{"gene":"PF3D7_1342400","run_date":"2026-09-08T14:19:06","timeline":{"discoveries":[{"year":2008,"finding":"PF3D7_1342400 (PfCK2beta2) interacts with the catalytic subunit PfCK2alpha in vitro, as demonstrated by in vitro interaction assays using recombinant proteins.","method":"In vitro protein interaction assay with recombinant proteins (pulldown)","journal":"Eukaryotic cell","confidence":"Medium","confidence_rationale":"Tier 3 / Moderate — single in vitro pulldown result, single lab, but replicated in the 2012 follow-up study confirming the interaction","pmids":["19114502"],"is_preprint":false,"attribution":[{"species":"Plasmodium falciparum","strain":""}]},{"year":2012,"finding":"PF3D7_1342400 (PfCK2beta2) is essential for completion of the asexual erythrocytic cycle, as gene disruption attempts failed, indicating the gene is refractory to knockout.","method":"Gene disruption (reverse genetics) — failed disruption indicating essentiality","journal":"BMC biology","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — genetic essentiality established by failed gene disruption in a single lab, consistent with parallel result for PfCK2beta1","pmids":["22293287"],"is_preprint":false,"attribution":[{"species":"Plasmodium falciparum","strain":""}]},{"year":2012,"finding":"PF3D7_1342400 (PfCK2beta2) localizes to both cytoplasmic and nuclear compartments of the intra-erythrocytic parasite, as determined by immunofluorescence and electron microscopy of HA-tagged transgenic parasite lines.","method":"Immunofluorescence and electron microscopy of HA-tagged transgenic parasites","journal":"BMC biology","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — direct localization by two orthogonal imaging methods (IFA + EM) in a single lab","pmids":["22293287"],"is_preprint":false,"attribution":[{"species":"Plasmodium falciparum","strain":""}]},{"year":2012,"finding":"PF3D7_1342400 (PfCK2beta2)-containing complexes, purified by immunoprecipitation from transgenic parasites expressing HA-PfCK2beta2 and analyzed by mass spectrometry, are enriched for components of the chromatin assembly pathway, including nucleosome assembly proteins (Naps), histones, and Alba family members, implicating PfCK2beta2 in chromatin dynamics.","method":"Affinity purification (HA-tag immunoprecipitation) followed by mass spectrometry interactome analysis","journal":"BMC biology","confidence":"Medium","confidence_rationale":"Tier 3 / Moderate — AP-MS from a single lab; enrichment of chromatin assembly components in both PfCK2beta1 and PfCK2beta2 precipitates adds convergent support, but no functional validation specific to PfCK2beta2 alone","pmids":["22293287"],"is_preprint":false,"attribution":[{"species":"Plasmodium falciparum","strain":""}]}],"current_model":"PF3D7_1342400 (PfCK2beta2) is an essential regulatory beta subunit of the P. falciparum CK2 holoenzyme that interacts with the catalytic subunit PfCK2alpha in vitro, localizes to both cytoplasmic and nuclear compartments during intra-erythrocytic development, and associates via its containing complex with chromatin assembly pathway components (nucleosome assembly proteins, histones, Alba family members), suggesting a role in chromatin dynamics; the gene cannot be disrupted, indicating it is required for asexual blood-stage parasite survival."},"narrative":{"mechanistic_narrative":"PF3D7_1342400 (PfCK2beta2) is a regulatory beta subunit of the Plasmodium falciparum CK2 holoenzyme that is required for asexual blood-stage parasite survival [PMID:22293287]. It interacts in vitro with the catalytic subunit PfCK2alpha [PMID:19114502] and distributes to both cytoplasmic and nuclear compartments of the intra-erythrocytic parasite [PMID:22293287]. Affinity purification of PfCK2beta2-containing complexes recovers components of the chromatin assembly pathway, including nucleosome assembly proteins (Naps), histones, and Alba family members, linking the subunit to chromatin dynamics [PMID:22293287]. Gene disruption attempts fail, establishing that PfCK2beta2 is essential for completion of the erythrocytic cycle [PMID:22293287]. Beyond these associations, no PfCK2beta2-specific catalytic or regulatory mechanism distinct from its complex membership has been characterized in the available corpus.","teleology":[{"year":2008,"claim":"Whether PfCK2beta2 physically engages the CK2 catalytic machinery was unknown; demonstrating a direct interaction established it as a bona fide beta subunit of the parasite CK2 system.","evidence":"in vitro pulldown of recombinant PfCK2beta2 and PfCK2alpha","pmids":["19114502"],"confidence":"Medium","gaps":["in vitro recombinant assay does not confirm the interaction occurs in the parasite","no stoichiometry or structural basis of the alpha-beta interaction","effect of PfCK2beta2 on PfCK2alpha catalytic activity not measured"],"attribution":[{"species":"Plasmodium falciparum","strain":""}]},{"year":2012,"claim":"Whether PfCK2beta2 is dispensable was unresolved; the failure to disrupt the gene established it as essential for asexual erythrocytic development.","evidence":"reverse-genetic gene disruption attempt scored as refractory to knockout","pmids":["22293287"],"confidence":"Medium","gaps":["failed disruption does not reveal which molecular function is essential","no conditional knockdown to define the essential process","essentiality outside asexual blood stages untested"],"attribution":[{"species":"Plasmodium falciparum","strain":""}]},{"year":2012,"claim":"The subcellular context of PfCK2beta2 action was unknown; dual imaging placed it in both cytoplasm and nucleus, indicating it can participate in nuclear as well as cytoplasmic processes.","evidence":"immunofluorescence and electron microscopy of HA-tagged transgenic parasites","pmids":["22293287"],"confidence":"Medium","gaps":["does not define which compartment hosts the essential function","tag-dependent localization not excluded","stage-specific redistribution not quantified"],"attribution":[{"species":"Plasmodium falciparum","strain":""}]},{"year":2012,"claim":"The functional pathway of PfCK2beta2 was undefined; interactome analysis of its complexes linked it to chromatin assembly machinery, implicating it in chromatin dynamics.","evidence":"HA-tag affinity purification followed by mass spectrometry from transgenic parasites","pmids":["22293287"],"confidence":"Medium","gaps":["co-purification with Naps, histones, and Alba proteins is not functional validation specific to PfCK2beta2","does not establish whether PfCK2beta2 recruits or regulates these components","phosphorylation of chromatin substrates by the PfCK2beta2-containing holoenzyme not demonstrated"],"attribution":[{"species":"Plasmodium falciparum","strain":""}]},{"year":null,"claim":"It remains unknown how PfCK2beta2 regulates CK2 catalytic activity, what substrates it directs, and whether its essential role reflects a chromatin function distinct from that of the paralogous beta subunit.","evidence":"","pmids":[],"confidence":"Medium","gaps":["no functional assay isolating PfCK2beta2 from its complex","no substrate directed specifically by PfCK2beta2","no conditional-depletion phenotype mapping the essential step"],"attribution":[{"species":"Plasmodium falciparum","strain":""}]}],"mechanism_profile":{"molecular_activity":[],"localization":[],"pathway":[],"complexes":["CK2 holoenzyme (with catalytic subunit PfCK2alpha)","PfCK2beta2-containing chromatin-assembly-associated complex"],"partners":["PFCK2ALPHA (CATALYTIC SUBUNIT)","NUCLEOSOME ASSEMBLY PROTEINS (NAPS)","HISTONES","ALBA FAMILY PROTEINS"],"other_free_text":["Essential for completion of the asexual erythrocytic cycle (refractory to gene disruption).","Corpus establishes PfCK2beta2 primarily through its interaction with PfCK2alpha and its co-purification with chromatin assembly components; no PfCK2beta2-specific enzymatic function independent of the complex has been characterized."]}},"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":"19114502","id":"PMC_19114502","title":"Functional analysis of protein kinase CK2 of the human malaria parasite Plasmodium falciparum.","date":"2008","source":"Eukaryotic cell","url":"https://pubmed.ncbi.nlm.nih.gov/19114502","citation_count":41,"is_preprint":false,"source_species":["Pf"],"role":"primary","match_terms":["PfCK2beta2"],"competing_organism_flag":false,"competing_organism_match":"","competing_organism_only":false},{"pmid":"22293287","id":"PMC_22293287","title":"Involvement of Plasmodium falciparum protein kinase CK2 in the chromatin assembly pathway.","date":"2012","source":"BMC biology","url":"https://pubmed.ncbi.nlm.nih.gov/22293287","citation_count":36,"is_preprint":false,"source_species":["Pf"],"role":"primary","match_terms":["PfCK2beta2"],"competing_organism_flag":false,"competing_organism_match":"","competing_organism_only":false}],"cost":{"stage1":{"model":"claude-sonnet-4-6","input_tokens":4520,"output_tokens":1112,"usd":0.01512,"stage1_stop_reason":"end_turn"},"stage2":{"model":"claude-opus-4-8","input_tokens":5920,"output_tokens":2195,"usd":0.042237,"stage2_stop_reason":"end_turn"},"total_usd":0.057357,"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\": 2008,\n      \"finding\": \"PF3D7_1342400 (PfCK2beta2) interacts with the catalytic subunit PfCK2alpha in vitro, as demonstrated by in vitro interaction assays using recombinant proteins.\",\n      \"method\": \"In vitro protein interaction assay with recombinant proteins (pulldown)\",\n      \"journal\": \"Eukaryotic cell\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 3 / Moderate — single in vitro pulldown result, single lab, but replicated in the 2012 follow-up study confirming the interaction\",\n      \"pmids\": [\"19114502\"],\n      \"is_preprint\": false,\n      \"attribution\": [\n        {\"species\": \"Plasmodium falciparum\", \"strain\": \"\"}\n      ]\n    },\n    {\n      \"year\": 2012,\n      \"finding\": \"PF3D7_1342400 (PfCK2beta2) is essential for completion of the asexual erythrocytic cycle, as gene disruption attempts failed, indicating the gene is refractory to knockout.\",\n      \"method\": \"Gene disruption (reverse genetics) — failed disruption indicating essentiality\",\n      \"journal\": \"BMC biology\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — genetic essentiality established by failed gene disruption in a single lab, consistent with parallel result for PfCK2beta1\",\n      \"pmids\": [\"22293287\"],\n      \"is_preprint\": false,\n      \"attribution\": [\n        {\"species\": \"Plasmodium falciparum\", \"strain\": \"\"}\n      ]\n    },\n    {\n      \"year\": 2012,\n      \"finding\": \"PF3D7_1342400 (PfCK2beta2) localizes to both cytoplasmic and nuclear compartments of the intra-erythrocytic parasite, as determined by immunofluorescence and electron microscopy of HA-tagged transgenic parasite lines.\",\n      \"method\": \"Immunofluorescence and electron microscopy of HA-tagged transgenic parasites\",\n      \"journal\": \"BMC biology\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — direct localization by two orthogonal imaging methods (IFA + EM) in a single lab\",\n      \"pmids\": [\"22293287\"],\n      \"is_preprint\": false,\n      \"attribution\": [\n        {\"species\": \"Plasmodium falciparum\", \"strain\": \"\"}\n      ]\n    },\n    {\n      \"year\": 2012,\n      \"finding\": \"PF3D7_1342400 (PfCK2beta2)-containing complexes, purified by immunoprecipitation from transgenic parasites expressing HA-PfCK2beta2 and analyzed by mass spectrometry, are enriched for components of the chromatin assembly pathway, including nucleosome assembly proteins (Naps), histones, and Alba family members, implicating PfCK2beta2 in chromatin dynamics.\",\n      \"method\": \"Affinity purification (HA-tag immunoprecipitation) followed by mass spectrometry interactome analysis\",\n      \"journal\": \"BMC biology\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 3 / Moderate — AP-MS from a single lab; enrichment of chromatin assembly components in both PfCK2beta1 and PfCK2beta2 precipitates adds convergent support, but no functional validation specific to PfCK2beta2 alone\",\n      \"pmids\": [\"22293287\"],\n      \"is_preprint\": false,\n      \"attribution\": [\n        {\"species\": \"Plasmodium falciparum\", \"strain\": \"\"}\n      ]\n    }\n  ],\n  \"current_model\": \"PF3D7_1342400 (PfCK2beta2) is an essential regulatory beta subunit of the P. falciparum CK2 holoenzyme that interacts with the catalytic subunit PfCK2alpha in vitro, localizes to both cytoplasmic and nuclear compartments during intra-erythrocytic development, and associates via its containing complex with chromatin assembly pathway components (nucleosome assembly proteins, histones, Alba family members), suggesting a role in chromatin dynamics; the gene cannot be disrupted, indicating it is required for asexual blood-stage parasite survival.\"\n}\n```","stage2_raw":"{\n  \"mechanistic_narrative\": \"PF3D7_1342400 (PfCK2beta2) is a regulatory beta subunit of the Plasmodium falciparum CK2 holoenzyme that is required for asexual blood-stage parasite survival [#1, #3]. It interacts in vitro with the catalytic subunit PfCK2alpha [#0] and distributes to both cytoplasmic and nuclear compartments of the intra-erythrocytic parasite [#2]. Affinity purification of PfCK2beta2-containing complexes recovers components of the chromatin assembly pathway, including nucleosome assembly proteins (Naps), histones, and Alba family members, linking the subunit to chromatin dynamics [#3]. Gene disruption attempts fail, establishing that PfCK2beta2 is essential for completion of the erythrocytic cycle [#1]. Beyond these associations, no PfCK2beta2-specific catalytic or regulatory mechanism distinct from its complex membership has been characterized in the available corpus.\",\n  \"teleology\": [\n    {\n      \"year\": 2008,\n      \"claim\": \"Whether PfCK2beta2 physically engages the CK2 catalytic machinery was unknown; demonstrating a direct interaction established it as a bona fide beta subunit of the parasite CK2 system.\",\n      \"evidence\": \"in vitro pulldown of recombinant PfCK2beta2 and PfCK2alpha\",\n      \"pmids\": [\"19114502\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\n        \"in vitro recombinant assay does not confirm the interaction occurs in the parasite\",\n        \"no stoichiometry or structural basis of the alpha-beta interaction\",\n        \"effect of PfCK2beta2 on PfCK2alpha catalytic activity not measured\"\n      ],\n      \"attribution\": [\n        {\"species\": \"Plasmodium falciparum\", \"strain\": \"\"}\n      ]\n    },\n    {\n      \"year\": 2012,\n      \"claim\": \"Whether PfCK2beta2 is dispensable was unresolved; the failure to disrupt the gene established it as essential for asexual erythrocytic development.\",\n      \"evidence\": \"reverse-genetic gene disruption attempt scored as refractory to knockout\",\n      \"pmids\": [\"22293287\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\n        \"failed disruption does not reveal which molecular function is essential\",\n        \"no conditional knockdown to define the essential process\",\n        \"essentiality outside asexual blood stages untested\"\n      ],\n      \"attribution\": [\n        {\"species\": \"Plasmodium falciparum\", \"strain\": \"\"}\n      ]\n    },\n    {\n      \"year\": 2012,\n      \"claim\": \"The subcellular context of PfCK2beta2 action was unknown; dual imaging placed it in both cytoplasm and nucleus, indicating it can participate in nuclear as well as cytoplasmic processes.\",\n      \"evidence\": \"immunofluorescence and electron microscopy of HA-tagged transgenic parasites\",\n      \"pmids\": [\"22293287\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\n        \"does not define which compartment hosts the essential function\",\n        \"tag-dependent localization not excluded\",\n        \"stage-specific redistribution not quantified\"\n      ],\n      \"attribution\": [\n        {\"species\": \"Plasmodium falciparum\", \"strain\": \"\"}\n      ]\n    },\n    {\n      \"year\": 2012,\n      \"claim\": \"The functional pathway of PfCK2beta2 was undefined; interactome analysis of its complexes linked it to chromatin assembly machinery, implicating it in chromatin dynamics.\",\n      \"evidence\": \"HA-tag affinity purification followed by mass spectrometry from transgenic parasites\",\n      \"pmids\": [\"22293287\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\n        \"co-purification with Naps, histones, and Alba proteins is not functional validation specific to PfCK2beta2\",\n        \"does not establish whether PfCK2beta2 recruits or regulates these components\",\n        \"phosphorylation of chromatin substrates by the PfCK2beta2-containing holoenzyme not demonstrated\"\n      ],\n      \"attribution\": [\n        {\"species\": \"Plasmodium falciparum\", \"strain\": \"\"}\n      ]\n    },\n    {\n      \"year\": null,\n      \"claim\": \"It remains unknown how PfCK2beta2 regulates CK2 catalytic activity, what substrates it directs, and whether its essential role reflects a chromatin function distinct from that of the paralogous beta subunit.\",\n      \"evidence\": \"\",\n      \"pmids\": [],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\n        \"no functional assay isolating PfCK2beta2 from its complex\",\n        \"no substrate directed specifically by PfCK2beta2\",\n        \"no conditional-depletion phenotype mapping the essential step\"\n      ],\n      \"attribution\": [\n        {\"species\": \"Plasmodium falciparum\", \"strain\": \"\"}\n      ]\n    }\n  ],\n  \"mechanism_profile\": {\n    \"molecular_activity\": [\n      {\"term_id\": \"GO:0008427\", \"supporting_discovery_ids\": [0]},\n      {\"term_id\": \"GO:0019887\", \"supporting_discovery_ids\": [0]}\n    ],\n    \"localization\": [\n      {\"term_id\": \"GO:0005737\", \"supporting_discovery_ids\": [2]},\n      {\"term_id\": \"GO:0005634\", \"supporting_discovery_ids\": [2]}\n    ],\n    \"pathway\": [\n      {\"term_id\": \"GO:0006333\", \"supporting_discovery_ids\": [3]}\n    ],\n    \"complexes\": [\n      \"CK2 holoenzyme (with catalytic subunit PfCK2alpha)\",\n      \"PfCK2beta2-containing chromatin-assembly-associated complex\"\n    ],\n    \"partners\": [\n      \"PfCK2alpha (catalytic subunit)\",\n      \"Nucleosome assembly proteins (Naps)\",\n      \"Histones\",\n      \"Alba family proteins\"\n    ],\n    \"other_free_text\": [\n      \"Essential for completion of the asexual erythrocytic cycle (refractory to gene disruption).\",\n      \"Corpus establishes PfCK2beta2 primarily through its interaction with PfCK2alpha and its co-purification with chromatin assembly components; no PfCK2beta2-specific enzymatic function independent of the complex has been characterized.\"\n    ]\n  }\n}","audit_flag":null,"strains":[{"strain":"Pf3D7","gene_id":"PF3D7_1342400","name":null,"product":"casein kinase II beta chain","uniprot_acc":null,"chromosome":null,"start_pos":null},{"strain":"PbANKA","gene_id":"PBANKA_1355500","name":null,"product":"casein kinase II beta chain, putative","uniprot_acc":null,"chromosome":null,"start_pos":null},{"strain":"PkH","gene_id":"PKNH_1259000","name":null,"product":"casein kinase II beta chain, putative","uniprot_acc":null,"chromosome":null,"start_pos":null}],"gene_symbol":"CK2beta2","evaluation":null}