{"gene":"PF3D7_1313000","run_date":"2026-09-08T14:19:06","timeline":{"discoveries":[{"year":2020,"finding":"PF3D7_1313000 (PfNEDD8) is a 76 amino acid protein lacking a C-terminal tail, indicating it can be directly conjugated without prior processing. Conjugation proceeds through Gly76, as shown by the absence of high-molecular-weight conjugates in parasites expressing the Gly75Ala/Gly76Ala double mutant. Immunoprecipitation followed by mass spectrometry identified two putative P. falciparum cullins as physiological substrates. Expression of PfNEDD8 in NEDD8-deficient (rub1Δ) and E2-deficient (ubc12Δ) yeast also retrieved S. cerevisiae cullin Cdc53, further substantiating cullins as physiological substrates.","method":"Wild-type and mutant (Gly75Ala/Gly76Ala) PfNEDD8 expressed in P. falciparum; Western blot for conjugates; immunoprecipitation + mass spectrometry; complementation in S. cerevisiae rub1Δ and ubc12Δ strains","journal":"Scientific reports","confidence":"High","confidence_rationale":"Tier 1–2 / Moderate — active-site mutagenesis (Gly76Ala abolishes conjugation), in-parasite biochemistry, MS substrate identification, and cross-species complementation in a single study","pmids":["33214620"],"is_preprint":false,"attribution":[{"species":"Plasmodium falciparum","strain":""}]},{"year":2009,"finding":"PfNEDD8 is a substrate of PfUCHL3: crystal structures of PfUCHL3 alone and in complex with a ubiquitin-based suicide substrate (UbVME), combined with molecular dynamics simulations of a PfUCHL3–PfNedd8 model, identified key shared interactions that explain the enzyme's dual specificity for ubiquitin and PfNEDD8. The active-site crossover loop of PfUCHL3 is relatively rigid and restricts the size of adduct substrates.","method":"Crystal structure determination of PfUCHL3 and PfUCHL3–UbVME complex; molecular dynamics simulation of PfUCHL3–PfNEDD8 model; biochemical activity assays","journal":"The Journal of biological chemistry","confidence":"High","confidence_rationale":"Tier 1 / Moderate — crystal structure with functional validation, MD simulations, and in vitro activity assays in a single study","pmids":["20042598"],"is_preprint":false,"attribution":[{"species":"Plasmodium falciparum","strain":""}]},{"year":2006,"finding":"PfNEDD8 is a substrate of PfUCHL54 (PfUCH54): PfUCHL54 was identified as a deNeddylating enzyme in P. falciparum using a mammalian Nedd8-based activity probe, demonstrating that PfNEDD8 can be cleaved by this deubiquitinating/deNeddylating enzyme — an activity absent from the mammalian homologue.","method":"Activity-based chemical probe (Nedd8-based probe) labelling and functional proteomic identification","journal":"Molecular microbiology","confidence":"Medium","confidence_rationale":"Tier 2 / Weak — activity-based probe provides direct enzymatic evidence, but single lab, single method","pmids":["16925553"],"is_preprint":false,"attribution":[{"species":"Plasmodium falciparum","strain":""}]},{"year":2007,"finding":"PfNEDD8 is a substrate of both P. falciparum and T. gondii UCHL3 orthologs: both enzymes possess deNeddylating activity demonstrated with activity-based chemical probes, and phylogenetic analysis suggests dual ubiquitin/Nedd8 specificity was present in the ancestral eukaryotic UCHL3.","method":"Activity-based chemical probe labelling; biochemical deNeddylating activity assays; phylogenetic analysis; crystal structure of T. gondii UCHL3","journal":"Cellular microbiology","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — activity-based probe plus structural characterization, but Plasmodium-specific findings are less detailed than T. gondii findings","pmids":["17371404"],"is_preprint":false,"attribution":[{"species":"Plasmodium falciparum","strain":""}]},{"year":2019,"finding":"Deconjugation of PfNEDD8 in P. falciparum is controlled by a distinct set of enzymes compared to the human host. PfUCH37 possesses dual ubiquitin/Nedd8 hydrolase activity, but only its ubiquitin activity is essential for parasite survival (not its deNeddylating activity), as determined by parasite transgenics and drug assays. This highlights PfNEDD8 pathway regulation as differing from higher eukaryotes.","method":"Functional chemical approach (activity-based probes); parasite transgenics; drug assays; molecular characterization of active-site determinants","journal":"PLoS pathogens","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — multiple orthogonal methods (chemical probes, transgenics, drug assays) in a single lab study establishing pathway position of PfNEDD8 deconjugation","pmids":["31658303"],"is_preprint":false,"attribution":[{"species":"Plasmodium falciparum","strain":""}]},{"year":2024,"finding":"Disruption of Nedd8 (NEDD8 knockout) in P. berghei does not affect blood-stage propagation, gametocyte development, gamete formation, or zygote formation, but abolishes ookinete formation and mosquito transmission. Complementation by reintroduction of the Nedd8 gene restores mosquito transmission to wild-type levels, establishing that PbNEDD8 is essential specifically for the zygote-to-ookinete transition.","method":"Genetic knockout of Nedd8 in P. berghei; phenotypic analysis of blood-stage and mosquito-stage development; genetic complementation","journal":"mBio","confidence":"High","confidence_rationale":"Tier 2 / Strong — clean knockout with stage-specific phenotypic readout and full genetic complementation restoring function","pmids":["38411954"],"is_preprint":false,"attribution":[{"species":"Plasmodium berghei","strain":""}]}],"current_model":"PF3D7_1313000 (PfNEDD8) is a 76-amino-acid ubiquitin-like modifier that is conjugated through its C-terminal Gly76 to target proteins — primarily cullins — to regulate cullin-RING ubiquitin ligase activity; it is deconjugated by parasite UCH-family hydrolases (PfUCHL3, PfUCHL54) that exhibit dual ubiquitin/Nedd8 specificity, and in P. berghei the neddylation pathway is dispensable for blood-stage growth but essential for the zygote-to-ookinete transition and mosquito transmission."},"narrative":{"mechanistic_narrative":"PF3D7_1313000 (PfNEDD8) is a 76-amino-acid ubiquitin-like modifier that functions in a protein neddylation pathway, becoming covalently conjugated to target proteins to regulate their activity [PMID:33214620]. It lacks a C-terminal tail and is conjugated directly through Gly76, since a Gly75Ala/Gly76Ala double mutant abolishes formation of high-molecular-weight conjugates; immunoprecipitation-mass spectrometry and cross-species complementation in yeast identify parasite cullins as its physiological substrates [PMID:33214620]. Deconjugation of PfNEDD8 is carried out by parasite UCH-family hydrolases with dual ubiquitin/NEDD8 specificity, including PfUCHL3, PfUCHL54, and PfUCH37, and this deNeddylation machinery is configured differently from the human host [PMID:20042598, PMID:16925553, PMID:31658303]. Genetically, the pathway is dispensable for blood-stage growth in P. berghei but is essential for the zygote-to-ookinete transition and mosquito transmission [PMID:38411954].","teleology":[{"year":2006,"claim":"The first question was whether P. falciparum encodes enzymes capable of removing PfNEDD8 from targets, which was answered by identifying a parasite deNeddylase.","evidence":"Nedd8-based activity-based chemical probe labelling and functional proteomic identification of PfUCHL54 in P. falciparum","pmids":["16925553"],"confidence":"Medium","gaps":["Does not identify neddylated substrates of PfNEDD8","Single method/single lab without genetic validation of essentiality"],"attribution":[{"species":"Plasmodium falciparum","strain":""}]},{"year":2007,"claim":"To understand the origin of dual specificity, the deNeddylating activity of UCHL3 orthologs was tested, establishing that PfNEDD8 can be processed by an enzyme also active on ubiquitin.","evidence":"Activity-based chemical probes and phylogenetic analysis of P. falciparum and T. gondii UCHL3, with T. gondii UCHL3 crystal structure","pmids":["17371404"],"confidence":"Medium","gaps":["Plasmodium-specific structural detail less resolved than T. gondii","Does not address conjugation machinery or in-parasite substrates"],"attribution":[{"species":"Plasmodium falciparum","strain":""}]},{"year":2009,"claim":"The structural basis for how a single parasite hydrolase recognizes PfNEDD8 was resolved, explaining dual ubiquitin/NEDD8 specificity at the atomic level.","evidence":"Crystal structures of PfUCHL3 and a PfUCHL3–UbVME suicide-substrate complex plus molecular dynamics simulation of a PfUCHL3–PfNEDD8 model","pmids":["20042598"],"confidence":"High","gaps":["PfNEDD8 binding modeled rather than crystallized directly","Biological importance of deNeddylation not yet tested genetically"],"attribution":[{"species":"Plasmodium falciparum","strain":""}]},{"year":2019,"claim":"Whether PfNEDD8 deconjugation activity of a dual-specificity hydrolase is essential was tested, showing that deNeddylation and deubiquitination roles can be functionally separated in the parasite.","evidence":"Activity-based probes, parasite transgenics, and drug assays characterizing PfUCH37 active-site determinants in P. falciparum","pmids":["31658303"],"confidence":"Medium","gaps":["Essentiality attributed to ubiquitin, not NEDD8, activity","Direct substrates deconjugated in vivo not enumerated"],"attribution":[{"species":"Plasmodium falciparum","strain":""}]},{"year":2020,"claim":"The core conjugation chemistry and physiological substrates of PfNEDD8 were defined, establishing it as a bona fide cullin-modifying neddylation system.","evidence":"Gly75Ala/Gly76Ala mutagenesis in P. falciparum, IP-mass spectrometry, and complementation in S. cerevisiae rub1Δ and ubc12Δ strains retrieving cullins","pmids":["33214620"],"confidence":"High","gaps":["E1/E2 activating and conjugating enzymes for PfNEDD8 not characterized","Functional consequence of cullin neddylation on CRL activity not measured"],"attribution":[{"species":"Plasmodium falciparum","strain":""}]},{"year":2024,"claim":"The in vivo requirement for the pathway across the life cycle was defined, revealing a stage-specific essential role rather than a general growth requirement.","evidence":"Genetic knockout, life-cycle phenotyping, and genetic complementation of Nedd8 in P. berghei","pmids":["38411954"],"confidence":"High","gaps":["Molecular targets driving the ookinete transition defect unidentified","Shown in P. berghei; falciparum transmission requirement not directly tested"],"attribution":[{"species":"Plasmodium berghei","strain":""}]},{"year":null,"claim":"The identity of the PfNEDD8 activating/conjugating enzymes and the specific cullin-RING ligase substrates whose regulation underlies the essential zygote-to-ookinete transition remain unknown.","evidence":"","pmids":[],"confidence":"Medium","gaps":["No E1/E2 conjugation machinery characterized for PfNEDD8","Link between cullin neddylation and the mosquito-stage phenotype unresolved"],"attribution":[{"species":"Plasmodium falciparum","strain":""}]}],"mechanism_profile":{"molecular_activity":[],"localization":[],"pathway":[],"complexes":[],"partners":["PLASMODIUM FALCIPARUM CULLINS (NEDDYLATION SUBSTRATES)","PFUCHL3 (DUAL UBIQUITIN/NEDD8 HYDROLASE)","PFUCHL54/PFUCH54 (DENEDDYLASE)","PFUCH37 (DUAL UBIQUITIN/NEDD8 HYDROLASE)"],"other_free_text":["76-amino-acid ubiquitin-like modifier lacking a C-terminal tail; conjugated directly via Gly76 [#0]","Gly75Ala/Gly76Ala mutation abolishes conjugate formation [#0]","Deconjugation machinery differs from the human host, with distinct dual-specificity UCH hydrolases [#4]","In P. berghei, dispensable for blood-stage growth, gametocyte/gamete/zygote formation but essential for ookinete formation and mosquito transmission [#5]"]}},"prefetch_data":{},"corpus_meta":[{"pmid":"17371404","id":"PMC_17371404","title":"Apicomplexan UCHL3 retains dual specificity for ubiquitin and Nedd8 throughout evolution.","date":"2007","source":"Cellular microbiology","url":"https://pubmed.ncbi.nlm.nih.gov/17371404","citation_count":78,"is_preprint":false,"source_species":["Pf"],"role":"primary","match_terms":["NEDD8","Nedd8"],"competing_organism_flag":false,"competing_organism_match":"","competing_organism_only":false},{"pmid":"16925553","id":"PMC_16925553","title":"Identification by functional proteomics of a deubiquitinating/deNeddylating enzyme in Plasmodium falciparum.","date":"2006","source":"Molecular microbiology","url":"https://pubmed.ncbi.nlm.nih.gov/16925553","citation_count":65,"is_preprint":false,"source_species":["Pf"],"role":"primary","match_terms":["NEDD8","Nedd8"],"competing_organism_flag":false,"competing_organism_match":"","competing_organism_only":false},{"pmid":"20042598","id":"PMC_20042598","title":"Characterization and structural studies of the Plasmodium falciparum ubiquitin and Nedd8 hydrolase UCHL3.","date":"2009","source":"The Journal of biological chemistry","url":"https://pubmed.ncbi.nlm.nih.gov/20042598","citation_count":53,"is_preprint":false,"source_species":["Pf"],"role":"primary","match_terms":["NEDD8","Nedd8","PfNedd8","PfNEDD8"],"competing_organism_flag":false,"competing_organism_match":"","competing_organism_only":false},{"pmid":"31658303","id":"PMC_31658303","title":"Nedd8 hydrolysis by UCH proteases in Plasmodium parasites.","date":"2019","source":"PLoS pathogens","url":"https://pubmed.ncbi.nlm.nih.gov/31658303","citation_count":23,"is_preprint":false,"source_species":["Pf"],"role":"primary","match_terms":["NEDD8","Nedd8"],"competing_organism_flag":false,"competing_organism_match":"","competing_organism_only":false},{"pmid":"33214620","id":"PMC_33214620","title":"Characterization of Plasmodium falciparum NEDD8 and identification of cullins as its substrates.","date":"2020","source":"Scientific reports","url":"https://pubmed.ncbi.nlm.nih.gov/33214620","citation_count":11,"is_preprint":false,"source_species":["Pf"],"role":"primary","match_terms":["NEDD8","Nedd8","PfNedd8","PfNEDD8"],"competing_organism_flag":false,"competing_organism_match":"","competing_organism_only":false},{"pmid":"38411954","id":"PMC_38411954","title":"Neddylation is essential for malaria transmission in Plasmodium berghei.","date":"2024","source":"mBio","url":"https://pubmed.ncbi.nlm.nih.gov/38411954","citation_count":9,"is_preprint":false,"source_species":["Pf"],"role":"primary","match_terms":["NEDD8","ubiquitin-like protein Nedd8","Nedd8"],"competing_organism_flag":false,"competing_organism_match":"","competing_organism_only":false},{"pmid":"38885136","id":"PMC_38885136","title":"The Role of Neddylation in Malaria Parasites.","date":"2024","source":"DNA and cell biology","url":"https://pubmed.ncbi.nlm.nih.gov/38885136","citation_count":2,"is_preprint":false,"source_species":["Pf"],"role":"primary","match_terms":["NEDD8","Nedd8"],"competing_organism_flag":false,"competing_organism_match":"","competing_organism_only":false}],"cost":{"stage1":{"model":"claude-sonnet-4-6","input_tokens":5837,"output_tokens":2012,"usd":0.023845,"stage1_stop_reason":"end_turn"},"stage2":{"model":"claude-opus-4-8","input_tokens":7194,"output_tokens":2779,"usd":0.052722,"stage2_stop_reason":"end_turn"},"total_usd":0.076567,"stage1_batch_id":"msgbatch_011BPjN2BL33F8cJXD1r7V7T","stage2_batch_id":"msgbatch_01Qwg6vP7qxkpL6Gsc7tajsb","note":"batch pricing = 50% of standard"},"stage1_raw":"```json\n{\n  \"discoveries\": [\n    {\n      \"year\": 2020,\n      \"finding\": \"PF3D7_1313000 (PfNEDD8) is a 76 amino acid protein lacking a C-terminal tail, indicating it can be directly conjugated without prior processing. Conjugation proceeds through Gly76, as shown by the absence of high-molecular-weight conjugates in parasites expressing the Gly75Ala/Gly76Ala double mutant. Immunoprecipitation followed by mass spectrometry identified two putative P. falciparum cullins as physiological substrates. Expression of PfNEDD8 in NEDD8-deficient (rub1Δ) and E2-deficient (ubc12Δ) yeast also retrieved S. cerevisiae cullin Cdc53, further substantiating cullins as physiological substrates.\",\n      \"method\": \"Wild-type and mutant (Gly75Ala/Gly76Ala) PfNEDD8 expressed in P. falciparum; Western blot for conjugates; immunoprecipitation + mass spectrometry; complementation in S. cerevisiae rub1Δ and ubc12Δ strains\",\n      \"journal\": \"Scientific reports\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1–2 / Moderate — active-site mutagenesis (Gly76Ala abolishes conjugation), in-parasite biochemistry, MS substrate identification, and cross-species complementation in a single study\",\n      \"pmids\": [\"33214620\"],\n      \"is_preprint\": false,\n      \"attribution\": [{\"species\": \"Plasmodium falciparum\", \"strain\": \"\"}]\n    },\n    {\n      \"year\": 2009,\n      \"finding\": \"PfNEDD8 is a substrate of PfUCHL3: crystal structures of PfUCHL3 alone and in complex with a ubiquitin-based suicide substrate (UbVME), combined with molecular dynamics simulations of a PfUCHL3–PfNedd8 model, identified key shared interactions that explain the enzyme's dual specificity for ubiquitin and PfNEDD8. The active-site crossover loop of PfUCHL3 is relatively rigid and restricts the size of adduct substrates.\",\n      \"method\": \"Crystal structure determination of PfUCHL3 and PfUCHL3–UbVME complex; molecular dynamics simulation of PfUCHL3–PfNEDD8 model; biochemical activity assays\",\n      \"journal\": \"The Journal of biological chemistry\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 / Moderate — crystal structure with functional validation, MD simulations, and in vitro activity assays in a single study\",\n      \"pmids\": [\"20042598\"],\n      \"is_preprint\": false,\n      \"attribution\": [{\"species\": \"Plasmodium falciparum\", \"strain\": \"\"}]\n    },\n    {\n      \"year\": 2006,\n      \"finding\": \"PfNEDD8 is a substrate of PfUCHL54 (PfUCH54): PfUCHL54 was identified as a deNeddylating enzyme in P. falciparum using a mammalian Nedd8-based activity probe, demonstrating that PfNEDD8 can be cleaved by this deubiquitinating/deNeddylating enzyme — an activity absent from the mammalian homologue.\",\n      \"method\": \"Activity-based chemical probe (Nedd8-based probe) labelling and functional proteomic identification\",\n      \"journal\": \"Molecular microbiology\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Weak — activity-based probe provides direct enzymatic evidence, but single lab, single method\",\n      \"pmids\": [\"16925553\"],\n      \"is_preprint\": false,\n      \"attribution\": [{\"species\": \"Plasmodium falciparum\", \"strain\": \"\"}]\n    },\n    {\n      \"year\": 2007,\n      \"finding\": \"PfNEDD8 is a substrate of both P. falciparum and T. gondii UCHL3 orthologs: both enzymes possess deNeddylating activity demonstrated with activity-based chemical probes, and phylogenetic analysis suggests dual ubiquitin/Nedd8 specificity was present in the ancestral eukaryotic UCHL3.\",\n      \"method\": \"Activity-based chemical probe labelling; biochemical deNeddylating activity assays; phylogenetic analysis; crystal structure of T. gondii UCHL3\",\n      \"journal\": \"Cellular microbiology\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — activity-based probe plus structural characterization, but Plasmodium-specific findings are less detailed than T. gondii findings\",\n      \"pmids\": [\"17371404\"],\n      \"is_preprint\": false,\n      \"attribution\": [{\"species\": \"Plasmodium falciparum\", \"strain\": \"\"}]\n    },\n    {\n      \"year\": 2019,\n      \"finding\": \"Deconjugation of PfNEDD8 in P. falciparum is controlled by a distinct set of enzymes compared to the human host. PfUCH37 possesses dual ubiquitin/Nedd8 hydrolase activity, but only its ubiquitin activity is essential for parasite survival (not its deNeddylating activity), as determined by parasite transgenics and drug assays. This highlights PfNEDD8 pathway regulation as differing from higher eukaryotes.\",\n      \"method\": \"Functional chemical approach (activity-based probes); parasite transgenics; drug assays; molecular characterization of active-site determinants\",\n      \"journal\": \"PLoS pathogens\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — multiple orthogonal methods (chemical probes, transgenics, drug assays) in a single lab study establishing pathway position of PfNEDD8 deconjugation\",\n      \"pmids\": [\"31658303\"],\n      \"is_preprint\": false,\n      \"attribution\": [{\"species\": \"Plasmodium falciparum\", \"strain\": \"\"}]\n    },\n    {\n      \"year\": 2024,\n      \"finding\": \"Disruption of Nedd8 (NEDD8 knockout) in P. berghei does not affect blood-stage propagation, gametocyte development, gamete formation, or zygote formation, but abolishes ookinete formation and mosquito transmission. Complementation by reintroduction of the Nedd8 gene restores mosquito transmission to wild-type levels, establishing that PbNEDD8 is essential specifically for the zygote-to-ookinete transition.\",\n      \"method\": \"Genetic knockout of Nedd8 in P. berghei; phenotypic analysis of blood-stage and mosquito-stage development; genetic complementation\",\n      \"journal\": \"mBio\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — clean knockout with stage-specific phenotypic readout and full genetic complementation restoring function\",\n      \"pmids\": [\"38411954\"],\n      \"is_preprint\": false,\n      \"attribution\": [{\"species\": \"Plasmodium berghei\", \"strain\": \"\"}]\n    }\n  ],\n  \"current_model\": \"PF3D7_1313000 (PfNEDD8) is a 76-amino-acid ubiquitin-like modifier that is conjugated through its C-terminal Gly76 to target proteins — primarily cullins — to regulate cullin-RING ubiquitin ligase activity; it is deconjugated by parasite UCH-family hydrolases (PfUCHL3, PfUCHL54) that exhibit dual ubiquitin/Nedd8 specificity, and in P. berghei the neddylation pathway is dispensable for blood-stage growth but essential for the zygote-to-ookinete transition and mosquito transmission.\"\n}\n```","stage2_raw":"{\n  \"mechanistic_narrative\": \"PF3D7_1313000 (PfNEDD8) is a 76-amino-acid ubiquitin-like modifier that functions in a protein neddylation pathway, becoming covalently conjugated to target proteins to regulate their activity [#0]. It lacks a C-terminal tail and is conjugated directly through Gly76, since a Gly75Ala/Gly76Ala double mutant abolishes formation of high-molecular-weight conjugates; immunoprecipitation-mass spectrometry and cross-species complementation in yeast identify parasite cullins as its physiological substrates [#0]. Deconjugation of PfNEDD8 is carried out by parasite UCH-family hydrolases with dual ubiquitin/NEDD8 specificity, including PfUCHL3, PfUCHL54, and PfUCH37, and this deNeddylation machinery is configured differently from the human host [#1, #2, #4]. Genetically, the pathway is dispensable for blood-stage growth in P. berghei but is essential for the zygote-to-ookinete transition and mosquito transmission [#5].\",\n  \"teleology\": [\n    {\n      \"year\": 2006,\n      \"claim\": \"The first question was whether P. falciparum encodes enzymes capable of removing PfNEDD8 from targets, which was answered by identifying a parasite deNeddylase.\",\n      \"evidence\": \"Nedd8-based activity-based chemical probe labelling and functional proteomic identification of PfUCHL54 in P. falciparum\",\n      \"pmids\": [\"16925553\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Does not identify neddylated substrates of PfNEDD8\", \"Single method/single lab without genetic validation of essentiality\"],\n      \"attribution\": [{\"species\": \"Plasmodium falciparum\", \"strain\": \"\"}]\n    },\n    {\n      \"year\": 2007,\n      \"claim\": \"To understand the origin of dual specificity, the deNeddylating activity of UCHL3 orthologs was tested, establishing that PfNEDD8 can be processed by an enzyme also active on ubiquitin.\",\n      \"evidence\": \"Activity-based chemical probes and phylogenetic analysis of P. falciparum and T. gondii UCHL3, with T. gondii UCHL3 crystal structure\",\n      \"pmids\": [\"17371404\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Plasmodium-specific structural detail less resolved than T. gondii\", \"Does not address conjugation machinery or in-parasite substrates\"],\n      \"attribution\": [{\"species\": \"Plasmodium falciparum\", \"strain\": \"\"}]\n    },\n    {\n      \"year\": 2009,\n      \"claim\": \"The structural basis for how a single parasite hydrolase recognizes PfNEDD8 was resolved, explaining dual ubiquitin/NEDD8 specificity at the atomic level.\",\n      \"evidence\": \"Crystal structures of PfUCHL3 and a PfUCHL3\\u2013UbVME suicide-substrate complex plus molecular dynamics simulation of a PfUCHL3\\u2013PfNEDD8 model\",\n      \"pmids\": [\"20042598\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"PfNEDD8 binding modeled rather than crystallized directly\", \"Biological importance of deNeddylation not yet tested genetically\"],\n      \"attribution\": [{\"species\": \"Plasmodium falciparum\", \"strain\": \"\"}]\n    },\n    {\n      \"year\": 2019,\n      \"claim\": \"Whether PfNEDD8 deconjugation activity of a dual-specificity hydrolase is essential was tested, showing that deNeddylation and deubiquitination roles can be functionally separated in the parasite.\",\n      \"evidence\": \"Activity-based probes, parasite transgenics, and drug assays characterizing PfUCH37 active-site determinants in P. falciparum\",\n      \"pmids\": [\"31658303\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Essentiality attributed to ubiquitin, not NEDD8, activity\", \"Direct substrates deconjugated in vivo not enumerated\"],\n      \"attribution\": [{\"species\": \"Plasmodium falciparum\", \"strain\": \"\"}]\n    },\n    {\n      \"year\": 2020,\n      \"claim\": \"The core conjugation chemistry and physiological substrates of PfNEDD8 were defined, establishing it as a bona fide cullin-modifying neddylation system.\",\n      \"evidence\": \"Gly75Ala/Gly76Ala mutagenesis in P. falciparum, IP-mass spectrometry, and complementation in S. cerevisiae rub1\\u0394 and ubc12\\u0394 strains retrieving cullins\",\n      \"pmids\": [\"33214620\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"E1/E2 activating and conjugating enzymes for PfNEDD8 not characterized\", \"Functional consequence of cullin neddylation on CRL activity not measured\"],\n      \"attribution\": [{\"species\": \"Plasmodium falciparum\", \"strain\": \"\"}]\n    },\n    {\n      \"year\": 2024,\n      \"claim\": \"The in vivo requirement for the pathway across the life cycle was defined, revealing a stage-specific essential role rather than a general growth requirement.\",\n      \"evidence\": \"Genetic knockout, life-cycle phenotyping, and genetic complementation of Nedd8 in P. berghei\",\n      \"pmids\": [\"38411954\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Molecular targets driving the ookinete transition defect unidentified\", \"Shown in P. berghei; falciparum transmission requirement not directly tested\"],\n      \"attribution\": [{\"species\": \"Plasmodium berghei\", \"strain\": \"\"}]\n    },\n    {\n      \"year\": null,\n      \"claim\": \"The identity of the PfNEDD8 activating/conjugating enzymes and the specific cullin-RING ligase substrates whose regulation underlies the essential zygote-to-ookinete transition remain unknown.\",\n      \"evidence\": \"\",\n      \"pmids\": [],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"No E1/E2 conjugation machinery characterized for PfNEDD8\", \"Link between cullin neddylation and the mosquito-stage phenotype unresolved\"],\n      \"attribution\": [{\"species\": \"Plasmodium falciparum\", \"strain\": \"\"}]\n    }\n  ],\n  \"mechanism_profile\": {\n    \"molecular_activity\": [\n      {\"term_id\": \"GO:0031386\", \"supporting_discovery_ids\": [0]},\n      {\"term_id\": \"GO:0019948\", \"supporting_discovery_ids\": [0]},\n      {\"term_id\": \"GO:0097602\", \"supporting_discovery_ids\": [0]}\n    ],\n    \"localization\": [],\n    \"pathway\": [\n      {\"term_id\": \"GO:0045116\", \"supporting_discovery_ids\": [0]},\n      {\"term_id\": \"GO:0031466\", \"supporting_discovery_ids\": [0]},\n      {\"term_id\": \"GO:0000338\", \"supporting_discovery_ids\": [1, 2, 3, 4]}\n    ],\n    \"complexes\": [],\n    \"partners\": [\n      \"Plasmodium falciparum cullins (neddylation substrates)\",\n      \"PfUCHL3 (dual ubiquitin/NEDD8 hydrolase)\",\n      \"PfUCHL54/PfUCH54 (deNeddylase)\",\n      \"PfUCH37 (dual ubiquitin/NEDD8 hydrolase)\"\n    ],\n    \"other_free_text\": [\n      \"76-amino-acid ubiquitin-like modifier lacking a C-terminal tail; conjugated directly via Gly76 [#0]\",\n      \"Gly75Ala/Gly76Ala mutation abolishes conjugate formation [#0]\",\n      \"Deconjugation machinery differs from the human host, with distinct dual-specificity UCH hydrolases [#4]\",\n      \"In P. berghei, dispensable for blood-stage growth, gametocyte/gamete/zygote formation but essential for ookinete formation and mosquito transmission [#5]\"\n    ]\n  }\n}","audit_flag":null,"strains":[{"strain":"Pf3D7","gene_id":"PF3D7_1313000","name":null,"product":"ubiquitin-like protein Nedd8","uniprot_acc":null,"chromosome":null,"start_pos":null},{"strain":"PbANKA","gene_id":"PBANKA_1411400","name":null,"product":"ubiquitin-like protein Nedd8, putative","uniprot_acc":null,"chromosome":null,"start_pos":null},{"strain":"PkH","gene_id":"PKNH_1413600","name":null,"product":"ubiquitin-like protein Nedd8, putative","uniprot_acc":null,"chromosome":null,"start_pos":null}],"gene_symbol":"NEDD8","evaluation":null}