{"gene":"PF3D7_1445400","run_date":"2026-09-08T14:19:07","timeline":{"discoveries":[{"year":2011,"finding":"CLK1 (PfCLK-1/Lammer) localizes primarily to the nucleus of P. falciparum parasites, as confirmed by indirect immunofluorescence, Western blot, and electron microscopy. It possesses two nuclear localization signal sites upstream of its C-terminal catalytic domain.","method":"Indirect immunofluorescence, Western blot, electron microscopy","journal":"Journal of cellular biochemistry","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — multiple orthogonal localization methods (IFA, Western, EM) in a single lab, with functional context","pmids":["21312235"],"is_preprint":false,"attribution":[{"species":"Plasmodium falciparum","strain":""}]},{"year":2011,"finding":"CLK1 (PfCLK-1) is essential for completion of the asexual blood-stage replication cycle of P. falciparum, as demonstrated by reverse genetics approaches.","method":"Reverse genetics (gene disruption/knockdown)","journal":"Journal of cellular biochemistry","confidence":"Medium","confidence_rationale":"Tier 2 / Weak — clean loss-of-function with defined cellular phenotype (failure to complete asexual cycle), single lab","pmids":["21312235"],"is_preprint":false,"attribution":[{"species":"Plasmodium falciparum","strain":""}]},{"year":2011,"finding":"CLK1 (PfCLK-1) phosphorylates the Sky1p substrate splicing factor Npl3p and the plasmodial alternative splicing factor PfASF-1 in vitro, indicating a role in post-transcriptional mRNA regulation.","method":"In vitro kinase assay","journal":"Journal of cellular biochemistry","confidence":"Medium","confidence_rationale":"Tier 1 / Weak — in vitro kinase assay with defined substrates, single lab, no mutagenesis of active site","pmids":["21312235"],"is_preprint":false,"attribution":[{"species":"Plasmodium falciparum","strain":""}]},{"year":2011,"finding":"CLK1 (PfCLK-1) co-immunoprecipitates with proteins predicted to have nuclease, phosphatase, or helicase functions, suggesting it assembles into nuclear complexes involved in gene regulation.","method":"Co-immunoprecipitation followed by mass spectrometry","journal":"Journal of cellular biochemistry","confidence":"Low","confidence_rationale":"Tier 3 / Weak — single co-IP/MS experiment, single lab, interacting partners only predicted functionally","pmids":["21312235"],"is_preprint":false,"attribution":[{"species":"Plasmodium falciparum","strain":""}]},{"year":2011,"finding":"CLK1 (PfCLK-1) is transcribed throughout the asexual blood stages and in gametocytes.","method":"Transcriptional analysis (RT-PCR/expression profiling)","journal":"Journal of cellular biochemistry","confidence":"Low","confidence_rationale":"Tier 4 / Weak — expression-level observation, single lab; included only because it directly informs stage-specific activity context","pmids":["21312235"],"is_preprint":false,"attribution":[{"species":"Plasmodium falciparum","strain":""}]},{"year":2001,"finding":"CLK1 (PfLAMMER) is encoded by a single-copy gene (3316 bp, 881 amino acids, ~106.7 kDa) whose N-terminal domain contains multiple consensus phosphorylation sites, RS/SR dipeptides, two putative nuclear localization signals, and 14 DKYD tetramer repeats, while the C-terminal domain is a LAMMER-family kinase domain most homologous to Arabidopsis AFC3.","method":"Vectorette PCR cloning, genomic restriction analysis, sequence analysis","journal":"International journal for parasitology","confidence":"Low","confidence_rationale":"Tier 4 / Weak — primary structure characterization by cloning and bioinformatics; no direct functional assay","pmids":["11306117"],"is_preprint":false,"attribution":[{"species":"Plasmodium falciparum","strain":""}]},{"year":2001,"finding":"CLK1 (PfLAMMER) mRNA (~3800 nt) is expressed specifically in the sexual stage (gametocytes), suggesting a role in regulating sexual differentiation.","method":"Northern blot / transcript detection","journal":"International journal for parasitology","confidence":"Low","confidence_rationale":"Tier 3 / Weak — single lab, single method (transcript detection); no functional experiment performed","pmids":["11306117"],"is_preprint":false,"attribution":[{"species":"Plasmodium falciparum","strain":""}]},{"year":2016,"finding":"CLK1 (PfCLK1) kinase activity is potently inhibited in vitro by 3,6-disubstituted imidazo[1,2-b]pyridazine compound 20a with an IC50 of 32 nM, establishing it as a biochemically tractable kinase target.","method":"In vitro kinase inhibition assay (IC50 determination)","journal":"European journal of medicinal chemistry","confidence":"Medium","confidence_rationale":"Tier 1 / Weak — direct enzymatic inhibition assay with defined IC50, single lab, no structural or mutagenesis follow-up reported","pmids":["27721154"],"is_preprint":false,"attribution":[{"species":"Plasmodium falciparum","strain":""}]}],"current_model":"P. falciparum CLK1 (PF3D7_1445400) is a nuclear-localized LAMMER-family serine/threonine kinase essential for asexual blood-stage replication that phosphorylates SR-protein splicing factors (including PfASF-1) in vitro and co-assembles with nuclease/phosphatase/helicase-containing nuclear complexes, implicating it in post-transcriptional mRNA regulation; its kinase activity can be potently inhibited by small-molecule imidazo[1,2-b]pyridazine compounds."},"narrative":{"mechanistic_narrative":"PF3D7_1445400 (CLK1) is a nuclear LAMMER-family serine/threonine protein kinase of Plasmodium falciparum that is essential for completion of the asexual blood-stage replication cycle [PMID:21312235]. It phosphorylates SR/splicing-factor substrates in vitro, including the plasmodial alternative splicing factor PfASF-1 and the Sky1p substrate Npl3p, implicating CLK1 in post-transcriptional mRNA regulation [PMID:21312235]. Consistent with this role, CLK1 localizes to the nucleus via nuclear localization signals upstream of its C-terminal catalytic domain [PMID:21312235], and co-immunoprecipitates with proteins predicted to carry nuclease, phosphatase, or helicase activities, indicating assembly into nuclear gene-regulatory complexes [PMID:21312235]. Its kinase activity is potently inhibited in vitro by a 3,6-disubstituted imidazo[1,2-b]pyridazine compound (IC50 32 nM), establishing CLK1 as a biochemically tractable drug target [PMID:27721154]. Beyond substrate phosphorylation, nuclear localization, and complex membership, no further mechanistic detail (e.g. in vivo substrates, structural basis of catalysis, or the identity of complex partners) has been characterized in the available corpus.","teleology":[{"year":2001,"claim":"Establishing the primary structure defined CLK1 as a LAMMER-family kinase with regulatory features (RS/SR dipeptides, NLSs, DKYD repeats) hinting at splicing-related and nuclear function before any activity was measured.","evidence":"Vectorette PCR cloning, genomic restriction analysis, and sequence analysis of the single-copy gene","pmids":["11306117"],"confidence":"Low","gaps":["Bioinformatic domain assignment without direct functional assay","Sequence homology to Arabidopsis AFC3 does not establish substrate specificity","Northern-blot-based sexual-stage expression claim not reconciled with later asexual-stage data"],"attribution":[{"species":"Plasmodium falciparum","strain":""}]},{"year":2011,"claim":"Reverse genetics, orthogonal localization, and in vitro kinase assays together established CLK1 as a nucleus-localized, essential kinase acting on splicing factors, converting a sequence prediction into a functional model of post-transcriptional regulation.","evidence":"Reverse genetics for essentiality, IFA/Western/EM for nuclear localization, and in vitro kinase assays on Npl3p and PfASF-1","pmids":["21312235"],"confidence":"Medium","gaps":["In vitro substrate phosphorylation not confirmed for endogenous substrates in vivo","No active-site mutagenesis to prove the phosphorylation depends on CLK1 catalytic activity","Essentiality phenotype describes failure to complete the asexual cycle but does not pinpoint the arrested step"],"attribution":[{"species":"Plasmodium falciparum","strain":""}]},{"year":2011,"claim":"Co-IP/MS asked which partners CLK1 works with, placing it in nuclear complexes containing predicted nuclease, phosphatase, and helicase activities and framing it as part of a gene-regulatory machine.","evidence":"Single co-immunoprecipitation followed by mass spectrometry","pmids":["21312235"],"confidence":"Low","gaps":["Single co-IP/MS without reciprocal validation of interactions","Partner functions only predicted bioinformatically, not experimentally confirmed","Direct versus indirect association within the complex not resolved"],"attribution":[{"species":"Plasmodium falciparum","strain":""}]},{"year":2016,"claim":"Enzymatic inhibitor profiling addressed whether CLK1 is druggable, showing potent nanomolar inhibition by an imidazo[1,2-b]pyridazine and validating it as a biochemical target for antimalarial development.","evidence":"In vitro kinase inhibition assay with IC50 determination (compound 20a, 32 nM)","pmids":["27721154"],"confidence":"Medium","gaps":["No structural or mutagenesis follow-up to define the binding mode","In vitro inhibition not linked to on-target killing of parasites in cellulo","Selectivity over host or parasite sibling kinases not established"],"attribution":[{"species":"Plasmodium falciparum","strain":""}]},{"year":null,"claim":"The in vivo substrate repertoire, the composition and function of the CLK1 nuclear complex, and the mechanistic basis of its essentiality remain unresolved.","evidence":"","pmids":[],"confidence":"Low","gaps":["No endogenous phosphoproteomic identification of CLK1 substrates","Identity and direct-binding status of nuclear complex partners unknown","No structural model of the catalytic domain or inhibitor-bound state"],"attribution":[{"species":"Plasmodium falciparum","strain":""}]}],"mechanism_profile":{"molecular_activity":[],"localization":[],"pathway":[],"complexes":["Nuclear complex containing predicted nuclease/phosphatase/helicase-function proteins (partners predicted only) [#3]"],"partners":["PFASF-1 (ALTERNATIVE SPLICING FACTOR; IN VITRO SUBSTRATE) [#2]","NPL3P (SKY1P SUBSTRATE SPLICING FACTOR; IN VITRO SUBSTRATE) [#2]"],"other_free_text":["Single-copy gene encoding an ~106.7 kDa, 881-aa protein with an N-terminal regulatory region (RS/SR dipeptides, two NLSs, 14 DKYD repeats) and a C-terminal LAMMER kinase domain homologous to Arabidopsis AFC3 [#5]","Transcribed throughout asexual blood stages and in gametocytes [#4]; a 2001 report described sexual-stage (gametocyte) mRNA expression [#6]","Essential for completion of the asexual blood-stage replication cycle [#1]","Potently inhibited in vitro by 3,6-disubstituted imidazo[1,2-b]pyridazine compound 20a (IC50 32 nM) [#7]"]}},"prefetch_data":{},"corpus_meta":[{"pmid":"15479470","id":"PMC_15479470","title":"Protein kinases of the human malaria parasite Plasmodium falciparum: the kinome of a divergent eukaryote.","date":"2004","source":"BMC genomics","url":"https://pubmed.ncbi.nlm.nih.gov/15479470","citation_count":421,"is_preprint":false,"source_species":["Pf"],"role":"primary","match_terms":["curated_ref"],"competing_organism_flag":false,"competing_organism_match":"","competing_organism_only":false},{"pmid":"34205123","id":"PMC_34205123","title":"Dual-Specificity, Tyrosine Phosphorylation-Regulated Kinases (DYRKs) and cdc2-Like Kinases (CLKs) in Human Disease, an Overview.","date":"2021","source":"International journal of molecular sciences","url":"https://pubmed.ncbi.nlm.nih.gov/34205123","citation_count":87,"is_preprint":false,"source_species":["Pf"],"role":"primary","match_terms":["CLK1"],"competing_organism_flag":false,"competing_organism_match":"","competing_organism_only":false},{"pmid":"21312235","id":"PMC_21312235","title":"Two nucleus-localized CDK-like kinases with crucial roles for malaria parasite erythrocytic replication are involved in phosphorylation of splicing factor.","date":"2011","source":"Journal of cellular biochemistry","url":"https://pubmed.ncbi.nlm.nih.gov/21312235","citation_count":38,"is_preprint":false,"source_species":["Pf"],"role":"primary","match_terms":["PfCLK1"],"competing_organism_flag":false,"competing_organism_match":"","competing_organism_only":false},{"pmid":"27721154","id":"PMC_27721154","title":"Exploration of the imidazo[1,2-b]pyridazine scaffold as a protein kinase inhibitor.","date":"2016","source":"European journal of medicinal chemistry","url":"https://pubmed.ncbi.nlm.nih.gov/27721154","citation_count":20,"is_preprint":false,"source_species":["Pf"],"role":"primary","match_terms":["CLK1","PfCLK1"],"competing_organism_flag":false,"competing_organism_match":"","competing_organism_only":false},{"pmid":"11306117","id":"PMC_11306117","title":"Primary structure and sexual stage-specific expression of a LAMMER protein kinase of Plasmodium falciparum.","date":"2001","source":"International journal for parasitology","url":"https://pubmed.ncbi.nlm.nih.gov/11306117","citation_count":15,"is_preprint":false,"source_species":["Pf"],"role":"primary","match_terms":["curated_ref"],"competing_organism_flag":false,"competing_organism_match":"","competing_organism_only":false},{"pmid":"37208735","id":"PMC_37208735","title":"Isoliensinine from Cissampelos pariera rhizomes exhibits potential gametocytocidal and anti-malarial activities against Plasmodium falciparum clinical isolates.","date":"2023","source":"Malaria journal","url":"https://pubmed.ncbi.nlm.nih.gov/37208735","citation_count":3,"is_preprint":false,"source_species":["Pf"],"role":"primary","match_terms":["PfCLK1"],"competing_organism_flag":false,"competing_organism_match":"","competing_organism_only":false}],"cost":{"stage1":{"model":"claude-sonnet-4-6","input_tokens":6133,"output_tokens":1824,"usd":0.02288,"stage1_stop_reason":"end_turn"},"stage2":{"model":"claude-opus-4-8","input_tokens":6995,"output_tokens":2579,"usd":0.049725,"stage2_stop_reason":"end_turn"},"total_usd":0.072605,"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\": 2011,\n      \"finding\": \"CLK1 (PfCLK-1/Lammer) localizes primarily to the nucleus of P. falciparum parasites, as confirmed by indirect immunofluorescence, Western blot, and electron microscopy. It possesses two nuclear localization signal sites upstream of its C-terminal catalytic domain.\",\n      \"method\": \"Indirect immunofluorescence, Western blot, electron microscopy\",\n      \"journal\": \"Journal of cellular biochemistry\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — multiple orthogonal localization methods (IFA, Western, EM) in a single lab, with functional context\",\n      \"pmids\": [\"21312235\"],\n      \"is_preprint\": false,\n      \"attribution\": [{\"species\": \"Plasmodium falciparum\", \"strain\": \"\"}]\n    },\n    {\n      \"year\": 2011,\n      \"finding\": \"CLK1 (PfCLK-1) is essential for completion of the asexual blood-stage replication cycle of P. falciparum, as demonstrated by reverse genetics approaches.\",\n      \"method\": \"Reverse genetics (gene disruption/knockdown)\",\n      \"journal\": \"Journal of cellular biochemistry\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Weak — clean loss-of-function with defined cellular phenotype (failure to complete asexual cycle), single lab\",\n      \"pmids\": [\"21312235\"],\n      \"is_preprint\": false,\n      \"attribution\": [{\"species\": \"Plasmodium falciparum\", \"strain\": \"\"}]\n    },\n    {\n      \"year\": 2011,\n      \"finding\": \"CLK1 (PfCLK-1) phosphorylates the Sky1p substrate splicing factor Npl3p and the plasmodial alternative splicing factor PfASF-1 in vitro, indicating a role in post-transcriptional mRNA regulation.\",\n      \"method\": \"In vitro kinase assay\",\n      \"journal\": \"Journal of cellular biochemistry\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 1 / Weak — in vitro kinase assay with defined substrates, single lab, no mutagenesis of active site\",\n      \"pmids\": [\"21312235\"],\n      \"is_preprint\": false,\n      \"attribution\": [{\"species\": \"Plasmodium falciparum\", \"strain\": \"\"}]\n    },\n    {\n      \"year\": 2011,\n      \"finding\": \"CLK1 (PfCLK-1) co-immunoprecipitates with proteins predicted to have nuclease, phosphatase, or helicase functions, suggesting it assembles into nuclear complexes involved in gene regulation.\",\n      \"method\": \"Co-immunoprecipitation followed by mass spectrometry\",\n      \"journal\": \"Journal of cellular biochemistry\",\n      \"confidence\": \"Low\",\n      \"confidence_rationale\": \"Tier 3 / Weak — single co-IP/MS experiment, single lab, interacting partners only predicted functionally\",\n      \"pmids\": [\"21312235\"],\n      \"is_preprint\": false,\n      \"attribution\": [{\"species\": \"Plasmodium falciparum\", \"strain\": \"\"}]\n    },\n    {\n      \"year\": 2011,\n      \"finding\": \"CLK1 (PfCLK-1) is transcribed throughout the asexual blood stages and in gametocytes.\",\n      \"method\": \"Transcriptional analysis (RT-PCR/expression profiling)\",\n      \"journal\": \"Journal of cellular biochemistry\",\n      \"confidence\": \"Low\",\n      \"confidence_rationale\": \"Tier 4 / Weak — expression-level observation, single lab; included only because it directly informs stage-specific activity context\",\n      \"pmids\": [\"21312235\"],\n      \"is_preprint\": false,\n      \"attribution\": [{\"species\": \"Plasmodium falciparum\", \"strain\": \"\"}]\n    },\n    {\n      \"year\": 2001,\n      \"finding\": \"CLK1 (PfLAMMER) is encoded by a single-copy gene (3316 bp, 881 amino acids, ~106.7 kDa) whose N-terminal domain contains multiple consensus phosphorylation sites, RS/SR dipeptides, two putative nuclear localization signals, and 14 DKYD tetramer repeats, while the C-terminal domain is a LAMMER-family kinase domain most homologous to Arabidopsis AFC3.\",\n      \"method\": \"Vectorette PCR cloning, genomic restriction analysis, sequence analysis\",\n      \"journal\": \"International journal for parasitology\",\n      \"confidence\": \"Low\",\n      \"confidence_rationale\": \"Tier 4 / Weak — primary structure characterization by cloning and bioinformatics; no direct functional assay\",\n      \"pmids\": [\"11306117\"],\n      \"is_preprint\": false,\n      \"attribution\": [{\"species\": \"Plasmodium falciparum\", \"strain\": \"\"}]\n    },\n    {\n      \"year\": 2001,\n      \"finding\": \"CLK1 (PfLAMMER) mRNA (~3800 nt) is expressed specifically in the sexual stage (gametocytes), suggesting a role in regulating sexual differentiation.\",\n      \"method\": \"Northern blot / transcript detection\",\n      \"journal\": \"International journal for parasitology\",\n      \"confidence\": \"Low\",\n      \"confidence_rationale\": \"Tier 3 / Weak — single lab, single method (transcript detection); no functional experiment performed\",\n      \"pmids\": [\"11306117\"],\n      \"is_preprint\": false,\n      \"attribution\": [{\"species\": \"Plasmodium falciparum\", \"strain\": \"\"}]\n    },\n    {\n      \"year\": 2016,\n      \"finding\": \"CLK1 (PfCLK1) kinase activity is potently inhibited in vitro by 3,6-disubstituted imidazo[1,2-b]pyridazine compound 20a with an IC50 of 32 nM, establishing it as a biochemically tractable kinase target.\",\n      \"method\": \"In vitro kinase inhibition assay (IC50 determination)\",\n      \"journal\": \"European journal of medicinal chemistry\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 1 / Weak — direct enzymatic inhibition assay with defined IC50, single lab, no structural or mutagenesis follow-up reported\",\n      \"pmids\": [\"27721154\"],\n      \"is_preprint\": false,\n      \"attribution\": [{\"species\": \"Plasmodium falciparum\", \"strain\": \"\"}]\n    }\n  ],\n  \"current_model\": \"P. falciparum CLK1 (PF3D7_1445400) is a nuclear-localized LAMMER-family serine/threonine kinase essential for asexual blood-stage replication that phosphorylates SR-protein splicing factors (including PfASF-1) in vitro and co-assembles with nuclease/phosphatase/helicase-containing nuclear complexes, implicating it in post-transcriptional mRNA regulation; its kinase activity can be potently inhibited by small-molecule imidazo[1,2-b]pyridazine compounds.\"\n}\n```","stage2_raw":"```json\n{\n  \"mechanistic_narrative\": \"PF3D7_1445400 (CLK1) is a nuclear LAMMER-family serine/threonine protein kinase of Plasmodium falciparum that is essential for completion of the asexual blood-stage replication cycle [#0, #1]. It phosphorylates SR/splicing-factor substrates in vitro, including the plasmodial alternative splicing factor PfASF-1 and the Sky1p substrate Npl3p, implicating CLK1 in post-transcriptional mRNA regulation [#2]. Consistent with this role, CLK1 localizes to the nucleus via nuclear localization signals upstream of its C-terminal catalytic domain [#0], and co-immunoprecipitates with proteins predicted to carry nuclease, phosphatase, or helicase activities, indicating assembly into nuclear gene-regulatory complexes [#3]. Its kinase activity is potently inhibited in vitro by a 3,6-disubstituted imidazo[1,2-b]pyridazine compound (IC50 32 nM), establishing CLK1 as a biochemically tractable drug target [#7]. Beyond substrate phosphorylation, nuclear localization, and complex membership, no further mechanistic detail (e.g. in vivo substrates, structural basis of catalysis, or the identity of complex partners) has been characterized in the available corpus.\",\n  \"teleology\": [\n    {\n      \"year\": 2001,\n      \"claim\": \"Establishing the primary structure defined CLK1 as a LAMMER-family kinase with regulatory features (RS/SR dipeptides, NLSs, DKYD repeats) hinting at splicing-related and nuclear function before any activity was measured.\",\n      \"evidence\": \"Vectorette PCR cloning, genomic restriction analysis, and sequence analysis of the single-copy gene\",\n      \"pmids\": [\"11306117\"],\n      \"confidence\": \"Low\",\n      \"gaps\": [\n        \"Bioinformatic domain assignment without direct functional assay\",\n        \"Sequence homology to Arabidopsis AFC3 does not establish substrate specificity\",\n        \"Northern-blot-based sexual-stage expression claim not reconciled with later asexual-stage data\"\n      ],\n      \"attribution\": [{\"species\": \"Plasmodium falciparum\", \"strain\": \"\"}]\n    },\n    {\n      \"year\": 2011,\n      \"claim\": \"Reverse genetics, orthogonal localization, and in vitro kinase assays together established CLK1 as a nucleus-localized, essential kinase acting on splicing factors, converting a sequence prediction into a functional model of post-transcriptional regulation.\",\n      \"evidence\": \"Reverse genetics for essentiality, IFA/Western/EM for nuclear localization, and in vitro kinase assays on Npl3p and PfASF-1\",\n      \"pmids\": [\"21312235\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\n        \"In vitro substrate phosphorylation not confirmed for endogenous substrates in vivo\",\n        \"No active-site mutagenesis to prove the phosphorylation depends on CLK1 catalytic activity\",\n        \"Essentiality phenotype describes failure to complete the asexual cycle but does not pinpoint the arrested step\"\n      ],\n      \"attribution\": [{\"species\": \"Plasmodium falciparum\", \"strain\": \"\"}]\n    },\n    {\n      \"year\": 2011,\n      \"claim\": \"Co-IP/MS asked which partners CLK1 works with, placing it in nuclear complexes containing predicted nuclease, phosphatase, and helicase activities and framing it as part of a gene-regulatory machine.\",\n      \"evidence\": \"Single co-immunoprecipitation followed by mass spectrometry\",\n      \"pmids\": [\"21312235\"],\n      \"confidence\": \"Low\",\n      \"gaps\": [\n        \"Single co-IP/MS without reciprocal validation of interactions\",\n        \"Partner functions only predicted bioinformatically, not experimentally confirmed\",\n        \"Direct versus indirect association within the complex not resolved\"\n      ],\n      \"attribution\": [{\"species\": \"Plasmodium falciparum\", \"strain\": \"\"}]\n    },\n    {\n      \"year\": 2016,\n      \"claim\": \"Enzymatic inhibitor profiling addressed whether CLK1 is druggable, showing potent nanomolar inhibition by an imidazo[1,2-b]pyridazine and validating it as a biochemical target for antimalarial development.\",\n      \"evidence\": \"In vitro kinase inhibition assay with IC50 determination (compound 20a, 32 nM)\",\n      \"pmids\": [\"27721154\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\n        \"No structural or mutagenesis follow-up to define the binding mode\",\n        \"In vitro inhibition not linked to on-target killing of parasites in cellulo\",\n        \"Selectivity over host or parasite sibling kinases not established\"\n      ],\n      \"attribution\": [{\"species\": \"Plasmodium falciparum\", \"strain\": \"\"}]\n    },\n    {\n      \"year\": null,\n      \"claim\": \"The in vivo substrate repertoire, the composition and function of the CLK1 nuclear complex, and the mechanistic basis of its essentiality remain unresolved.\",\n      \"evidence\": \"\",\n      \"pmids\": [],\n      \"confidence\": \"Low\",\n      \"gaps\": [\n        \"No endogenous phosphoproteomic identification of CLK1 substrates\",\n        \"Identity and direct-binding status of nuclear complex partners unknown\",\n        \"No structural model of the catalytic domain or inhibitor-bound state\"\n      ],\n      \"attribution\": [{\"species\": \"Plasmodium falciparum\", \"strain\": \"\"}]\n    }\n  ],\n  \"mechanism_profile\": {\n    \"molecular_activity\": [\n      {\"term_id\": \"GO:0004674\", \"supporting_discovery_ids\": [2, 5, 7]},\n      {\"term_id\": \"GO:0106310\", \"supporting_discovery_ids\": [2]}\n    ],\n    \"localization\": [\n      {\"term_id\": \"GO:0005634\", \"supporting_discovery_ids\": [0, 5]}\n    ],\n    \"pathway\": [\n      {\"term_id\": \"GO:0043484\", \"supporting_discovery_ids\": [2, 3]},\n      {\"term_id\": \"GO:0008380\", \"supporting_discovery_ids\": [2]}\n    ],\n    \"complexes\": [\n      \"Nuclear complex containing predicted nuclease/phosphatase/helicase-function proteins (partners predicted only) [#3]\"\n    ],\n    \"partners\": [\n      \"PfASF-1 (alternative splicing factor; in vitro substrate) [#2]\",\n      \"Npl3p (Sky1p substrate splicing factor; in vitro substrate) [#2]\"\n    ],\n    \"other_free_text\": [\n      \"Single-copy gene encoding an ~106.7 kDa, 881-aa protein with an N-terminal regulatory region (RS/SR dipeptides, two NLSs, 14 DKYD repeats) and a C-terminal LAMMER kinase domain homologous to Arabidopsis AFC3 [#5]\",\n      \"Transcribed throughout asexual blood stages and in gametocytes [#4]; a 2001 report described sexual-stage (gametocyte) mRNA expression [#6]\",\n      \"Essential for completion of the asexual blood-stage replication cycle [#1]\",\n      \"Potently inhibited in vitro by 3,6-disubstituted imidazo[1,2-b]pyridazine compound 20a (IC50 32 nM) [#7]\"\n    ]\n  }\n}\n```","audit_flag":null,"strains":[{"strain":"Pf3D7","gene_id":"PF3D7_1445400","name":null,"product":"protein serine/threonine kinase-1","uniprot_acc":null,"chromosome":null,"start_pos":null},{"strain":"PbANKA","gene_id":"PBANKA_1309200","name":null,"product":"serine/threonine kinase-1, putative","uniprot_acc":null,"chromosome":null,"start_pos":null},{"strain":"PkH","gene_id":"PKNH_1236900","name":null,"product":"serine/threonine kinase-1, putative","uniprot_acc":null,"chromosome":null,"start_pos":null}],"gene_symbol":"CLK1","evaluation":null}