| 2010 |
PI3K (PfPI3K) is exported to the host erythrocyte by the parasite in an active form. Within the parasite, it localizes to vesicular compartments near the membrane and in the food vacuole. It can generate various 3'-phosphorylated PIPs. Inhibition of PfPI3K by wortmannin or LY294002 resulted in entrapment of hemoglobin in vesicles in the parasite cytoplasm, preventing its transport to the food vacuole, attenuating hemoglobin digestion and parasite growth. |
Subcellular fractionation and export assay, PI3K inhibitor treatment (wortmannin, LY294002), fluorescence microscopy, in vitro parasite growth assay |
Blood |
Medium |
20093402
|
| 2010 |
The PI3K gene could not be deleted in P. berghei, indicating it is essential in Plasmodium blood stages. In P. falciparum, in vitro growth was sensitive to a PI3K inhibitor. The class III PI3K encoded by the Plasmodium genome is of unusual size with large insertions and repetitive sequence motifs. PI3P production was parasite-dependent, sensitive to a PI3K inhibitor, and predominant in late parasite stages. |
Gene deletion attempt (knockout failure) in P. berghei, PI3K inhibitor treatment in P. falciparum, PI3P quantification in parasite-infected erythrocytes |
Eukaryotic cell |
Medium |
20709789
|
| 2015 |
Artemisinins are potent inhibitors of PfPI3K. In artemisinin-resistant clinical strains, increased PfPI3K levels were associated with the C580Y mutation in PfKelch13. Polyubiquitination of PfPI3K and its binding to PfKelch13 were reduced by the PfKelch13 C580Y mutation, limiting proteolysis of PfPI3K and thereby increasing kinase levels and its lipid product PI3P. Elevated PI3P was identified as the key mediator of artemisinin resistance. PI3P levels were predictive of artemisinin resistance across clinical and laboratory parasite strains. |
Biochemical inhibition assays, polyubiquitination assay, co-immunoprecipitation (PfPI3K–PfKelch13 binding), PI3P quantification in clinical and engineered parasites, transgenic parasite expression, proteolysis assays |
Nature |
High |
25874676
|
| 2017 |
PfPI3K is a class III ('Vps34'-type) PI3K. When heterologously expressed in yeast and purified to homogeneity, it produces phosphatidylinositol 3'-phosphate from phosphatidylinositol. It is inhibited by artemisinin and related drugs, but only under conditions that cleave the endoperoxide bridge to generate reactive alkylating agents (i.e., irreversible inhibition by Fe2+-mediated covalent modification). Mutagenesis of key residues in the catalytic and N-lobe domains was used to investigate their importance. |
Heterologous expression in yeast, protein purification to homogeneity, quantitative PI3P production assay, drug inhibition assay, active-site mutagenesis |
Biochemistry |
High |
28719180
|
| 2020 |
PI3P generated by PfPI3K stabilizes the digestive vacuole (DV) under heat stress. PI3K inhibitors destabilized the DV before parasite death, and this was reversible upon withdrawal of the inhibitor and heat stress. A chemoproteomic approach identified PfHsp70-1 as a PI3P-binding protein. Knockdown of PfHsp70-1 phenocopied PI3P-deficient parasites under heat shock, and PfHsp70-1 downregulation hypersensitized parasites to heat shock and PI3K inhibitors, establishing a mechanistic link between PI3P and PfHsp70-1 in DV stabilization during fever-like stress. |
Live cell microscopy with chemical and genetic PI3P reporters, PI3K inhibitor treatment, chemoproteomic pulldown to identify PI3P-binding proteins, Hsp70-1 knockdown, Hsp70 inhibitor treatment |
eLife |
High |
32975513
|
| 2020 |
MMV390048, a putative PfPI4KIIIβ inhibitor in advanced trials, was found to also potently inhibit PfPI3K (PfVps34) in vitro using purified enzyme, demonstrating dual PIK inhibitory activity. |
In vitro enzyme inhibition assay with purified PfPI3K and PfPI4KIIIβ proteins |
Biochemistry |
Medium |
32543181
|
| 2023 |
PfK13-R539T ART-resistant parasites exhibited increased basal autophagy compared to wild-type. Suppression of PI3K activity rendered ART-resistant parasites unable to survive, establishing PI3K as a master autophagy regulator required for the pro-survival autophagic response in ART-resistant parasites. |
Autophagic flux assays, PI3K inhibitor treatment of PfK13-R539T and wild-type parasites, parasite survival assays |
Cell death discovery |
Medium |
37173329
|
| 2024 |
PfPI3K is upregulated in P. falciparum-infected red blood cells during intraerythrocytic development. PfPI3K phosphorylated and activated erythrocytic ubiquitin-protein E3 ligase, leading to increased ubiquitination and selective degradation of α-spectrin (but not β-spectrin) of the host erythrocyte. Inhibition of PfPI3K activity impaired P. falciparum development in vitro and P. berghei infectivity in mice. |
Western blot for PfPI3K expression, ubiquitination assays of erythrocytic α-spectrin, PI3K inhibitor treatment in vitro and in vivo (mouse model), co-immunoprecipitation/kinase activity assays |
mBio |
Medium |
38470053
|
| 2026 |
PfPI3K interacts with PfVps15 (a pseudokinase/Vps15 orthologue) as shown by co-immunoprecipitation, but unlike in yeast and mammalian cells, they are potentially not part of a heterotetrameric complex. Knock-sideways removal of PfVps15 led to rapid parasite death, decreased PI3P levels, abrogation of host-cell cytosol delivery to the food vacuole, and defects in apicoplast biogenesis and mitochondrial fission, establishing that the PfVps15–PfPI3K interaction is required for PI3P synthesis and vesicular trafficking of host-cell cytosol. |
Co-immunoprecipitation (PfVps15–PfPI3K interaction), knock-sideways conditional mislocalisation, PI3P level quantification, live-cell fluorescence microscopy of vesicular trafficking, apicoplast and mitochondrion dynamics |
PLoS pathogens |
High |
42611934
|
| 2026 |
PI3K was characterised for the first time via expansion microscopy in P. falciparum. Inhibition of the PI3K-mediated pathway significantly reduced the number of Mtphagy-positive parasites (mitochondrial stress marker) and was associated with delayed recrudescence in DHA-treated parasites, implicating PI3K activity in the mitochondrial dynamics underlying artemisinin-induced growth arrest and recrudescence. |
Expansion microscopy (PI3K localisation), PI3K pathway inhibition combined with Mtphagy fluorescence assay, recrudescence assays after DHA treatment |
mSphere |
Medium |
42429611
|
| 2025 |
Idelalisib, a PI3K inhibitor, effectively inhibited PfPI3K activity in P. falciparum, causing a decline in PI3P levels. This led to ROS accumulation, apoptosis-like parasite death, and accumulation of ubiquitinated proteins, downregulation of molecular chaperone gene expression, and increased eIF2α phosphorylation. Combination of idelalisib with dihydroartemisinin exerted synergistic antimalarial effects and reversed ART resistance. |
PfPI3K activity assay with idelalisib, PI3P level quantification, ROS measurement, ubiquitinated protein quantification, gene expression analysis of chaperones, eIF2α phosphorylation assay, in vitro drug combination assay |
Communications biology |
Medium |
41286015
|