{"gene":"WNK2","run_date":"2026-06-11T09:02:06","timeline":{"discoveries":[{"year":2011,"finding":"WNK2 is a neuron-enriched kinase that reciprocally activates NKCC1 and inhibits KCC2 in a kinase-dependent manner, promoting chloride accumulation; WNK2 forms a protein complex in mammalian brain with SPAK, in which SPAK is phosphorylated at Ser-383 (a consensus WNK recognition site), as demonstrated by TiO2 enrichment, tandem mass spectrometry, and Xenopus oocyte uptake assays.","method":"86Rb+ uptake assays in Xenopus oocytes, TiO2 phosphopeptide enrichment, tandem mass spectrometry, kinase-dead mutant analysis","journal":"The Journal of biological chemistry","confidence":"High","confidence_rationale":"Tier 1-2 / Moderate — functional reconstitution in Xenopus oocytes with kinase-dead mutant, plus direct identification of SPAK complex and phosphorylation site by mass spectrometry; multiple orthogonal methods in one study","pmids":["21733846"],"is_preprint":false},{"year":2007,"finding":"WNK2 depletion by RNAi activates ERK1/2 via MEK1 phosphorylation at serine 298, increasing MEK1 activity; expression of a kinase-dead WNK2-K207M mutant also activates ERK1/2, indicating that WNK2 catalytic activity is required for this suppression; WNK2 depletion increases G1/S progression and potentiates EGF-induced proliferation.","method":"RNA interference, kinase-dead mutant (K207M) overexpression, Western blot for pMEK1(S298) and pERK1/2, cell cycle analysis in HeLa and HT29 cells","journal":"Oncogene","confidence":"High","confidence_rationale":"Tier 2 / Moderate — reciprocal loss-of-function (RNAi) and kinase-dead mutant with specific phosphorylation site readout; two cell lines; multiple orthogonal methods","pmids":["17667937"],"is_preprint":false},{"year":2007,"finding":"WNK2 exhibits autophosphorylation and serine/threonine protein kinase activity that is enhanced under hypertonic conditions; WNK2 inhibits colony formation of glioma cells in a kinase-independent manner.","method":"In vitro kinase assay (autophosphorylation), hypertonic stress exposure, colony formation assay with wild-type and kinase-mutant WNK2","journal":"Proceedings of the National Academy of Sciences of the United States of America","confidence":"Medium","confidence_rationale":"Tier 1-2 / Weak — in vitro kinase assay demonstrated autophosphorylation; kinase-independence of colony suppression shown by mutant, but single lab single study","pmids":["17578925"],"is_preprint":false},{"year":2008,"finding":"WNK2 controls a RhoA–Rac1 cross-talk mechanism: WNK2 depletion decreases RhoA activation and increases GTP-loaded Rac1, which stimulates the Rac1-effector PAK1; PAK1 then phosphorylates MEK1 at serine 298, increasing MEK1 affinity for ERK1/2 and thereby activating ERK1/2 upon growth factor stimulation.","method":"RNAi-mediated WNK2 depletion, GTPase pull-down (active RhoA/Rac1 assays), Western blot for pPAK1, pMEK1(S298), pERK1/2 in HeLa cells","journal":"Cellular signalling","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — pathway placement by GTPase activity assays and epistasis using RNAi; two orthogonal methods (GTPase pulldown + kinase phosphorylation); single lab","pmids":["18593598"],"is_preprint":false},{"year":2012,"finding":"WNK2 controls GTP-loading of Rac1; re-expression of WNK2 in glioblastoma cells reduces Rac1 activation and decreases cell invasion and migration, while depletion of endogenous WNK2 increases Rac1 activation and invasion.","method":"WNK2 re-expression in methylation-silenced glioblastoma cells, WNK2 siRNA knockdown, active Rac1 pull-down assay, invasion/migration assays, in vivo xenograft","journal":"Human molecular genetics","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — bidirectional manipulation (re-expression and knockdown) with Rac1 GTPase pulldown and phenotypic readouts in vitro and in vivo; single lab","pmids":["23035050"],"is_preprint":false},{"year":2015,"finding":"WNK2 silencing is associated with activation of JNK and upregulation of MMP2 expression and activity in glioma cells; WNK2 inhibits JNK, and this is mechanistically linked to decreased MMP2 levels.","method":"WNK2 knockdown/re-expression in glioma cell lines, JNK activity assay, MMP2 zymography, Western blot","journal":"Oncotarget","confidence":"Medium","confidence_rationale":"Tier 2 / Weak — defined pathway placement (WNK2→JNK→MMP2) using loss/gain of function with enzymatic readouts; single lab, single study","pmids":["25596741"],"is_preprint":false},{"year":2013,"finding":"WNK2 overexpression in pancreatic ductal adenocarcinoma cells reduces cell growth, and WNK2 expression in tissues correlates negatively with pERK1/2, indicating WNK2 suppresses ERK-MAPK-driven proliferation in pancreatic cancer.","method":"WNK2 overexpression in PDAC cell lines, cell growth assays, immunohistochemistry for pERK1/2 in patient tissues","journal":"Oncogene","confidence":"Low","confidence_rationale":"Tier 3 / Weak — overexpression growth assay with correlative IHC evidence; no direct epistasis experiment; single lab","pmids":["23912455"],"is_preprint":false},{"year":2019,"finding":"WNK2 inactivation in hepatocellular carcinoma leads to ERK1/2 signaling activation and promotes tumor growth, metastasis, and tumor-associated macrophage infiltration; WNK2 acts as a tumor suppressor through the ERK1/2 pathway in HCC.","method":"WNK2 loss-of-function in HCC cell lines, pERK1/2 Western blot, in vivo xenograft, somatic mutation and copy number analysis in patient samples","journal":"Journal of hepatology","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — functional cell and in vivo assays with defined ERK1/2 pathway readout; corroborated by genomic data; single lab","pmids":["31349001"],"is_preprint":false},{"year":2020,"finding":"WNK2 overexpression inhibits autophagic flux in glioblastoma cells through a mTOR-independent pathway, as evidenced by decreased LC3B and p62 protein levels and reduced LC3A/B ratio under bafilomycin A1 + everolimus treatment.","method":"WNK2 overexpression in A172 glioblastoma cells, Western blot and immunofluorescence for LC3A/B and p62, autophagy inducer/inhibitor pharmacological assays, mTOR pathway analysis","journal":"Cells","confidence":"Low","confidence_rationale":"Tier 3 / Weak — single overexpression experiment with autophagic flux markers; mTOR independence inferred indirectly; single lab","pmids":["32093151"],"is_preprint":false},{"year":2020,"finding":"CBX8 interacts with the WNK2 promoter to suppress WNK2 expression; decreased WNK2 results in increased Rac1 GTP-loading and MMP2 activity, promoting cancer cell invasion and migration; WNK2 negatively regulates both Rac1 and MMP2.","method":"ChIP assay of CBX8 at WNK2 promoter, WNK2 knockdown/overexpression, Rac1 GTPase pull-down, MMP2 activity assay, invasion/migration assays in glioblastoma, breast, and lung cancer cells","journal":"Molecular therapy oncolytics","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — ChIP for promoter binding plus GTPase and MMP activity readouts with bidirectional WNK2 manipulation; multiple cell types; single lab","pmids":["33251331"],"is_preprint":false},{"year":2022,"finding":"Germline WNK2 variants (p.Pro702Leu, p.Ala1607Val, p.Val2053Ile) display elevated phospho-PAK1/2, phospho-ERK1/2, CCND1 levels and increased clonogenic capacity and MMP2 activity compared to wild-type WNK2, confirming that WNK2 normally suppresses the MAPK pathway via PAK1/2 regulation.","method":"CRISPR/Cas9 WNK2 gene disruption in HT-29 cells, lentiviral WNK2 variant overexpression, immunoblot for pPAK1/2 and pERK1/2, colony formation and MMP2 assays","journal":"Journal of medical genetics","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — loss-of-function by gene editing plus gain-of-function with multiple variants and orthogonal pathway readouts; single lab","pmids":["36270769"],"is_preprint":false},{"year":2024,"finding":"WNK2 is a downstream transcriptional target of PAX6 in corneal epithelial cells; WNK2 knockdown impairs expression of corneal differentiation markers (KRT12, ALDH3A1, CLU) and activates keratinization, inflammation, and cell proliferation programs, indicating WNK2 is required for corneal epithelial cell differentiation and homeostasis.","method":"PAX6 shRNA knockdown followed by RNA-seq, WNK2 knockdown in LSC differentiation (air-liquid culture), qRT-PCR and immunofluorescence for CEC markers","journal":"Investigative ophthalmology & visual science","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — loss-of-function with transcriptome-wide readout and specific marker validation; PAX6→WNK2 axis established by epistasis; single lab","pmids":["39453672"],"is_preprint":false},{"year":2025,"finding":"Elevated WNK2 expression combined with hyperosmotic stress promotes an OA-associated transcriptional response in chondrocytes; OA-associated WNK2 coding variants exacerbate this response, indicating WNK2 functions in sensing and transducing hyperosmotic signals in chondrocytes.","method":"WNK2 variant overexpression and loss-of-function in immortalized and primary human chondrocytes, transcriptomic analysis under hyperosmotic stress, immunohistochemistry on human and mouse OA tissue","journal":"RMD open","confidence":"Low","confidence_rationale":"Tier 3 / Weak — single lab, transcriptomics-based pathway identification with limited biochemical resolution of mechanism; no defined downstream effector assay","pmids":["40592720"],"is_preprint":false}],"current_model":"WNK2 is a serine/threonine kinase that suppresses cell proliferation and invasion by maintaining RhoA activity to prevent Rac1/PAK1-mediated phosphorylation of MEK1 at S298, thereby limiting ERK1/2 activation; in neurons it activates NKCC1 and inhibits KCC2 via SPAK phosphorylation to regulate chloride homeostasis; and in non-neuronal contexts it additionally suppresses JNK/MMP2-dependent invasion, Rac1/MMP2-driven migration, and autophagic flux, while acting downstream of PAX6 to control corneal epithelial differentiation and responding to hyperosmotic stress in chondrocytes."},"narrative":{"mechanistic_narrative":"WNK2 is a serine/threonine protein kinase that acts as a tumor suppressor by restraining mitogenic ERK1/2 signaling and small-GTPase-driven motility [PMID:17667937, PMID:18593598, PMID:31349001]. Its catalytic activity, which is autophosphorylating and enhanced by hypertonic stress, is required to suppress ERK1/2 activation: loss of WNK2 by RNAi or a kinase-dead K207M mutant increases MEK1 phosphorylation at Ser298 and potentiates EGF-induced G1/S progression [PMID:17667937, PMID:17578925]. Mechanistically, WNK2 maintains RhoA activation and limits GTP-loading of Rac1; depletion shifts this balance toward active Rac1, engaging the Rac1 effector PAK1 to phosphorylate MEK1(S298) and drive ERK1/2 activity [PMID:18593598, PMID:23035050]. Through control of Rac1, WNK2 also limits MMP2 activity and JNK signaling, thereby suppressing cell invasion and migration across glioma, breast, and lung cancer cells [PMID:23035050, PMID:25596741, PMID:33251331]. WNK2 is silenced in cancers by promoter-level repression via CBX8 [PMID:33251331], and germline WNK2 variants that elevate phospho-PAK1/2, phospho-ERK1/2, CCND1, and MMP2 activity confirm its normal suppressive role in the MAPK pathway [PMID:36270769]. Independent of its proliferative-control role, WNK2 is a neuron-enriched kinase that complexes with SPAK and phosphorylates it at Ser383, reciprocally activating NKCC1 and inhibiting KCC2 to promote intracellular chloride accumulation [PMID:21733846]. WNK2 additionally acts downstream of PAX6 to drive corneal epithelial differentiation [PMID:39453672].","teleology":[{"year":2007,"claim":"Established that WNK2 catalytic activity restrains the ERK-MAPK proliferative pathway, answering whether WNK2 is a positive or negative regulator of mitogenic signaling.","evidence":"RNAi depletion and kinase-dead K207M overexpression with pMEK1(S298)/pERK1/2 readout and cell cycle analysis in HeLa and HT29 cells","pmids":["17667937"],"confidence":"High","gaps":["Did not resolve the intermediate GTPases linking WNK2 to MEK1(S298)","Direct kinase substrate of WNK2 in this pathway not identified"]},{"year":2007,"claim":"Demonstrated that WNK2 is an active autophosphorylating kinase stimulated by hypertonicity, but that its suppression of glioma colony formation can proceed kinase-independently, separating catalytic from non-catalytic functions.","evidence":"In vitro autophosphorylation kinase assay under hypertonic stress and colony formation with wild-type versus kinase-mutant WNK2","pmids":["17578925"],"confidence":"Medium","gaps":["Mechanism of kinase-independent colony suppression undefined","Single lab, single study"]},{"year":2008,"claim":"Resolved the missing pathway link by showing WNK2 controls a RhoA-Rac1 cross-talk that gates PAK1-mediated MEK1(S298) phosphorylation.","evidence":"RNAi depletion with active RhoA/Rac1 GTPase pull-downs and pPAK1/pMEK1(S298)/pERK1/2 immunoblots in HeLa cells","pmids":["18593598"],"confidence":"Medium","gaps":["How WNK2 biochemically maintains RhoA activity not established","Single lab"]},{"year":2011,"claim":"Identified a distinct neuronal function: WNK2 controls chloride homeostasis through SPAK, answering how WNK2 couples to ion cotransporters.","evidence":"86Rb+ uptake in Xenopus oocytes, TiO2 phosphopeptide enrichment and mass spectrometry identifying SPAK Ser383 phosphorylation, kinase-dead analysis","pmids":["21733846"],"confidence":"High","gaps":["Physiological consequences in intact neurons not tested","Relationship between neuronal SPAK axis and tumor-suppressive GTPase axis unexplored"]},{"year":2012,"claim":"Extended WNK2's role to invasion/migration by showing WNK2 re-expression in silenced glioblastoma suppresses Rac1 activation and motility in vitro and in vivo.","evidence":"WNK2 re-expression and siRNA knockdown with active Rac1 pull-down, invasion/migration assays, and xenografts","pmids":["23035050"],"confidence":"Medium","gaps":["Direct molecular link between WNK2 and Rac1 GEFs/GAPs not defined","Single lab"]},{"year":2013,"claim":"Generalized WNK2 ERK suppression to pancreatic cancer via overexpression growth assays and inverse correlation with pERK1/2 in tissue.","evidence":"WNK2 overexpression in PDAC cell lines with growth assays and pERK1/2 IHC in patient tissues","pmids":["23912455"],"confidence":"Low","gaps":["Correlative IHC without epistasis experiment","Single lab"]},{"year":2015,"claim":"Added a parallel invasion-suppressing branch by placing WNK2 upstream of JNK and MMP2.","evidence":"WNK2 knockdown/re-expression in glioma with JNK activity assay, MMP2 zymography, Western blot","pmids":["25596741"],"confidence":"Medium","gaps":["Mechanism by which WNK2 inhibits JNK undefined","Single lab, single study"]},{"year":2019,"claim":"Confirmed WNK2 as a bona fide tumor suppressor in hepatocellular carcinoma acting through ERK1/2, with in vivo and genomic support.","evidence":"WNK2 loss-of-function in HCC cells, pERK1/2 immunoblot, xenografts, and patient somatic mutation/copy number analysis","pmids":["31349001"],"confidence":"Medium","gaps":["Mechanism of tumor-associated macrophage recruitment not detailed","Single lab"]},{"year":2020,"claim":"Identified an additional cellular output of WNK2 by showing overexpression inhibits autophagic flux independently of mTOR.","evidence":"WNK2 overexpression in A172 cells with LC3A/B and p62 markers under bafilomycin/everolimus treatment","pmids":["32093151"],"confidence":"Low","gaps":["mTOR independence inferred indirectly","Single overexpression experiment, single lab"]},{"year":2020,"claim":"Defined the upstream silencing mechanism, showing CBX8 represses WNK2 to derepress Rac1/MMP2-driven invasion across multiple cancer types.","evidence":"ChIP of CBX8 at WNK2 promoter, bidirectional WNK2 manipulation, Rac1 pull-down and MMP2 activity in glioblastoma, breast, and lung cells","pmids":["33251331"],"confidence":"Medium","gaps":["Whether CBX8 repression operates in non-cancer contexts unknown","Single lab"]},{"year":2022,"claim":"Demonstrated that germline WNK2 variants impair its suppression of the PAK1/2-MAPK axis, linking genetic variation to dysregulated proliferation.","evidence":"CRISPR/Cas9 WNK2 disruption in HT-29 plus lentiviral variant overexpression with pPAK1/2, pERK1/2, CCND1 immunoblots and colony/MMP2 assays","pmids":["36270769"],"confidence":"Medium","gaps":["Clinical phenotype associated with these variants not established","Single lab"]},{"year":2024,"claim":"Revealed a developmental role placing WNK2 downstream of PAX6 in corneal epithelial differentiation.","evidence":"PAX6 shRNA knockdown with RNA-seq, WNK2 knockdown in air-liquid LSC differentiation, marker qRT-PCR/immunofluorescence","pmids":["39453672"],"confidence":"Medium","gaps":["Effector mechanism downstream of WNK2 in corneal cells not defined","Single lab"]},{"year":2025,"claim":"Implicated WNK2 in hyperosmotic stress sensing in chondrocytes relevant to osteoarthritis.","evidence":"WNK2 variant overexpression and loss-of-function in human chondrocytes with transcriptomics under hyperosmotic stress and OA tissue IHC","pmids":["40592720"],"confidence":"Low","gaps":["No defined downstream effector assay","Mechanism of osmosensing transduction unresolved","Single lab"]},{"year":null,"claim":"How WNK2 biochemically maintains RhoA activation and selectively restrains Rac1 GTP-loading, and whether its neuronal SPAK/ion-cotransporter axis and its tumor-suppressive GTPase axis share a common catalytic mechanism, remain unresolved.","evidence":"","pmids":[],"confidence":"Medium","gaps":["Direct GTPase regulators (GEF/GAP) targeted by WNK2 not identified","No structural model linking kinase activity to GTPase control","Integration of neuronal and oncogenic functions unexplored"]}],"mechanism_profile":{"molecular_activity":[{"term_id":"GO:0140096","term_label":"catalytic activity, acting on a protein","supporting_discovery_ids":[0,1,2]},{"term_id":"GO:0016740","term_label":"transferase activity","supporting_discovery_ids":[0,2]},{"term_id":"GO:0098772","term_label":"molecular function regulator activity","supporting_discovery_ids":[3,4]}],"localization":[],"pathway":[{"term_id":"R-HSA-162582","term_label":"Signal Transduction","supporting_discovery_ids":[1,3,7]},{"term_id":"R-HSA-1643685","term_label":"Disease","supporting_discovery_ids":[4,7,9]},{"term_id":"R-HSA-382551","term_label":"Transport of small molecules","supporting_discovery_ids":[0]}],"complexes":[],"partners":["SPAK","MEK1","PAK1"],"other_free_text":[]}},"prefetch_data":{"uniprot":{"accession":"Q9Y3S1","full_name":"Serine/threonine-protein kinase WNK2","aliases":["Antigen NY-CO-43","Protein kinase lysine-deficient 2","Protein kinase with no lysine 2","Serologically defined colon cancer antigen 43"],"length_aa":2297,"mass_kda":242.7,"function":"Serine/threonine-protein kinase component of the WNK2-SPAK/OSR1 kinase cascade, which plays an important role in the regulation of electrolyte homeostasis, cell signaling, survival, and proliferation (PubMed:17667937, PubMed:18593598, PubMed:21733846). The WNK2-SPAK/OSR1 kinase cascade is composed of WNK2, which mediates phosphorylation and activation of downstream kinases OXSR1/OSR1 and STK39/SPAK (By similarity). Following activation, OXSR1/OSR1 and STK39/SPAK catalyze phosphorylation of ion cotransporters, regulating their activity (By similarity). Acts as an activator and inhibitor of sodium-coupled chloride cotransporters and potassium-coupled chloride cotransporters respectively (PubMed:21733846). Activates SLC12A2, SCNN1A, SCNN1B, SCNN1D and SGK1 and inhibits SLC12A5 (PubMed:21733846). Negatively regulates the EGF-induced activation of the ERK/MAPK-pathway and the downstream cell cycle progression (PubMed:17667937, PubMed:18593598). Affects MAPK3/MAPK1 activity by modulating the activity of MAP2K1 and this modulation depends on phosphorylation of MAP2K1 by PAK1 (PubMed:17667937, PubMed:18593598). WNK2 acts by interfering with the activity of PAK1 by controlling the balance of the activity of upstream regulators of PAK1 activity, RHOA and RAC1, which display reciprocal activity (PubMed:17667937, PubMed:18593598)","subcellular_location":"Cytoplasm; Cell membrane","url":"https://www.uniprot.org/uniprotkb/Q9Y3S1/entry"},"depmap":{"release":"DepMap","has_data":true,"is_common_essential":false,"resolved_as":"","url":"https://depmap.org/portal/gene/WNK2","classification":"Not Classified","n_dependent_lines":0,"n_total_lines":77,"dependency_fraction":0.0},"opencell":{"profiled":false,"resolved_as":"","ensg_id":"","cell_line_id":"","localizations":[],"interactors":[{"gene":"WNK1","stoichiometry":4.0},{"gene":"OXSR1","stoichiometry":0.2}],"url":"https://opencell.sf.czbiohub.org/search/WNK2","total_profiled":1310},"omim":[{"mim_id":"606249","title":"PROTEIN KINASE, LYSINE-DEFICIENT 2; WNK2","url":"https://www.omim.org/entry/606249"},{"mim_id":"605232","title":"PROTEIN KINASE, LYSINE-DEFICIENT 1; WNK1","url":"https://www.omim.org/entry/605232"},{"mim_id":"300358","title":"PROTEIN KINASE, LYSINE-DEFICIENT 3; WNK3","url":"https://www.omim.org/entry/300358"}],"hpa":{"profiled":true,"resolved_as":"","reliability":"Approved","locations":[{"location":"Cytosol","reliability":"Approved"}],"tissue_specificity":"Tissue enhanced","tissue_distribution":"Detected in many","driving_tissues":[{"tissue":"heart muscle","ntpm":63.5}],"url":"https://www.proteinatlas.org/search/WNK2"},"hgnc":{"alias_symbol":["NY-CO-43","KIAA1760"],"prev_symbol":["SDCCAG43","PRKWNK2"]},"alphafold":{"accession":"Q9Y3S1","domains":[{"cath_id":"3.30.200.20","chopping":"183-278","consensus_level":"medium","plddt":86.2956,"start":183,"end":278},{"cath_id":"1.10.510.10","chopping":"281-454","consensus_level":"medium","plddt":88.0979,"start":281,"end":454},{"cath_id":"3.10.20.90","chopping":"457-548","consensus_level":"medium","plddt":85.9466,"start":457,"end":548},{"cath_id":"3.10.20.90","chopping":"1185-1261_1303-1320","consensus_level":"medium","plddt":77.7414,"start":1185,"end":1320}],"viewer_url":"https://alphafold.ebi.ac.uk/entry/Q9Y3S1","model_url":"https://alphafold.ebi.ac.uk/files/AF-Q9Y3S1-F1-model_v6.cif","pae_url":"https://alphafold.ebi.ac.uk/files/AF-Q9Y3S1-F1-predicted_aligned_error_v6.png","plddt_mean":43.12},"mouse_models":{"mgi_url":"https://www.informatics.jax.org/marker/summary?nomen=WNK2","jax_strain_url":"https://www.jax.org/strain/search?query=WNK2"},"sequence":{"accession":"Q9Y3S1","fasta_url":"https://rest.uniprot.org/uniprotkb/Q9Y3S1.fasta","uniprot_url":"https://www.uniprot.org/uniprotkb/Q9Y3S1/entry","alphafold_viewer_url":"https://alphafold.ebi.ac.uk/entry/Q9Y3S1"}},"corpus_meta":[{"pmid":"21733846","id":"PMC_21733846","title":"WNK2 kinase is a novel regulator of essential neuronal cation-chloride cotransporters.","date":"2011","source":"The Journal of biological chemistry","url":"https://pubmed.ncbi.nlm.nih.gov/21733846","citation_count":76,"is_preprint":false},{"pmid":"17667937","id":"PMC_17667937","title":"Protein kinase WNK2 inhibits cell proliferation by negatively modulating the activation of MEK1/ERK1/2.","date":"2007","source":"Oncogene","url":"https://pubmed.ncbi.nlm.nih.gov/17667937","citation_count":69,"is_preprint":false},{"pmid":"17578925","id":"PMC_17578925","title":"Epigenome scans and cancer genome sequencing converge on WNK2, a kinase-independent suppressor of cell growth.","date":"2007","source":"Proceedings of the National Academy of Sciences of the United States of America","url":"https://pubmed.ncbi.nlm.nih.gov/17578925","citation_count":59,"is_preprint":false},{"pmid":"31349001","id":"PMC_31349001","title":"Genomic sequencing identifies WNK2 as a driver in hepatocellular carcinoma and a risk factor for early recurrence.","date":"2019","source":"Journal of hepatology","url":"https://pubmed.ncbi.nlm.nih.gov/31349001","citation_count":59,"is_preprint":false},{"pmid":"23035050","id":"PMC_23035050","title":"Loss of WNK2 expression by promoter gene methylation occurs in adult gliomas and triggers Rac1-mediated tumour cell invasiveness.","date":"2012","source":"Human molecular genetics","url":"https://pubmed.ncbi.nlm.nih.gov/23035050","citation_count":46,"is_preprint":false},{"pmid":"19001526","id":"PMC_19001526","title":"Epigenetic silencing of the kinase tumor suppressor WNK2 is tumor-type and tumor-grade specific.","date":"2008","source":"Neuro-oncology","url":"https://pubmed.ncbi.nlm.nih.gov/19001526","citation_count":45,"is_preprint":false},{"pmid":"23912455","id":"PMC_23912455","title":"Early epigenetic downregulation of WNK2 kinase during pancreatic ductal adenocarcinoma development.","date":"2013","source":"Oncogene","url":"https://pubmed.ncbi.nlm.nih.gov/23912455","citation_count":33,"is_preprint":false},{"pmid":"31884577","id":"PMC_31884577","title":"Long non-coding RNA LINC00858 exerts a tumor-promoting role in colon cancer via HNF4α and WNK2 regulation.","date":"2019","source":"Cellular oncology (Dordrecht, Netherlands)","url":"https://pubmed.ncbi.nlm.nih.gov/31884577","citation_count":28,"is_preprint":false},{"pmid":"18593598","id":"PMC_18593598","title":"WNK2 modulates MEK1 activity through the Rho GTPase pathway.","date":"2008","source":"Cellular signalling","url":"https://pubmed.ncbi.nlm.nih.gov/18593598","citation_count":25,"is_preprint":false},{"pmid":"25596741","id":"PMC_25596741","title":"Silencing of the tumor suppressor gene WNK2 is associated with upregulation of MMP2 and JNK in gliomas.","date":"2015","source":"Oncotarget","url":"https://pubmed.ncbi.nlm.nih.gov/25596741","citation_count":24,"is_preprint":false},{"pmid":"33251331","id":"PMC_33251331","title":"Upregulated CBX8 Promotes Cancer Metastasis via the WNK2/MMP2 Pathway.","date":"2020","source":"Molecular therapy oncolytics","url":"https://pubmed.ncbi.nlm.nih.gov/33251331","citation_count":24,"is_preprint":false},{"pmid":"32768499","id":"PMC_32768499","title":"Long non-coding RNA LINC00858 inhibits colon cancer cell apoptosis, autophagy, and senescence by activating WNK2 promoter methylation.","date":"2020","source":"Experimental cell research","url":"https://pubmed.ncbi.nlm.nih.gov/32768499","citation_count":22,"is_preprint":false},{"pmid":"31009242","id":"PMC_31009242","title":"microRNA-370 Promotes Cell Growth by Targeting WNK2 in Breast Cancer.","date":"2019","source":"DNA and cell 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pathway.","date":"2022","source":"Bioengineered","url":"https://pubmed.ncbi.nlm.nih.gov/35549643","citation_count":7,"is_preprint":false},{"pmid":"34918065","id":"PMC_34918065","title":"CircRNA-WNK2 Acts as a ceRNA for miR-328a-3p to Promote AANAT Expression in the Male Rat Pineal Gland.","date":"2022","source":"Endocrinology","url":"https://pubmed.ncbi.nlm.nih.gov/34918065","citation_count":7,"is_preprint":false},{"pmid":"39453672","id":"PMC_39453672","title":"PAX6-WNK2 Axis Governs Corneal Epithelial Homeostasis.","date":"2024","source":"Investigative ophthalmology & visual science","url":"https://pubmed.ncbi.nlm.nih.gov/39453672","citation_count":6,"is_preprint":false},{"pmid":"32093151","id":"PMC_32093151","title":"WNK2 Inhibits Autophagic Flux in Human Glioblastoma Cell Line.","date":"2020","source":"Cells","url":"https://pubmed.ncbi.nlm.nih.gov/32093151","citation_count":6,"is_preprint":false},{"pmid":"36270769","id":"PMC_36270769","title":"Germline mutations in WNK2 could be associated with serrated polyposis syndrome.","date":"2022","source":"Journal of medical genetics","url":"https://pubmed.ncbi.nlm.nih.gov/36270769","citation_count":4,"is_preprint":false},{"pmid":"40592720","id":"PMC_40592720","title":"WNK2 variants associated with familial osteoarthritis alter the chondrocyte response to hyperosmotic stress.","date":"2025","source":"RMD open","url":"https://pubmed.ncbi.nlm.nih.gov/40592720","citation_count":1,"is_preprint":false},{"pmid":"38091885","id":"PMC_38091885","title":"Regional bias of tumor suppressor gene mutations of STARD8 and WNK2 in colon cancers.","date":"2023","source":"Pathology, research and practice","url":"https://pubmed.ncbi.nlm.nih.gov/38091885","citation_count":1,"is_preprint":false},{"pmid":"41628111","id":"PMC_41628111","title":"WNK2 may promote ovarian cancer progression by upregulating POU5F1B.","date":"2026","source":"PloS one","url":"https://pubmed.ncbi.nlm.nih.gov/41628111","citation_count":0,"is_preprint":false},{"pmid":"39056814","id":"PMC_39056814","title":"Correction: Alves et al. WNK2 Inhibits Autophagic Flux in Human Glioblastoma Cell Line. Cells 2020, 9, 485.","date":"2024","source":"Cells","url":"https://pubmed.ncbi.nlm.nih.gov/39056814","citation_count":0,"is_preprint":false},{"pmid":null,"id":"bio_10.1101_2025.08.26.25334517","title":"WNK2 facilitates ovarian cancer progression by upregulating POU5F1B","date":"2025-08-29","source":"bioRxiv","url":"https://doi.org/10.1101/2025.08.26.25334517","citation_count":0,"is_preprint":true},{"pmid":null,"id":"bio_10.1101_2025.03.25.645260","title":"A Phenotype-Driven Multi-Omic Atlas of Glioblastoma Invasion","date":"2025-03-28","source":"bioRxiv","url":"https://doi.org/10.1101/2025.03.25.645260","citation_count":0,"is_preprint":true}],"cost":{"stage1":{"model":"claude-sonnet-4-6","input_tokens":14951,"output_tokens":3516,"usd":0.048796,"stage1_stop_reason":"end_turn"},"stage2":{"model":"claude-opus-4-8","input_tokens":10939,"output_tokens":3925,"usd":0.07641,"stage2_stop_reason":"end_turn"},"total_usd":0.125206,"stage1_batch_id":"msgbatch_01UT1AahFPCAyn2uVweS7A9z","stage2_batch_id":"msgbatch_01HuKWtKNT4Pqj1bc8eEP5RV","note":"batch pricing = 50% of standard"},"stage1_raw":"```json\n{\n  \"discoveries\": [\n    {\n      \"year\": 2011,\n      \"finding\": \"WNK2 is a neuron-enriched kinase that reciprocally activates NKCC1 and inhibits KCC2 in a kinase-dependent manner, promoting chloride accumulation; WNK2 forms a protein complex in mammalian brain with SPAK, in which SPAK is phosphorylated at Ser-383 (a consensus WNK recognition site), as demonstrated by TiO2 enrichment, tandem mass spectrometry, and Xenopus oocyte uptake assays.\",\n      \"method\": \"86Rb+ uptake assays in Xenopus oocytes, TiO2 phosphopeptide enrichment, tandem mass spectrometry, kinase-dead mutant analysis\",\n      \"journal\": \"The Journal of biological chemistry\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1-2 / Moderate — functional reconstitution in Xenopus oocytes with kinase-dead mutant, plus direct identification of SPAK complex and phosphorylation site by mass spectrometry; multiple orthogonal methods in one study\",\n      \"pmids\": [\"21733846\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2007,\n      \"finding\": \"WNK2 depletion by RNAi activates ERK1/2 via MEK1 phosphorylation at serine 298, increasing MEK1 activity; expression of a kinase-dead WNK2-K207M mutant also activates ERK1/2, indicating that WNK2 catalytic activity is required for this suppression; WNK2 depletion increases G1/S progression and potentiates EGF-induced proliferation.\",\n      \"method\": \"RNA interference, kinase-dead mutant (K207M) overexpression, Western blot for pMEK1(S298) and pERK1/2, cell cycle analysis in HeLa and HT29 cells\",\n      \"journal\": \"Oncogene\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — reciprocal loss-of-function (RNAi) and kinase-dead mutant with specific phosphorylation site readout; two cell lines; multiple orthogonal methods\",\n      \"pmids\": [\"17667937\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2007,\n      \"finding\": \"WNK2 exhibits autophosphorylation and serine/threonine protein kinase activity that is enhanced under hypertonic conditions; WNK2 inhibits colony formation of glioma cells in a kinase-independent manner.\",\n      \"method\": \"In vitro kinase assay (autophosphorylation), hypertonic stress exposure, colony formation assay with wild-type and kinase-mutant WNK2\",\n      \"journal\": \"Proceedings of the National Academy of Sciences of the United States of America\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 1-2 / Weak — in vitro kinase assay demonstrated autophosphorylation; kinase-independence of colony suppression shown by mutant, but single lab single study\",\n      \"pmids\": [\"17578925\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2008,\n      \"finding\": \"WNK2 controls a RhoA–Rac1 cross-talk mechanism: WNK2 depletion decreases RhoA activation and increases GTP-loaded Rac1, which stimulates the Rac1-effector PAK1; PAK1 then phosphorylates MEK1 at serine 298, increasing MEK1 affinity for ERK1/2 and thereby activating ERK1/2 upon growth factor stimulation.\",\n      \"method\": \"RNAi-mediated WNK2 depletion, GTPase pull-down (active RhoA/Rac1 assays), Western blot for pPAK1, pMEK1(S298), pERK1/2 in HeLa cells\",\n      \"journal\": \"Cellular signalling\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — pathway placement by GTPase activity assays and epistasis using RNAi; two orthogonal methods (GTPase pulldown + kinase phosphorylation); single lab\",\n      \"pmids\": [\"18593598\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2012,\n      \"finding\": \"WNK2 controls GTP-loading of Rac1; re-expression of WNK2 in glioblastoma cells reduces Rac1 activation and decreases cell invasion and migration, while depletion of endogenous WNK2 increases Rac1 activation and invasion.\",\n      \"method\": \"WNK2 re-expression in methylation-silenced glioblastoma cells, WNK2 siRNA knockdown, active Rac1 pull-down assay, invasion/migration assays, in vivo xenograft\",\n      \"journal\": \"Human molecular genetics\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — bidirectional manipulation (re-expression and knockdown) with Rac1 GTPase pulldown and phenotypic readouts in vitro and in vivo; single lab\",\n      \"pmids\": [\"23035050\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2015,\n      \"finding\": \"WNK2 silencing is associated with activation of JNK and upregulation of MMP2 expression and activity in glioma cells; WNK2 inhibits JNK, and this is mechanistically linked to decreased MMP2 levels.\",\n      \"method\": \"WNK2 knockdown/re-expression in glioma cell lines, JNK activity assay, MMP2 zymography, Western blot\",\n      \"journal\": \"Oncotarget\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Weak — defined pathway placement (WNK2→JNK→MMP2) using loss/gain of function with enzymatic readouts; single lab, single study\",\n      \"pmids\": [\"25596741\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2013,\n      \"finding\": \"WNK2 overexpression in pancreatic ductal adenocarcinoma cells reduces cell growth, and WNK2 expression in tissues correlates negatively with pERK1/2, indicating WNK2 suppresses ERK-MAPK-driven proliferation in pancreatic cancer.\",\n      \"method\": \"WNK2 overexpression in PDAC cell lines, cell growth assays, immunohistochemistry for pERK1/2 in patient tissues\",\n      \"journal\": \"Oncogene\",\n      \"confidence\": \"Low\",\n      \"confidence_rationale\": \"Tier 3 / Weak — overexpression growth assay with correlative IHC evidence; no direct epistasis experiment; single lab\",\n      \"pmids\": [\"23912455\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2019,\n      \"finding\": \"WNK2 inactivation in hepatocellular carcinoma leads to ERK1/2 signaling activation and promotes tumor growth, metastasis, and tumor-associated macrophage infiltration; WNK2 acts as a tumor suppressor through the ERK1/2 pathway in HCC.\",\n      \"method\": \"WNK2 loss-of-function in HCC cell lines, pERK1/2 Western blot, in vivo xenograft, somatic mutation and copy number analysis in patient samples\",\n      \"journal\": \"Journal of hepatology\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — functional cell and in vivo assays with defined ERK1/2 pathway readout; corroborated by genomic data; single lab\",\n      \"pmids\": [\"31349001\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2020,\n      \"finding\": \"WNK2 overexpression inhibits autophagic flux in glioblastoma cells through a mTOR-independent pathway, as evidenced by decreased LC3B and p62 protein levels and reduced LC3A/B ratio under bafilomycin A1 + everolimus treatment.\",\n      \"method\": \"WNK2 overexpression in A172 glioblastoma cells, Western blot and immunofluorescence for LC3A/B and p62, autophagy inducer/inhibitor pharmacological assays, mTOR pathway analysis\",\n      \"journal\": \"Cells\",\n      \"confidence\": \"Low\",\n      \"confidence_rationale\": \"Tier 3 / Weak — single overexpression experiment with autophagic flux markers; mTOR independence inferred indirectly; single lab\",\n      \"pmids\": [\"32093151\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2020,\n      \"finding\": \"CBX8 interacts with the WNK2 promoter to suppress WNK2 expression; decreased WNK2 results in increased Rac1 GTP-loading and MMP2 activity, promoting cancer cell invasion and migration; WNK2 negatively regulates both Rac1 and MMP2.\",\n      \"method\": \"ChIP assay of CBX8 at WNK2 promoter, WNK2 knockdown/overexpression, Rac1 GTPase pull-down, MMP2 activity assay, invasion/migration assays in glioblastoma, breast, and lung cancer cells\",\n      \"journal\": \"Molecular therapy oncolytics\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — ChIP for promoter binding plus GTPase and MMP activity readouts with bidirectional WNK2 manipulation; multiple cell types; single lab\",\n      \"pmids\": [\"33251331\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2022,\n      \"finding\": \"Germline WNK2 variants (p.Pro702Leu, p.Ala1607Val, p.Val2053Ile) display elevated phospho-PAK1/2, phospho-ERK1/2, CCND1 levels and increased clonogenic capacity and MMP2 activity compared to wild-type WNK2, confirming that WNK2 normally suppresses the MAPK pathway via PAK1/2 regulation.\",\n      \"method\": \"CRISPR/Cas9 WNK2 gene disruption in HT-29 cells, lentiviral WNK2 variant overexpression, immunoblot for pPAK1/2 and pERK1/2, colony formation and MMP2 assays\",\n      \"journal\": \"Journal of medical genetics\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — loss-of-function by gene editing plus gain-of-function with multiple variants and orthogonal pathway readouts; single lab\",\n      \"pmids\": [\"36270769\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2024,\n      \"finding\": \"WNK2 is a downstream transcriptional target of PAX6 in corneal epithelial cells; WNK2 knockdown impairs expression of corneal differentiation markers (KRT12, ALDH3A1, CLU) and activates keratinization, inflammation, and cell proliferation programs, indicating WNK2 is required for corneal epithelial cell differentiation and homeostasis.\",\n      \"method\": \"PAX6 shRNA knockdown followed by RNA-seq, WNK2 knockdown in LSC differentiation (air-liquid culture), qRT-PCR and immunofluorescence for CEC markers\",\n      \"journal\": \"Investigative ophthalmology & visual science\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — loss-of-function with transcriptome-wide readout and specific marker validation; PAX6→WNK2 axis established by epistasis; single lab\",\n      \"pmids\": [\"39453672\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2025,\n      \"finding\": \"Elevated WNK2 expression combined with hyperosmotic stress promotes an OA-associated transcriptional response in chondrocytes; OA-associated WNK2 coding variants exacerbate this response, indicating WNK2 functions in sensing and transducing hyperosmotic signals in chondrocytes.\",\n      \"method\": \"WNK2 variant overexpression and loss-of-function in immortalized and primary human chondrocytes, transcriptomic analysis under hyperosmotic stress, immunohistochemistry on human and mouse OA tissue\",\n      \"journal\": \"RMD open\",\n      \"confidence\": \"Low\",\n      \"confidence_rationale\": \"Tier 3 / Weak — single lab, transcriptomics-based pathway identification with limited biochemical resolution of mechanism; no defined downstream effector assay\",\n      \"pmids\": [\"40592720\"],\n      \"is_preprint\": false\n    }\n  ],\n  \"current_model\": \"WNK2 is a serine/threonine kinase that suppresses cell proliferation and invasion by maintaining RhoA activity to prevent Rac1/PAK1-mediated phosphorylation of MEK1 at S298, thereby limiting ERK1/2 activation; in neurons it activates NKCC1 and inhibits KCC2 via SPAK phosphorylation to regulate chloride homeostasis; and in non-neuronal contexts it additionally suppresses JNK/MMP2-dependent invasion, Rac1/MMP2-driven migration, and autophagic flux, while acting downstream of PAX6 to control corneal epithelial differentiation and responding to hyperosmotic stress in chondrocytes.\"\n}\n```","stage2_raw":"{\n  \"mechanistic_narrative\": \"WNK2 is a serine/threonine protein kinase that acts as a tumor suppressor by restraining mitogenic ERK1/2 signaling and small-GTPase-driven motility [#1, #3, #7]. Its catalytic activity, which is autophosphorylating and enhanced by hypertonic stress, is required to suppress ERK1/2 activation: loss of WNK2 by RNAi or a kinase-dead K207M mutant increases MEK1 phosphorylation at Ser298 and potentiates EGF-induced G1/S progression [#1, #2]. Mechanistically, WNK2 maintains RhoA activation and limits GTP-loading of Rac1; depletion shifts this balance toward active Rac1, engaging the Rac1 effector PAK1 to phosphorylate MEK1(S298) and drive ERK1/2 activity [#3, #4]. Through control of Rac1, WNK2 also limits MMP2 activity and JNK signaling, thereby suppressing cell invasion and migration across glioma, breast, and lung cancer cells [#4, #5, #9]. WNK2 is silenced in cancers by promoter-level repression via CBX8 [#9], and germline WNK2 variants that elevate phospho-PAK1/2, phospho-ERK1/2, CCND1, and MMP2 activity confirm its normal suppressive role in the MAPK pathway [#10]. Independent of its proliferative-control role, WNK2 is a neuron-enriched kinase that complexes with SPAK and phosphorylates it at Ser383, reciprocally activating NKCC1 and inhibiting KCC2 to promote intracellular chloride accumulation [#0]. WNK2 additionally acts downstream of PAX6 to drive corneal epithelial differentiation [#11].\",\n  \"teleology\": [\n    {\n      \"year\": 2007,\n      \"claim\": \"Established that WNK2 catalytic activity restrains the ERK-MAPK proliferative pathway, answering whether WNK2 is a positive or negative regulator of mitogenic signaling.\",\n      \"evidence\": \"RNAi depletion and kinase-dead K207M overexpression with pMEK1(S298)/pERK1/2 readout and cell cycle analysis in HeLa and HT29 cells\",\n      \"pmids\": [\"17667937\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Did not resolve the intermediate GTPases linking WNK2 to MEK1(S298)\", \"Direct kinase substrate of WNK2 in this pathway not identified\"]\n    },\n    {\n      \"year\": 2007,\n      \"claim\": \"Demonstrated that WNK2 is an active autophosphorylating kinase stimulated by hypertonicity, but that its suppression of glioma colony formation can proceed kinase-independently, separating catalytic from non-catalytic functions.\",\n      \"evidence\": \"In vitro autophosphorylation kinase assay under hypertonic stress and colony formation with wild-type versus kinase-mutant WNK2\",\n      \"pmids\": [\"17578925\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Mechanism of kinase-independent colony suppression undefined\", \"Single lab, single study\"]\n    },\n    {\n      \"year\": 2008,\n      \"claim\": \"Resolved the missing pathway link by showing WNK2 controls a RhoA-Rac1 cross-talk that gates PAK1-mediated MEK1(S298) phosphorylation.\",\n      \"evidence\": \"RNAi depletion with active RhoA/Rac1 GTPase pull-downs and pPAK1/pMEK1(S298)/pERK1/2 immunoblots in HeLa cells\",\n      \"pmids\": [\"18593598\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"How WNK2 biochemically maintains RhoA activity not established\", \"Single lab\"]\n    },\n    {\n      \"year\": 2011,\n      \"claim\": \"Identified a distinct neuronal function: WNK2 controls chloride homeostasis through SPAK, answering how WNK2 couples to ion cotransporters.\",\n      \"evidence\": \"86Rb+ uptake in Xenopus oocytes, TiO2 phosphopeptide enrichment and mass spectrometry identifying SPAK Ser383 phosphorylation, kinase-dead analysis\",\n      \"pmids\": [\"21733846\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Physiological consequences in intact neurons not tested\", \"Relationship between neuronal SPAK axis and tumor-suppressive GTPase axis unexplored\"]\n    },\n    {\n      \"year\": 2012,\n      \"claim\": \"Extended WNK2's role to invasion/migration by showing WNK2 re-expression in silenced glioblastoma suppresses Rac1 activation and motility in vitro and in vivo.\",\n      \"evidence\": \"WNK2 re-expression and siRNA knockdown with active Rac1 pull-down, invasion/migration assays, and xenografts\",\n      \"pmids\": [\"23035050\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Direct molecular link between WNK2 and Rac1 GEFs/GAPs not defined\", \"Single lab\"]\n    },\n    {\n      \"year\": 2013,\n      \"claim\": \"Generalized WNK2 ERK suppression to pancreatic cancer via overexpression growth assays and inverse correlation with pERK1/2 in tissue.\",\n      \"evidence\": \"WNK2 overexpression in PDAC cell lines with growth assays and pERK1/2 IHC in patient tissues\",\n      \"pmids\": [\"23912455\"],\n      \"confidence\": \"Low\",\n      \"gaps\": [\"Correlative IHC without epistasis experiment\", \"Single lab\"]\n    },\n    {\n      \"year\": 2015,\n      \"claim\": \"Added a parallel invasion-suppressing branch by placing WNK2 upstream of JNK and MMP2.\",\n      \"evidence\": \"WNK2 knockdown/re-expression in glioma with JNK activity assay, MMP2 zymography, Western blot\",\n      \"pmids\": [\"25596741\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Mechanism by which WNK2 inhibits JNK undefined\", \"Single lab, single study\"]\n    },\n    {\n      \"year\": 2019,\n      \"claim\": \"Confirmed WNK2 as a bona fide tumor suppressor in hepatocellular carcinoma acting through ERK1/2, with in vivo and genomic support.\",\n      \"evidence\": \"WNK2 loss-of-function in HCC cells, pERK1/2 immunoblot, xenografts, and patient somatic mutation/copy number analysis\",\n      \"pmids\": [\"31349001\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Mechanism of tumor-associated macrophage recruitment not detailed\", \"Single lab\"]\n    },\n    {\n      \"year\": 2020,\n      \"claim\": \"Identified an additional cellular output of WNK2 by showing overexpression inhibits autophagic flux independently of mTOR.\",\n      \"evidence\": \"WNK2 overexpression in A172 cells with LC3A/B and p62 markers under bafilomycin/everolimus treatment\",\n      \"pmids\": [\"32093151\"],\n      \"confidence\": \"Low\",\n      \"gaps\": [\"mTOR independence inferred indirectly\", \"Single overexpression experiment, single lab\"]\n    },\n    {\n      \"year\": 2020,\n      \"claim\": \"Defined the upstream silencing mechanism, showing CBX8 represses WNK2 to derepress Rac1/MMP2-driven invasion across multiple cancer types.\",\n      \"evidence\": \"ChIP of CBX8 at WNK2 promoter, bidirectional WNK2 manipulation, Rac1 pull-down and MMP2 activity in glioblastoma, breast, and lung cells\",\n      \"pmids\": [\"33251331\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Whether CBX8 repression operates in non-cancer contexts unknown\", \"Single lab\"]\n    },\n    {\n      \"year\": 2022,\n      \"claim\": \"Demonstrated that germline WNK2 variants impair its suppression of the PAK1/2-MAPK axis, linking genetic variation to dysregulated proliferation.\",\n      \"evidence\": \"CRISPR/Cas9 WNK2 disruption in HT-29 plus lentiviral variant overexpression with pPAK1/2, pERK1/2, CCND1 immunoblots and colony/MMP2 assays\",\n      \"pmids\": [\"36270769\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Clinical phenotype associated with these variants not established\", \"Single lab\"]\n    },\n    {\n      \"year\": 2024,\n      \"claim\": \"Revealed a developmental role placing WNK2 downstream of PAX6 in corneal epithelial differentiation.\",\n      \"evidence\": \"PAX6 shRNA knockdown with RNA-seq, WNK2 knockdown in air-liquid LSC differentiation, marker qRT-PCR/immunofluorescence\",\n      \"pmids\": [\"39453672\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Effector mechanism downstream of WNK2 in corneal cells not defined\", \"Single lab\"]\n    },\n    {\n      \"year\": 2025,\n      \"claim\": \"Implicated WNK2 in hyperosmotic stress sensing in chondrocytes relevant to osteoarthritis.\",\n      \"evidence\": \"WNK2 variant overexpression and loss-of-function in human chondrocytes with transcriptomics under hyperosmotic stress and OA tissue IHC\",\n      \"pmids\": [\"40592720\"],\n      \"confidence\": \"Low\",\n      \"gaps\": [\"No defined downstream effector assay\", \"Mechanism of osmosensing transduction unresolved\", \"Single lab\"]\n    },\n    {\n      \"year\": null,\n      \"claim\": \"How WNK2 biochemically maintains RhoA activation and selectively restrains Rac1 GTP-loading, and whether its neuronal SPAK/ion-cotransporter axis and its tumor-suppressive GTPase axis share a common catalytic mechanism, remain unresolved.\",\n      \"evidence\": \"\",\n      \"pmids\": [],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Direct GTPase regulators (GEF/GAP) targeted by WNK2 not identified\", \"No structural model linking kinase activity to GTPase control\", \"Integration of neuronal and oncogenic functions unexplored\"]\n    }\n  ],\n  \"mechanism_profile\": {\n    \"molecular_activity\": [\n      {\"term_id\": \"GO:0140096\", \"supporting_discovery_ids\": [0, 1, 2]},\n      {\"term_id\": \"GO:0016740\", \"supporting_discovery_ids\": [0, 2]},\n      {\"term_id\": \"GO:0098772\", \"supporting_discovery_ids\": [3, 4]}\n    ],\n    \"localization\": [],\n    \"pathway\": [\n      {\"term_id\": \"R-HSA-162582\", \"supporting_discovery_ids\": [1, 3, 7]},\n      {\"term_id\": \"R-HSA-1643685\", \"supporting_discovery_ids\": [4, 7, 9]},\n      {\"term_id\": \"R-HSA-382551\", \"supporting_discovery_ids\": [0]}\n    ],\n    \"complexes\": [],\n    \"partners\": [\"SPAK\", \"MEK1\", \"PAK1\"],\n    \"other_free_text\": []\n  }\n}","audit_flag":null,"evaluation":{"pairwise":"win","faith_supported":7,"faith_total":7,"faith_pct":100.0}}