{"gene":"PF3D7_0903700","run_date":"2026-09-08T12:51:27","timeline":{"discoveries":[{"year":1989,"finding":"Alpha-tubulin I (PF3D7_0903700) of P. falciparum was isolated and sequenced from genomic clones; the gene contains two introns and encodes a 453 amino acid, ~50.3 kDa protein with high homology to other alpha-tubulins (94% identity to Toxoplasma gondii alpha-tubulin); intron positions are identical to those of T. gondii alpha-tubulin I.","method":"Genomic library screening, DNA sequencing, Southern blotting","journal":"Molecular microbiology","confidence":"Medium","confidence_rationale":"Tier 1 / Weak — direct sequencing and structural characterization of the gene, single lab, no functional mutagenesis","pmids":["2693901"],"is_preprint":false,"attribution":[{"species":"Plasmodium falciparum","strain":""}]},{"year":1990,"finding":"Alpha-tubulin I (PF3D7_0903700) is located on chromosome 9 of P. falciparum, as determined by pulsed-field gel electrophoresis, and is expressed in a stage-specific manner distinct from alpha-tubulin II (chromosome 4) and beta-tubulin (chromosome 10).","method":"Pulsed-field gel electrophoresis, chromosomal mapping, Northern blotting","journal":"Molecular and biochemical parasitology","confidence":"Medium","confidence_rationale":"Tier 2 / Weak — direct chromosomal localization by PFGE, single lab","pmids":["2090947"],"is_preprint":false,"attribution":[{"species":"Plasmodium falciparum","strain":""}]},{"year":1993,"finding":"In erythrocytic P. falciparum, the C-terminal tyrosine-containing epitope of alpha-tubulin I (PF3D7_0903700) is present and recognized by antibodies specific for that post-translational modification, similar to other organisms. However, Lysine-40 of alpha-tubulin I is NOT acetylated in blood stages examined, although the epitope it contributes to is conformationally conserved (recognizable after in vitro acetylation), despite lack of primary sequence homology immediately downstream of K40.","method":"Immunofluorescence microscopy with PTM-specific antibodies; in vitro acetylation assay followed by antibody recognition","journal":"Parasitology","confidence":"Medium","confidence_rationale":"Tier 2 / Weak — direct antibody-based detection of PTM status and in vitro acetylation assay, single lab, two orthogonal approaches","pmids":["8488059"],"is_preprint":false,"attribution":[{"species":"Plasmodium falciparum","strain":""}]},{"year":1993,"finding":"A peptide derived from P. falciparum alpha-tubulin (alpha-tubulin I, PF3D7_0903700) acts as a selective competitive inhibitor of P. falciparum aldolase (PfAldo) in vitro; the inhibitory activity depends on the presence of tandem lysine residues and the fine structure of the peptide, supporting a matrix organisation of glycolytic enzymes in the parasite.","method":"In vitro enzyme inhibition assay using synthetic peptide; site-directed mutagenesis of PfAldo","journal":"Molecular and biochemical parasitology","confidence":"Medium","confidence_rationale":"Tier 1 / Weak — in vitro biochemical assay with mutagenesis, single lab, but only a peptide fragment tested rather than full-length alpha-tubulin I","pmids":["8459825"],"is_preprint":false,"attribution":[{"species":"Plasmodium falciparum","strain":""}]},{"year":2007,"finding":"Alpha-tubulin I (PF3D7_0903700) protein is produced in both asexual and sexual blood-stage P. falciparum parasites, with production reaching maximum levels in schizonts and segmenters. Evidence of post-translational polyglutamylation of P. falciparum tubulin (including alpha-tubulin I) was found, localised specifically to microtubule-organising centres and post-mitotic microtubular structures, suggesting roles in spindle pole body formation and merozoite biogenesis.","method":"Western blotting with isotype-specific antibodies; immunofluorescence with glutamylation-specific antibodies; stage-specific protein fractionation","journal":"International journal for parasitology","confidence":"Medium","confidence_rationale":"Tier 2 / Weak — direct immunological detection with multiple antibodies and fractionation, single lab","pmids":["17977543"],"is_preprint":false,"attribution":[{"species":"Plasmodium falciparum","strain":""}]},{"year":2013,"finding":"Antimitotic herbicides (dinitroanilines, phosphorothioamidates) bind to P. falciparum alpha-tubulin I (PF3D7_0903700) at an unidentified site distinct from three previously proposed overlapping sites; site-directed mutagenesis introducing six amino acid changes designed to occlude the proposed herbicide-binding sites on recombinant alpha-tubulin I had little to no effect on herbicide binding affinity (Kd changes ≤1.6-fold). These herbicides also block liver-stage parasite development.","method":"Site-directed mutagenesis of alpha-tubulin I; recombinant protein expression in E. coli; fluorescence quenching binding assay; liver-stage parasite inhibition assay","journal":"Molecular and biochemical parasitology","confidence":"High","confidence_rationale":"Tier 1 / Moderate — in vitro reconstitution with mutagenesis and direct binding measurement, single lab, multiple orthogonal methods","pmids":["23523992"],"is_preprint":false,"attribution":[{"species":"Plasmodium falciparum","strain":""}]},{"year":2017,"finding":"Alpha-tubulin (including alpha-tubulin I, PF3D7_0903700) of P. falciparum is O-GlcNAcylated in late trophozoites, as identified by proteomics; this was confirmed by probing click-chemistry-enriched O-GlcNAcylated proteins with an anti-alpha-tubulin antibody.","method":"Click chemistry labelling followed by mass spectrometry (nano-LC MS/MS); antibody confirmation of O-GlcNAcylated alpha-tubulin","journal":"Malaria journal","confidence":"Medium","confidence_rationale":"Tier 2 / Weak — two orthogonal methods (MS and antibody), single lab; cannot unambiguously assign to alpha-tubulin I vs II from abstract","pmids":["29187233"],"is_preprint":false,"attribution":[{"species":"Plasmodium falciparum","strain":"3D7"}]},{"year":2019,"finding":"In P. berghei, gene deletion and replacement targeting one of the two alpha-tubulin genes (alpha-tubulin I, the ortholog of PF3D7_0903700) showed that alpha-tubulin expression levels directly determine the number of subpellicular microtubules in sporozoites. Fewer and shorter microtubules severely impaired sporozoite formation, motility, and infectivity; infectious sporozoites required at least 10 microtubules. Chromosome segregation in oocysts proceeded even in the absence of microtubules.","method":"Gene deletion and replacement strategy; quantitative electron microscopy of microtubule number/length; sporozoite motility and infectivity assays; mathematical modelling","journal":"The EMBO journal","confidence":"High","confidence_rationale":"Tier 2 / Strong — clean genetic KO/replacement with defined cellular phenotype, quantitative structural analysis, infectivity assays, mathematical model support; multiple orthogonal methods in one rigorous study","pmids":["31368598"],"is_preprint":false,"attribution":[{"species":"Plasmodium berghei","strain":""}]},{"year":2021,"finding":"P. falciparum apicortin interacts with alpha-tubulin I (PF3D7_0903700) in vitro; disruption of this interaction using tamoxifen (a p25-domain binding drug) inhibited parasite blood stage growth and progression.","method":"In silico modelling; in vitro interaction assay (pulldown); growth inhibition assay with tamoxifen","journal":"Scientific reports","confidence":"Low","confidence_rationale":"Tier 3 / Weak — single lab, in vitro pulldown supported by in silico modelling; no reciprocal Co-IP or structural validation described in abstract","pmids":["33633135"],"is_preprint":false,"attribution":[{"species":"Plasmodium falciparum","strain":""}]},{"year":2023,"finding":"P. falciparum alpha-tubulin I (PF3D7_0903700) is accessible on the surface of the apical complex of live ookinetes, and interacts with the mosquito midgut protein FREP1 (fibrinogen-related protein 1), as demonstrated by ELISA and pull-down assay. Polyclonal and monoclonal antibodies against recombinant alpha-tubulin I significantly reduced P. falciparum oocyst numbers in Anopheles gambiae midguts. The interaction between FREP1 and alpha-tubulin I is proposed to anchor and orient the ookinete invasive apparatus toward the midgut epithelium.","method":"Immunofluorescence assay on live ookinetes; ELISA; pull-down assay with insect cell-expressed FREP1; standard membrane feeding assay with polyclonal and monoclonal antibodies","journal":"Frontiers in cellular and infection microbiology","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — reciprocal binding assays (ELISA + pulldown), functional transmission-blocking assay, direct surface localization on live cells; single lab but multiple orthogonal methods","pmids":["37009496"],"is_preprint":false,"attribution":[{"species":"Plasmodium falciparum","strain":""}]},{"year":2024,"finding":"P. falciparum Prefoldin subunits (PFD1-6) interact with alpha-tubulin I (PF3D7_0903700) as a substrate, as identified by immunoprecipitation coupled to MS/MS analysis. An FDA-approved drug Biperiden inhibits the Prefoldin complex interaction with alpha-tubulin I and inhibits parasite growth in both ART-sensitive and ART-resistant strains.","method":"Immunoprecipitation coupled MS/MS; biophysical interaction analysis; growth inhibition assay; ring survival assay","journal":"The Journal of biological chemistry","confidence":"Medium","confidence_rationale":"Tier 2 / Weak — Co-IP/MS identification of interaction, functional drug assay, single lab","pmids":["38925325"],"is_preprint":false,"attribution":[{"species":"Plasmodium falciparum","strain":"3D7"}]},{"year":2025,"finding":"In P. berghei, introduction of a Q40K mutation in alpha-tubulin I (ortholog of PF3D7_0903700, which naturally has Q40 instead of K40) did not affect parasite development or infectivity, indicating that the absence of K40 acetylation (which would require the lysine) is not detrimental to microtubule function in this species.","method":"Site-directed mutagenesis (Q40K knock-in); parasite phenotypic characterization across life cycle stages","journal":"Microbial cell (Graz, Austria)","confidence":"Medium","confidence_rationale":"Tier 2 / Weak — clean genetic mutagenesis with life-cycle phenotyping, single lab, negative result for acetylation necessity","pmids":["41531934"],"is_preprint":false,"attribution":[{"species":"Plasmodium berghei","strain":""}]}],"current_model":"P. falciparum alpha-tubulin I (PF3D7_0903700) is a component of the subpellicular and spindle microtubule cytoskeleton expressed throughout the intraerythrocytic cycle with peak levels in schizonts; its expression level directly determines microtubule number and thus sporozoite morphology, motility, and infectivity in Plasmodium berghei; it undergoes post-translational polyglutamylation (at spindle pole bodies and post-mitotic structures) and O-GlcNAcylation, but K40 acetylation is not essential; it interacts with PfAldolase (via a lysine-rich C-terminal peptide), P. falciparum Prefoldin subunits, and apicortin as a cytoskeletal substrate; it is exposed on the surface of ookinetes where it binds mosquito midgut FREP1 to facilitate midgut invasion; and antimitotic herbicides bind it at a site that remains structurally unresolved despite mutagenesis attempts to identify it."},"narrative":{"mechanistic_narrative":"Alpha-tubulin I (PF3D7_0903700) is a core structural component of the Plasmodium microtubule cytoskeleton, encoded by a two-intron gene on chromosome 9 and expressed in a stage-specific manner distinct from alpha-tubulin II, with protein accumulation peaking in schizonts and segmenters and evidence of assembly into spindle-pole and post-mitotic microtubular structures [PMID:2693901, PMID:2090947, PMID:17977543]. Its expression level is rate-limiting for cytoskeletal architecture: in P. berghei, deleting or replacing the orthologous alpha-tubulin gene showed that tubulin abundance directly sets the number of subpellicular microtubules in sporozoites, with fewer/shorter microtubules crippling sporozoite formation, motility, and infectivity (a threshold of ~10 microtubules for infectivity), while chromosome segregation in oocysts proceeded even without microtubules [PMID:31368598]. The protein carries several post-translational modifications — a C-terminal tyrosine epitope and MTOC-localized polyglutamylation [PMID:8488059, PMID:17977543], and O-GlcNAcylation in late trophozoites [PMID:29187233] — but K40 acetylation is not a feature of this protein: blood-stage alpha-tubulin I is unacetylated at K40, and in P. berghei a Q40K knock-in permitting acetylation had no phenotypic consequence, indicating this modification is dispensable [PMID:8488059, PMID:41531934]. Alpha-tubulin I engages multiple partners: a lysine-rich C-terminal peptide competitively inhibits P. falciparum aldolase, consistent with a cytoskeletal scaffold for glycolytic enzymes [PMID:8459825]; it is bound by apicortin and by Prefoldin subunits as a chaperone substrate, both interactions being druggable growth-dependencies [PMID:33633135, PMID:38925325]; and it is displayed on the apical surface of live ookinetes where it binds the mosquito midgut protein FREP1 to orient midgut invasion, with anti-alpha-tubulin I antibodies reducing oocyst burden [PMID:37009496]. It is also the target of antimitotic dinitroaniline and phosphorothioamidate herbicides, which bind at a site that has resisted structural definition by mutagenesis [PMID:23523992].","teleology":[{"year":1989,"claim":"Establishing the gene's sequence and structure was the necessary first step to define alpha-tubulin I as a discrete tubulin gene rather than an undifferentiated tubulin activity.","evidence":"Genomic library screening and DNA sequencing of P. falciparum clones","pmids":["2693901"],"confidence":"Medium","gaps":["No functional or expression data at this stage","Protein product not directly characterized"],"attribution":[{"species":"Plasmodium falciparum","strain":""}]},{"year":1990,"claim":"Chromosomal mapping distinguished alpha-tubulin I from alpha-tubulin II and beta-tubulin and showed stage-specific expression, establishing it as an independently regulated gene.","evidence":"Pulsed-field gel electrophoresis, chromosomal mapping and Northern blotting","pmids":["2090947"],"confidence":"Medium","gaps":["Functional distinction between alpha-tubulin I and II not tested","Regulatory basis of stage specificity unknown"],"attribution":[{"species":"Plasmodium falciparum","strain":""}]},{"year":1993,"claim":"Defining the PTM status resolved which conserved tubulin modifications apply to this parasite protein, showing K40 is not acetylated in blood stages while the C-terminal tyrosine epitope is retained.","evidence":"PTM-specific antibody immunofluorescence and in vitro acetylation assay","pmids":["8488059"],"confidence":"Medium","gaps":["Functional consequence of missing K40 acetylation not tested","Antibody-based, no site-resolved mass spectrometry"],"attribution":[{"species":"Plasmodium falciparum","strain":""}]},{"year":1993,"claim":"A lysine-rich alpha-tubulin peptide inhibiting aldolase implicated the cytoskeleton as an organizing matrix for glycolytic enzymes, extending tubulin's role beyond structure.","evidence":"In vitro enzyme inhibition with synthetic peptide plus site-directed mutagenesis of aldolase","pmids":["8459825"],"confidence":"Medium","gaps":["Only a peptide fragment, not full-length alpha-tubulin I, was tested","In vivo relevance of the interaction not demonstrated"],"attribution":[{"species":"Plasmodium falciparum","strain":""}]},{"year":2007,"claim":"Mapping protein abundance across stages and detecting polyglutamylation at MTOCs linked alpha-tubulin I to spindle-pole/merozoite biogenesis and pinpointed its peak in schizonts.","evidence":"Isotype- and glutamylation-specific antibody Western blotting and immunofluorescence with stage fractionation","pmids":["17977543"],"confidence":"Medium","gaps":["Enzymes mediating polyglutamylation not identified","Functional requirement of the modification not tested"],"attribution":[{"species":"Plasmodium falciparum","strain":""}]},{"year":2013,"claim":"Confirming direct herbicide binding to recombinant alpha-tubulin I identified it as the antimitotic drug target, but mutagenesis failed to localize the binding site.","evidence":"Recombinant expression, site-directed mutagenesis, fluorescence-quenching binding assay and liver-stage inhibition","pmids":["23523992"],"confidence":"High","gaps":["Structural location of the herbicide site remains unresolved","Six designed mutations did not alter binding, so the true contact residues are unknown"],"attribution":[{"species":"Plasmodium falciparum","strain":""}]},{"year":2017,"claim":"Detecting O-GlcNAcylation added another PTM to the alpha-tubulin repertoire in late trophozoites, though assignment to isoform I versus II was not fully resolved.","evidence":"Click-chemistry enrichment with nano-LC MS/MS and antibody confirmation","pmids":["29187233"],"confidence":"Medium","gaps":["Cannot unambiguously assign to alpha-tubulin I versus II","Functional role of O-GlcNAcylation not tested"],"attribution":[{"species":"Plasmodium falciparum","strain":"3D7"}]},{"year":2019,"claim":"Genetic titration of tubulin in P. berghei established that alpha-tubulin expression level quantitatively sets microtubule number and thereby sporozoite morphology, motility, and infectivity, defining a mechanistic threshold.","evidence":"Gene deletion/replacement, quantitative EM, motility/infectivity assays and mathematical modelling in P. berghei","pmids":["31368598"],"confidence":"High","gaps":["Shown in P. berghei ortholog, not directly in PF3D7_0903700","Mechanism coupling tubulin level to microtubule count not molecularly dissected"],"attribution":[{"species":"Plasmodium berghei","strain":""}]},{"year":2021,"claim":"Identifying apicortin as a binding partner and showing tamoxifen-mediated disruption impairs growth suggested this interaction supports blood-stage progression.","evidence":"In silico modelling, in vitro pulldown and tamoxifen growth-inhibition assay","pmids":["33633135"],"confidence":"Low","gaps":["No reciprocal Co-IP or structural validation described","Tamoxifen effect may not be specific to the alpha-tubulin I–apicortin interaction"],"attribution":[{"species":"Plasmodium falciparum","strain":""}]},{"year":2023,"claim":"Demonstrating surface accessibility on ookinetes and FREP1 binding revealed a moonlighting adhesion role for alpha-tubulin I in mosquito midgut invasion and defined it as a transmission-blocking target.","evidence":"Live-cell IFA, ELISA, pull-down with FREP1 and antibody-based membrane feeding assays","pmids":["37009496"],"confidence":"Medium","gaps":["Mechanism by which cytoskeletal tubulin reaches the ookinete surface unclear","Structural basis of the FREP1 interaction not defined"],"attribution":[{"species":"Plasmodium falciparum","strain":""}]},{"year":2024,"claim":"Identifying Prefoldin subunits as interactors positioned alpha-tubulin I as a chaperone substrate and revealed Biperiden as a growth-inhibitory drug acting on this axis across resistant strains.","evidence":"Co-IP MS/MS, biophysical interaction analysis and growth/ring-survival assays","pmids":["38925325"],"confidence":"Medium","gaps":["Direct effect of Biperiden on the interaction versus off-target not fully separated","Consequence of Prefoldin loss for tubulin folding in vivo not shown"],"attribution":[{"species":"Plasmodium falciparum","strain":"3D7"}]},{"year":2025,"claim":"A Q40K knock-in in P. berghei testing whether restoring the acetylatable lysine matters showed K40 acetylation capacity is dispensable, confirming this modification is not required for microtubule function.","evidence":"Q40K site-directed mutagenesis and life-cycle phenotyping in P. berghei","pmids":["41531934"],"confidence":"Medium","gaps":["Shown in P. berghei ortholog, not directly in PF3D7_0903700","Does not address whether other K40-linked functions exist"],"attribution":[{"species":"Plasmodium berghei","strain":""}]},{"year":null,"claim":"The structural location of the antimitotic herbicide binding site and the molecular basis for how a cytoskeletal tubulin becomes surface-exposed to bind FREP1 remain unresolved.","evidence":"","pmids":[],"confidence":"Low","gaps":["No structure of alpha-tubulin I with bound herbicide","No mechanism explaining ookinete surface display of tubulin","Direct requirement of PF3D7_0903700 itself (versus P. berghei ortholog) for microtubule count not genetically shown in P. falciparum"],"attribution":[]}],"mechanism_profile":{"molecular_activity":[],"localization":[],"pathway":[],"complexes":["Prefoldin complex (as substrate, PFD1-6) [#10]"],"partners":["PFALDOLASE (VIA LYSINE-RICH C-TERMINAL PEPTIDE) [#3]","APICORTIN [#8]","PREFOLDIN SUBUNITS PFD1-6 [#10]","MOSQUITO MIDGUT FREP1 [#9]"],"other_free_text":["Encoded by a two-intron gene on chromosome 9; 453 aa, ~50.3 kDa; distinct from alpha-tubulin II (chromosome 4) [#0, #1]","Post-translationally polyglutamylated at MTOCs/post-mitotic structures and O-GlcNAcylated in late trophozoites; retains C-terminal tyrosine epitope [#2, #4, #6]","K40 is not acetylated in blood stages and Q40K restoration is dispensable in P. berghei [#2, #11]","Direct target of dinitroaniline and phosphorothioamidate antimitotic herbicides at a structurally unresolved site [#5]","In P. berghei, alpha-tubulin expression level sets subpellicular microtubule number governing sporozoite motility and infectivity [#7]","Interactions with apicortin, Prefoldin and FREP1 are druggable (tamoxifen, Biperiden, transmission-blocking antibodies) [#8, #9, #10]"]}},"prefetch_data":{},"corpus_meta":[{"pmid":"24736563","id":"PMC_24736563","title":"A flow cytometry-based quantitative drug sensitivity assay for all Plasmodium falciparum gametocyte stages.","date":"2014","source":"PloS one","url":"https://pubmed.ncbi.nlm.nih.gov/24736563","citation_count":102,"is_preprint":false,"source_species":["Pf"],"role":"primary","match_terms":["alpha 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microbiology","url":"https://pubmed.ncbi.nlm.nih.gov/33154955","citation_count":18,"is_preprint":false,"source_species":["Pf"],"role":"primary","match_terms":["alpha tubulin"],"competing_organism_flag":false,"competing_organism_match":"","competing_organism_only":false},{"pmid":"2459618","id":"PMC_2459618","title":"Molecular clones of alpha-tubulin genes of Plasmodium yoelii reveal an unusual feature of the carboxy terminus.","date":"1988","source":"Molecular and biochemical parasitology","url":"https://pubmed.ncbi.nlm.nih.gov/2459618","citation_count":16,"is_preprint":false,"source_species":["Pf"],"role":"primary","match_terms":["alpha tubulin"],"competing_organism_flag":false,"competing_organism_match":"","competing_organism_only":false},{"pmid":"30304836","id":"PMC_30304836","title":"Specific Targeting of Plant and Apicomplexa Parasite Tubulin through Differential Screening Using In Silico and Assay-Based Approaches.","date":"2018","source":"International journal of molecular sciences","url":"https://pubmed.ncbi.nlm.nih.gov/30304836","citation_count":14,"is_preprint":false,"source_species":["Pf"],"role":"primary","match_terms":["alpha tubulin"],"competing_organism_flag":false,"competing_organism_match":"","competing_organism_only":false},{"pmid":"37009496","id":"PMC_37009496","title":"Targeting plasmodium α-tubulin-1 to block malaria transmission to mosquitoes.","date":"2023","source":"Frontiers in cellular and infection microbiology","url":"https://pubmed.ncbi.nlm.nih.gov/37009496","citation_count":13,"is_preprint":false,"source_species":["Pf"],"role":"primary","match_terms":["alpha tubulin","alpha tubulin 1"],"competing_organism_flag":false,"competing_organism_match":"","competing_organism_only":false},{"pmid":"8459825","id":"PMC_8459825","title":"Selective inhibition of Plasmodium falciparum aldolase by a tubulin derived peptide and identification of the binding site.","date":"1993","source":"Molecular and biochemical parasitology","url":"https://pubmed.ncbi.nlm.nih.gov/8459825","citation_count":12,"is_preprint":false,"source_species":["Pf"],"role":"primary","match_terms":["alpha tubulin"],"competing_organism_flag":false,"competing_organism_match":"","competing_organism_only":false},{"pmid":"27057354","id":"PMC_27057354","title":"In Silico Designing and Analysis of Inhibitors against Target Protein Identified through Host-Pathogen Protein Interactions in Malaria.","date":"2016","source":"International journal of medicinal chemistry","url":"https://pubmed.ncbi.nlm.nih.gov/27057354","citation_count":6,"is_preprint":false,"source_species":["Pf"],"role":"primary","match_terms":["alpha tubulin"],"competing_organism_flag":false,"competing_organism_match":"","competing_organism_only":false},{"pmid":"39549507","id":"PMC_39549507","title":"Multicomponent syntheses enable the discovery of novel quisinostat-derived chemotypes as histone deacetylase inhibitors.","date":"2024","source":"European journal of medicinal chemistry","url":"https://pubmed.ncbi.nlm.nih.gov/39549507","citation_count":4,"is_preprint":false,"source_species":["Pf"],"role":"primary","match_terms":["alpha tubulin"],"competing_organism_flag":false,"competing_organism_match":"","competing_organism_only":false},{"pmid":"31713698","id":"PMC_31713698","title":"Investigation of the reactivity indices for the formation of substituted dinitroanilines and correlations to their dockings on α-tubulin of Plasmodium falciparum.","date":"2019","source":"Journal of molecular modeling","url":"https://pubmed.ncbi.nlm.nih.gov/31713698","citation_count":1,"is_preprint":false,"source_species":["Pf"],"role":"primary","match_terms":["alpha tubulin"],"competing_organism_flag":false,"competing_organism_match":"","competing_organism_only":false},{"pmid":"41531934","id":"PMC_41531934","title":"Luminal acetylation of microtubules is not essential for Plasmodium berghei and Toxoplasma gondii survival.","date":"2025","source":"Microbial cell (Graz, Austria)","url":"https://pubmed.ncbi.nlm.nih.gov/41531934","citation_count":1,"is_preprint":false,"source_species":["Pf"],"role":"primary","match_terms":["alpha tubulin"],"competing_organism_flag":true,"competing_organism_match":"Toxoplasma","competing_organism_only":false},{"pmid":"38925325","id":"PMC_38925325","title":"Prefoldins are novel regulators of the unfolded protein response in artemisinin resistant Plasmodium falciparum malaria.","date":"2024","source":"The Journal of biological chemistry","url":"https://pubmed.ncbi.nlm.nih.gov/38925325","citation_count":1,"is_preprint":false,"source_species":["Pf"],"role":"primary","match_terms":["alpha tubulin"],"competing_organism_flag":false,"competing_organism_match":"","competing_organism_only":false}],"cost":{"stage1":{"model":"claude-sonnet-4-6","input_tokens":17999,"output_tokens":3642,"usd":0.054314,"stage1_stop_reason":"end_turn"},"stage2":{"model":"claude-opus-4-8","input_tokens":9481,"output_tokens":4824,"usd":0.084002,"stage2_stop_reason":"end_turn"},"total_usd":0.138316,"stage1_batch_id":"msgbatch_01DisAaTypwmC8QwdMBuePHo","stage2_batch_id":"msgbatch_0184zxZTqxiEfdYYfPMfkqjb","note":"batch pricing = 50% of standard"},"stage1_raw":"```json\n{\n  \"discoveries\": [\n    {\n      \"year\": 1989,\n      \"finding\": \"Alpha-tubulin I (PF3D7_0903700) of P. falciparum was isolated and sequenced from genomic clones; the gene contains two introns and encodes a 453 amino acid, ~50.3 kDa protein with high homology to other alpha-tubulins (94% identity to Toxoplasma gondii alpha-tubulin); intron positions are identical to those of T. gondii alpha-tubulin I.\",\n      \"method\": \"Genomic library screening, DNA sequencing, Southern blotting\",\n      \"journal\": \"Molecular microbiology\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 1 / Weak — direct sequencing and structural characterization of the gene, single lab, no functional mutagenesis\",\n      \"pmids\": [\"2693901\"],\n      \"is_preprint\": false,\n      \"attribution\": [{\"species\": \"Plasmodium falciparum\", \"strain\": \"\"}]\n    },\n    {\n      \"year\": 1990,\n      \"finding\": \"Alpha-tubulin I (PF3D7_0903700) is located on chromosome 9 of P. falciparum, as determined by pulsed-field gel electrophoresis, and is expressed in a stage-specific manner distinct from alpha-tubulin II (chromosome 4) and beta-tubulin (chromosome 10).\",\n      \"method\": \"Pulsed-field gel electrophoresis, chromosomal mapping, Northern blotting\",\n      \"journal\": \"Molecular and biochemical parasitology\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Weak — direct chromosomal localization by PFGE, single lab\",\n      \"pmids\": [\"2090947\"],\n      \"is_preprint\": false,\n      \"attribution\": [{\"species\": \"Plasmodium falciparum\", \"strain\": \"\"}]\n    },\n    {\n      \"year\": 1993,\n      \"finding\": \"In erythrocytic P. falciparum, the C-terminal tyrosine-containing epitope of alpha-tubulin I (PF3D7_0903700) is present and recognized by antibodies specific for that post-translational modification, similar to other organisms. However, Lysine-40 of alpha-tubulin I is NOT acetylated in blood stages examined, although the epitope it contributes to is conformationally conserved (recognizable after in vitro acetylation), despite lack of primary sequence homology immediately downstream of K40.\",\n      \"method\": \"Immunofluorescence microscopy with PTM-specific antibodies; in vitro acetylation assay followed by antibody recognition\",\n      \"journal\": \"Parasitology\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Weak — direct antibody-based detection of PTM status and in vitro acetylation assay, single lab, two orthogonal approaches\",\n      \"pmids\": [\"8488059\"],\n      \"is_preprint\": false,\n      \"attribution\": [{\"species\": \"Plasmodium falciparum\", \"strain\": \"\"}]\n    },\n    {\n      \"year\": 1993,\n      \"finding\": \"A peptide derived from P. falciparum alpha-tubulin (alpha-tubulin I, PF3D7_0903700) acts as a selective competitive inhibitor of P. falciparum aldolase (PfAldo) in vitro; the inhibitory activity depends on the presence of tandem lysine residues and the fine structure of the peptide, supporting a matrix organisation of glycolytic enzymes in the parasite.\",\n      \"method\": \"In vitro enzyme inhibition assay using synthetic peptide; site-directed mutagenesis of PfAldo\",\n      \"journal\": \"Molecular and biochemical parasitology\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 1 / Weak — in vitro biochemical assay with mutagenesis, single lab, but only a peptide fragment tested rather than full-length alpha-tubulin I\",\n      \"pmids\": [\"8459825\"],\n      \"is_preprint\": false,\n      \"attribution\": [{\"species\": \"Plasmodium falciparum\", \"strain\": \"\"}]\n    },\n    {\n      \"year\": 2007,\n      \"finding\": \"Alpha-tubulin I (PF3D7_0903700) protein is produced in both asexual and sexual blood-stage P. falciparum parasites, with production reaching maximum levels in schizonts and segmenters. Evidence of post-translational polyglutamylation of P. falciparum tubulin (including alpha-tubulin I) was found, localised specifically to microtubule-organising centres and post-mitotic microtubular structures, suggesting roles in spindle pole body formation and merozoite biogenesis.\",\n      \"method\": \"Western blotting with isotype-specific antibodies; immunofluorescence with glutamylation-specific antibodies; stage-specific protein fractionation\",\n      \"journal\": \"International journal for parasitology\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Weak — direct immunological detection with multiple antibodies and fractionation, single lab\",\n      \"pmids\": [\"17977543\"],\n      \"is_preprint\": false,\n      \"attribution\": [{\"species\": \"Plasmodium falciparum\", \"strain\": \"\"}]\n    },\n    {\n      \"year\": 2013,\n      \"finding\": \"Antimitotic herbicides (dinitroanilines, phosphorothioamidates) bind to P. falciparum alpha-tubulin I (PF3D7_0903700) at an unidentified site distinct from three previously proposed overlapping sites; site-directed mutagenesis introducing six amino acid changes designed to occlude the proposed herbicide-binding sites on recombinant alpha-tubulin I had little to no effect on herbicide binding affinity (Kd changes ≤1.6-fold). These herbicides also block liver-stage parasite development.\",\n      \"method\": \"Site-directed mutagenesis of alpha-tubulin I; recombinant protein expression in E. coli; fluorescence quenching binding assay; liver-stage parasite inhibition assay\",\n      \"journal\": \"Molecular and biochemical parasitology\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 / Moderate — in vitro reconstitution with mutagenesis and direct binding measurement, single lab, multiple orthogonal methods\",\n      \"pmids\": [\"23523992\"],\n      \"is_preprint\": false,\n      \"attribution\": [{\"species\": \"Plasmodium falciparum\", \"strain\": \"\"}]\n    },\n    {\n      \"year\": 2017,\n      \"finding\": \"Alpha-tubulin (including alpha-tubulin I, PF3D7_0903700) of P. falciparum is O-GlcNAcylated in late trophozoites, as identified by proteomics; this was confirmed by probing click-chemistry-enriched O-GlcNAcylated proteins with an anti-alpha-tubulin antibody.\",\n      \"method\": \"Click chemistry labelling followed by mass spectrometry (nano-LC MS/MS); antibody confirmation of O-GlcNAcylated alpha-tubulin\",\n      \"journal\": \"Malaria journal\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Weak — two orthogonal methods (MS and antibody), single lab; cannot unambiguously assign to alpha-tubulin I vs II from abstract\",\n      \"pmids\": [\"29187233\"],\n      \"is_preprint\": false,\n      \"attribution\": [{\"species\": \"Plasmodium falciparum\", \"strain\": \"3D7\"}]\n    },\n    {\n      \"year\": 2019,\n      \"finding\": \"In P. berghei, gene deletion and replacement targeting one of the two alpha-tubulin genes (alpha-tubulin I, the ortholog of PF3D7_0903700) showed that alpha-tubulin expression levels directly determine the number of subpellicular microtubules in sporozoites. Fewer and shorter microtubules severely impaired sporozoite formation, motility, and infectivity; infectious sporozoites required at least 10 microtubules. Chromosome segregation in oocysts proceeded even in the absence of microtubules.\",\n      \"method\": \"Gene deletion and replacement strategy; quantitative electron microscopy of microtubule number/length; sporozoite motility and infectivity assays; mathematical modelling\",\n      \"journal\": \"The EMBO journal\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — clean genetic KO/replacement with defined cellular phenotype, quantitative structural analysis, infectivity assays, mathematical model support; multiple orthogonal methods in one rigorous study\",\n      \"pmids\": [\"31368598\"],\n      \"is_preprint\": false,\n      \"attribution\": [{\"species\": \"Plasmodium berghei\", \"strain\": \"\"}]\n    },\n    {\n      \"year\": 2021,\n      \"finding\": \"P. falciparum apicortin interacts with alpha-tubulin I (PF3D7_0903700) in vitro; disruption of this interaction using tamoxifen (a p25-domain binding drug) inhibited parasite blood stage growth and progression.\",\n      \"method\": \"In silico modelling; in vitro interaction assay (pulldown); growth inhibition assay with tamoxifen\",\n      \"journal\": \"Scientific reports\",\n      \"confidence\": \"Low\",\n      \"confidence_rationale\": \"Tier 3 / Weak — single lab, in vitro pulldown supported by in silico modelling; no reciprocal Co-IP or structural validation described in abstract\",\n      \"pmids\": [\"33633135\"],\n      \"is_preprint\": false,\n      \"attribution\": [{\"species\": \"Plasmodium falciparum\", \"strain\": \"\"}]\n    },\n    {\n      \"year\": 2023,\n      \"finding\": \"P. falciparum alpha-tubulin I (PF3D7_0903700) is accessible on the surface of the apical complex of live ookinetes, and interacts with the mosquito midgut protein FREP1 (fibrinogen-related protein 1), as demonstrated by ELISA and pull-down assay. Polyclonal and monoclonal antibodies against recombinant alpha-tubulin I significantly reduced P. falciparum oocyst numbers in Anopheles gambiae midguts. The interaction between FREP1 and alpha-tubulin I is proposed to anchor and orient the ookinete invasive apparatus toward the midgut epithelium.\",\n      \"method\": \"Immunofluorescence assay on live ookinetes; ELISA; pull-down assay with insect cell-expressed FREP1; standard membrane feeding assay with polyclonal and monoclonal antibodies\",\n      \"journal\": \"Frontiers in cellular and infection microbiology\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — reciprocal binding assays (ELISA + pulldown), functional transmission-blocking assay, direct surface localization on live cells; single lab but multiple orthogonal methods\",\n      \"pmids\": [\"37009496\"],\n      \"is_preprint\": false,\n      \"attribution\": [{\"species\": \"Plasmodium falciparum\", \"strain\": \"\"}]\n    },\n    {\n      \"year\": 2024,\n      \"finding\": \"P. falciparum Prefoldin subunits (PFD1-6) interact with alpha-tubulin I (PF3D7_0903700) as a substrate, as identified by immunoprecipitation coupled to MS/MS analysis. An FDA-approved drug Biperiden inhibits the Prefoldin complex interaction with alpha-tubulin I and inhibits parasite growth in both ART-sensitive and ART-resistant strains.\",\n      \"method\": \"Immunoprecipitation coupled MS/MS; biophysical interaction analysis; growth inhibition assay; ring survival assay\",\n      \"journal\": \"The Journal of biological chemistry\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Weak — Co-IP/MS identification of interaction, functional drug assay, single lab\",\n      \"pmids\": [\"38925325\"],\n      \"is_preprint\": false,\n      \"attribution\": [{\"species\": \"Plasmodium falciparum\", \"strain\": \"3D7\"}]\n    },\n    {\n      \"year\": 2025,\n      \"finding\": \"In P. berghei, introduction of a Q40K mutation in alpha-tubulin I (ortholog of PF3D7_0903700, which naturally has Q40 instead of K40) did not affect parasite development or infectivity, indicating that the absence of K40 acetylation (which would require the lysine) is not detrimental to microtubule function in this species.\",\n      \"method\": \"Site-directed mutagenesis (Q40K knock-in); parasite phenotypic characterization across life cycle stages\",\n      \"journal\": \"Microbial cell (Graz, Austria)\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Weak — clean genetic mutagenesis with life-cycle phenotyping, single lab, negative result for acetylation necessity\",\n      \"pmids\": [\"41531934\"],\n      \"is_preprint\": false,\n      \"attribution\": [{\"species\": \"Plasmodium berghei\", \"strain\": \"\"}]\n    }\n  ],\n  \"current_model\": \"P. falciparum alpha-tubulin I (PF3D7_0903700) is a component of the subpellicular and spindle microtubule cytoskeleton expressed throughout the intraerythrocytic cycle with peak levels in schizonts; its expression level directly determines microtubule number and thus sporozoite morphology, motility, and infectivity in Plasmodium berghei; it undergoes post-translational polyglutamylation (at spindle pole bodies and post-mitotic structures) and O-GlcNAcylation, but K40 acetylation is not essential; it interacts with PfAldolase (via a lysine-rich C-terminal peptide), P. falciparum Prefoldin subunits, and apicortin as a cytoskeletal substrate; it is exposed on the surface of ookinetes where it binds mosquito midgut FREP1 to facilitate midgut invasion; and antimitotic herbicides bind it at a site that remains structurally unresolved despite mutagenesis attempts to identify it.\"\n}\n```","stage2_raw":"{\n  \"mechanistic_narrative\": \"Alpha-tubulin I (PF3D7_0903700) is a core structural component of the Plasmodium microtubule cytoskeleton, encoded by a two-intron gene on chromosome 9 and expressed in a stage-specific manner distinct from alpha-tubulin II, with protein accumulation peaking in schizonts and segmenters and evidence of assembly into spindle-pole and post-mitotic microtubular structures [#0, #1, #4]. Its expression level is rate-limiting for cytoskeletal architecture: in P. berghei, deleting or replacing the orthologous alpha-tubulin gene showed that tubulin abundance directly sets the number of subpellicular microtubules in sporozoites, with fewer/shorter microtubules crippling sporozoite formation, motility, and infectivity (a threshold of ~10 microtubules for infectivity), while chromosome segregation in oocysts proceeded even without microtubules [#7]. The protein carries several post-translational modifications — a C-terminal tyrosine epitope and MTOC-localized polyglutamylation [#2, #4], and O-GlcNAcylation in late trophozoites [#6] — but K40 acetylation is not a feature of this protein: blood-stage alpha-tubulin I is unacetylated at K40, and in P. berghei a Q40K knock-in permitting acetylation had no phenotypic consequence, indicating this modification is dispensable [#2, #11]. Alpha-tubulin I engages multiple partners: a lysine-rich C-terminal peptide competitively inhibits P. falciparum aldolase, consistent with a cytoskeletal scaffold for glycolytic enzymes [#3]; it is bound by apicortin and by Prefoldin subunits as a chaperone substrate, both interactions being druggable growth-dependencies [#8, #10]; and it is displayed on the apical surface of live ookinetes where it binds the mosquito midgut protein FREP1 to orient midgut invasion, with anti-alpha-tubulin I antibodies reducing oocyst burden [#9]. It is also the target of antimitotic dinitroaniline and phosphorothioamidate herbicides, which bind at a site that has resisted structural definition by mutagenesis [#5].\",\n  \"teleology\": [\n    {\n      \"year\": 1989,\n      \"claim\": \"Establishing the gene's sequence and structure was the necessary first step to define alpha-tubulin I as a discrete tubulin gene rather than an undifferentiated tubulin activity.\",\n      \"evidence\": \"Genomic library screening and DNA sequencing of P. falciparum clones\",\n      \"pmids\": [\"2693901\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"No functional or expression data at this stage\", \"Protein product not directly characterized\"],\n      \"attribution\": [{\"species\": \"Plasmodium falciparum\", \"strain\": \"\"}]\n    },\n    {\n      \"year\": 1990,\n      \"claim\": \"Chromosomal mapping distinguished alpha-tubulin I from alpha-tubulin II and beta-tubulin and showed stage-specific expression, establishing it as an independently regulated gene.\",\n      \"evidence\": \"Pulsed-field gel electrophoresis, chromosomal mapping and Northern blotting\",\n      \"pmids\": [\"2090947\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Functional distinction between alpha-tubulin I and II not tested\", \"Regulatory basis of stage specificity unknown\"],\n      \"attribution\": [{\"species\": \"Plasmodium falciparum\", \"strain\": \"\"}]\n    },\n    {\n      \"year\": 1993,\n      \"claim\": \"Defining the PTM status resolved which conserved tubulin modifications apply to this parasite protein, showing K40 is not acetylated in blood stages while the C-terminal tyrosine epitope is retained.\",\n      \"evidence\": \"PTM-specific antibody immunofluorescence and in vitro acetylation assay\",\n      \"pmids\": [\"8488059\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Functional consequence of missing K40 acetylation not tested\", \"Antibody-based, no site-resolved mass spectrometry\"],\n      \"attribution\": [{\"species\": \"Plasmodium falciparum\", \"strain\": \"\"}]\n    },\n    {\n      \"year\": 1993,\n      \"claim\": \"A lysine-rich alpha-tubulin peptide inhibiting aldolase implicated the cytoskeleton as an organizing matrix for glycolytic enzymes, extending tubulin's role beyond structure.\",\n      \"evidence\": \"In vitro enzyme inhibition with synthetic peptide plus site-directed mutagenesis of aldolase\",\n      \"pmids\": [\"8459825\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Only a peptide fragment, not full-length alpha-tubulin I, was tested\", \"In vivo relevance of the interaction not demonstrated\"],\n      \"attribution\": [{\"species\": \"Plasmodium falciparum\", \"strain\": \"\"}]\n    },\n    {\n      \"year\": 2007,\n      \"claim\": \"Mapping protein abundance across stages and detecting polyglutamylation at MTOCs linked alpha-tubulin I to spindle-pole/merozoite biogenesis and pinpointed its peak in schizonts.\",\n      \"evidence\": \"Isotype- and glutamylation-specific antibody Western blotting and immunofluorescence with stage fractionation\",\n      \"pmids\": [\"17977543\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Enzymes mediating polyglutamylation not identified\", \"Functional requirement of the modification not tested\"],\n      \"attribution\": [{\"species\": \"Plasmodium falciparum\", \"strain\": \"\"}]\n    },\n    {\n      \"year\": 2013,\n      \"claim\": \"Confirming direct herbicide binding to recombinant alpha-tubulin I identified it as the antimitotic drug target, but mutagenesis failed to localize the binding site.\",\n      \"evidence\": \"Recombinant expression, site-directed mutagenesis, fluorescence-quenching binding assay and liver-stage inhibition\",\n      \"pmids\": [\"23523992\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Structural location of the herbicide site remains unresolved\", \"Six designed mutations did not alter binding, so the true contact residues are unknown\"],\n      \"attribution\": [{\"species\": \"Plasmodium falciparum\", \"strain\": \"\"}]\n    },\n    {\n      \"year\": 2017,\n      \"claim\": \"Detecting O-GlcNAcylation added another PTM to the alpha-tubulin repertoire in late trophozoites, though assignment to isoform I versus II was not fully resolved.\",\n      \"evidence\": \"Click-chemistry enrichment with nano-LC MS/MS and antibody confirmation\",\n      \"pmids\": [\"29187233\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Cannot unambiguously assign to alpha-tubulin I versus II\", \"Functional role of O-GlcNAcylation not tested\"],\n      \"attribution\": [{\"species\": \"Plasmodium falciparum\", \"strain\": \"3D7\"}]\n    },\n    {\n      \"year\": 2019,\n      \"claim\": \"Genetic titration of tubulin in P. berghei established that alpha-tubulin expression level quantitatively sets microtubule number and thereby sporozoite morphology, motility, and infectivity, defining a mechanistic threshold.\",\n      \"evidence\": \"Gene deletion/replacement, quantitative EM, motility/infectivity assays and mathematical modelling in P. berghei\",\n      \"pmids\": [\"31368598\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Shown in P. berghei ortholog, not directly in PF3D7_0903700\", \"Mechanism coupling tubulin level to microtubule count not molecularly dissected\"],\n      \"attribution\": [{\"species\": \"Plasmodium berghei\", \"strain\": \"\"}]\n    },\n    {\n      \"year\": 2021,\n      \"claim\": \"Identifying apicortin as a binding partner and showing tamoxifen-mediated disruption impairs growth suggested this interaction supports blood-stage progression.\",\n      \"evidence\": \"In silico modelling, in vitro pulldown and tamoxifen growth-inhibition assay\",\n      \"pmids\": [\"33633135\"],\n      \"confidence\": \"Low\",\n      \"gaps\": [\"No reciprocal Co-IP or structural validation described\", \"Tamoxifen effect may not be specific to the alpha-tubulin I–apicortin interaction\"],\n      \"attribution\": [{\"species\": \"Plasmodium falciparum\", \"strain\": \"\"}]\n    },\n    {\n      \"year\": 2023,\n      \"claim\": \"Demonstrating surface accessibility on ookinetes and FREP1 binding revealed a moonlighting adhesion role for alpha-tubulin I in mosquito midgut invasion and defined it as a transmission-blocking target.\",\n      \"evidence\": \"Live-cell IFA, ELISA, pull-down with FREP1 and antibody-based membrane feeding assays\",\n      \"pmids\": [\"37009496\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Mechanism by which cytoskeletal tubulin reaches the ookinete surface unclear\", \"Structural basis of the FREP1 interaction not defined\"],\n      \"attribution\": [{\"species\": \"Plasmodium falciparum\", \"strain\": \"\"}]\n    },\n    {\n      \"year\": 2024,\n      \"claim\": \"Identifying Prefoldin subunits as interactors positioned alpha-tubulin I as a chaperone substrate and revealed Biperiden as a growth-inhibitory drug acting on this axis across resistant strains.\",\n      \"evidence\": \"Co-IP MS/MS, biophysical interaction analysis and growth/ring-survival assays\",\n      \"pmids\": [\"38925325\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Direct effect of Biperiden on the interaction versus off-target not fully separated\", \"Consequence of Prefoldin loss for tubulin folding in vivo not shown\"],\n      \"attribution\": [{\"species\": \"Plasmodium falciparum\", \"strain\": \"3D7\"}]\n    },\n    {\n      \"year\": 2025,\n      \"claim\": \"A Q40K knock-in in P. berghei testing whether restoring the acetylatable lysine matters showed K40 acetylation capacity is dispensable, confirming this modification is not required for microtubule function.\",\n      \"evidence\": \"Q40K site-directed mutagenesis and life-cycle phenotyping in P. berghei\",\n      \"pmids\": [\"41531934\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Shown in P. berghei ortholog, not directly in PF3D7_0903700\", \"Does not address whether other K40-linked functions exist\"],\n      \"attribution\": [{\"species\": \"Plasmodium berghei\", \"strain\": \"\"}]\n    },\n    {\n      \"year\": null,\n      \"claim\": \"The structural location of the antimitotic herbicide binding site and the molecular basis for how a cytoskeletal tubulin becomes surface-exposed to bind FREP1 remain unresolved.\",\n      \"evidence\": \"\",\n      \"pmids\": [],\n      \"confidence\": \"Low\",\n      \"gaps\": [\"No structure of alpha-tubulin I with bound herbicide\", \"No mechanism explaining ookinete surface display of tubulin\", \"Direct requirement of PF3D7_0903700 itself (versus P. berghei ortholog) for microtubule count not genetically shown in P. falciparum\"],\n      \"attribution\": []\n    }\n  ],\n  \"mechanism_profile\": {\n    \"molecular_activity\": [\n      {\"term_id\": \"GO:0005200\", \"supporting_discovery_ids\": [4, 7]},\n      {\"term_id\": \"GO:0005525\", \"supporting_discovery_ids\": [0]},\n      {\"term_id\": \"GO:0005515\", \"supporting_discovery_ids\": [3, 8, 9, 10]}\n    ],\n    \"localization\": [\n      {\"term_id\": \"GO:0005874\", \"supporting_discovery_ids\": [4, 7]},\n      {\"term_id\": \"GO:0005819\", \"supporting_discovery_ids\": [4]},\n      {\"term_id\": \"GO:0005815\", \"supporting_discovery_ids\": [4]},\n      {\"term_id\": \"GO:0009986\", \"supporting_discovery_ids\": [9]}\n    ],\n    \"pathway\": [\n      {\"term_id\": \"GO:0007017\", \"supporting_discovery_ids\": [7]},\n      {\"term_id\": \"GO:0000226\", \"supporting_discovery_ids\": [7, 4]}\n    ],\n    \"complexes\": [\n      \"Prefoldin complex (as substrate, PFD1-6) [#10]\"\n    ],\n    \"partners\": [\n      \"PfAldolase (via lysine-rich C-terminal peptide) [#3]\",\n      \"Apicortin [#8]\",\n      \"Prefoldin subunits PFD1-6 [#10]\",\n      \"Mosquito midgut FREP1 [#9]\"\n    ],\n    \"other_free_text\": [\n      \"Encoded by a two-intron gene on chromosome 9; 453 aa, ~50.3 kDa; distinct from alpha-tubulin II (chromosome 4) [#0, #1]\",\n      \"Post-translationally polyglutamylated at MTOCs/post-mitotic structures and O-GlcNAcylated in late trophozoites; retains C-terminal tyrosine epitope [#2, #4, #6]\",\n      \"K40 is not acetylated in blood stages and Q40K restoration is dispensable in P. berghei [#2, #11]\",\n      \"Direct target of dinitroaniline and phosphorothioamidate antimitotic herbicides at a structurally unresolved site [#5]\",\n      \"In P. berghei, alpha-tubulin expression level sets subpellicular microtubule number governing sporozoite motility and infectivity [#7]\",\n      \"Interactions with apicortin, Prefoldin and FREP1 are druggable (tamoxifen, Biperiden, transmission-blocking antibodies) [#8, #9, #10]\"\n    ]\n  }\n}","audit_flag":null,"strains":[{"strain":"Pf3D7","gene_id":"PF3D7_0903700","name":null,"product":"alpha tubulin 1","uniprot_acc":null,"chromosome":null,"start_pos":null},{"strain":"PbANKA","gene_id":"PBANKA_0417700","name":null,"product":"alpha tubulin 1","uniprot_acc":null,"chromosome":null,"start_pos":null},{"strain":"PkH","gene_id":"PKNH_0701400","name":null,"product":"alpha tubulin, putative","uniprot_acc":null,"chromosome":null,"start_pos":null}],"gene_symbol":"","evaluation":null}