{"gene":"PF3D7_1404700","run_date":"2026-09-08T14:19:07","timeline":{"discoveries":[{"year":2022,"finding":"PfCSS forms a heteromeric disulfide-linked complex with PfPTRAMP, and this PfCSS-PfPTRAMP sub-complex binds the RCR complex (PfRH5-PfCyRPA-PfRIPR) to form the pentameric PCRCR complex. PfCSS is essential for merozoite invasion of human erythrocytes, as demonstrated by conditional knockout and invasion-inhibitory nanobodies. The PCRCR complex functions to anchor contact between the merozoite and erythrocyte membranes. The structure of nanobody-PfCSS complexes was solved to identify an inhibitory epitope on PfCSS.","method":"Conditional knockout lines, invasion-inhibitory nanobodies, lattice light-sheet microscopy, crystal structure of nanobody-PfCSS complexes","journal":"Nature microbiology","confidence":"High","confidence_rationale":"Tier 1–2 / Strong — conditional KO with defined invasion phenotype, neutralizing nanobodies, structural determination, multiple orthogonal methods in one study","pmids":["36396942"],"is_preprint":false,"attribution":[{"species":"Plasmodium falciparum","strain":""}]},{"year":2023,"finding":"The elongated tail of PfRIPR binds to the PfCSS-PfPTRAMP complex on the parasite membrane, linking the modular PfRIPR (and thereby the RCR sub-complex presenting PfCyRPA and PfRH5) to the merozoite surface. This was established by cryo-EM structure of the PfRCR complex and a direct erythrocyte-binding assay.","method":"Cryo-electron microscopy structure of PfRCR complex, erythrocyte-binding assay, structural modelling","journal":"Nature","confidence":"High","confidence_rationale":"Tier 1 / Moderate — cryo-EM structure plus functional binding assay, single study but multiple orthogonal methods","pmids":["38123677"],"is_preprint":false,"attribution":[{"species":"Plasmodium falciparum","strain":""}]},{"year":2026,"finding":"PfCSS and PfPTRAMP form a disulfide-linked heterodimer conserved across P. falciparum, P. vivax, and P. knowlesi, and this heterodimer binds the C-terminal region of Ripr to constitute the PTRAMP-CSS-Ripr (PCR) complex in all three species. Cryo-EM of the P. knowlesi PCR complex confirmed this architecture as a core invasion scaffold.","method":"Biochemical complex reconstitution (disulfide-linked heterodimer identification), cryo-EM of P. knowlesi PCR complex, cross-reactive antibody inhibition assays","journal":"Nature communications","confidence":"High","confidence_rationale":"Tier 1–2 / Strong — cryo-EM structural confirmation plus biochemical reconstitution across three species, peer-reviewed","pmids":["41587959"],"is_preprint":false,"attribution":[{"species":"Plasmodium falciparum","strain":""},{"species":"Plasmodium vivax","strain":""},{"species":"Plasmodium knowlesi","strain":""}]},{"year":2026,"finding":"Anti-RIPR antibodies targeting EGF-like domains 6–8 dissociate PfCSS-PfPTRAMP from RIPR, thereby exposing additional epitopes on PfCSS and enabling further antibody binding. This identifies PfCSS-PfPTRAMP binding to the RIPR tail as a mechanistically important interaction whose disruption potentiates invasion inhibition.","method":"Monoclonal antibody characterization (83 human IgG mAbs), structural characterization, molecular dynamics simulations, growth inhibition assays","journal":"Immunity","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — structural and functional characterization with dissociation assay, single lab, multiple antibodies","pmids":["42285102"],"is_preprint":false,"attribution":[{"species":"Plasmodium falciparum","strain":""}]}],"current_model":"PfCSS (PF3D7_1404700) forms a disulfide-linked heterodimer with PfPTRAMP on the merozoite surface; this heterodimer binds the C-terminal tail of PfRIPR to anchor the pentameric PCRCR complex (PfCSS–PfPTRAMP–PfRIPR–PfCyRPA–PfRH5) at the merozoite membrane, where it is essential for erythrocyte invasion by mediating membrane contact between parasite and host cell, with this PTRAMP–CSS–Ripr sub-complex conserved across multiple Plasmodium species."},"narrative":{"mechanistic_narrative":"PfCSS (PF3D7_1404700) is a cysteine-rich small secreted protein that acts as an essential structural component of the merozoite invasion machinery in Plasmodium falciparum [PMID:36396942]. It forms a disulfide-linked heterodimer with PfPTRAMP on the merozoite surface, and this heterodimer binds the elongated C-terminal tail of PfRIPR, thereby anchoring the RCR sub-complex (PfRIPR-PfCyRPA-PfRH5) to the parasite membrane to constitute the pentameric PCRCR complex [PMID:36396942, PMID:38123677]. Through this scaffold, PfCSS mediates the membrane contact between merozoite and erythrocyte required for invasion, and it is essential for invasion of human erythrocytes as shown by conditional knockout and invasion-inhibitory nanobodies that define a neutralizing epitope on PfCSS [PMID:36396942]. The PfPTRAMP-CSS-Ripr sub-complex is a conserved core invasion scaffold across P. falciparum, P. vivax, and P. knowlesi [PMID:41587959]. Beyond its role as a membrane-anchoring component of this complex, no independent molecular activity of PfCSS has been characterized in the available corpus.","teleology":[{"year":2022,"claim":"Establishing whether PfCSS is a functional invasion factor rather than merely a co-purifying protein, this work showed it is essential and defined its place in a larger invasion complex.","evidence":"Conditional knockout, invasion-inhibitory nanobodies, lattice light-sheet microscopy, and crystal structure of nanobody-PfCSS complexes in P. falciparum","pmids":["36396942"],"confidence":"High","gaps":["The precise molecular basis of how the heterodimer promotes membrane contact was not resolved","No structure of the full assembled PCRCR complex reported here","Whether PfCSS has any activity independent of PfPTRAMP was not addressed"],"attribution":[{"species":"Plasmodium falciparum","strain":""}]},{"year":2023,"claim":"How the RCR sub-complex is physically tethered to the merozoite surface was unknown; this defined the PfRIPR tail as the direct link to the PfCSS-PfPTRAMP heterodimer.","evidence":"Cryo-EM structure of the PfRCR complex and erythrocyte-binding assay in P. falciparum","pmids":["38123677"],"confidence":"High","gaps":["The heterodimer-membrane attachment geometry of PfCSS was not resolved at the surface","Contribution of PfCSS versus PfPTRAMP to RIPR tail binding not separately dissected"],"attribution":[{"species":"Plasmodium falciparum","strain":""}]},{"year":2026,"claim":"Whether the PfCSS-containing scaffold is a conserved invasion module across species was open; cross-species reconstitution and structure established the PTRAMP-CSS-Ripr complex as a conserved core scaffold.","evidence":"Biochemical disulfide-linked heterodimer reconstitution and cryo-EM of the P. knowlesi PCR complex, with cross-reactive antibody inhibition, across P. falciparum, P. vivax, and P. knowlesi","pmids":["41587959"],"confidence":"High","gaps":["Functional essentiality of CSS orthologs in P. vivax and P. knowlesi not tested by genetics","Species-specific differences in complex regulation not characterized"],"attribution":[{"species":"Plasmodium falciparum","strain":""},{"species":"Plasmodium vivax","strain":""},{"species":"Plasmodium knowlesi","strain":""}]},{"year":2026,"claim":"Whether the PfCSS-PfPTRAMP/RIPR interaction is a vaccine-relevant vulnerability was addressed by showing antibody-driven dissociation of the heterodimer from RIPR potentiates invasion inhibition.","evidence":"Characterization of 83 human IgG mAbs targeting RIPR EGF-like domains 6-8, structural analysis, molecular dynamics, and growth inhibition assays in P. falciparum","pmids":["42285102"],"confidence":"Medium","gaps":["Antibodies target RIPR, so direct inhibitory targeting of PfCSS itself was not the primary readout","In vivo protective relevance not established","Mechanism by which dissociation exposes new PfCSS epitopes not structurally resolved"],"attribution":[{"species":"Plasmodium falciparum","strain":""}]},{"year":null,"claim":"The intrinsic biochemical activity of PfCSS beyond serving as a disulfide-linked membrane-anchoring partner of PfPTRAMP remains undefined.","evidence":"","pmids":[],"confidence":"Low","gaps":["No ligand or enzymatic activity attributed to PfCSS alone","The functional consequence of the cysteine-rich fold beyond heterodimer formation is uncharacterized","Contribution of PfCSS to the erythrocyte-contact step at molecular resolution is unresolved"],"attribution":[]}],"mechanism_profile":{"molecular_activity":[],"localization":[],"pathway":[],"complexes":["PCRCR complex (PfCSS-PfPTRAMP-PfRIPR-PfCyRPA-PfRH5)","PfCSS-PfPTRAMP disulfide-linked heterodimer","PTRAMP-CSS-Ripr (PCR) core invasion scaffold"],"partners":["PFPTRAMP","PFRIPR","PFCYRPA","PFRH5"],"other_free_text":["PfCSS is essential for P. falciparum merozoite invasion of human erythrocytes (conditional knockout) [#0]","Invasion-inhibitory nanobodies define a neutralizing epitope on PfCSS [#0]","PfCSS-PfPTRAMP binds the C-terminal/elongated tail of PfRIPR to anchor the RCR sub-complex to the merozoite membrane [#1, #2]","The PTRAMP-CSS-Ripr scaffold is conserved across P. falciparum, P. vivax, and P. knowlesi [#2]","Anti-RIPR antibodies (EGF-like domains 6-8) dissociate PfCSS-PfPTRAMP from RIPR, exposing further PfCSS epitopes [#3]"]}},"prefetch_data":{},"corpus_meta":[{"pmid":"36396942","id":"PMC_36396942","title":"PCRCR complex is essential for invasion of human erythrocytes by Plasmodium falciparum.","date":"2022","source":"Nature microbiology","url":"https://pubmed.ncbi.nlm.nih.gov/36396942","citation_count":58,"is_preprint":false,"source_species":["Pf"],"role":"primary","match_terms":["PfCSS"],"competing_organism_flag":false,"competing_organism_match":"","competing_organism_only":false},{"pmid":"31185066","id":"PMC_31185066","title":"Divergent roles for the RH5 complex components, CyRPA and RIPR in human-infective malaria parasites.","date":"2019","source":"PLoS pathogens","url":"https://pubmed.ncbi.nlm.nih.gov/31185066","citation_count":40,"is_preprint":false,"source_species":["Pf"],"role":"primary","match_terms":["curated_ref"],"competing_organism_flag":false,"competing_organism_match":"","competing_organism_only":false},{"pmid":"38123677","id":"PMC_38123677","title":"The PfRCR complex bridges malaria parasite and erythrocyte during invasion.","date":"2023","source":"Nature","url":"https://pubmed.ncbi.nlm.nih.gov/38123677","citation_count":32,"is_preprint":false,"source_species":["Pf"],"role":"primary","match_terms":["PfCSS"],"competing_organism_flag":false,"competing_organism_match":"","competing_organism_only":false},{"pmid":"37713419","id":"PMC_37713419","title":"The dual action of human antibodies specific to Plasmodium falciparum PfRH5 and PfCyRPA: Blocking invasion and inactivating extracellular merozoites.","date":"2023","source":"PLoS pathogens","url":"https://pubmed.ncbi.nlm.nih.gov/37713419","citation_count":5,"is_preprint":false,"source_species":["Pf"],"role":"primary","match_terms":["CSS"],"competing_organism_flag":false,"competing_organism_match":"","competing_organism_only":false},{"pmid":"39203985","id":"PMC_39203985","title":"Leveraging Immunofocusing and Virus-like Particle Display to Enhance Antibody Responses to the Malaria Blood-Stage Invasion Complex Antigen PfCyRPA.","date":"2024","source":"Vaccines","url":"https://pubmed.ncbi.nlm.nih.gov/39203985","citation_count":3,"is_preprint":false,"source_species":["Pf"],"role":"primary","match_terms":["PfCSS"],"competing_organism_flag":false,"competing_organism_match":"","competing_organism_only":false},{"pmid":"41587959","id":"PMC_41587959","title":"PTRAMP, CSS and Ripr form a conserved complex required for merozoite invasion of Plasmodium species into erythrocytes.","date":"2026","source":"Nature communications","url":"https://pubmed.ncbi.nlm.nih.gov/41587959","citation_count":2,"is_preprint":false,"source_species":["Pf"],"role":"primary","match_terms":["CSS","PfCSS"],"competing_organism_flag":false,"competing_organism_match":"","competing_organism_only":false},{"pmid":"40196582","id":"PMC_40196582","title":"PTRAMP, CSS and Ripr form a conserved complex required for merozoite invasion of Plasmodium species into erythrocytes.","date":"2025","source":"bioRxiv : the preprint server for biology","url":"https://pubmed.ncbi.nlm.nih.gov/40196582","citation_count":2,"is_preprint":false,"source_species":["Pf"],"role":"primary","match_terms":["CSS","PfCSS"],"competing_organism_flag":false,"competing_organism_match":"","competing_organism_only":false},{"pmid":"41676142","id":"PMC_41676142","title":"Identification of a growth-inhibitory epitope in PfRipr5, a malaria vaccine candidate against Plasmodium falciparum.","date":"2026","source":"Frontiers in immunology","url":"https://pubmed.ncbi.nlm.nih.gov/41676142","citation_count":2,"is_preprint":false,"source_species":["Pf"],"role":"primary","match_terms":["CSS"],"competing_organism_flag":false,"competing_organism_match":"","competing_organism_only":false},{"pmid":"40343341","id":"PMC_40343341","title":"PTRAMP, CSS and Ripr form a conserved complex required for merozoite invasion of Plasmodium species into erythrocytes.","date":"2025","source":"Research square","url":"https://pubmed.ncbi.nlm.nih.gov/40343341","citation_count":0,"is_preprint":false,"source_species":["Pf"],"role":"primary","match_terms":["CSS","PfCSS"],"competing_organism_flag":false,"competing_organism_match":"","competing_organism_only":false},{"pmid":"42285102","id":"PMC_42285102","title":"Analysis of monoclonal antibodies against the malaria invasion complex protein RIPR reveals the structural basis for synergistic antibody protection.","date":"2026","source":"Immunity","url":"https://pubmed.ncbi.nlm.nih.gov/42285102","citation_count":0,"is_preprint":false,"source_species":["Pf"],"role":"primary","match_terms":["CSS"],"competing_organism_flag":false,"competing_organism_match":"","competing_organism_only":false}],"cost":{"stage1":{"model":"claude-sonnet-4-6","input_tokens":7953,"output_tokens":1349,"usd":0.022047,"stage1_stop_reason":"end_turn"},"stage2":{"model":"claude-opus-4-8","input_tokens":6260,"output_tokens":2601,"usd":0.048162,"stage2_stop_reason":"end_turn"},"total_usd":0.070209,"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\": \"PfCSS forms a heteromeric disulfide-linked complex with PfPTRAMP, and this PfCSS-PfPTRAMP sub-complex binds the RCR complex (PfRH5-PfCyRPA-PfRIPR) to form the pentameric PCRCR complex. PfCSS is essential for merozoite invasion of human erythrocytes, as demonstrated by conditional knockout and invasion-inhibitory nanobodies. The PCRCR complex functions to anchor contact between the merozoite and erythrocyte membranes. The structure of nanobody-PfCSS complexes was solved to identify an inhibitory epitope on PfCSS.\",\n      \"method\": \"Conditional knockout lines, invasion-inhibitory nanobodies, lattice light-sheet microscopy, crystal structure of nanobody-PfCSS complexes\",\n      \"journal\": \"Nature microbiology\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1–2 / Strong — conditional KO with defined invasion phenotype, neutralizing nanobodies, structural determination, multiple orthogonal methods in one study\",\n      \"pmids\": [\"36396942\"],\n      \"is_preprint\": false,\n      \"attribution\": [{\"species\": \"Plasmodium falciparum\", \"strain\": \"\"}]\n    },\n    {\n      \"year\": 2023,\n      \"finding\": \"The elongated tail of PfRIPR binds to the PfCSS-PfPTRAMP complex on the parasite membrane, linking the modular PfRIPR (and thereby the RCR sub-complex presenting PfCyRPA and PfRH5) to the merozoite surface. This was established by cryo-EM structure of the PfRCR complex and a direct erythrocyte-binding assay.\",\n      \"method\": \"Cryo-electron microscopy structure of PfRCR complex, erythrocyte-binding assay, structural modelling\",\n      \"journal\": \"Nature\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 / Moderate — cryo-EM structure plus functional binding assay, single study but multiple orthogonal methods\",\n      \"pmids\": [\"38123677\"],\n      \"is_preprint\": false,\n      \"attribution\": [{\"species\": \"Plasmodium falciparum\", \"strain\": \"\"}]\n    },\n    {\n      \"year\": 2026,\n      \"finding\": \"PfCSS and PfPTRAMP form a disulfide-linked heterodimer conserved across P. falciparum, P. vivax, and P. knowlesi, and this heterodimer binds the C-terminal region of Ripr to constitute the PTRAMP-CSS-Ripr (PCR) complex in all three species. Cryo-EM of the P. knowlesi PCR complex confirmed this architecture as a core invasion scaffold.\",\n      \"method\": \"Biochemical complex reconstitution (disulfide-linked heterodimer identification), cryo-EM of P. knowlesi PCR complex, cross-reactive antibody inhibition assays\",\n      \"journal\": \"Nature communications\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1–2 / Strong — cryo-EM structural confirmation plus biochemical reconstitution across three species, peer-reviewed\",\n      \"pmids\": [\"41587959\"],\n      \"is_preprint\": false,\n      \"attribution\": [\n        {\"species\": \"Plasmodium falciparum\", \"strain\": \"\"},\n        {\"species\": \"Plasmodium vivax\", \"strain\": \"\"},\n        {\"species\": \"Plasmodium knowlesi\", \"strain\": \"\"}\n      ]\n    },\n    {\n      \"year\": 2026,\n      \"finding\": \"Anti-RIPR antibodies targeting EGF-like domains 6–8 dissociate PfCSS-PfPTRAMP from RIPR, thereby exposing additional epitopes on PfCSS and enabling further antibody binding. This identifies PfCSS-PfPTRAMP binding to the RIPR tail as a mechanistically important interaction whose disruption potentiates invasion inhibition.\",\n      \"method\": \"Monoclonal antibody characterization (83 human IgG mAbs), structural characterization, molecular dynamics simulations, growth inhibition assays\",\n      \"journal\": \"Immunity\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — structural and functional characterization with dissociation assay, single lab, multiple antibodies\",\n      \"pmids\": [\"42285102\"],\n      \"is_preprint\": false,\n      \"attribution\": [{\"species\": \"Plasmodium falciparum\", \"strain\": \"\"}]\n    }\n  ],\n  \"current_model\": \"PfCSS (PF3D7_1404700) forms a disulfide-linked heterodimer with PfPTRAMP on the merozoite surface; this heterodimer binds the C-terminal tail of PfRIPR to anchor the pentameric PCRCR complex (PfCSS–PfPTRAMP–PfRIPR–PfCyRPA–PfRH5) at the merozoite membrane, where it is essential for erythrocyte invasion by mediating membrane contact between parasite and host cell, with this PTRAMP–CSS–Ripr sub-complex conserved across multiple Plasmodium species.\"\n}\n```","stage2_raw":"{\n  \"mechanistic_narrative\": \"PfCSS (PF3D7_1404700) is a cysteine-rich small secreted protein that acts as an essential structural component of the merozoite invasion machinery in Plasmodium falciparum [#0]. It forms a disulfide-linked heterodimer with PfPTRAMP on the merozoite surface, and this heterodimer binds the elongated C-terminal tail of PfRIPR, thereby anchoring the RCR sub-complex (PfRIPR-PfCyRPA-PfRH5) to the parasite membrane to constitute the pentameric PCRCR complex [#0, #1]. Through this scaffold, PfCSS mediates the membrane contact between merozoite and erythrocyte required for invasion, and it is essential for invasion of human erythrocytes as shown by conditional knockout and invasion-inhibitory nanobodies that define a neutralizing epitope on PfCSS [#0]. The PfPTRAMP-CSS-Ripr sub-complex is a conserved core invasion scaffold across P. falciparum, P. vivax, and P. knowlesi [#2]. Beyond its role as a membrane-anchoring component of this complex, no independent molecular activity of PfCSS has been characterized in the available corpus.\",\n  \"teleology\": [\n    {\n      \"year\": 2022,\n      \"claim\": \"Establishing whether PfCSS is a functional invasion factor rather than merely a co-purifying protein, this work showed it is essential and defined its place in a larger invasion complex.\",\n      \"evidence\": \"Conditional knockout, invasion-inhibitory nanobodies, lattice light-sheet microscopy, and crystal structure of nanobody-PfCSS complexes in P. falciparum\",\n      \"pmids\": [\"36396942\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\n        \"The precise molecular basis of how the heterodimer promotes membrane contact was not resolved\",\n        \"No structure of the full assembled PCRCR complex reported here\",\n        \"Whether PfCSS has any activity independent of PfPTRAMP was not addressed\"\n      ],\n      \"attribution\": [{\"species\": \"Plasmodium falciparum\", \"strain\": \"\"}]\n    },\n    {\n      \"year\": 2023,\n      \"claim\": \"How the RCR sub-complex is physically tethered to the merozoite surface was unknown; this defined the PfRIPR tail as the direct link to the PfCSS-PfPTRAMP heterodimer.\",\n      \"evidence\": \"Cryo-EM structure of the PfRCR complex and erythrocyte-binding assay in P. falciparum\",\n      \"pmids\": [\"38123677\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\n        \"The heterodimer-membrane attachment geometry of PfCSS was not resolved at the surface\",\n        \"Contribution of PfCSS versus PfPTRAMP to RIPR tail binding not separately dissected\"\n      ],\n      \"attribution\": [{\"species\": \"Plasmodium falciparum\", \"strain\": \"\"}]\n    },\n    {\n      \"year\": 2026,\n      \"claim\": \"Whether the PfCSS-containing scaffold is a conserved invasion module across species was open; cross-species reconstitution and structure established the PTRAMP-CSS-Ripr complex as a conserved core scaffold.\",\n      \"evidence\": \"Biochemical disulfide-linked heterodimer reconstitution and cryo-EM of the P. knowlesi PCR complex, with cross-reactive antibody inhibition, across P. falciparum, P. vivax, and P. knowlesi\",\n      \"pmids\": [\"41587959\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\n        \"Functional essentiality of CSS orthologs in P. vivax and P. knowlesi not tested by genetics\",\n        \"Species-specific differences in complex regulation not characterized\"\n      ],\n      \"attribution\": [\n        {\"species\": \"Plasmodium falciparum\", \"strain\": \"\"},\n        {\"species\": \"Plasmodium vivax\", \"strain\": \"\"},\n        {\"species\": \"Plasmodium knowlesi\", \"strain\": \"\"}\n      ]\n    },\n    {\n      \"year\": 2026,\n      \"claim\": \"Whether the PfCSS-PfPTRAMP/RIPR interaction is a vaccine-relevant vulnerability was addressed by showing antibody-driven dissociation of the heterodimer from RIPR potentiates invasion inhibition.\",\n      \"evidence\": \"Characterization of 83 human IgG mAbs targeting RIPR EGF-like domains 6-8, structural analysis, molecular dynamics, and growth inhibition assays in P. falciparum\",\n      \"pmids\": [\"42285102\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\n        \"Antibodies target RIPR, so direct inhibitory targeting of PfCSS itself was not the primary readout\",\n        \"In vivo protective relevance not established\",\n        \"Mechanism by which dissociation exposes new PfCSS epitopes not structurally resolved\"\n      ],\n      \"attribution\": [{\"species\": \"Plasmodium falciparum\", \"strain\": \"\"}]\n    },\n    {\n      \"year\": null,\n      \"claim\": \"The intrinsic biochemical activity of PfCSS beyond serving as a disulfide-linked membrane-anchoring partner of PfPTRAMP remains undefined.\",\n      \"evidence\": \"\",\n      \"pmids\": [],\n      \"confidence\": \"Low\",\n      \"gaps\": [\n        \"No ligand or enzymatic activity attributed to PfCSS alone\",\n        \"The functional consequence of the cysteine-rich fold beyond heterodimer formation is uncharacterized\",\n        \"Contribution of PfCSS to the erythrocyte-contact step at molecular resolution is unresolved\"\n      ],\n      \"attribution\": []\n    }\n  ],\n  \"mechanism_profile\": {\n    \"molecular_activity\": [\n      {\"term_id\": \"GO:0005515\", \"supporting_discovery_ids\": [0, 1, 2]}\n    ],\n    \"localization\": [\n      {\"term_id\": \"GO:0009986\", \"supporting_discovery_ids\": [0]}\n    ],\n    \"pathway\": [\n      {\"term_id\": \"GO:0044409\", \"supporting_discovery_ids\": [0, 1, 2]}\n    ],\n    \"complexes\": [\n      \"PCRCR complex (PfCSS-PfPTRAMP-PfRIPR-PfCyRPA-PfRH5)\",\n      \"PfCSS-PfPTRAMP disulfide-linked heterodimer\",\n      \"PTRAMP-CSS-Ripr (PCR) core invasion scaffold\"\n    ],\n    \"partners\": [\n      \"PfPTRAMP\",\n      \"PfRIPR\",\n      \"PfCyRPA\",\n      \"PfRH5\"\n    ],\n    \"other_free_text\": [\n      \"PfCSS is essential for P. falciparum merozoite invasion of human erythrocytes (conditional knockout) [#0]\",\n      \"Invasion-inhibitory nanobodies define a neutralizing epitope on PfCSS [#0]\",\n      \"PfCSS-PfPTRAMP binds the C-terminal/elongated tail of PfRIPR to anchor the RCR sub-complex to the merozoite membrane [#1, #2]\",\n      \"The PTRAMP-CSS-Ripr scaffold is conserved across P. falciparum, P. vivax, and P. knowlesi [#2]\",\n      \"Anti-RIPR antibodies (EGF-like domains 6-8) dissociate PfCSS-PfPTRAMP from RIPR, exposing further PfCSS epitopes [#3]\"\n    ]\n  }\n}","audit_flag":null,"strains":[{"strain":"Pf3D7","gene_id":"PF3D7_1404700","name":null,"product":"cysteine-rich small secreted protein CSS, putative","uniprot_acc":null,"chromosome":null,"start_pos":null},{"strain":"PbANKA","gene_id":"PBANKA_1037400","name":null,"product":"cysteine-rich small secreted protein CSS, putative","uniprot_acc":null,"chromosome":null,"start_pos":null},{"strain":"PkH","gene_id":"PKNH_1353400","name":null,"product":"cysteine-rich small secreted protein CSS","uniprot_acc":null,"chromosome":null,"start_pos":null}],"gene_symbol":"CSS","evaluation":null}