{"gene":"PTP4A2","run_date":"2026-06-10T06:43:36","timeline":{"discoveries":[{"year":1998,"finding":"PRL-2 (PTP4A2) contains a C-terminal CAAX consensus sequence for prenylation (farnesylation), placing it in a subgroup of prenylated protein tyrosine phosphatases homologous to PRL-1 and Cdc14p/PTEN.","method":"Sequence analysis and database searches identifying conserved prenylation motif","journal":"Biochemical and biophysical research communications","confidence":"Medium","confidence_rationale":"Tier 3 / Strong — sequence-based identification replicated across multiple PRL family studies; prenylation confirmed biochemically in subsequent work","pmids":["9514946"],"is_preprint":false},{"year":2001,"finding":"Farnesylated PRL-2 specifically interacts with the beta-subunit of Rab geranylgeranyltransferase II (betaGGT II); this interaction requires the C-terminal region of PRL-2 and its prenylation. PRL-2 is not a substrate of GGT II but inhibits endogenous alpha/betaGGT II activity when overexpressed, and binding of alphaGGT II and PRL-2 to betaGGT II is mutually exclusive. Prenylated PRL-2 localizes to early endosomes.","method":"Yeast two-hybrid screening, co-immunoprecipitation in HeLa cells, chimeric PRL-1/-2 domain mapping, isoprenoid analysis, enzymatic activity assay","journal":"The Journal of biological chemistry","confidence":"High","confidence_rationale":"Tier 2 / Strong — reciprocal yeast two-hybrid + Co-IP in mammalian cells + domain mapping + biochemical isoprenoid analysis + functional enzyme inhibition assay in a single study","pmids":["11447212"],"is_preprint":false},{"year":2010,"finding":"PRL-2 promotes cell migration and augments growth responses to hematopoietic cytokines (Epo, IL-3) in hematopoietic cells, increasing Epo-induced colony formation and stem cell marker Bmi-1 expression.","method":"Ectopic overexpression in Baf3ER pre-B cells and mouse bone marrow cells; cell migration, adhesion, and colony formation assays","journal":"Blood cells, molecules & diseases","confidence":"Medium","confidence_rationale":"Tier 3 / Moderate — functional phenotypes in two cell systems with multiple readouts but no molecular mechanism established","pmids":["20226699"],"is_preprint":false},{"year":2010,"finding":"PRL-2 overexpression in breast cancer cells activates ERK1/2 signaling and promotes tumor formation in vivo; PRL-2 knockdown decreases anchorage-independent growth and cell migration in metastatic MDA-MB-231 cells.","method":"siRNA knockdown, stable overexpression in mouse mammary tumor cell lines, mammary fat pad xenograft injection, MMTV-PRL-2 transgenic and MMTV-ErbB2 bigenic mice","journal":"Cancer research","confidence":"High","confidence_rationale":"Tier 2 / Strong — loss-of-function and gain-of-function in multiple cell lines plus in vivo mouse models with defined molecular readout (ERK1/2 phosphorylation)","pmids":["20841483"],"is_preprint":false},{"year":2011,"finding":"PRL-2 promotes tumor cell migration and invasion through an ERK-dependent, Src-independent p130Cas signaling pathway. PRL-2 knockdown decreases p130Cas and vinculin expression, decreases ERK phosphorylation, and increases phosphorylation of ezrin at Tyr146. Both catalytic activity (C101S mutant inactive) and the C-terminal CAAX prenylation site are required for ERK phosphorylation and nuclear translocation.","method":"siRNA knockdown with siRNA-resistant rescue constructs, catalytic-dead mutant (C101S) and CAAX-deletion mutant expression, Western blotting for pathway components, cell migration and invasion assays","journal":"Oncogene","confidence":"High","confidence_rationale":"Tier 2 / Strong — loss-of-function with siRNA-resistant rescue, active-site mutagenesis, prenylation motif deletion, and multiple defined molecular readouts in a single study","pmids":["21765462"],"is_preprint":false},{"year":2014,"finding":"PRL-2 forms a functional heterodimer with magnesium transporter CNNM3 through the CBS/Bateman domain loop of CNNM3. This interaction regulates intracellular magnesium levels; PRL-2 knockdown substantially decreases cellular magnesium influx, and Ptp4a2 knockout mice show elevated serum magnesium. CNNM3 is not a phosphorylated substrate of PRL-2. Increased magnesium depletion enhances endogenous PRL-2/CNNM3 interaction.","method":"Co-immunoprecipitation of endogenous proteins, PRL-2 knockdown with magnesium influx measurement, Ptp4a2 knockout mouse serum magnesium quantification, xenograft tumor assay with CNNM3 binding mutant","journal":"Oncogene","confidence":"High","confidence_rationale":"Tier 2 / Strong — reciprocal endogenous Co-IP, KO mouse phenotype, KD functional assay, domain mapping, and in vivo xenograft with binding mutant across multiple orthogonal methods","pmids":["24632616"],"is_preprint":false},{"year":2014,"finding":"PTP4A2/PRL-2 is required for hematopoietic stem cell (HSC) self-renewal; Ptp4a2-null HSPCs are more quiescent and show reduced AKT and ERK signaling activation. Enhancement of HSPC proliferation and AKT/ERK activation by PTP4A2 depends on its phosphatase activity. PTP4A2 mediates SCF/KIT signaling in HSPCs.","method":"Serial bone marrow transplantation in Ptp4a2 knockout mice, phosphatase-dead mutant rescue, AKT/ERK phosphorylation assays, SCF stimulation experiments, oncogenic KIT/D814V epistasis","journal":"Stem cells (Dayton, Ohio)","confidence":"High","confidence_rationale":"Tier 2 / Strong — KO mouse with functional self-renewal readout, phosphatase-dead mutant, defined signaling pathway, and genetic epistasis with oncogenic KIT","pmids":["24753135"],"is_preprint":false},{"year":2016,"finding":"A single point mutation D426A in the Bateman domain loop of CNNM3 completely disrupts PRL-2·CNNM3 complex formation. The Asp-426 side chain of CNNM3 buries into the catalytic cavity of PRL-2. CNNM3 expression influences whole-cell surface current (voltage clamping), whereas the D426A binding mutant has no effect, indicating that PRL-2 binding is required for CNNM3 channel activity. A PRL inhibitor abrogates PRL-2·CNNM3 complex formation and decreases breast cancer cell proliferation.","method":"Site-directed mutagenesis of CNNM3 (D426A), whole-cell voltage clamping, molecular modeling, orthotopic xenograft breast cancer model, Co-IP, proliferation assays with PRL inhibitor","journal":"The Journal of biological chemistry","confidence":"High","confidence_rationale":"Tier 1–2 / Strong — active-site/interface mutagenesis, electrophysiology, molecular modeling, and in vivo xenograft; multiple orthogonal methods confirming the same molecular interface","pmids":["26969161"],"is_preprint":false},{"year":2020,"finding":"PTP4A2 (PRL-2) is required for endothelial cell migration and vascular morphogenesis; inducible endothelial-specific and global Ptp4a2 deletion in mice causes defective retinal vascular outgrowth, arteriovenous differentiation, and sprouting angiogenesis. Mechanistically, PTP4A2 deletion inhibits VEGF-A and DLL-4/NOTCH-1 signaling in endothelial cells.","method":"Inducible endothelial-specific Ptp4a2 conditional knockout and global KO mice, postnatal retinal vascular outgrowth analysis, cell migration assays, VEGF-A/DLL-4/NOTCH-1 pathway readouts","journal":"Communications biology","confidence":"High","confidence_rationale":"Tier 2 / Strong — cell-type-specific conditional KO mice with defined vascular phenotype and molecular pathway readouts (VEGF-A, NOTCH-1 signaling)","pmids":["33097786"],"is_preprint":false},{"year":2022,"finding":"PTP4A2 dephosphorylates VCP/p97 at Tyr805, enabling VCP to associate with its C-terminal cofactors UBXN6/UBXD1 and PLAA (components of the ELDR complex). This promotes lysophagy (autophagic clearance of damaged lysosomes) by facilitating ELDR-mediated K48-linked ubiquitin conjugate removal and autophagosome formation on damaged lysosomes. Ptp4a2 deletion in vivo impairs recovery from glycerol-induced acute kidney injury due to defective lysophagy.","method":"Unbiased substrate trapping with mass spectrometry, biochemical dephosphorylation assay, Co-IP of VCP with UBXN6/PLAA, Ptp4a2 knockout MEFs and mice, glycerol-injection acute kidney injury model, lysosomal damage assays (LLOMe treatment)","journal":"Autophagy","confidence":"High","confidence_rationale":"Tier 1 / Strong — unbiased substrate trapping + mass spectrometry + biochemical dephosphorylation assay + Co-IP of VCP cofactors + in vivo KO phenotype, multiple orthogonal methods establishing substrate identity and functional consequence","pmids":["36300783"],"is_preprint":false},{"year":2026,"finding":"PTP4A2 directly interacts with p53 and dephosphorylates it at serine 392, decreasing p53 stability and activity in leukemia-initiating cells (LICs). Ptp4a2 deficiency activates p53, induces LIC apoptosis and senescence, and extends survival of recipient mice in a KMT2A-MLLT3-driven AML model.","method":"Co-immunoprecipitation of PTP4A2 and p53, phosphorylation assay (Ser392 dephosphorylation), Ptp4a2 knockout in LICs, in vivo AML mouse model with survival readout, apoptosis and senescence assays","journal":"Blood advances","confidence":"High","confidence_rationale":"Tier 2 / Strong — reciprocal Co-IP, defined dephosphorylation site on p53, KO mouse AML model with survival readout, and multiple cellular phenotype readouts in a single study","pmids":["41985006"],"is_preprint":false}],"current_model":"PTP4A2/PRL-2 is a farnesylated, endosome-localized protein tyrosine phosphatase that promotes cell proliferation, migration, and oncogenesis through multiple mechanisms: it forms a functional complex with CNNM3 magnesium transporter (via CNNM3's Bateman domain loop inserting into the PTP4A2 catalytic pocket) to regulate intracellular magnesium and confer oncogenic growth advantage; it dephosphorylates VCP/p97 at Tyr805 to enable ELDR complex assembly and lysophagy; it dephosphorylates p53 at Ser392 to destabilize p53 and promote leukemia-initiating cell survival; it mediates SCF/KIT-driven AKT and ERK activation in hematopoietic stem cells; and it supports VEGF-A/DLL-4/NOTCH-1-dependent angiogenesis in endothelial cells, with both catalytic activity and C-terminal prenylation required for its pro-migratory ERK-dependent functions."},"narrative":{"mechanistic_narrative":"PTP4A2/PRL-2 is a prenylated protein tyrosine phosphatase that drives cell proliferation, migration, and oncogenesis across hematopoietic, endothelial, and epithelial lineages [PMID:20841483, PMID:24753135]. Its C-terminal CAAX motif directs farnesylation [PMID:9514946] and early-endosome localization, and the prenylated protein engages the beta-subunit of Rab geranylgeranyltransferase II [PMID:11447212]. Both catalytic activity and C-terminal prenylation are required for PRL-2 to drive ERK phosphorylation and nuclear translocation, acting through an ERK-dependent, Src-independent p130Cas pathway to promote migration and invasion [PMID:21765462]. PRL-2 forms a functional heterodimer with the magnesium transporter CNNM3, with an Asp residue in the CNNM3 Bateman/CBS-domain loop inserting into the PRL-2 catalytic cavity; this non-catalytic interaction regulates intracellular magnesium and confers an oncogenic growth advantage, and disrupting the interface impairs CNNM3 channel activity and breast cancer proliferation [PMID:24632616, PMID:26969161]. PRL-2 also acts as a catalytic phosphatase on defined substrates: it dephosphorylates VCP/p97 at Tyr805 to enable assembly of the ELDR cofactor complex (UBXN6/UBXD1, PLAA) and drive lysophagy [PMID:36300783], and it dephosphorylates p53 at Ser392 to destabilize p53 and sustain leukemia-initiating cells [PMID:41985006]. In stem and vascular compartments PRL-2 mediates SCF/KIT-driven AKT and ERK activation for hematopoietic stem cell self-renewal [PMID:24753135] and VEGF-A/DLL-4/NOTCH-1 signaling for sprouting angiogenesis [PMID:33097786].","teleology":[{"year":1998,"claim":"Establishing that PRL-2 carries a C-terminal CAAX prenylation motif defined it as a membrane-targeted phosphatase rather than a soluble enzyme, framing all later localization and function studies.","evidence":"Sequence analysis identifying a conserved prenylation motif placing PRL-2 with PRL-1 and Cdc14p/PTEN","pmids":["9514946"],"confidence":"Medium","gaps":["Prenylation inferred from motif, not yet biochemically demonstrated in this study","No functional consequence of prenylation established"]},{"year":2001,"claim":"Demonstrating that farnesylated PRL-2 binds betaGGT II and localizes to early endosomes provided the first physical partner and subcellular address, linking prenylation to a defined location.","evidence":"Yeast two-hybrid, Co-IP in HeLa cells, chimeric domain mapping, isoprenoid analysis, and GGT II activity assay","pmids":["11447212"],"confidence":"High","gaps":["Functional role of betaGGT II binding for downstream signaling unresolved","Whether endosomal localization is required for catalytic substrate access not tested"]},{"year":2010,"claim":"Gain- and loss-of-function studies showed PRL-2 promotes migration, cytokine-driven growth, and ERK1/2-dependent tumor formation, establishing it as a pro-oncogenic phosphatase in vivo.","evidence":"Overexpression in hematopoietic cells and breast cancer lines, siRNA knockdown, xenograft and transgenic mouse models with ERK1/2 readout","pmids":["20226699","20841483"],"confidence":"High","gaps":["Direct phosphatase substrates not identified","Mechanism linking PRL-2 to ERK activation undefined"]},{"year":2011,"claim":"Showing that both catalytic activity and prenylation are required for ERK phosphorylation, nuclear translocation, and the p130Cas migration pathway connected PRL-2's two structural features to its pro-invasive output.","evidence":"siRNA knockdown with resistant rescue, C101S catalytic-dead and CAAX-deletion mutants, pathway Western blots, migration/invasion assays","pmids":["21765462"],"confidence":"High","gaps":["Direct dephosphorylation target upstream of ERK/p130Cas not identified","How prenylation contributes mechanistically beyond localization unclear"]},{"year":2014,"claim":"Identifying the PRL-2·CNNM3 heterodimer and the Ptp4a2-null magnesium phenotype revealed a non-catalytic, interaction-based mechanism for regulating cellular magnesium and oncogenic growth.","evidence":"Endogenous reciprocal Co-IP, magnesium influx measurement, Ptp4a2 knockout mouse serum magnesium, xenograft with CNNM3 binding mutant","pmids":["24632616"],"confidence":"High","gaps":["CNNM3 is not a phosphorylated substrate, leaving the molecular basis of magnesium regulation incomplete","Link between magnesium handling and growth advantage not mechanistically dissected"]},{"year":2014,"claim":"Conditional knockout established a physiological requirement for PTP4A2 phosphatase activity in HSC self-renewal via SCF/KIT-driven AKT and ERK signaling.","evidence":"Serial bone marrow transplantation in Ptp4a2 KO mice, phosphatase-dead rescue, SCF stimulation, oncogenic KIT epistasis","pmids":["24753135"],"confidence":"High","gaps":["Direct substrate within the SCF/KIT-AKT/ERK axis not identified","Whether the same mechanism operates outside hematopoiesis untested here"]},{"year":2016,"claim":"Mapping the CNNM3 Asp-426 residue into the PRL-2 catalytic cavity and showing a PRL inhibitor disrupts the complex defined a druggable interface controlling CNNM3 channel activity and tumor proliferation.","evidence":"D426A mutagenesis, whole-cell voltage clamping, molecular modeling, orthotopic xenograft, Co-IP, inhibitor proliferation assays","pmids":["26969161"],"confidence":"High","gaps":["How catalytic-pocket occupancy by CNNM3 relates to PRL-2 phosphatase activity on other substrates unresolved","In vivo selectivity of the PRL inhibitor not addressed"]},{"year":2020,"claim":"Endothelial-specific knockout demonstrated PTP4A2 is required for sprouting angiogenesis and arteriovenous differentiation through VEGF-A and DLL-4/NOTCH-1 signaling, extending its role to vascular development.","evidence":"Inducible endothelial-specific and global Ptp4a2 KO mice, retinal vascular outgrowth analysis, migration assays, VEGF-A/NOTCH-1 readouts","pmids":["33097786"],"confidence":"High","gaps":["Direct substrate in the VEGF-A/NOTCH axis not identified","Whether ERK-dependent migration mechanism from epithelial cells applies in endothelium not confirmed"]},{"year":2022,"claim":"Unbiased substrate trapping identified VCP/p97 Tyr805 as a direct PTP4A2 substrate, linking the phosphatase to ELDR complex assembly and lysophagy with an in vivo kidney-injury phenotype.","evidence":"Substrate trapping with mass spectrometry, biochemical dephosphorylation assay, Co-IP of VCP cofactors, Ptp4a2 KO MEFs and mice, acute kidney injury model","pmids":["36300783"],"confidence":"High","gaps":["How VCP dephosphorylation is spatially coordinated with endosomal/lysosomal localization not detailed","Relationship between lysophagy role and oncogenic functions unexplored"]},{"year":2026,"claim":"Identifying p53 Ser392 as a PTP4A2 dephosphorylation target showed how the phosphatase destabilizes p53 to sustain leukemia-initiating cells, providing a direct oncogenic substrate.","evidence":"Reciprocal Co-IP, Ser392 dephosphorylation assay, Ptp4a2 KO in LICs, KMT2A-MLLT3 AML mouse survival model, apoptosis/senescence assays","pmids":["41985006"],"confidence":"High","gaps":["Structural basis of PTP4A2-p53 recognition not defined","Whether p53 regulation operates in non-leukemic PTP4A2 contexts untested"]},{"year":null,"claim":"How PTP4A2 selects among its diverse substrates (VCP, p53) and non-catalytic partners (CNNM3) in different cellular contexts, and how prenylation/endosomal localization gates these activities, remains unresolved.","evidence":"","pmids":[],"confidence":"High","gaps":["No unifying model for substrate selection across tissues","Direct substrates underlying ERK/AKT activation in stem and endothelial cells still unidentified","Structural integration of catalytic vs. CNNM3-binding modes not established"]}],"mechanism_profile":{"molecular_activity":[{"term_id":"GO:0140096","term_label":"catalytic activity, acting on a protein","supporting_discovery_ids":[4,6,9,10]},{"term_id":"GO:0016787","term_label":"hydrolase activity","supporting_discovery_ids":[4,9,10]},{"term_id":"GO:0098772","term_label":"molecular function regulator activity","supporting_discovery_ids":[5,7]}],"localization":[{"term_id":"GO:0005768","term_label":"endosome","supporting_discovery_ids":[1]},{"term_id":"GO:0005634","term_label":"nucleus","supporting_discovery_ids":[4]}],"pathway":[{"term_id":"R-HSA-162582","term_label":"Signal Transduction","supporting_discovery_ids":[4,6,8]},{"term_id":"R-HSA-9612973","term_label":"Autophagy","supporting_discovery_ids":[9]},{"term_id":"R-HSA-1643685","term_label":"Disease","supporting_discovery_ids":[3,10]},{"term_id":"R-HSA-1266738","term_label":"Developmental Biology","supporting_discovery_ids":[8]}],"complexes":["PRL-2·CNNM3 heterodimer","ELDR complex (with VCP/p97, UBXN6/UBXD1, PLAA)"],"partners":["CNNM3","VCP","TP53","UBXN6","PLAA"],"other_free_text":[]}},"prefetch_data":{"uniprot":{"accession":"Q12974","full_name":"Protein tyrosine phosphatase type IVA 2","aliases":["HU-PP-1","OV-1","PTP(CAAXII)","Protein-tyrosine phosphatase 4a2","Protein-tyrosine phosphatase of regenerating liver 2","PRL-2"],"length_aa":167,"mass_kda":19.1,"function":"Protein tyrosine phosphatase which stimulates progression from G1 into S phase during mitosis. Promotes tumors. Inhibits geranylgeranyl transferase type II activity by blocking the association between RABGGTA and RABGGTB","subcellular_location":"Cell membrane; Early endosome; Cytoplasm","url":"https://www.uniprot.org/uniprotkb/Q12974/entry"},"depmap":{"release":"DepMap","has_data":true,"is_common_essential":false,"resolved_as":"","url":"https://depmap.org/portal/gene/PTP4A2","classification":"Not Classified","n_dependent_lines":275,"n_total_lines":1208,"dependency_fraction":0.22764900662251655},"opencell":{"profiled":false,"resolved_as":"","ensg_id":"","cell_line_id":"","localizations":[],"interactors":[],"url":"https://opencell.sf.czbiohub.org/search/PTP4A2","total_profiled":1310},"omim":[{"mim_id":"606449","title":"PROTEIN-TYROSINE PHOSPHATASE, TYPE 4A, 3; PTP4A3","url":"https://www.omim.org/entry/606449"},{"mim_id":"601584","title":"PROTEIN-TYROSINE PHOSPHATASE, TYPE 4A, 2; PTP4A2","url":"https://www.omim.org/entry/601584"}],"hpa":{"profiled":true,"resolved_as":"","reliability":"","locations":[],"tissue_specificity":"Low tissue specificity","tissue_distribution":"Detected in all","driving_tissues":[],"url":"https://www.proteinatlas.org/search/PTP4A2"},"hgnc":{"alias_symbol":["HU-PP-1","PTPCAAX2","OV-1","ptp-IV1a","PRL-2","PRL2"],"prev_symbol":["PTP4A"]},"alphafold":{"accession":"Q12974","domains":[{"cath_id":"3.90.190.10","chopping":"6-147","consensus_level":"high","plddt":94.628,"start":6,"end":147}],"viewer_url":"https://alphafold.ebi.ac.uk/entry/Q12974","model_url":"https://alphafold.ebi.ac.uk/files/AF-Q12974-F1-model_v6.cif","pae_url":"https://alphafold.ebi.ac.uk/files/AF-Q12974-F1-predicted_aligned_error_v6.png","plddt_mean":90.44},"mouse_models":{"mgi_url":"https://www.informatics.jax.org/marker/summary?nomen=PTP4A2","jax_strain_url":"https://www.jax.org/strain/search?query=PTP4A2"},"sequence":{"accession":"Q12974","fasta_url":"https://rest.uniprot.org/uniprotkb/Q12974.fasta","uniprot_url":"https://www.uniprot.org/uniprotkb/Q12974/entry","alphafold_viewer_url":"https://alphafold.ebi.ac.uk/entry/Q12974"}},"corpus_meta":[{"pmid":"9514946","id":"PMC_9514946","title":"Mouse PRL-2 and PRL-3, two potentially prenylated protein tyrosine phosphatases homologous to PRL-1.","date":"1998","source":"Biochemical and biophysical research communications","url":"https://pubmed.ncbi.nlm.nih.gov/9514946","citation_count":164,"is_preprint":false},{"pmid":"24632616","id":"PMC_24632616","title":"The protein tyrosine phosphatase PRL-2 interacts with the magnesium transporter CNNM3 to promote oncogenesis.","date":"2014","source":"Oncogene","url":"https://pubmed.ncbi.nlm.nih.gov/24632616","citation_count":100,"is_preprint":false},{"pmid":"9363447","id":"PMC_9363447","title":"Hepatic stem-like cells in hepatoblastoma: expression of cytokeratin 7, albumin and oval cell associated antigens detected by OV-1 and OV-6.","date":"1997","source":"Histopathology","url":"https://pubmed.ncbi.nlm.nih.gov/9363447","citation_count":74,"is_preprint":false},{"pmid":"20841483","id":"PMC_20841483","title":"Overexpression of the protein tyrosine phosphatase PRL-2 correlates with breast tumor formation and progression.","date":"2010","source":"Cancer research","url":"https://pubmed.ncbi.nlm.nih.gov/20841483","citation_count":57,"is_preprint":false},{"pmid":"11734337","id":"PMC_11734337","title":"Analysis of stromal-epithelial interactions in prostate cancer identifies PTPCAAX2 as a potential oncogene.","date":"2002","source":"Cancer letters","url":"https://pubmed.ncbi.nlm.nih.gov/11734337","citation_count":52,"is_preprint":false},{"pmid":"26969161","id":"PMC_26969161","title":"Inhibition of PRL-2·CNNM3 Protein Complex Formation Decreases Breast Cancer Proliferation and Tumor Growth.","date":"2016","source":"The Journal of biological chemistry","url":"https://pubmed.ncbi.nlm.nih.gov/26969161","citation_count":47,"is_preprint":false},{"pmid":"24753135","id":"PMC_24753135","title":"PRL2/PTP4A2 phosphatase is important for hematopoietic stem cell self-renewal.","date":"2014","source":"Stem cells (Dayton, Ohio)","url":"https://pubmed.ncbi.nlm.nih.gov/24753135","citation_count":42,"is_preprint":false},{"pmid":"21765462","id":"PMC_21765462","title":"Metastasis-associated phosphatase PRL-2 regulates tumor cell migration and invasion.","date":"2011","source":"Oncogene","url":"https://pubmed.ncbi.nlm.nih.gov/21765462","citation_count":34,"is_preprint":false},{"pmid":"37869777","id":"PMC_37869777","title":"Circular RNA PTP4A2 regulates microglial polarization through STAT3 to promote neuroinflammation in ischemic stroke.","date":"2023","source":"CNS neuroscience & therapeutics","url":"https://pubmed.ncbi.nlm.nih.gov/37869777","citation_count":33,"is_preprint":false},{"pmid":"11447212","id":"PMC_11447212","title":"Interaction of farnesylated PRL-2, a protein-tyrosine phosphatase, with the beta-subunit of geranylgeranyltransferase II.","date":"2001","source":"The Journal of biological chemistry","url":"https://pubmed.ncbi.nlm.nih.gov/11447212","citation_count":30,"is_preprint":false},{"pmid":"22347524","id":"PMC_22347524","title":"Tissue-specific alterations of PRL-1 and PRL-2 expression in cancer.","date":"2012","source":"American journal of translational research","url":"https://pubmed.ncbi.nlm.nih.gov/22347524","citation_count":20,"is_preprint":false},{"pmid":"36300783","id":"PMC_36300783","title":"PTP4A2 promotes lysophagy by dephosphorylation of VCP/p97 at Tyr805.","date":"2022","source":"Autophagy","url":"https://pubmed.ncbi.nlm.nih.gov/36300783","citation_count":13,"is_preprint":false},{"pmid":"33097786","id":"PMC_33097786","title":"PRL-2 phosphatase is required for vascular morphogenesis and angiogenic signaling.","date":"2020","source":"Communications biology","url":"https://pubmed.ncbi.nlm.nih.gov/33097786","citation_count":11,"is_preprint":false},{"pmid":"20226699","id":"PMC_20226699","title":"PRL-2 increases Epo and IL-3 responses in hematopoietic cells.","date":"2010","source":"Blood cells, molecules & diseases","url":"https://pubmed.ncbi.nlm.nih.gov/20226699","citation_count":7,"is_preprint":false},{"pmid":"38904264","id":"PMC_38904264","title":"PTP4A2 Promotes Glioblastoma Progression and Macrophage Polarization under Microenvironmental Pressure.","date":"2024","source":"Cancer research communications","url":"https://pubmed.ncbi.nlm.nih.gov/38904264","citation_count":6,"is_preprint":false},{"pmid":"17683965","id":"PMC_17683965","title":"Differential expression and functional constraint of PRL-2 in hibernating bat.","date":"2007","source":"Comparative biochemistry and physiology. Part B, Biochemistry & molecular biology","url":"https://pubmed.ncbi.nlm.nih.gov/17683965","citation_count":4,"is_preprint":false},{"pmid":"39549466","id":"PMC_39549466","title":"Silencing of circular RNA PTP4A2 ameliorates depressive-like behaviors by inhibiting microglia activation in mice.","date":"2024","source":"Journal of neuroimmunology","url":"https://pubmed.ncbi.nlm.nih.gov/39549466","citation_count":3,"is_preprint":false},{"pmid":"34992672","id":"PMC_34992672","title":"Downregulated Expression of miRNA-130a-5p Aggravates Hepatoma Progression via Targeting PTP4A2.","date":"2021","source":"Computational and mathematical methods in medicine","url":"https://pubmed.ncbi.nlm.nih.gov/34992672","citation_count":1,"is_preprint":false},{"pmid":"41985006","id":"PMC_41985006","title":"PTP4A2 Promotes Leukemogenesis through Inhibiting the p53 Tumor Suppressor Signaling Pathway in Leukemia-initiating Cells.","date":"2026","source":"Blood advances","url":"https://pubmed.ncbi.nlm.nih.gov/41985006","citation_count":0,"is_preprint":false},{"pmid":"37416140","id":"PMC_37416140","title":"Retracted: Downregulated Expression of miRNA-130a-5p Aggravates Hepatoma Progression via Targeting PTP4A2.","date":"2023","source":"Computational and mathematical methods in medicine","url":"https://pubmed.ncbi.nlm.nih.gov/37416140","citation_count":0,"is_preprint":false},{"pmid":"17666324","id":"PMC_17666324","title":"[Construction of an eukaryotic expression vector for PRL-2 and its effect on human hepatocellular carcinoma cell invasiveness and migration in vitro].","date":"2007","source":"Nan fang yi ke da xue xue bao = Journal of Southern Medical University","url":"https://pubmed.ncbi.nlm.nih.gov/17666324","citation_count":0,"is_preprint":false},{"pmid":"15367352","id":"PMC_15367352","title":"[Expression of GST-PRL-2 fusion protein in prokaryotic cells and preparation of Hen egg yolk immunoglobulin (IgY) against PRL-2].","date":"2004","source":"Xi bao yu fen zi mian yi xue za zhi = Chinese journal of cellular and molecular immunology","url":"https://pubmed.ncbi.nlm.nih.gov/15367352","citation_count":0,"is_preprint":false}],"cost":{"stage1":{"model":"claude-sonnet-4-6","input_tokens":13038,"output_tokens":3383,"usd":0.044929,"stage1_stop_reason":"end_turn"},"stage2":{"model":"claude-opus-4-8","input_tokens":10870,"output_tokens":3947,"usd":0.076512,"stage2_stop_reason":"end_turn"},"total_usd":0.121441,"stage1_batch_id":"msgbatch_01CNoDbkChHEkgrJnL7BwtGJ","stage2_batch_id":"msgbatch_016Y4x9E9Wg5VQDANj9quSQD","note":"batch pricing = 50% of standard"},"stage1_raw":"```json\n{\n  \"discoveries\": [\n    {\n      \"year\": 1998,\n      \"finding\": \"PRL-2 (PTP4A2) contains a C-terminal CAAX consensus sequence for prenylation (farnesylation), placing it in a subgroup of prenylated protein tyrosine phosphatases homologous to PRL-1 and Cdc14p/PTEN.\",\n      \"method\": \"Sequence analysis and database searches identifying conserved prenylation motif\",\n      \"journal\": \"Biochemical and biophysical research communications\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 3 / Strong — sequence-based identification replicated across multiple PRL family studies; prenylation confirmed biochemically in subsequent work\",\n      \"pmids\": [\"9514946\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2001,\n      \"finding\": \"Farnesylated PRL-2 specifically interacts with the beta-subunit of Rab geranylgeranyltransferase II (betaGGT II); this interaction requires the C-terminal region of PRL-2 and its prenylation. PRL-2 is not a substrate of GGT II but inhibits endogenous alpha/betaGGT II activity when overexpressed, and binding of alphaGGT II and PRL-2 to betaGGT II is mutually exclusive. Prenylated PRL-2 localizes to early endosomes.\",\n      \"method\": \"Yeast two-hybrid screening, co-immunoprecipitation in HeLa cells, chimeric PRL-1/-2 domain mapping, isoprenoid analysis, enzymatic activity assay\",\n      \"journal\": \"The Journal of biological chemistry\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — reciprocal yeast two-hybrid + Co-IP in mammalian cells + domain mapping + biochemical isoprenoid analysis + functional enzyme inhibition assay in a single study\",\n      \"pmids\": [\"11447212\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2010,\n      \"finding\": \"PRL-2 promotes cell migration and augments growth responses to hematopoietic cytokines (Epo, IL-3) in hematopoietic cells, increasing Epo-induced colony formation and stem cell marker Bmi-1 expression.\",\n      \"method\": \"Ectopic overexpression in Baf3ER pre-B cells and mouse bone marrow cells; cell migration, adhesion, and colony formation assays\",\n      \"journal\": \"Blood cells, molecules & diseases\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 3 / Moderate — functional phenotypes in two cell systems with multiple readouts but no molecular mechanism established\",\n      \"pmids\": [\"20226699\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2010,\n      \"finding\": \"PRL-2 overexpression in breast cancer cells activates ERK1/2 signaling and promotes tumor formation in vivo; PRL-2 knockdown decreases anchorage-independent growth and cell migration in metastatic MDA-MB-231 cells.\",\n      \"method\": \"siRNA knockdown, stable overexpression in mouse mammary tumor cell lines, mammary fat pad xenograft injection, MMTV-PRL-2 transgenic and MMTV-ErbB2 bigenic mice\",\n      \"journal\": \"Cancer research\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — loss-of-function and gain-of-function in multiple cell lines plus in vivo mouse models with defined molecular readout (ERK1/2 phosphorylation)\",\n      \"pmids\": [\"20841483\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2011,\n      \"finding\": \"PRL-2 promotes tumor cell migration and invasion through an ERK-dependent, Src-independent p130Cas signaling pathway. PRL-2 knockdown decreases p130Cas and vinculin expression, decreases ERK phosphorylation, and increases phosphorylation of ezrin at Tyr146. Both catalytic activity (C101S mutant inactive) and the C-terminal CAAX prenylation site are required for ERK phosphorylation and nuclear translocation.\",\n      \"method\": \"siRNA knockdown with siRNA-resistant rescue constructs, catalytic-dead mutant (C101S) and CAAX-deletion mutant expression, Western blotting for pathway components, cell migration and invasion assays\",\n      \"journal\": \"Oncogene\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — loss-of-function with siRNA-resistant rescue, active-site mutagenesis, prenylation motif deletion, and multiple defined molecular readouts in a single study\",\n      \"pmids\": [\"21765462\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2014,\n      \"finding\": \"PRL-2 forms a functional heterodimer with magnesium transporter CNNM3 through the CBS/Bateman domain loop of CNNM3. This interaction regulates intracellular magnesium levels; PRL-2 knockdown substantially decreases cellular magnesium influx, and Ptp4a2 knockout mice show elevated serum magnesium. CNNM3 is not a phosphorylated substrate of PRL-2. Increased magnesium depletion enhances endogenous PRL-2/CNNM3 interaction.\",\n      \"method\": \"Co-immunoprecipitation of endogenous proteins, PRL-2 knockdown with magnesium influx measurement, Ptp4a2 knockout mouse serum magnesium quantification, xenograft tumor assay with CNNM3 binding mutant\",\n      \"journal\": \"Oncogene\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — reciprocal endogenous Co-IP, KO mouse phenotype, KD functional assay, domain mapping, and in vivo xenograft with binding mutant across multiple orthogonal methods\",\n      \"pmids\": [\"24632616\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2014,\n      \"finding\": \"PTP4A2/PRL-2 is required for hematopoietic stem cell (HSC) self-renewal; Ptp4a2-null HSPCs are more quiescent and show reduced AKT and ERK signaling activation. Enhancement of HSPC proliferation and AKT/ERK activation by PTP4A2 depends on its phosphatase activity. PTP4A2 mediates SCF/KIT signaling in HSPCs.\",\n      \"method\": \"Serial bone marrow transplantation in Ptp4a2 knockout mice, phosphatase-dead mutant rescue, AKT/ERK phosphorylation assays, SCF stimulation experiments, oncogenic KIT/D814V epistasis\",\n      \"journal\": \"Stem cells (Dayton, Ohio)\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — KO mouse with functional self-renewal readout, phosphatase-dead mutant, defined signaling pathway, and genetic epistasis with oncogenic KIT\",\n      \"pmids\": [\"24753135\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2016,\n      \"finding\": \"A single point mutation D426A in the Bateman domain loop of CNNM3 completely disrupts PRL-2·CNNM3 complex formation. The Asp-426 side chain of CNNM3 buries into the catalytic cavity of PRL-2. CNNM3 expression influences whole-cell surface current (voltage clamping), whereas the D426A binding mutant has no effect, indicating that PRL-2 binding is required for CNNM3 channel activity. A PRL inhibitor abrogates PRL-2·CNNM3 complex formation and decreases breast cancer cell proliferation.\",\n      \"method\": \"Site-directed mutagenesis of CNNM3 (D426A), whole-cell voltage clamping, molecular modeling, orthotopic xenograft breast cancer model, Co-IP, proliferation assays with PRL inhibitor\",\n      \"journal\": \"The Journal of biological chemistry\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1–2 / Strong — active-site/interface mutagenesis, electrophysiology, molecular modeling, and in vivo xenograft; multiple orthogonal methods confirming the same molecular interface\",\n      \"pmids\": [\"26969161\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2020,\n      \"finding\": \"PTP4A2 (PRL-2) is required for endothelial cell migration and vascular morphogenesis; inducible endothelial-specific and global Ptp4a2 deletion in mice causes defective retinal vascular outgrowth, arteriovenous differentiation, and sprouting angiogenesis. Mechanistically, PTP4A2 deletion inhibits VEGF-A and DLL-4/NOTCH-1 signaling in endothelial cells.\",\n      \"method\": \"Inducible endothelial-specific Ptp4a2 conditional knockout and global KO mice, postnatal retinal vascular outgrowth analysis, cell migration assays, VEGF-A/DLL-4/NOTCH-1 pathway readouts\",\n      \"journal\": \"Communications biology\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — cell-type-specific conditional KO mice with defined vascular phenotype and molecular pathway readouts (VEGF-A, NOTCH-1 signaling)\",\n      \"pmids\": [\"33097786\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2022,\n      \"finding\": \"PTP4A2 dephosphorylates VCP/p97 at Tyr805, enabling VCP to associate with its C-terminal cofactors UBXN6/UBXD1 and PLAA (components of the ELDR complex). This promotes lysophagy (autophagic clearance of damaged lysosomes) by facilitating ELDR-mediated K48-linked ubiquitin conjugate removal and autophagosome formation on damaged lysosomes. Ptp4a2 deletion in vivo impairs recovery from glycerol-induced acute kidney injury due to defective lysophagy.\",\n      \"method\": \"Unbiased substrate trapping with mass spectrometry, biochemical dephosphorylation assay, Co-IP of VCP with UBXN6/PLAA, Ptp4a2 knockout MEFs and mice, glycerol-injection acute kidney injury model, lysosomal damage assays (LLOMe treatment)\",\n      \"journal\": \"Autophagy\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 / Strong — unbiased substrate trapping + mass spectrometry + biochemical dephosphorylation assay + Co-IP of VCP cofactors + in vivo KO phenotype, multiple orthogonal methods establishing substrate identity and functional consequence\",\n      \"pmids\": [\"36300783\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2026,\n      \"finding\": \"PTP4A2 directly interacts with p53 and dephosphorylates it at serine 392, decreasing p53 stability and activity in leukemia-initiating cells (LICs). Ptp4a2 deficiency activates p53, induces LIC apoptosis and senescence, and extends survival of recipient mice in a KMT2A-MLLT3-driven AML model.\",\n      \"method\": \"Co-immunoprecipitation of PTP4A2 and p53, phosphorylation assay (Ser392 dephosphorylation), Ptp4a2 knockout in LICs, in vivo AML mouse model with survival readout, apoptosis and senescence assays\",\n      \"journal\": \"Blood advances\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — reciprocal Co-IP, defined dephosphorylation site on p53, KO mouse AML model with survival readout, and multiple cellular phenotype readouts in a single study\",\n      \"pmids\": [\"41985006\"],\n      \"is_preprint\": false\n    }\n  ],\n  \"current_model\": \"PTP4A2/PRL-2 is a farnesylated, endosome-localized protein tyrosine phosphatase that promotes cell proliferation, migration, and oncogenesis through multiple mechanisms: it forms a functional complex with CNNM3 magnesium transporter (via CNNM3's Bateman domain loop inserting into the PTP4A2 catalytic pocket) to regulate intracellular magnesium and confer oncogenic growth advantage; it dephosphorylates VCP/p97 at Tyr805 to enable ELDR complex assembly and lysophagy; it dephosphorylates p53 at Ser392 to destabilize p53 and promote leukemia-initiating cell survival; it mediates SCF/KIT-driven AKT and ERK activation in hematopoietic stem cells; and it supports VEGF-A/DLL-4/NOTCH-1-dependent angiogenesis in endothelial cells, with both catalytic activity and C-terminal prenylation required for its pro-migratory ERK-dependent functions.\"\n}\n```","stage2_raw":"{\n  \"mechanistic_narrative\": \"PTP4A2/PRL-2 is a prenylated protein tyrosine phosphatase that drives cell proliferation, migration, and oncogenesis across hematopoietic, endothelial, and epithelial lineages [#3, #6]. Its C-terminal CAAX motif directs farnesylation [#0] and early-endosome localization, and the prenylated protein engages the beta-subunit of Rab geranylgeranyltransferase II [#1]. Both catalytic activity and C-terminal prenylation are required for PRL-2 to drive ERK phosphorylation and nuclear translocation, acting through an ERK-dependent, Src-independent p130Cas pathway to promote migration and invasion [#4]. PRL-2 forms a functional heterodimer with the magnesium transporter CNNM3, with an Asp residue in the CNNM3 Bateman/CBS-domain loop inserting into the PRL-2 catalytic cavity; this non-catalytic interaction regulates intracellular magnesium and confers an oncogenic growth advantage, and disrupting the interface impairs CNNM3 channel activity and breast cancer proliferation [#5, #7]. PRL-2 also acts as a catalytic phosphatase on defined substrates: it dephosphorylates VCP/p97 at Tyr805 to enable assembly of the ELDR cofactor complex (UBXN6/UBXD1, PLAA) and drive lysophagy [#9], and it dephosphorylates p53 at Ser392 to destabilize p53 and sustain leukemia-initiating cells [#10]. In stem and vascular compartments PRL-2 mediates SCF/KIT-driven AKT and ERK activation for hematopoietic stem cell self-renewal [#6] and VEGF-A/DLL-4/NOTCH-1 signaling for sprouting angiogenesis [#8].\",\n  \"teleology\": [\n    {\n      \"year\": 1998,\n      \"claim\": \"Establishing that PRL-2 carries a C-terminal CAAX prenylation motif defined it as a membrane-targeted phosphatase rather than a soluble enzyme, framing all later localization and function studies.\",\n      \"evidence\": \"Sequence analysis identifying a conserved prenylation motif placing PRL-2 with PRL-1 and Cdc14p/PTEN\",\n      \"pmids\": [\"9514946\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Prenylation inferred from motif, not yet biochemically demonstrated in this study\", \"No functional consequence of prenylation established\"]\n    },\n    {\n      \"year\": 2001,\n      \"claim\": \"Demonstrating that farnesylated PRL-2 binds betaGGT II and localizes to early endosomes provided the first physical partner and subcellular address, linking prenylation to a defined location.\",\n      \"evidence\": \"Yeast two-hybrid, Co-IP in HeLa cells, chimeric domain mapping, isoprenoid analysis, and GGT II activity assay\",\n      \"pmids\": [\"11447212\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Functional role of betaGGT II binding for downstream signaling unresolved\", \"Whether endosomal localization is required for catalytic substrate access not tested\"]\n    },\n    {\n      \"year\": 2010,\n      \"claim\": \"Gain- and loss-of-function studies showed PRL-2 promotes migration, cytokine-driven growth, and ERK1/2-dependent tumor formation, establishing it as a pro-oncogenic phosphatase in vivo.\",\n      \"evidence\": \"Overexpression in hematopoietic cells and breast cancer lines, siRNA knockdown, xenograft and transgenic mouse models with ERK1/2 readout\",\n      \"pmids\": [\"20226699\", \"20841483\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Direct phosphatase substrates not identified\", \"Mechanism linking PRL-2 to ERK activation undefined\"]\n    },\n    {\n      \"year\": 2011,\n      \"claim\": \"Showing that both catalytic activity and prenylation are required for ERK phosphorylation, nuclear translocation, and the p130Cas migration pathway connected PRL-2's two structural features to its pro-invasive output.\",\n      \"evidence\": \"siRNA knockdown with resistant rescue, C101S catalytic-dead and CAAX-deletion mutants, pathway Western blots, migration/invasion assays\",\n      \"pmids\": [\"21765462\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Direct dephosphorylation target upstream of ERK/p130Cas not identified\", \"How prenylation contributes mechanistically beyond localization unclear\"]\n    },\n    {\n      \"year\": 2014,\n      \"claim\": \"Identifying the PRL-2·CNNM3 heterodimer and the Ptp4a2-null magnesium phenotype revealed a non-catalytic, interaction-based mechanism for regulating cellular magnesium and oncogenic growth.\",\n      \"evidence\": \"Endogenous reciprocal Co-IP, magnesium influx measurement, Ptp4a2 knockout mouse serum magnesium, xenograft with CNNM3 binding mutant\",\n      \"pmids\": [\"24632616\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"CNNM3 is not a phosphorylated substrate, leaving the molecular basis of magnesium regulation incomplete\", \"Link between magnesium handling and growth advantage not mechanistically dissected\"]\n    },\n    {\n      \"year\": 2014,\n      \"claim\": \"Conditional knockout established a physiological requirement for PTP4A2 phosphatase activity in HSC self-renewal via SCF/KIT-driven AKT and ERK signaling.\",\n      \"evidence\": \"Serial bone marrow transplantation in Ptp4a2 KO mice, phosphatase-dead rescue, SCF stimulation, oncogenic KIT epistasis\",\n      \"pmids\": [\"24753135\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Direct substrate within the SCF/KIT-AKT/ERK axis not identified\", \"Whether the same mechanism operates outside hematopoiesis untested here\"]\n    },\n    {\n      \"year\": 2016,\n      \"claim\": \"Mapping the CNNM3 Asp-426 residue into the PRL-2 catalytic cavity and showing a PRL inhibitor disrupts the complex defined a druggable interface controlling CNNM3 channel activity and tumor proliferation.\",\n      \"evidence\": \"D426A mutagenesis, whole-cell voltage clamping, molecular modeling, orthotopic xenograft, Co-IP, inhibitor proliferation assays\",\n      \"pmids\": [\"26969161\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"How catalytic-pocket occupancy by CNNM3 relates to PRL-2 phosphatase activity on other substrates unresolved\", \"In vivo selectivity of the PRL inhibitor not addressed\"]\n    },\n    {\n      \"year\": 2020,\n      \"claim\": \"Endothelial-specific knockout demonstrated PTP4A2 is required for sprouting angiogenesis and arteriovenous differentiation through VEGF-A and DLL-4/NOTCH-1 signaling, extending its role to vascular development.\",\n      \"evidence\": \"Inducible endothelial-specific and global Ptp4a2 KO mice, retinal vascular outgrowth analysis, migration assays, VEGF-A/NOTCH-1 readouts\",\n      \"pmids\": [\"33097786\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Direct substrate in the VEGF-A/NOTCH axis not identified\", \"Whether ERK-dependent migration mechanism from epithelial cells applies in endothelium not confirmed\"]\n    },\n    {\n      \"year\": 2022,\n      \"claim\": \"Unbiased substrate trapping identified VCP/p97 Tyr805 as a direct PTP4A2 substrate, linking the phosphatase to ELDR complex assembly and lysophagy with an in vivo kidney-injury phenotype.\",\n      \"evidence\": \"Substrate trapping with mass spectrometry, biochemical dephosphorylation assay, Co-IP of VCP cofactors, Ptp4a2 KO MEFs and mice, acute kidney injury model\",\n      \"pmids\": [\"36300783\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"How VCP dephosphorylation is spatially coordinated with endosomal/lysosomal localization not detailed\", \"Relationship between lysophagy role and oncogenic functions unexplored\"]\n    },\n    {\n      \"year\": 2026,\n      \"claim\": \"Identifying p53 Ser392 as a PTP4A2 dephosphorylation target showed how the phosphatase destabilizes p53 to sustain leukemia-initiating cells, providing a direct oncogenic substrate.\",\n      \"evidence\": \"Reciprocal Co-IP, Ser392 dephosphorylation assay, Ptp4a2 KO in LICs, KMT2A-MLLT3 AML mouse survival model, apoptosis/senescence assays\",\n      \"pmids\": [\"41985006\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Structural basis of PTP4A2-p53 recognition not defined\", \"Whether p53 regulation operates in non-leukemic PTP4A2 contexts untested\"]\n    },\n    {\n      \"year\": null,\n      \"claim\": \"How PTP4A2 selects among its diverse substrates (VCP, p53) and non-catalytic partners (CNNM3) in different cellular contexts, and how prenylation/endosomal localization gates these activities, remains unresolved.\",\n      \"evidence\": \"\",\n      \"pmids\": [],\n      \"confidence\": \"High\",\n      \"gaps\": [\"No unifying model for substrate selection across tissues\", \"Direct substrates underlying ERK/AKT activation in stem and endothelial cells still unidentified\", \"Structural integration of catalytic vs. CNNM3-binding modes not established\"]\n    }\n  ],\n  \"mechanism_profile\": {\n    \"molecular_activity\": [\n      {\"term_id\": \"GO:0140096\", \"supporting_discovery_ids\": [4, 6, 9, 10]},\n      {\"term_id\": \"GO:0016787\", \"supporting_discovery_ids\": [4, 9, 10]},\n      {\"term_id\": \"GO:0098772\", \"supporting_discovery_ids\": [5, 7]}\n    ],\n    \"localization\": [\n      {\"term_id\": \"GO:0005768\", \"supporting_discovery_ids\": [1]},\n      {\"term_id\": \"GO:0005634\", \"supporting_discovery_ids\": [4]}\n    ],\n    \"pathway\": [\n      {\"term_id\": \"R-HSA-162582\", \"supporting_discovery_ids\": [4, 6, 8]},\n      {\"term_id\": \"R-HSA-9612973\", \"supporting_discovery_ids\": [9]},\n      {\"term_id\": \"R-HSA-1643685\", \"supporting_discovery_ids\": [3, 10]},\n      {\"term_id\": \"R-HSA-1266738\", \"supporting_discovery_ids\": [8]}\n    ],\n    \"complexes\": [\n      \"PRL-2·CNNM3 heterodimer\",\n      \"ELDR complex (with VCP/p97, UBXN6/UBXD1, PLAA)\"\n    ],\n    \"partners\": [\n      \"CNNM3\",\n      \"VCP\",\n      \"TP53\",\n      \"UBXN6\",\n      \"PLAA\"\n    ],\n    \"other_free_text\": []\n  }\n}","audit_flag":null,"evaluation":{"pairwise":"win","faith_supported":6,"faith_total":6,"faith_pct":100.0}}