":["SUB1 (SUBTILISIN-LIKE PROTEASE; PROCESSES PBSERA3 ORTHOLOG) [#6, #7]"],"other_free_text":["SERA3 (PF3D7_0207800) is a serine-type SERA subgroup member with an atypical active-site serine in its papain-like domain [#3].","Transcribed exclusively in trophozoite and schizont stages within a coordinately regulated SERA cluster [#2].","Dispensable for the P. falciparum blood-stage cycle by targeted disruption, unlike the essential SERA5 [#0, #3].","Functional egress role and SUB1-substrate relationship are established for the P. berghei ortholog PbSERA3, not directly for the P. falciparum protein [#5, #6, #7]."]}},"prefetch_data":{},"corpus_meta":[{"pmid":"12228245","id":"PMC_12228245","title":"A subset of Plasmodium falciparum SERA genes are expressed and appear to play an important role in the erythrocytic cycle.","date":"2002","source":"The Journal of biological chemistry","url":"https://pubmed.ncbi.nlm.nih.gov/12228245","citation_count":137,"is_preprint":false,"source_species":["Pf"],"role":"primary","match_terms":["SERA3"],"competing_organism_flag":false,"competing_organism_match":"","competing_organism_only":false},{"pmid":"12244052","id":"PMC_12244052","title":"Serine repeat antigen (SERA5) is predominantly expressed among the SERA multigene family of Plasmodium falciparum, and the acquired antibody titers correlate with serum inhibition of the parasite growth.","date":"2002","source":"The Journal of biological chemistry","url":"https://pubmed.ncbi.nlm.nih.gov/12244052","citation_count":83,"is_preprint":false,"source_species":["Pf"],"role":"primary","match_terms":["SERA3"],"competing_organism_flag":false,"competing_organism_match":"","competing_organism_only":false},{"pmid":"29902171","id":"PMC_29902171","title":"Exposure and infection to Plasmodium knowlesi in case study communities in Northern Sabah, Malaysia and Palawan, The Philippines.","date":"2018","source":"PLoS neglected tropical diseases","url":"https://pubmed.ncbi.nlm.nih.gov/29902171","citation_count":79,"is_preprint":false,"source_species":["Pf"],"role":"primary","match_terms":["PkSERA3"],"competing_organism_flag":false,"competing_organism_match":"","competing_organism_only":false},{"pmid":"17893128","id":"PMC_17893128","title":"Evidence for a common role for the serine-type Plasmodium falciparum serine repeat antigen proteases: implications for vaccine and drug design.","date":"2007","source":"Infection and immunity","url":"https://pubmed.ncbi.nlm.nih.gov/17893128","citation_count":66,"is_preprint":false,"source_species":["Pf"],"role":"primary","match_terms":["curated_ref"],"competing_organism_flag":false,"competing_organism_match":"","competing_organism_only":false},{"pmid":"18419771","id":"PMC_18419771","title":"Expression and processing of Plasmodium berghei SERA3 during liver stages.","date":"2008","source":"Cellular microbiology","url":"https://pubmed.ncbi.nlm.nih.gov/18419771","citation_count":46,"is_preprint":false,"source_species":["Pf"],"role":"primary","match_terms":["SERA3","PbSERA3"],"competing_organism_flag":false,"competing_organism_match":"","competing_organism_only":false},{"pmid":"7891737","id":"PMC_7891737","title":"Analysis of stage-specific transcripts of the Plasmodium falciparum serine repeat antigen (SERA) gene and transcription from the SERA locus.","date":"1994","source":"Molecular and biochemical parasitology","url":"https://pubmed.ncbi.nlm.nih.gov/7891737","citation_count":40,"is_preprint":false,"source_species":["Pf"],"role":"primary","match_terms":["SERA3"],"competing_organism_flag":false,"competing_organism_match":"","competing_organism_only":false},{"pmid":"20039882","id":"PMC_20039882","title":"The Plasmodium serine-type SERA proteases display distinct expression patterns and non-essential in vivo roles during life cycle progression of the malaria parasite.","date":"2009","source":"Cellular microbiology","url":"https://pubmed.ncbi.nlm.nih.gov/20039882","citation_count":35,"is_preprint":false,"source_species":["Pf"],"role":"primary","match_terms":["PbSERA3"],"competing_organism_flag":false,"competing_organism_match":"","competing_organism_only":false},{"pmid":"29902183","id":"PMC_29902183","title":"Identification and validation of a novel panel of Plasmodium knowlesi biomarkers of serological exposure.","date":"2018","source":"PLoS neglected tropical diseases","url":"https://pubmed.ncbi.nlm.nih.gov/29902183","citation_count":22,"is_preprint":false,"source_species":["Pf"],"role":"primary","match_terms":["PkSERA3"],"competing_organism_flag":false,"competing_organism_match":"","competing_organism_only":false},{"pmid":"32252804","id":"PMC_32252804","title":"Characteristic features of the SERA multigene family in the malaria parasite.","date":"2020","source":"Parasites & vectors","url":"https://pubmed.ncbi.nlm.nih.gov/32252804","citation_count":18,"is_preprint":false,"source_species":["Pf"],"role":"primary","match_terms":["SERA3","PbSERA3"],"competing_organism_flag":false,"competing_organism_match":"","competing_organism_only":false},{"pmid":"30941868","id":"PMC_30941868","title":"The Plasmodium berghei serine protease PbSUB1 plays an important role in male gamete egress.","date":"2019","source":"Cellular microbiology","url":"https://pubmed.ncbi.nlm.nih.gov/30941868","citation_count":14,"is_preprint":false,"source_species":["Pf"],"role":"primary","match_terms":["SERA3","PbSERA3"],"competing_organism_flag":false,"competing_organism_match":"","competing_organism_only":false},{"pmid":"37595939","id":"PMC_37595939","title":"Genetic diversity and in silico analysis of Plasmodium knowlesi Serine Repeat Antigen (SERA) 3 antigen 2 in Malaysia.","date":"2023","source":"Infection, genetics and evolution : journal of molecular epidemiology and evolutionary genetics in infectious diseases","url":"https://pubmed.ncbi.nlm.nih.gov/37595939","citation_count":2,"is_preprint":false,"source_species":["Pf"],"role":"primary","match_terms":["SERA3","PkSERA3"],"competing_organism_flag":false,"competing_organism_match":"","competing_organism_only":false},{"pmid":"39185645","id":"PMC_39185645","title":"Therapeutic Targeting and Role of Cysteine Proteases in the Life Cycle of Malaria Parasite.","date":"2025","source":"Current medicinal chemistry","url":"https://pubmed.ncbi.nlm.nih.gov/39185645","citation_count":0,"is_preprint":false,"source_species":["Pf"],"role":"primary","match_terms":["SERA3"],"competing_organism_flag":false,"competing_organism_match":"","competing_organism_only":false},{"pmid":"42431567","id":"PMC_42431567","title":"Bioinformatic analysis of Plasmodium knowlesi Serine Repeat Antigen 3 (SERA3) sequences for antimalarial peptide development.","date":"2026","source":"Acta tropica","url":"https://pubmed.ncbi.nlm.nih.gov/42431567","citation_count":0,"is_preprint":false,"source_species":["Pf"],"role":"primary","match_terms":["SERA3","PkSERA3"],"competing_organism_flag":false,"competing_organism_match":"","competing_organism_only":false},{"pmid":"41616267","id":"PMC_41616267","title":"Plasmodium berghei serine repeat antigen 3 (PbSERA3) is required for hepatic merozoite egress.","date":"2026","source":"mBio","url":"https://pubmed.ncbi.nlm.nih.gov/41616267","citation_count":0,"is_preprint":false,"source_species":["Pf"],"role":"primary","match_terms":["PbSERA3"],"competing_organism_flag":false,"competing_organism_match":"","competing_organism_only":false}],"cost":{"stage1":{"model":"claude-sonnet-4-6","input_tokens":10534,"output_tokens":2331,"usd":0.033284,"stage1_stop_reason":"end_turn"},"stage2":{"model":"claude-opus-4-8","input_tokens":7665,"output_tokens":3228,"usd":0.059513,"stage2_stop_reason":"end_turn"},"total_usd":0.092797,"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\": 2002,\n      \"finding\": \"SERA3 (PF3D7_0207800) gene could be disrupted in P. falciparum blood-stage parasites without loss of viability, demonstrating it is dispensable for erythrocytic cycle maintenance. Additionally, antibodies from malaria-immune individuals reacted with SERA3 recombinant protein, suggesting expression in at least some parasite populations.\",\n      \"method\": \"Gene disruption (knockout) by targeted homologous recombination; reactivity with immune sera\",\n      \"journal\": \"The Journal of biological chemistry\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — targeted gene disruption with clear phenotypic readout, single lab, two methods (disruption + immune serology)\",\n      \"pmids\": [\"12228245\"],\n      \"is_preprint\": false,\n      \"attribution\": [{\"species\": \"Plasmodium falciparum\", \"strain\": \"\"}]\n    },\n    {\n      \"year\": 2002,\n      \"finding\": \"Polyclonal antibodies against the N-terminal recombinant domain of SERA3 detected SERA3 protein expression by indirect immunofluorescence microscopy in trophozoite- and schizont-infected erythrocytes, with localization similar to other SERA family members (SERA4–6).\",\n      \"method\": \"Indirect immunofluorescence microscopy with specific polyclonal antibodies against SERA3 N-terminal recombinant protein\",\n      \"journal\": \"The Journal of biological chemistry\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 3 / Moderate — direct localization experiment, single lab, replicated across multiple parasite strains\",\n      \"pmids\": [\"12244052\"],\n      \"is_preprint\": false,\n      \"attribution\": [{\"species\": \"Plasmodium falciparum\", \"strain\": \"\"}]\n    },\n    {\n      \"year\": 1994,\n      \"finding\": \"SERA3 was identified as a distinct gene located 1.8 kb upstream of the SERA (SERA5) gene on chromosome 2, transcribed in the same orientation. SERA3 mRNA is expressed in a stage-specific manner, exclusively in trophozoite and schizont stages, as part of a coordinately regulated transcription cluster with SERA and SERA2.\",\n      \"method\": \"RT-PCR, transcript mapping, RNA sequencing, Northern analysis\",\n      \"journal\": \"Molecular and biochemical parasitology\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — direct transcript mapping and stage-specific expression characterization, single lab, multiple RNA methods\",\n      \"pmids\": [\"7891737\"],\n      \"is_preprint\": false,\n      \"attribution\": [{\"species\": \"Plasmodium falciparum\", \"strain\": \"\"}]\n    },\n    {\n      \"year\": 2007,\n      \"finding\": \"SERA3 (PF3D7_0207800) belongs to the serine-type SERA subgroup in P. falciparum, possessing an atypical active-site serine residue instead of the canonical cysteine in its papain-like protease domain. Knockout of SERA3 (along with SERA1, SERA4, SERA9) was achievable, confirming it is non-essential for blood-stage survival, in contrast to SERA5 which could not be disrupted.\",\n      \"method\": \"Targeted gene knockout by homologous recombination; phylogenetic analysis of active-site residues\",\n      \"journal\": \"Infection and immunity\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — targeted gene disruption with phenotypic readout, single lab, supported by sequence/phylogenetic analysis\",\n      \"pmids\": [\"17893128\"],\n      \"is_preprint\": false,\n      \"attribution\": [{\"species\": \"Plasmodium falciparum\", \"strain\": \"\"}]\n    },\n    {\n      \"year\": 2008,\n      \"finding\": \"P. berghei SERA3 (PbSERA3), the ortholog studied in a rodent malaria model, is transcribed in late liver stages and its protein is processed and detected by Western blot in schizont-infected cells and merozoite-infected detached hepatic cells. Immunofluorescence assays showed PbSERA3 leaks into the host cell cytoplasm during merozoite development in hepatocytes, potentially contributing to host cell death or activating host cell proteases.\",\n      \"method\": \"RT-PCR, transgenic P. berghei expressing TAP-tagged PbSERA3 under endogenous promoter, immunofluorescence assay, Western blot\",\n      \"journal\": \"Cellular microbiology\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — multiple orthogonal methods (transgenic tagging, IFA, Western blot), single lab\",\n      \"pmids\": [\"18419771\"],\n      \"is_preprint\": false,\n      \"attribution\": [{\"species\": \"Plasmodium berghei\", \"strain\": \"\"}]\n    },\n    {\n      \"year\": 2009,\n      \"finding\": \"In P. berghei, deletion of the serine-type SERAs (PbSERA1 and PbSERA2, the serine-type subfamily members) resulted in increased expression of the cysteine-type PbSERA3, indicating compensatory upregulation between SERA subfamilies. P. berghei serine-type SERA knockouts progressed normally through the parasite life cycle, further supporting non-essential roles for serine-type SERAs when cysteine-type members can compensate.\",\n      \"method\": \"Single and double gene knockouts by targeted gene replacement; fluorescent tagging with mCherry for localization; antibody localization; expression analysis\",\n      \"journal\": \"Cellular microbiology\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — genetic epistasis via double knockout with compensatory expression readout, single lab, multiple methods\",\n      \"pmids\": [\"20039882\"],\n      \"is_preprint\": false,\n      \"attribution\": [{\"species\": \"Plasmodium berghei\", \"strain\": \"\"}]\n    },\n    {\n      \"year\": 2019,\n      \"finding\": \"PbSERA3 (the P. berghei ortholog) is expressed in gametocytes and is processed by the subtilisin-like serine protease PbSUB1 upon gametocyte activation, establishing PbSERA3 as a substrate of PbSUB1 in sexual stages.\",\n      \"method\": \"Transgenic P. berghei lines deficient in PbSUB1 expression or enzyme activity; Western blot detection of PbSERA3 processing products\",\n      \"journal\": \"Cellular microbiology\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — substrate-protease relationship established by genetic loss-of-function of the protease with direct detection of processing, single lab\",\n      \"pmids\": [\"30941868\"],\n      \"is_preprint\": false,\n      \"attribution\": [{\"species\": \"Plasmodium berghei\", \"strain\": \"\"}]\n    },\n    {\n      \"year\": 2026,\n      \"finding\": \"PbSERA3 is required for hepatic merozoite egress in P. berghei. Conditional mutants (Flp/FRT system) developed normally through late liver stages but failed to initiate blood-stage infection, demonstrating a specific role in egress from hepatocytes. PbSERA3 was also found on the surface of ookinetes and sporozoites under non-permeabilized conditions (extracellular localization), and is processed in these stages into two products as in blood stages. PbSERA3 is identified as a substrate of SUB1, and its proteolytic maturation by SUB1 is implicated as a conserved and critical event for hepatic egress.\",\n      \"method\": \"Yeast-based Flp/FRT conditional mutagenesis; surface labeling under non-permeabilized conditions; Western blot for processing products; transgenic parasite lines\",\n      \"journal\": \"mBio\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — conditional genetic system with clear stage-specific phenotype, multiple orthogonal methods (conditional KO, surface localization, processing analysis), single rigorous study\",\n      \"pmids\": [\"41616267\"],\n      \"is_preprint\": false,\n      \"attribution\": [{\"species\": \"Plasmodium berghei\", \"strain\": \"\"}]\n    }\n  ],\n  \"current_model\": \"SERA3 (PF3D7_0207800) is a serine-type SERA family member with a papain-like protease domain bearing an atypical active-site serine residue; it is expressed in trophozoite and schizont stages, is dispensable for P. falciparum blood-stage survival (can be genetically disrupted), and its P. berghei ortholog (PbSERA3, which belongs to the cysteine-type subfamily) is an essential protease substrate of SUB1 that is processed at multiple life cycle stages and is specifically required for hepatic merozoite egress, with compensatory upregulation occurring when serine-type SERA family members are deleted.\"\n}\n```","stage2_raw":"{\n  \"mechanistic_narrative\": \"SERA3 (PF3D7_0207800) is a stage-specifically expressed member of the SERA family of papain-like proteins in Plasmodium, transcribed exclusively in trophozoite and schizont stages as part of a coordinately regulated cluster with SERA and SERA2 on chromosome 2 [#2]. In P. falciparum it belongs to the serine-type SERA subgroup, bearing an atypical active-site serine in place of the canonical papain-family cysteine [#3], and its protein is detectable in trophozoite- and schizont-infected erythrocytes with a distribution resembling other SERA members [#1]. SERA3 is dispensable for the P. falciparum erythrocytic cycle: it can be genetically disrupted without loss of viability, in contrast to the non-disruptable SERA5 [#0, #3]. Functional characterization of the gene itself comes largely from the rodent-malaria ortholog PbSERA3, which is a substrate of the subtilisin-like protease SUB1 processed at multiple life-cycle stages, localizes to the surface of ookinetes and sporozoites, and is specifically required for hepatic merozoite egress [#6, #7]; deletion of serine-type SERAs in P. berghei triggers compensatory upregulation of the cysteine-type PbSERA3 [#5]. Beyond this stage-specific expression, dispensability in blood stages, and the SUB1-substrate/egress role defined in P. berghei, no enzymatic activity or direct substrate of the P. falciparum protein has been characterized in the available corpus.\",\n  \"teleology\": [\n    {\n      \"year\": 1994,\n      \"claim\": \"Establishing that SERA3 is a discrete, stage-restricted gene distinguished it from the neighboring SERA5 locus and placed it within a coordinately regulated transcriptional program, framing when in the cycle it could act.\",\n      \"evidence\": \"RT-PCR, transcript mapping, and Northern analysis in P. falciparum\",\n      \"pmids\": [\"7891737\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Transcript timing does not reveal protein function\", \"No protease activity or substrate defined\"],\n      \"attribution\": [{\"species\": \"Plasmodium falciparum\", \"strain\": \"\"}]\n    },\n    {\n      \"year\": 2002,\n      \"claim\": \"Whether SERA3 was individually required for the blood-stage cycle was unknown; targeted disruption showed it is dispensable, while immune-serum reactivity confirmed it is expressed in infected individuals.\",\n      \"evidence\": \"Targeted homologous-recombination knockout plus immune-serum reactivity in P. falciparum\",\n      \"pmids\": [\"12228245\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Dispensability does not identify a positive function\", \"Possible redundancy with other SERA members untested here\"],\n      \"attribution\": [{\"species\": \"Plasmodium falciparum\", \"strain\": \"\"}]\n    },\n    {\n      \"year\": 2002,\n      \"claim\": \"The spatial context of SERA3 was undefined; immunofluorescence localized the protein in trophozoite- and schizont-infected erythrocytes similarly to SERA4-6, tying it to the same subcellular niche as other family members.\",\n      \"evidence\": \"Indirect immunofluorescence with anti-SERA3 N-terminal antibodies in P. falciparum\",\n      \"pmids\": [\"12244052\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Precise organellar compartment not resolved\", \"Function within that compartment unknown\"],\n      \"attribution\": [{\"species\": \"Plasmodium falciparum\", \"strain\": \"\"}]\n    },\n    {\n      \"year\": 2007,\n      \"claim\": \"The catalytic classification of SERA3 was open; phylogenetic and active-site analysis assigned it to the serine-type SERA subgroup with an atypical serine, and knockout confirmed non-essentiality versus the essential SERA5.\",\n      \"evidence\": \"Targeted knockout and active-site phylogenetic analysis in P. falciparum\",\n      \"pmids\": [\"17893128\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Whether the atypical serine confers catalytic activity untested\", \"No substrate identified\"],\n      \"attribution\": [{\"species\": \"Plasmodium falciparum\", \"strain\": \"\"}]\n    },\n    {\n      \"year\": 2008,\n      \"claim\": \"Whether the ortholog had a role beyond blood stages was unknown; PbSERA3 was shown to be expressed and processed in late liver stages and to leak into the hepatocyte cytoplasm during merozoite development.\",\n      \"evidence\": \"Transgenic TAP-tagged PbSERA3, RT-PCR, IFA, and Western blot in P. berghei\",\n      \"pmids\": [\"18419771\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Causal role in host-cell death not demonstrated\", \"Findings are ortholog-specific and may not transfer to P. falciparum\"],\n      \"attribution\": [{\"species\": \"Plasmodium berghei\", \"strain\": \"\"}]\n    },\n    {\n      \"year\": 2009,\n      \"claim\": \"Redundancy among SERA subfamilies was untested; deleting serine-type PbSERAs raised cysteine-type PbSERA3 expression, revealing compensatory regulation that explains blood-stage dispensability.\",\n      \"evidence\": \"Single and double gene knockouts with expression and localization analysis in P. berghei\",\n      \"pmids\": [\"20039882\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Mechanism of compensatory upregulation unknown\", \"Functional interchangeability of subfamilies not directly demonstrated\"],\n      \"attribution\": [{\"species\": \"Plasmodium berghei\", \"strain\": \"\"}]\n    },\n    {\n      \"year\": 2019,\n      \"claim\": \"The upstream protease acting on SERA3 was unidentified; loss of PbSUB1 activity abolished PbSERA3 processing in activated gametocytes, defining it as a SUB1 substrate in sexual stages.\",\n      \"evidence\": \"PbSUB1-deficient transgenic lines with Western blot of PbSERA3 processing in P. berghei\",\n      \"pmids\": [\"30941868\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Functional consequence of processing in gametocytes not established\", \"Direct cleavage-site mapping not shown\"],\n      \"attribution\": [{\"species\": \"Plasmodium berghei\", \"strain\": \"\"}]\n    },\n    {\n      \"year\": 2026,\n      \"claim\": \"A definitive essential function had not been assigned; conditional deletion showed PbSERA3 is specifically required for hepatic merozoite egress and is a SUB1 substrate processed across multiple stages with surface exposure on ookinetes and sporozoites.\",\n      \"evidence\": \"Flp/FRT conditional mutagenesis, surface labeling under non-permeabilized conditions, and processing analysis in P. berghei\",\n      \"pmids\": [\"41616267\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Molecular mechanism of egress action undefined\", \"Whether the P. falciparum protein performs the analogous liver-stage role untested\"],\n      \"attribution\": [{\"species\": \"Plasmodium berghei\", \"strain\": \"\"}]\n    },\n    {\n      \"year\": null,\n      \"claim\": \"It remains unknown whether the P. falciparum SERA3 protein is catalytically active, what its substrates or physiological cleavage products are, and whether it shares the liver-stage egress role defined for its P. berghei ortholog.\",\n      \"evidence\": \"No direct enzymatic or P. falciparum liver-stage functional evidence in the corpus\",\n      \"pmids\": [],\n      \"confidence\": \"Low\",\n      \"gaps\": [\"No demonstrated protease activity for the P. falciparum protein\", \"No substrate identified\", \"Cross-species functional conservation untested in P. falciparum\"],\n      \"attribution\": []\n    }\n  ],\n  \"mechanism_profile\": {\n    \"molecular_activity\": [\n      {\"term_id\": \"GO:0008236\", \"supporting_discovery_ids\": [3]},\n      {\"term_id\": \"GO:0030674\", \"supporting_discovery_ids\": [6, 7]}\n    ],\n    \"localization\": [\n      {\"term_id\": \"GO:0020020\", \"supporting_discovery_ids\": [1]},\n      {\"term_id\": \"GO:0009986\", \"supporting_discovery_ids\": [7]}\n    ],\n    \"pathway\": [\n      {\"term_id\": \"GO:0051806\", \"supporting_discovery_ids\": [7]}\n    ],\n    \"complexes\": [],\n    \"partners\": [\n      \"SUB1 (subtilisin-like protease; processes PbSERA3 ortholog) [#6, #7]\"\n    ],\n    \"other_free_text\": [\n      \"SERA3 (PF3D7_0207800) is a serine-type SERA subgroup member with an atypical active-site serine in its papain-like domain [#3].\",\n      \"Transcribed exclusively in trophozoite and schizont stages within a coordinately regulated SERA cluster [#2].\",\n      \"Dispensable for the P. falciparum blood-stage cycle by targeted disruption, unlike the essential SERA5 [#0, #3].\",\n      \"Functional egress role and SUB1-substrate relationship are established for the P. berghei ortholog PbSERA3, not directly for the P. falciparum protein [#5, #6, #7].\"\n    ]\n  }\n}","audit_flag":{"gene":"PF3D7_0207800","tier":"IDENTITY_CHECK","verdict":"identity unverified","subtype":"names_other_cards","uniprot_band":"","rules_fired":"R12","issue":"No cited paper names this card; 4 of 8 cited papers name other catalogue genes (PF3D7_0902800, PF3D7_0207500, PF3D7_0507500). The summary may describe one of those genes."},"strains":[{"strain":"Pf3D7","gene_id":"PF3D7_0207800","name":null,"product":"serine repeat antigen 3","uniprot_acc":null,"chromosome":null,"start_pos":null}],"gene_symbol":"SERA3","evaluation":null}