| 1999 |
PIKfyve (p235) is a phosphoinositide 5-kinase that phosphorylates PtdIns to generate PtdIns 5-P and PtdIns 3,5-P2 in vitro; recombinant PIKfyve expressed in COS cells showed striking substrate specificity for PtdIns over other PI substrates, and deletion mutant analysis showed that regions beyond the catalytic domain are critical for enzymatic activity. |
In vitro lipid kinase assay with HPLC product identification, COS cell expression of deletion mutants |
The Journal of biological chemistry |
High |
10419465
|
| 2000 |
PIKfyve possesses an intrinsic protein kinase (serine kinase) activity inseparable from its lipid kinase activity; PIKfyve autophosphorylation on serine residues downregulates its lipid product formation by ~70%, which is reversed by phosphatase treatment, establishing a self-regulatory feedback mechanism. |
In vitro kinase assay with immunopurified and affinity-purified PIKfyve from COS cells, Sf9 cells, and native adipocytes; phosphatase treatment reversal; lipid kinase dead mutants as controls |
Biochemistry |
High |
11123925
|
| 2001 |
PIKfyve FYVE domain specifically and with high affinity binds PtdIns 3-P-containing liposomes; this interaction requires the conserved core of basic residues in the FYVE finger and is absolutely necessary for PIKfyve targeting to late endocytic pathway membranes. Wortmannin treatment dissociates endosome-bound PIKfyve, confirming PI 3-kinase-dependent membrane targeting. |
Liposome binding assay with recombinant FYVE domain peptide, wortmannin treatment, fluorescence microscopy of localization mutants |
The Journal of biological chemistry |
High |
11706043
|
| 2001 |
PIKfyve enzymatic activity is required for endosomal membrane homeostasis in mammalian cells; a kinase-dead point mutant (K1831E) causes dominant-negative swollen vacuolation of late endocytic structures. Functional dissection using double mutants (K1999E/K2000E) established that it is specifically the PtdIns 3,5-P2-producing lipid kinase activity (not protein kinase or PtdIns 5-P synthesis) that is critical, as microinjection of PtdIns 3,5-P2 selectively rescued the endomembrane defects. |
Transient transfection of kinase-dead and activation-loop mutants in COS cells; phosphoinositide microinjection rescue experiments; dominant-negative morphological assay |
The Journal of biological chemistry |
High |
11285266 11714711
|
| 2002 |
PIKfyve is responsible for intracellular PtdIns 5-P production in cells; overexpression of PIKfyve(WT) increased PtdIns 5-P levels by 20-50% while dominant-negative PIKfyve(K1831E) decreased them by 60%. PtdIns 5-P levels decrease profoundly upon hypo-osmotic shock, implicating PIKfyve-produced PtdIns 5-P in osmotic response pathways. |
32P-labeling of multiple cell types (Sf9, 3T3-L1, HEK293) with HPLC head group analysis; type II PIP kinase-directed conversion assay for PtdIns 5-P quantification; kinase-dead dominant-negative expression |
The Journal of biological chemistry |
High |
12270933
|
| 2003 |
PIKfyve physically interacts with p40 (a Rab9 effector for endosome-to-TGN transport) via its chaperonin domain; PIKfyve enzymatic activity is required for membrane attachment of p40, and PIKfyve phosphorylates p40 on serine residues in vitro. Kinase-dead PIKfyve expression markedly depletes p40 from membrane fractions, suggesting PIKfyve-catalyzed p40 phosphorylation anchors p40 to facilitate late endosome-to-TGN transport. |
Yeast two-hybrid, GST pulldown, co-immunoprecipitation in HEK293 cells, differential centrifugation fractionation, in vitro kinase assay, liposome binding assay |
The Journal of biological chemistry |
High |
14530284
|
| 2004 |
PKB/Akt phosphorylates PIKfyve at Ser318 in a PI3-kinase-dependent manner in response to insulin, stimulating its PtdIns 3-P 5-kinase activity. A PIKfyve S318A phosphorylation-deficient mutant enhances insulin-stimulated IRAP/GLUT4 vesicle translocation to the plasma membrane in 3T3-L1 adipocytes, demonstrating that PKB-dependent phosphorylation of PIKfyve regulates GLUT4 trafficking. |
In vitro PKB kinase assay, phospho-specific detection in intact cells, 3T3-L1 adipocyte GLUT4 translocation assay with phosphorylation-deficient mutant, PIKfyve-IRAP/GLUT4 co-localization by fluorescence microscopy |
Journal of cell science |
High |
15546921
|
| 2004 |
Human Vac14 (ArPIKfyve/hVac14) is a positive regulator of PIKfyve enzymatic activity; it physically associates with PIKfyve, co-localizes on intracellular membranes, and its siRNA-mediated depletion reduces PIKfyve lipid kinase activity and PtdIns 3,5-P2 production while inducing vacuolar morphology. Ectopic hVac14 expression increases PIKfyve activity and PtdIns 3,5-P2 synthesis. |
Co-immunoprecipitation, co-fractionation, siRNA knockdown with lipid kinase assay and 32P-labeling, morphological vacuolation assay, ectopic overexpression |
Molecular and cellular biology |
High |
15542851
|
| 2006 |
PIKfyve is predominantly associated with dynamic tubular/vesicular elements of the early endosomal compartment; siRNA suppression of PIKfyve induces swollen endosomes and causes a specific defect in endosome-to-TGN retrograde transport without perturbing EGF receptor or transferrin receptor sorting. |
Fixed and live-cell fluorescence imaging, siRNA knockdown, receptor trafficking assays (EGFR degradation, transferrin recycling, CI-M6PR retrograde trafficking) |
Journal of cell science |
High |
16954148
|
| 2007 |
Sac3 (mammalian Fig4) is a PtdIns 3,5-P2-specific phosphatase that forms a stable ternary complex with ArPIKfyve and PIKfyve (the PAS complex); Sac3 preferentially hydrolyzes PtdIns 3,5-P2 in vitro; siRNA ablation of Sac3 elevated PtdIns 3,5-P2 levels; in vitro reconstitution of vesicle formation from early endosomes showed gain of function upon Sac3 loss and loss of function upon PIKfyve/ArPIKfyve depletion, demonstrating that PtdIns 3,5-P2 synthesis and turnover are coupled through this physical complex. |
Co-immunoprecipitation of endogenous proteins, co-fractionation, co-localization, in vitro phosphatase assay, 32P-labeling with HPLC, siRNA knockdown, in vitro vesicle formation reconstitution |
The Journal of biological chemistry |
High |
17556371
|
| 2007 |
PIKfyve physically interacts with kinesin adapter JLP (a splice variant of Jip4) via the PIKfyve cpn60_TCP1 domain; both PIKfyve and JLP siRNA knockdown profoundly delays microtubule-based transport of furin cargo from endosomes to the TGN, but not the microtubule-independent TGN38 trafficking pathway, indicating PIKfyve-JLP interaction is specifically required for microtubule-dependent endosome-to-TGN transport. |
Yeast two-hybrid, GST pulldown, co-immunoprecipitation, siRNA knockdown with Tac-furin and Tac-TGN38 trafficking assays, peptide microinjection, rescue with siRNA-resistant constructs |
The Journal of biological chemistry |
High |
19056739
|
| 2007 |
PIKfyve mediates HB-EGF-stimulated EGFR nuclear trafficking; RNA silencing of PIKfyve blocks EGFR transit to the nucleus, EGFR binding to the cyclin D1 promoter, and cell cycle progression in bladder cancer cells. PIKfyve was identified as a component of EGFR immune complexes by mass spectrometry. |
Mass spectrometry of EGFR immune complexes, RNA silencing, nuclear fractionation, ChIP assay, cell cycle analysis |
Cancer research |
Medium |
17909029
|
| 2007 |
PIKfyve localizes to a subpopulation of secretory granules in chromaffin and PC12 cells; PIKfyve activity negatively regulates regulated exocytosis. PIKfyve inhibition or knockdown potentiates secretory granule exocytosis, while PIKfyve overexpression or its yeast ortholog Fab1p overexpression inhibits it. A catalytically inactive PIKfyve mutant had no effect, indicating the lipid kinase activity is required for this inhibitory role. |
Live-cell imaging (PIKfyve-EGFP recruitment), siRNA knockdown, pharmacological inhibition (YM-201636), secretion assay in PC12 cells, overexpression of active and inactive mutants |
The Journal of biological chemistry |
High |
18039667
|
| 2008 |
ArPIKfyve organizes the PAS (PIKfyve-ArPIKfyve-Sac3) complex through homomeric interactions mediated by its conserved C-terminal domain; ArPIKfyve interacts with both PIKfyve and Sac3, while Sac3 is permissive for maximal PIKfyve-ArPIKfyve association. Introduction of the ArPIKfyve C-terminal peptide fragment disassembles the PAS complex, reduces PIKfyve lipid kinase activity in vitro, and inhibits GLUT4 surface accumulation in 3T3-L1 adipocytes. |
Co-immunoprecipitation in transfected mammalian cells with varied protein combinations, in vitro lipid kinase assay, GLUT4 translocation assay, dominant-interfering peptide |
Journal of molecular biology |
High |
18950639
|
| 2008 |
PIKfyve inhibition by YM201636 disrupts endosomal sorting and causes accumulation of a late endosomal compartment, blocking retroviral (HIV) exit. The specificity of PIKfyve inhibition was confirmed by siRNA knockdown and by rescue with the drug-resistant yeast ortholog Fab1. |
Pharmacological inhibition (YM201636), siRNA knockdown, rescue with drug-resistant yeast Fab1, 32P-labeling of phosphoinositides, electron microscopy, retroviral budding assay |
EMBO reports |
High |
18188180
|
| 2009 |
PIKfyve inhibition blocks lysosomal degradation of activated EGFR and Met receptors (trapping them in swollen endosomes) and causes accumulation of lipidated GFP-LC3 autophagosomes; combined siRNA knockdown of PIKfyve and its activator Vac14 is required to block EGFR degradation, suggesting a low threshold of PtdIns 3,5-P2 is sufficient for this pathway. |
siRNA knockdown, pharmacological inhibition (PIKfyve-specific compound), immunofluorescence, EGF/Met receptor degradation assay, GFP-LC3 autophagosome assay |
Traffic |
High |
19582903
|
| 2009 |
PIKfyve phosphorylates Ser318 on PIKfyve in a SGK consensus sequence; PIKfyve expression increases EAAT2 (glutamate transporter) current and protein abundance at the cell membrane in Xenopus oocytes; the S318A PIKfyve mutant lacking the SGK phosphorylation site abolishes PIKfyve's stimulatory effect on EAAT2. |
Xenopus oocyte expression system, dual-electrode voltage clamp, confocal microscopy of membrane protein abundance, kinase-dead and phosphorylation-site mutants |
Cellular physiology and biochemistry |
Medium |
19910676
|
| 2009 |
PIKfyve regulates degradation of the voltage-gated calcium channel CaV1.2; NMDA receptor activation recruits PIKfyve to CaV1.2 channels and increases cellular PtdIns(3,5)P2, promoting CaV1.2 targeting to lysosomes. PIKfyve knockdown prevents CaV1.2 degradation and increases neuronal susceptibility to excitotoxicity. |
Co-immunoprecipitation, PIKfyve knockdown (shRNA), lipid mass measurement, CaV1.2 internalization and degradation assays, excitotoxicity assay in neurons |
The Journal of cell biology |
High |
19841139
|
| 2009 |
PIKfyve Sac3 (assembled in the PAS complex) retains active PtdIns 3,5-P2 phosphatase activity; the Cpn60_TCP1 domain of PIKfyve is the major determinant for associating the ArPIKfyve-Sac3 subcomplex; phosphatase-dead Sac3(D488A) co-expressed with ArPIKfyve mitigates vacuolation caused by kinase-dead PIKfyve(K1831E), confirming that Sac3 activity within the complex turns over PtdIns 3,5-P2 at endosomes. |
Co-immunoprecipitation with truncation and point mutants, morphological vacuolation assay in triple-transfected COS cells |
The Journal of biological chemistry |
High |
19840946
|
| 2012 |
In vivo, Pikfyve generates all of the cellular PI(3,5)P2 pool and nearly all of the PI5P pool; PI5P is generated directly from PI(3,5)P2 likely via 3'-phosphatase activity. shRNA silencing of residual Pikfyve in hypomorphic fibroblasts demonstrated Pikfyve is required for the entire PI(3,5)P2 pool. |
Pikfyve gene-trap mouse hypomorph, shRNA silencing of residual Pikfyve transcript, 32P-lipid labeling with HPLC from fibroblasts and tissues |
Proceedings of the National Academy of Sciences |
High |
23047693
|
| 2012 |
PIKfyve-synthesized PtdIns 5-P (not PtdIns 3,5-P2) mediates insulin-induced actin stress fiber disassembly; low-dose YM201636 preferentially inhibits PtdIns 5-P synthesis over PtdIns 3,5-P2 synthesis and blocks actin disassembly but not GLUT4 translocation, providing first experimental separation of the two PIKfyve lipid products' cellular functions. |
Differential dose-response with PIKfyve inhibitor YM201636, 32P-labeling and HPLC lipid quantification, actin stress fiber assay, GLUT4 translocation assay in 3T3-L1 adipocytes and CHO-T cells |
American journal of physiology. Cell physiology |
High |
22621786
|
| 2012 |
PIKfyve and MTMR3 together produce PtdIns 5-P via a phosphoinositide loop (PtdIns → PtdIns 3-P → PtdIns(3,5)P2 → PtdIns 5-P) that promotes cell migration; direct addition of exogenous PtdIns 5-P or a PtdIns 5-P-producing bacterial enzyme stimulates migration, and PIKfyve knockdown reduces cell migration in fibroblasts. |
siRNA knockdown, exogenous PtdIns 5-P delivery, bacterial enzyme-driven PtdIns 5-P production, Drosophila in vivo model, cell migration screen |
EMBO reports |
High |
23154468
|
| 2013 |
AKT phosphorylates and activates PIKfyve upon EGF stimulation, promoting EGFR endocytic trafficking to lysosomes and degradation; AKT-impaired cells accumulate EGFR in early endosomes and show prolonged ERK/RSK signaling. This AKT→PIKfyve→vesicle trafficking axis was also observed for PDGFR, indicating a common RTK feedback mechanism. |
AKT inhibition, PIKfyve knockdown/overexpression, EGFR trafficking and degradation assays, co-immunoprecipitation, kinase assay, early endosome immunofluorescence, PDGFR validation |
Science signaling |
High |
23757022
|
| 2013 |
Apilimod binds directly to PIKfyve and blocks its phosphotransferase activity; pharmacological or genetic inactivation of PIKfyve is necessary and sufficient for suppression of TLR-induced IL-12/IL-23p40 expression, establishing PIKfyve as a critical player in TLR signaling. |
Chemical genetic affinity approach (apilimod as affinity tool), in vitro kinase assay, siRNA knockdown of PIKfyve, TLR stimulation assays, cytokine measurement |
Chemistry & biology |
High |
23890009
|
| 2013 |
AMPK phosphorylates PIKfyve at Ser307 both in vitro and in intact cells; contraction/AMPK activation increases PtdIns(3,5)P2 levels and PIKfyve phosphorylation in skeletal muscle; wild-type but not S307A PIKfyve is recruited to endosomal vesicles upon AMPK activation; PIKfyve inhibition reduces contraction- and AMPK-stimulated glucose uptake, positioning PIKfyve as an AMPK substrate linking contraction to GLUT4 translocation. |
In vitro AMPK kinase assay, intact cell phosphorylation, subcellular fractionation, siRNA knockdown in C2C12, PIKfyve inhibitor in rat muscles, S307A phosphorylation-site mutant |
The Biochemical journal |
High |
23905686
|
| 2014 |
PIKfyve inhibition in macrophages hinders phagosome maturation by delaying removal of PtdIns 3-P from phagosomes and reducing acquisition of LAMP1 and cathepsin D (lysosomal markers), reducing phagosomal degradative capacity; lysosomal trafficking and degradative capacity were also reduced, consistent with PIKfyve/PtdIns 3,5-P2 synthesis being required for phagolysosome maturation. |
FcγR-mediated phagocytosis assay in macrophages, pharmacological PIKfyve inhibition, immunofluorescence for PI3P, LAMP1, cathepsin D, degradation assays |
Traffic |
High |
25041080
|
| 2015 |
APP (Amyloid Precursor Protein) intracellular domain directly binds purified Vac14 (a PIKfyve complex scaffolding protein); APP associates with the PIKfyve complex (Vac14/PIKfyve/Fig4) and drives formation of PI(3,5)P2-positive vesicles. APP family members are required for PIKfyve function and the PIKfyve complex is required for APP trafficking, establishing a feedback loop. |
Proteo-liposome interactome assay, direct binding with purified Vac14, co-immunoprecipitation of APP with complex members, PI(3,5)P2 vesicle formation assay, C. elegans genetic epistasis |
Cellular and molecular life sciences |
High |
26125944 26216398
|
| 2016 |
PIKfyve inhibition increases exosome secretion and induces secretory autophagy; apilimod treatment or siRNA depletion of PIKfyve increased MVBs per cell and intraluminal vesicles per MVB; autophagy-related proteins (NBR1, p62, LC3, WIPI2) are enriched in exosomal fractions from PIKfyve-inhibited cells; both EGF and long-lived protein degradation were reduced. These data indicate PIKfyve is required for lysosome fusion with MVBs and autophagosomes. |
Apilimod treatment, siRNA knockdown, quantitative electron microscopy, mass spectrometry, immunoblotting, density gradients, EGF degradation assay, long-lived protein degradation assay |
Cellular and molecular life sciences |
High |
27438886
|
| 2016 |
PIKfyve regulates vacuole maturation and nutrient recovery during macropinocytosis, entosis, and phagocytosis partly through its downstream effector TRPML1 (a cationic transporter); PIKfyve activity promotes recovery of nutrients from vacuoles and protects nutrient-depleted Ras-mutant cells from starvation-induced cell death. |
PIKfyve inhibition, TRPML1 agonists/antagonists, vacuole maturation assay, nutrient recovery assay, cell death assay under starvation |
Developmental cell |
Medium |
27623384
|
| 2017 |
PIKfyve inhibition leads to lysosome enlargement through lysosome coalescence (fusion over fission imbalance) rather than through biosynthesis; PIKfyve inhibition activates TFEB/TFE3/MITF but this transcriptional response does not augment lysosomal protein levels during acute inhibition and deletion of TFEB/related proteins did not impair lysosome swelling; conditions reducing fusion curtailed lysosome swelling. |
Pharmacological PIKfyve inhibition, TFEB/TFE3/MITF reporter assays, lysosomal protein immunoblotting, live-cell imaging of lysosome dynamics, fusion-inhibiting conditions |
Journal of cell science |
High |
29661845
|
| 2017 |
PIKfyve activity is required for terminal lysosome reformation from endolysosomes; live-cell imaging and electron tomography show PIKfyve activity regulates extensive membrane remodeling that initiates lysosome reformation from acidic, hydrolase-active endolysosomes. |
Live-cell imaging, electron tomography, PIKfyve inhibition |
Traffic |
High |
28857423
|
| 2017 |
PIKfyve inhibition in neutrophils blocks phagosome-lysosome fusion (rescuable with Ca2+ ionophores or TRPML1 agonists), and inhibits chemotaxis and reactive oxygen species (ROS) production through failure to activate Rac GTPases; PtdIns 5-P (not PtdIns 3,5-P2) is proposed to control Rac and thus chemotaxis/ROS, while PtdIns 3,5-P2 activates TRPML1 to regulate phagosome maturation. |
Human and mouse neutrophil PIKfyve inhibition, granule morphology assay, degranulation assay, phagosome-lysosome fusion assay, Ca2+ ionophore rescue, TRPML1 agonist rescue, chemotaxis assay, ROS assay, Rac activation assay |
Journal of immunology |
High |
28779020
|
| 2018 |
PIKfyve inhibition blocks phago/lysosome maturation and acidification, elevates ROS, reduces cathepsin S and B activity (but not cathepsin X), impairs invariant chain processing, and disrupts MHC class II antigen presentation to CD4+ T cells. |
PIKfyve inhibitor treatment, phagosome acidification assay, ROS measurement, cathepsin activity assay, universal MHC class II presentation assay with bio-orthogonal antigen, T cell activation assay |
iScience |
High |
30612035
|
| 2019 |
PIKfyve activity regulates early melanosome homeostasis; PIKfyve activity controls membrane remodeling of stage I melanosomes regulating PMEL protein abundance and processing, controls kiss-and-run interactions with lysosomes required for PMEL amyloidogenesis, and promotes formation and release of membrane tubules from melanosomes by modulating endosomal actin branching. |
PIKfyve inhibition in melanocytes, live-cell imaging, immunofluorescence, Western blotting for PMEL processing, actin regulation assays |
Journal of cell science |
Medium |
30709920
|
| 2020 |
PIKfyve kinase activity is required for SARS-CoV-2 and Zaire ebolavirus (ZEBOV) endosomal content release and infection; apilimod (PIKfyve inhibitor) potently inhibits infection by VSV-ZEBOV, VSV-SARS-CoV-2 chimeras and authentic SARS-CoV-2, establishing PIKfyve-mediated endosomal trafficking as essential for viral entry through late endosomes. |
Chimeric VSV viral infection assays, authentic SARS-CoV-2 infection assay, apilimod pharmacological inhibition, Vacuolin-1 inhibition, live-cell imaging of viral trafficking |
Proceedings of the National Academy of Sciences |
High |
32764148
|
| 2020 |
The PIKfyve complex comprises five copies of the scaffolding protein Vac14 and one copy each of PIKfyve and Fig4 (by structural analysis); Fig4 is active as a lipid phosphatase within the complex; PIKfyve autophosphorylation represses its lipid kinase activity and stimulates Fig4 lipid phosphatase activity; Fig4 is also a protein phosphatase acting on PIKfyve to stimulate PIKfyve lipid kinase activity, explaining why catalytically active Fig4 is required for maximal PI(3,5)P2 production. |
Structural-biochemical analysis (cryo-EM/structural characterization), in vitro lipid phosphatase assays, in vitro kinase assays, mutagenesis, stoichiometry determination |
Molecular cell |
High |
33098764
|
| 2021 |
ULK1, activated by AMPK during glucose starvation, phosphorylates PIKfyve at S1548, increasing PIKfyve activity and PtdIns 5-P synthesis without changing PtdIns 3,5-P2 levels; ULK1-mediated PIKfyve activation enhances PI(5)P-containing autophagosome formation and autophagy flux; phospho-mimic PIKfyve S1548D drives autophagy upregulation. |
In vitro ULK1 kinase assay on PIKfyve, phospho-specific detection in cells, PI5P measurement, LC3 autophagy flux assay, phospho-mimic and phospho-dead PIKfyve mutants, AMPK-ULK1 inhibition |
Developmental cell |
High |
34107300
|
| 2021 |
PIKfyve is acylated by acyltransferases zDHHC9 and zDHHC21; prion infection or prolonged UPR disturbs the juxtavesicular topology of these acyltransferases, causing PIKfyve deacylation and rapid degradation, resulting in endolysosomal hypertrophy. Overexpression of zDHHC9/zDHHC21 or PI(3,5)P2 supplementation suppressed prion-induced vacuolation. |
Acylation assay, zDHHC9/21 overexpression and knockdown, PIKfyve protein stability measurement in prion-infected cells and brain, PI(3,5)P2 supplementation rescue, UPR induction experiments |
EMBO molecular medicine |
High |
34291577
|
| 2021 |
PIKfyve inhibition activates an unconventional protein clearance mechanism involving exocytosis of aggregation-prone proteins (rather than macroautophagy or the ubiquitin-proteasome system); reducing PIKfyve activity ameliorates ALS pathology in animal models and patient-derived motor neurons representing diverse ALS forms (C9ORF72, TARDBP, FUS, sporadic). |
PIKfyve inhibitor treatment, genetic knockdown in animal models, patient-derived motor neuron culture, exocytosis assay for aggregation-prone proteins, ALS pathology markers |
Cell |
High |
36754049
|
| 2021 |
PIKfyve inhibition impairs autophagic flux, causing accumulation of MHC-I at the cancer cell surface through reduced autophagic degradation; genetic depletion or pharmacological inhibition of PIKfyve elevated tumor-specific MHC-I surface expression and increased intratumoral functional CD8+ T cells; the effect was CD8+ T cell- and MHC-I-dependent. |
PIKfyve knockdown and pharmacological inhibition, MHC-I surface expression by flow cytometry, autophagy flux assays, CD8+ T cell depletion, B2m knockout, syngeneic mouse tumor models |
Nature cancer |
High |
34738088
|
| 2022 |
PIKfyve and its upstream PI3-kinase VPS34 coordinate a phosphoinositide cascade to regulate retriever-mediated recycling of cargo (including integrins) from endosomes to the plasma membrane; endogenous PIKfyve co-localizes with SNX17, Retriever, WASH, and CCC complexes on endosomes; PIKfyve inhibition displaces Retriever and CCC from endosomes. |
PIKfyve and VPS34 inhibition, integrin recycling assay, co-localization by immunofluorescence, fractionation, endosome displacement assay |
eLife |
High |
35040777
|
| 2022 |
PIKfyve inhibition selectively impairs mTORC1 interaction with TFEB (not other mTORC1 substrates), leading to TFEB dephosphorylation at Ser-211 by PP2A (not calcineurin) and TFEB nuclear translocation; this establishes that PI(3,5)P2 promotes TFEB phosphorylation by facilitating mTORC1 access to TFEB. |
PIKfyve inhibition, TFEB phosphorylation assay (Ser-211), mTORC1 activity toward multiple substrates, co-immunoprecipitation of TFEB-mTORC1, PP2A and calcineurin inhibitors, nuclear TFEB localization |
Molecular biology of the cell |
High |
35020443
|
| 2023 |
PIKfyve recruitment and activity on phagosomes/macropinosomes are separable events; PI(3,5)P2 accumulates on Dictyostelium phagosomes and macropinosomes ~3 min after engulfment but is retained differently on the two pathways, indicating pathway-specific regulation; PIKfyve activation stimulates its own dissociation from membranes (self-limiting mechanism). |
Novel PI(3,5)P2 reporter (GFP-SnxA, validated by PI(3,5)P2 selectivity assay), live-cell imaging of PIKfyve and PI(3,5)P2 dynamics in Dictyostelium and mammalian cells |
The Journal of cell biology |
High |
37382666
|
| 2011 |
PIKfyve KO/KO mouse embryos die before the 32-64-cell stage; kultured PIKfyve-null fibroblasts show severely reduced DNA synthesis, consistent with impaired cell division causing lethality; PIKfyve heterozygous mice are viable with 50-55% reduced PIKfyve protein and enzymatic activity but only 35-40% reduced PtdIns 3,5-P2/PtdIns 5-P, indicating nonlinear regulation of lipid product levels. |
Cre-loxP conditional knockout mice, embryo culture, DNA synthesis assay in Cre-treated floxed fibroblasts, 32P lipid labeling, in vitro PIKfyve kinase assay |
The Journal of biological chemistry |
High |
21349843
|
| 2000 |
PIKfyve localizes predominantly to cytosol (~76%), with ~20% on low-density microsomal (LDM) fraction coinciding with trans-Golgi network/multivesicular body markers (not recycling endosomes or GLUT4 storage compartment) in 3T3-L1 adipocytes; insulin stimulation recruits cytosolic PIKfyve to LDM membranes with concomitant increase in PIKfyve lipid kinase activity and electrophoretic mobility shift. |
Subcellular fractionation, density gradient sedimentation, immunoadsorption, fluorescence microscopy, immunoreactive PIKfyve measurement, in vitro lipid kinase assay |
The Journal of biological chemistry |
High |
11112776
|
| 2011 |
NPM-ALK oncogene interacts with PIKfyve (via the 181-300 region of NPM-ALK) and the tyrosine kinase activity of NPM-ALK controls PIKfyve lipid kinase activity (independent of complex formation); PIKfyve silencing or inhibition has no effect on proliferation or migration but strongly reduces invasive capacity of NPM-ALK cells and impairs MMP9 surface localization and maturation. |
Co-immunoprecipitation, siRNA knockdown, YM201636 inhibition, invasion assay, MMP9 localization by immunofluorescence, in vitro lipid kinase assay |
The Journal of biological chemistry |
Medium |
21737449
|
| 2015 |
TLR9 trafficking to LAMP1+ compartments required for type I IFN induction requires PIKfyve activity; PIKfyve inhibition preferentially blocks TLR9 signaling for type I IFN (not cytokine) induction in FLT3L-derived DCs; confocal analysis shows PIKfyve inhibition blocks TLR9 and CpG trafficking to LAMP1+ endosomes while VAMP3+ trafficking remains intact; AP-3 recruitment to TLR9 endosomes is impaired by PIKfyve inhibition. |
PIKfyve pharmacological inhibition, FLT3L-derived DC stimulation, type I IFN measurement, confocal microscopy of TLR9/CpG trafficking, AP-3 recruitment assay |
International immunology |
High |
25925170
|
| 2013 |
Muscle-specific Pikfyve gene disruption causes glucose intolerance, insulin resistance, and severely blunted insulin-stimulated glucose uptake and GLUT4 surface translocation in skeletal muscle, with premature attenuation of Akt phosphorylation in vivo, establishing PIKfyve as essential for insulin-regulated glucose metabolism in skeletal muscle. |
Muscle-specific Pikfyve conditional knockout mouse, glucose tolerance test, insulin tolerance test, ex vivo glucose uptake assay, GLUT4 surface translocation assay, Akt phosphorylation by Western blot |
American journal of physiology. Endocrinology and metabolism |
High |
23673157
|