| 2026 |
Cryo-EM structure of the endogenous moving junction purified from invasion-stalled P. falciparum parasites reveals that PfRON4 assembles with PfAMA1, PfRON2, and PfRON5 in a 1:1:1:1 'sailboat-shaped' complex; PfRON2/4/5 form a large, basic platform inside the red blood cell that electrostatically engages the RBC membrane and wedges seven amphipathic helices deep into the bilayer, implying an active role for the complex (including PfRON4) in host-membrane remodeling. |
Cryo-EM structure determination of endogenous complex purified directly from invasion-stalled parasites; structural analysis of transmembrane anchoring and membrane-interaction surfaces |
Cell |
High |
42379167
|
| 2006 |
PfRON4 co-immunoprecipitates with PfAMA1, establishing that the rhoptry neck protein PfRON4 physically interacts with the microneme protein AMA1 in P. falciparum merozoites; PfRON4 originates in the rhoptry necks, mirroring the TgRON4–TgAMA1 collaboration in Toxoplasma. |
Co-immunoprecipitation; immunofluorescence localization |
Eukaryotic cell |
Medium |
16835460
|
| 2008 |
Co-immunoprecipitation in P. falciparum confirmed that PfRON4 forms a complex with PfRON2 and PfAMA1, demonstrating conservation of the moving junction complex between T. gondii and P. falciparum. |
Co-immunoprecipitation |
Parasitology international |
Medium |
18952195
|
| 2010 |
The R1 peptide, which binds the PfAMA1 hydrophobic trough, blocks the interaction between PfAMA1 and the PfRON complex (containing PfRON4); this association occurs after merozoite reorientation and engagement of the actomyosin motor, placing PfRON4-containing complex formation at a defined step preceding rhoptry contents release. |
Peptide inhibition assay; invasion timing assays; co-immunoprecipitation competition |
The Journal of biological chemistry |
Medium |
20228060
|
| 2011 |
In P. berghei, RON4 is required for merozoite invasion of erythrocytes and also for sporozoite invasion of hepatocytes, and RON4 acts independently of AMA1 in the sporozoite context (RON4 knockdown impairs sporozoite hepatocyte invasion while AMA1 is dispensable for sporozoite TJ assembly). |
Genetic loss-of-function (gene knockdown/knockout) in P. berghei; invasion assays in erythrocytes and hepatocytes; immunofluorescence |
Cell host & microbe |
High |
22177563
|
| 2011 |
PfRON3 co-immunoprecipitates with PfRON4 (and PfRON2) but not with PfAMA1, indicating PfRON4 participates in a second RON complex (PfRON2/3/4) distinct from the canonical moving junction complex (PfRON2/4/5/AMA1). |
Co-immunoprecipitation |
Parasitology international |
Low |
21237287
|
| 2012 |
Super-resolution imaging during merozoite invasion places the actin ring posterior to, and not concentric with, PfRON4 at the tight junction, indicating that PfRON4 marks the adhesion site while dynamic actin microfilaments form a distinct, more posterior zone of traction. |
Super-resolution fluorescence microscopy (live imaging and fixed); co-localization with RON4 as junction marker |
PloS one |
Medium |
22389687
|
| 2014 |
In P. yoelii sporozoites, RON2 and RON4 are lost following rhoptry discharge during sporozoite entry into hepatocytes; rhoptry discharge of RON4 occurs only when host membrane protein CD81 is present, demonstrating that CD81 is required for productive sporozoite invasion upstream of RON4 secretion. |
Transgenic parasites expressing fluorescent RON4; live imaging of sporozoite entry; CD81-deficient vs. wild-type hepatocyte comparison |
Cellular microbiology |
Medium |
24798694
|
| 2018 |
Immunoprecipitation followed by mass spectrometry identified that PfRON4 interacts with SURFIN4.2 and GLURP to form the SURGE complex in the rhoptry neck of P. falciparum merozoites, implicating PfRON4 in a broader protein assembly at the merozoite apex–RBC contact site. |
Immunoprecipitation followed by mass spectrometry; immunofluorescence co-localization |
PloS one |
Low |
30092030
|
| 2019 |
Immuno-electron microscopy in P. berghei sporozoites shows that RON4 localizes to rhoptries (throughout the organelle rather than exclusively at the neck as in merozoites), demonstrating a stage-specific redistribution of RON4 subcellular localization. |
Immuno-electron microscopy; immunofluorescence assay in sporozoites |
Frontiers in cellular and infection microbiology |
Medium |
31552198
|
| 2020 |
Co-immunoprecipitation from P. berghei oocyst-derived sporozoite extracts demonstrated that RON2, RON4, and RON5 form a protein complex in sporozoites. Sporozoite stage-specific gene knockdown of RON4 significantly reduced sporozoite attachment to salivary gland cells and impaired salivary gland invasion. Reciprocal trafficking experiments showed that RON2 and RON4 mutually affect each other's stability and trafficking to rhoptries in developing sporozoites, while RON5 is independently transported. |
Co-immunoprecipitation from sporozoite extracts; sporozoite stage-specific gene knockdown (P. berghei); attachment and invasion assays; fluorescence microscopy of rhoptry trafficking |
mSphere |
High |
32817376
|
| 2022 |
Using DiCre-mediated conditional deletion in P. berghei, loss of RON4 in sporozoites impaired colonization of mosquito salivary glands and invasion of mammalian hepatocytes without affecting transcellular migration. 3D electron microscopy showed that absence of a functional AMA1-RON complex (including RON4) altered the morphology of the entry junction and caused epithelial cell damage, demonstrating that the AMA1-RON4-containing complex is required for efficient and safe host cell entry across transmission stages. |
DiCre-mediated conditional gene deletion in P. berghei; salivary gland colonization assay; hepatocyte invasion assay; 3D electron microscopy of entry junctions |
PLoS pathogens |
High |
35731833
|
| 2023 |
Sporozoite stage-specific knockdown of RON4 in P. berghei demonstrated that RON4 is required for traversal of sinusoidal cells and infection of hepatocytes in vivo; in vitro experiments showed that secreted RON4 mediates sporozoite adhesion to hepatocytes and is required for the onset of gliding motility (attachment to substrate), establishing RON4 as having multiple sequential functions during liver-stage infection. |
Sporozoite stage-specific gene silencing in P. berghei; in vivo intravenous inoculation into mice; in vitro hepatoma cell infection assays; in vitro motility assays |
mSphere |
High |
37272704
|
| 2023 |
Receptor-ligand binding assays with P. falciparum RON4-derived conserved peptides identified specific regions (PfRON4 residues 800–819 and 860–879) that bind erythrocytes via protease-sensitive protein receptors and HepG2 hepatocyte membranes via heparin- and chondroitin sulphate proteoglycan-type receptors; peptides corresponding to these regions inhibited in vitro merozoite invasion. |
Peptide synthesis; erythrocyte and HepG2 binding assays; enzyme treatment of host cells (trypsin, chymotrypsin, heparinase I, chondroitinase ABC); in vitro invasion inhibition assays; surface plasmon resonance (Kd determination) |
International journal of medical microbiology : IJMM |
Medium |
37030083
|
| 2009 |
Quantitative real-time PCR of synchronized P. falciparum cultures showed that PfRON4 gene transcription peaks at the mature schizont stage (36–40 hours post-invasion), consistent with its protein's role in erythrocyte invasion. |
Real-time quantitative PCR of synchronized P. falciparum parasites |
Zhongguo ji sheng chong xue yu ji sheng chong bing za zhi |
Low |
19852359
|
| 2008 |
PyP140/RON4 in P. yoelii localizes to the apical end of merozoites (rhoptries or micronemes) and forms a complex with AMA1; however, the conserved cysteine-rich domain, when expressed recombinantly, failed to elicit growth-inhibitory antibodies in mice, indicating this domain alone is not a protective immunogen. |
Monoclonal antibody screening of cDNA expression library; IFA localization; immunoprecipitation with AMA1; recombinant protein immunization and challenge in BALB/c mice |
Infection and immunity |
Medium |
18710865
|