{"gene":"PF3D7_1468400","run_date":"2026-09-08T14:19:07","timeline":{"discoveries":[{"year":2022,"finding":"CZIF1 (PF3D7_1468400) localizes to discrete foci on the periphery of the parasite's cytosol and biochemical assays indicate it is peripherally associated with a membrane.","method":"Immunofluorescence localization and biochemical membrane association assays","journal":"International journal for parasitology","confidence":"Medium","confidence_rationale":"Tier 3 / Moderate — direct localization experiment with biochemical fractionation, two orthogonal methods in a single study","pmids":["36400305"],"is_preprint":false,"attribution":[{"species":"Plasmodium falciparum","strain":""}]},{"year":2022,"finding":"Gene knockout of CZIF1 (PF3D7_1468400) alone is not lethal to blood-stage parasites; however, simultaneous knockout of both Pfczif1 and Pfczif2 could not be achieved, indicating that at least one of the two genes is required for in vitro blood-stage parasite growth.","method":"Gene knockout (CRISPR/genetic disruption) and growth assays","journal":"International journal for parasitology","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — clean genetic knockouts with defined growth phenotype, but functional redundancy interpretation relies on inability to generate double knockout","pmids":["36400305"],"is_preprint":false,"attribution":[{"species":"Plasmodium falciparum","strain":""}]},{"year":2022,"finding":"C-terminal truncation of CZIF1 (PF3D7_1468400) does not significantly perturb parasite transcriptome, indicating CZIF1 truncation alone does not alter global gene expression in blood-stage parasites.","method":"Transcriptomic analysis of C-terminal truncation mutants","journal":"International journal for parasitology","confidence":"Low","confidence_rationale":"Tier 3 / Weak — single lab, single method (transcriptomics), negative result with no orthogonal validation","pmids":["36400305"],"is_preprint":false,"attribution":[{"species":"Plasmodium falciparum","strain":""}]},{"year":2022,"finding":"Antibodies against CZIF1 (PF3D7_1468400) inhibit merozoite invasion of red blood cells, as reported by previous studies and cited in the characterization paper; however, direct functional experiments (gene knockout) in this study do not support an essential role for CZIF1 in RBC invasion.","method":"Gene knockout and invasion assays (current study); antibody inhibition assay (cited prior study)","journal":"International journal for parasitology","confidence":"Low","confidence_rationale":"Tier 3 / Weak — antibody inhibition cited from prior work without direct mechanism; knockout data from current study contradicts an invasion role, creating conflicting evidence","pmids":["36400305"],"is_preprint":false,"attribution":[{"species":"Plasmodium falciparum","strain":""}]},{"year":2022,"finding":"CZIF1 (PF3D7_1468400) has peak expression during late schizogony of blood stages, identifying it as one of only two C3H1-type zinc finger proteins with this expression pattern in P. falciparum.","method":"Transcriptomic/expression analysis identifying stage-specific expression","journal":"International journal for parasitology","confidence":"Low","confidence_rationale":"Tier 4 / Moderate — expression-based finding, no direct functional or mechanistic experiment establishing molecular role","pmids":["36400305"],"is_preprint":false,"attribution":[{"species":"Plasmodium falciparum","strain":""}]}],"current_model":"CZIF1 (PF3D7_1468400) is a C3H1-type zinc finger protein expressed at late schizogony that localizes to discrete peripheral foci in the parasite cytosol and is peripherally membrane-associated; it is individually dispensable for blood-stage growth but functionally redundant with PfCZIF2, as simultaneous loss of both proteins cannot be tolerated, and its C-terminal truncation does not detectably perturb global parasite gene expression."},"narrative":{"mechanistic_narrative":"CZIF1 (PF3D7_1468400) is a C3H1-type zinc finger protein of Plasmodium falciparum whose expression peaks during late schizogony of the blood stage [PMID:36400305]. It localizes to discrete foci at the periphery of the parasite cytosol and is peripherally associated with a membrane [PMID:36400305]. CZIF1 is individually dispensable for blood-stage growth, but simultaneous knockout of both Pfczif1 and Pfczif2 cannot be achieved, indicating that at least one of the two paralogous genes is required for in vitro blood-stage propagation and that CZIF1 is functionally redundant with PfCZIF2 [PMID:36400305]. C-terminal truncation of CZIF1 does not detectably alter the blood-stage transcriptome [PMID:36400305]. Beyond this expression, localization, and genetic-redundancy picture, no molecular activity, binding partner, or substrate of CZIF1 has been characterized in the available corpus.","teleology":[{"year":2022,"claim":"Establishing when CZIF1 acts defined the developmental window in which its function should be sought, placing it among only two C3H1 zinc finger proteins peaking at late schizogony.","evidence":"Stage-specific expression analysis in P. falciparum blood stages","pmids":["36400305"],"confidence":"Low","gaps":["Expression timing alone does not establish a molecular role","No protein-level quantification across stages reported","Does not distinguish CZIF1 from its paralog functionally"],"attribution":[{"species":"Plasmodium falciparum","strain":""}]},{"year":2022,"claim":"Determining where CZIF1 resides narrowed its candidate functions by placing it at peripheral cytosolic foci in membrane association rather than freely soluble.","evidence":"Immunofluorescence localization plus biochemical membrane-association fractionation in P. falciparum","pmids":["36400305"],"confidence":"Medium","gaps":["The identity of the membrane compartment is not defined","The molecular basis of peripheral membrane association is unknown","No interacting proteins at these foci were identified"],"attribution":[{"species":"Plasmodium falciparum","strain":""}]},{"year":2022,"claim":"Genetic disruption asked whether CZIF1 is essential and revealed dispensability of the single gene but a redundant essential requirement shared with PfCZIF2.","evidence":"CRISPR/genetic knockout of Pfczif1 alone and attempted Pfczif1/Pfczif2 double knockout with growth assays","pmids":["36400305"],"confidence":"Medium","gaps":["The redundant function shared by CZIF1 and PfCZIF2 is not defined","Inability to generate a double knockout is inferred rather than directly demonstrated as a lethal phenotype","The essential process either paralog supports remains unidentified"],"attribution":[{"species":"Plasmodium falciparum","strain":""}]},{"year":2022,"claim":"Transcriptomic profiling of a truncation mutant tested whether CZIF1 shapes gene expression and found no detectable global effect, arguing against a broad regulatory role for its C-terminus.","evidence":"Transcriptomic analysis of C-terminal truncation mutants in P. falciparum","pmids":["36400305"],"confidence":"Low","gaps":["Negative result from a single method with no orthogonal validation","Truncation may retain function; full loss was not assessed transcriptomically","Does not address post-transcriptional or non-transcriptional roles"],"attribution":[{"species":"Plasmodium falciparum","strain":""}]},{"year":2022,"claim":"A prior antibody-inhibition report implicated CZIF1 in merozoite invasion, but knockout data in the same characterization study did not support an essential invasion role, leaving the invasion association unresolved.","evidence":"Antibody inhibition of merozoite invasion (cited prior study) versus knockout invasion assays (current study) in P. falciparum","pmids":["36400305"],"confidence":"Low","gaps":["Antibody inhibition cited from prior work without direct mechanistic follow-up","Knockout data contradict an essential invasion role, creating conflicting evidence","No direct binding or invasion-step assignment for CZIF1"],"attribution":[{"species":"Plasmodium falciparum","strain":""}]},{"year":null,"claim":"The molecular activity of CZIF1's zinc finger, its RNA or protein targets, and the essential process it shares with PfCZIF2 remain unknown.","evidence":"No experiment in the corpus addresses CZIF1 biochemical activity or binding partners","pmids":[],"confidence":"Low","gaps":["No nucleic-acid or protein target of the C3H1 zinc finger identified","The redundant essential function shared with PfCZIF2 is undefined","No structural or interactome data for CZIF1"],"attribution":[{"species":"Plasmodium falciparum","strain":""}]}],"mechanism_profile":{"molecular_activity":[],"localization":[],"pathway":[],"complexes":[],"partners":["PFCZIF2 (FUNCTIONALLY REDUNDANT PARALOG; SIMULTANEOUS LOSS NOT TOLERATED)"],"other_free_text":["C3H1-type zinc finger protein [#4]","Peak expression during late schizogony of blood stages [#4]","Localizes to discrete peripheral foci in the parasite cytosol; peripherally membrane-associated [#0]","Individually dispensable for blood-stage growth; at least one of Pfczif1/Pfczif2 required for in vitro blood-stage growth [#1]","C-terminal truncation does not detectably alter the blood-stage transcriptome [#2]","Conflicting evidence on a role in merozoite invasion: prior antibody inhibition versus non-essential knockout phenotype [#3]"]}},"prefetch_data":{},"corpus_meta":[{"pmid":"34418264","id":"PMC_34418264","title":"Zinc finger proteins of Plasmodium falciparum.","date":"2021","source":"Cellular microbiology","url":"https://pubmed.ncbi.nlm.nih.gov/34418264","citation_count":33,"is_preprint":false,"source_species":["Pf"],"role":"primary","match_terms":["zinc finger protein"],"competing_organism_flag":false,"competing_organism_match":"","competing_organism_only":false},{"pmid":"36400305","id":"PMC_36400305","title":"Characterisation of PfCZIF1 and PfCZIF2 in Plasmodium falciparum asexual stages.","date":"2022","source":"International journal for parasitology","url":"https://pubmed.ncbi.nlm.nih.gov/36400305","citation_count":5,"is_preprint":false,"source_species":["Pf"],"role":"primary","match_terms":["C3H1","PfCZIF1"],"competing_organism_flag":false,"competing_organism_match":"","competing_organism_only":false}],"cost":{"stage1":{"model":"claude-sonnet-4-6","input_tokens":3785,"output_tokens":1204,"usd":0.014708,"stage1_stop_reason":"end_turn"},"stage2":{"model":"claude-opus-4-8","input_tokens":6095,"output_tokens":2282,"usd":0.043763,"stage2_stop_reason":"end_turn"},"total_usd":0.058471,"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\": 2022,\n      \"finding\": \"CZIF1 (PF3D7_1468400) localizes to discrete foci on the periphery of the parasite's cytosol and biochemical assays indicate it is peripherally associated with a membrane.\",\n      \"method\": \"Immunofluorescence localization and biochemical membrane association assays\",\n      \"journal\": \"International journal for parasitology\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 3 / Moderate — direct localization experiment with biochemical fractionation, two orthogonal methods in a single study\",\n      \"pmids\": [\"36400305\"],\n      \"is_preprint\": false,\n      \"attribution\": [{\"species\": \"Plasmodium falciparum\", \"strain\": \"\"}]\n    },\n    {\n      \"year\": 2022,\n      \"finding\": \"Gene knockout of CZIF1 (PF3D7_1468400) alone is not lethal to blood-stage parasites; however, simultaneous knockout of both Pfczif1 and Pfczif2 could not be achieved, indicating that at least one of the two genes is required for in vitro blood-stage parasite growth.\",\n      \"method\": \"Gene knockout (CRISPR/genetic disruption) and growth assays\",\n      \"journal\": \"International journal for parasitology\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — clean genetic knockouts with defined growth phenotype, but functional redundancy interpretation relies on inability to generate double knockout\",\n      \"pmids\": [\"36400305\"],\n      \"is_preprint\": false,\n      \"attribution\": [{\"species\": \"Plasmodium falciparum\", \"strain\": \"\"}]\n    },\n    {\n      \"year\": 2022,\n      \"finding\": \"C-terminal truncation of CZIF1 (PF3D7_1468400) does not significantly perturb parasite transcriptome, indicating CZIF1 truncation alone does not alter global gene expression in blood-stage parasites.\",\n      \"method\": \"Transcriptomic analysis of C-terminal truncation mutants\",\n      \"journal\": \"International journal for parasitology\",\n      \"confidence\": \"Low\",\n      \"confidence_rationale\": \"Tier 3 / Weak — single lab, single method (transcriptomics), negative result with no orthogonal validation\",\n      \"pmids\": [\"36400305\"],\n      \"is_preprint\": false,\n      \"attribution\": [{\"species\": \"Plasmodium falciparum\", \"strain\": \"\"}]\n    },\n    {\n      \"year\": 2022,\n      \"finding\": \"Antibodies against CZIF1 (PF3D7_1468400) inhibit merozoite invasion of red blood cells, as reported by previous studies and cited in the characterization paper; however, direct functional experiments (gene knockout) in this study do not support an essential role for CZIF1 in RBC invasion.\",\n      \"method\": \"Gene knockout and invasion assays (current study); antibody inhibition assay (cited prior study)\",\n      \"journal\": \"International journal for parasitology\",\n      \"confidence\": \"Low\",\n      \"confidence_rationale\": \"Tier 3 / Weak — antibody inhibition cited from prior work without direct mechanism; knockout data from current study contradicts an invasion role, creating conflicting evidence\",\n      \"pmids\": [\"36400305\"],\n      \"is_preprint\": false,\n      \"attribution\": [{\"species\": \"Plasmodium falciparum\", \"strain\": \"\"}]\n    },\n    {\n      \"year\": 2022,\n      \"finding\": \"CZIF1 (PF3D7_1468400) has peak expression during late schizogony of blood stages, identifying it as one of only two C3H1-type zinc finger proteins with this expression pattern in P. falciparum.\",\n      \"method\": \"Transcriptomic/expression analysis identifying stage-specific expression\",\n      \"journal\": \"International journal for parasitology\",\n      \"confidence\": \"Low\",\n      \"confidence_rationale\": \"Tier 4 / Moderate — expression-based finding, no direct functional or mechanistic experiment establishing molecular role\",\n      \"pmids\": [\"36400305\"],\n      \"is_preprint\": false,\n      \"attribution\": [{\"species\": \"Plasmodium falciparum\", \"strain\": \"\"}]\n    }\n  ],\n  \"current_model\": \"CZIF1 (PF3D7_1468400) is a C3H1-type zinc finger protein expressed at late schizogony that localizes to discrete peripheral foci in the parasite cytosol and is peripherally membrane-associated; it is individually dispensable for blood-stage growth but functionally redundant with PfCZIF2, as simultaneous loss of both proteins cannot be tolerated, and its C-terminal truncation does not detectably perturb global parasite gene expression.\"\n}\n```","stage2_raw":"{\n  \"mechanistic_narrative\": \"CZIF1 (PF3D7_1468400) is a C3H1-type zinc finger protein of Plasmodium falciparum whose expression peaks during late schizogony of the blood stage [#4]. It localizes to discrete foci at the periphery of the parasite cytosol and is peripherally associated with a membrane [#0]. CZIF1 is individually dispensable for blood-stage growth, but simultaneous knockout of both Pfczif1 and Pfczif2 cannot be achieved, indicating that at least one of the two paralogous genes is required for in vitro blood-stage propagation and that CZIF1 is functionally redundant with PfCZIF2 [#1]. C-terminal truncation of CZIF1 does not detectably alter the blood-stage transcriptome [#2]. Beyond this expression, localization, and genetic-redundancy picture, no molecular activity, binding partner, or substrate of CZIF1 has been characterized in the available corpus.\",\n  \"teleology\": [\n    {\n      \"year\": 2022,\n      \"claim\": \"Establishing when CZIF1 acts defined the developmental window in which its function should be sought, placing it among only two C3H1 zinc finger proteins peaking at late schizogony.\",\n      \"evidence\": \"Stage-specific expression analysis in P. falciparum blood stages\",\n      \"pmids\": [\"36400305\"],\n      \"confidence\": \"Low\",\n      \"gaps\": [\n        \"Expression timing alone does not establish a molecular role\",\n        \"No protein-level quantification across stages reported\",\n        \"Does not distinguish CZIF1 from its paralog functionally\"\n      ],\n      \"attribution\": [{\"species\": \"Plasmodium falciparum\", \"strain\": \"\"}]\n    },\n    {\n      \"year\": 2022,\n      \"claim\": \"Determining where CZIF1 resides narrowed its candidate functions by placing it at peripheral cytosolic foci in membrane association rather than freely soluble.\",\n      \"evidence\": \"Immunofluorescence localization plus biochemical membrane-association fractionation in P. falciparum\",\n      \"pmids\": [\"36400305\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\n        \"The identity of the membrane compartment is not defined\",\n        \"The molecular basis of peripheral membrane association is unknown\",\n        \"No interacting proteins at these foci were identified\"\n      ],\n      \"attribution\": [{\"species\": \"Plasmodium falciparum\", \"strain\": \"\"}]\n    },\n    {\n      \"year\": 2022,\n      \"claim\": \"Genetic disruption asked whether CZIF1 is essential and revealed dispensability of the single gene but a redundant essential requirement shared with PfCZIF2.\",\n      \"evidence\": \"CRISPR/genetic knockout of Pfczif1 alone and attempted Pfczif1/Pfczif2 double knockout with growth assays\",\n      \"pmids\": [\"36400305\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\n        \"The redundant function shared by CZIF1 and PfCZIF2 is not defined\",\n        \"Inability to generate a double knockout is inferred rather than directly demonstrated as a lethal phenotype\",\n        \"The essential process either paralog supports remains unidentified\"\n      ],\n      \"attribution\": [{\"species\": \"Plasmodium falciparum\", \"strain\": \"\"}]\n    },\n    {\n      \"year\": 2022,\n      \"claim\": \"Transcriptomic profiling of a truncation mutant tested whether CZIF1 shapes gene expression and found no detectable global effect, arguing against a broad regulatory role for its C-terminus.\",\n      \"evidence\": \"Transcriptomic analysis of C-terminal truncation mutants in P. falciparum\",\n      \"pmids\": [\"36400305\"],\n      \"confidence\": \"Low\",\n      \"gaps\": [\n        \"Negative result from a single method with no orthogonal validation\",\n        \"Truncation may retain function; full loss was not assessed transcriptomically\",\n        \"Does not address post-transcriptional or non-transcriptional roles\"\n      ],\n      \"attribution\": [{\"species\": \"Plasmodium falciparum\", \"strain\": \"\"}]\n    },\n    {\n      \"year\": 2022,\n      \"claim\": \"A prior antibody-inhibition report implicated CZIF1 in merozoite invasion, but knockout data in the same characterization study did not support an essential invasion role, leaving the invasion association unresolved.\",\n      \"evidence\": \"Antibody inhibition of merozoite invasion (cited prior study) versus knockout invasion assays (current study) in P. falciparum\",\n      \"pmids\": [\"36400305\"],\n      \"confidence\": \"Low\",\n      \"gaps\": [\n        \"Antibody inhibition cited from prior work without direct mechanistic follow-up\",\n        \"Knockout data contradict an essential invasion role, creating conflicting evidence\",\n        \"No direct binding or invasion-step assignment for CZIF1\"\n      ],\n      \"attribution\": [{\"species\": \"Plasmodium falciparum\", \"strain\": \"\"}]\n    },\n    {\n      \"year\": null,\n      \"claim\": \"The molecular activity of CZIF1's zinc finger, its RNA or protein targets, and the essential process it shares with PfCZIF2 remain unknown.\",\n      \"evidence\": \"No experiment in the corpus addresses CZIF1 biochemical activity or binding partners\",\n      \"pmids\": [],\n      \"confidence\": \"Low\",\n      \"gaps\": [\n        \"No nucleic-acid or protein target of the C3H1 zinc finger identified\",\n        \"The redundant essential function shared with PfCZIF2 is undefined\",\n        \"No structural or interactome data for CZIF1\"\n      ],\n      \"attribution\": [{\"species\": \"Plasmodium falciparum\", \"strain\": \"\"}]\n    }\n  ],\n  \"mechanism_profile\": {\n    \"molecular_activity\": [],\n    \"localization\": [],\n    \"pathway\": [],\n    \"complexes\": [],\n    \"partners\": [\"PfCZIF2 (functionally redundant paralog; simultaneous loss not tolerated)\"],\n    \"other_free_text\": [\n      \"C3H1-type zinc finger protein [#4]\",\n      \"Peak expression during late schizogony of blood stages [#4]\",\n      \"Localizes to discrete peripheral foci in the parasite cytosol; peripherally membrane-associated [#0]\",\n      \"Individually dispensable for blood-stage growth; at least one of Pfczif1/Pfczif2 required for in vitro blood-stage growth [#1]\",\n      \"C-terminal truncation does not detectably alter the blood-stage transcriptome [#2]\",\n      \"Conflicting evidence on a role in merozoite invasion: prior antibody inhibition versus non-essential knockout phenotype [#3]\"\n    ]\n  }\n}","audit_flag":null,"strains":[{"strain":"Pf3D7","gene_id":"PF3D7_1468400","name":null,"product":"C3H1-type zinc finger protein CZIF1","uniprot_acc":null,"chromosome":null,"start_pos":null},{"strain":"PbANKA","gene_id":"PBANKA_1331700","name":null,"product":"zinc finger protein, putative","uniprot_acc":null,"chromosome":null,"start_pos":null},{"strain":"PkH","gene_id":"PKNH_1212800","name":null,"product":"zinc finger protein, putative","uniprot_acc":null,"chromosome":null,"start_pos":null}],"gene_symbol":"CZIF1","evaluation":null}