{"gene":"PRKAR2B","run_date":"2026-04-28T19:45:45","timeline":{"discoveries":[{"year":1990,"finding":"PRKAR2B (RIIβ), as a type II regulatory subunit of cAMP-dependent protein kinase A (PKA), contains an autoinhibitory region that occupies the peptide-binding site of the catalytic subunit, thereby preventing substrate access; cAMP binding to the regulatory subunit relieves this inhibition and activates catalytic subunits.","method":"Biochemical reconstitution, recombinant protein expression, peptide binding assays, and protein chemistry","journal":"Annual review of biochemistry","confidence":"High","confidence_rationale":"Tier 1 — foundational reconstitution and mutagenesis work, highly cited, replicated across decades","pmids":["2165385"],"is_preprint":false},{"year":1997,"finding":"D-AKAP2, a dual-specificity A-kinase anchoring protein, physically interacts with both type I (RIα) and type II (RIIα, RIIβ/PRKAR2B) regulatory subunits of PKA via a C-terminal R-binding domain (residues 333–372), and this binding involves the N-terminal dimerization domain of the regulatory subunits; D-AKAP2 also contains a putative RGS domain, suggesting a link between G-protein signaling and PKA compartmentalization.","method":"Yeast two-hybrid screen, coprecipitation assays, cDNA cloning","journal":"Proceedings of the National Academy of Sciences of the United States of America","confidence":"High","confidence_rationale":"Tier 2 — reciprocal yeast two-hybrid plus coprecipitation, highly cited foundational paper","pmids":["9326583"],"is_preprint":false},{"year":2000,"finding":"PKA (whose activity is regulated by regulatory subunits including PRKAR2B) is assembled into a macromolecular complex at the ryanodine receptor RyR2 on the sarcoplasmic reticulum via the anchoring protein mAKAP; PKA phosphorylation of RyR2 dissociates FKBP12.6 and increases channel open probability, and in failing human hearts RyR2 is PKA-hyperphosphorylated, causing defective channel regulation.","method":"Cosedimentation, coimmunoprecipitation, functional channel recordings","journal":"Cell","confidence":"High","confidence_rationale":"Tier 1–2 — cosedimentation, Co-IP, and functional electrophysiology in one study; highly cited","pmids":["10830164"],"is_preprint":false},{"year":2002,"finding":"Beta-adrenergic receptor modulation of the IKs potassium channel (KCNQ1-KCNE1) requires assembly of a macromolecular signaling complex including PKA (regulatory subunits) and protein phosphatase 1 (PP1) anchored to hKCNQ1 via the scaffold protein yotiao through a leucine zipper motif; an LQTS mutation (hKCNQ1-G589D) disrupts this interaction.","method":"Coimmunoprecipitation, functional reconstitution in heterologous cells, mutagenesis","journal":"Science (New York, N.Y.)","confidence":"High","confidence_rationale":"Tier 1–2 — Co-IP, mutagenesis, functional reconstitution; highly cited","pmids":["11799244"],"is_preprint":false},{"year":2014,"finding":"In adrenocortical carcinoma cells (H295R), siRNA-mediated depletion of PRKAR2B activates both PKA and MEK/ERK signaling pathways and NF-κB pathway (via reduced IκB expression), promotes cell cycle progression with accumulation of cyclins A, B, cdk1, cdc2, and p21Cip, and induces anti-apoptotic Bcl-xL expression; notably, PRKAR2B depletion is compensated by upregulation of PRKAR1A protein, whereas PRKAR1A depletion does not affect PRKAR2B levels.","method":"siRNA knockdown, Western blotting, flow cytometry (cell cycle), apoptosis assays, signaling pathway analysis","journal":"Hormone and metabolic research","confidence":"Medium","confidence_rationale":"Tier 2 — clean KO with defined cellular phenotypes and pathway readouts, single lab","pmids":["25268545"],"is_preprint":false},{"year":2017,"finding":"PRKAR2B promotes castration-resistant prostate cancer (CRPC) cell proliferation and invasion and inhibits apoptosis; whole-genome transcriptome and GO analysis of PRKAR2B knockdown revealed that PRKAR2B accelerates cell cycle progression by modulating cell cycle genes including CCNB1, MCM2, PLK1, and AURKB.","method":"siRNA knockdown, whole-genome transcriptome analysis, GO enrichment, functional proliferation/invasion/apoptosis assays","journal":"Oncotarget","confidence":"Medium","confidence_rationale":"Tier 2 — loss-of-function with genome-wide transcriptome and functional phenotypes, single lab","pmids":["28008150"],"is_preprint":false},{"year":2018,"finding":"PRKAR2B promotes prostate cancer cell invasion and tumor metastasis in vivo by activating Wnt/β-catenin signaling, which in turn induces epithelial-mesenchymal transition (EMT) as evidenced by decreased E-cadherin and increased Vimentin, N-cadherin, and Fibronectin; pharmacological inhibition of Wnt/β-catenin attenuates PRKAR2B-induced EMT and invasion.","method":"Gain- and loss-of-function (overexpression and siRNA), in vitro invasion assays, in vivo metastasis model, Western blotting, Wnt pathway inhibitor rescue","journal":"Journal of cellular biochemistry","confidence":"Medium","confidence_rationale":"Tier 2 — reciprocal gain/loss-of-function with pathway inhibitor rescue and in vivo validation, single lab","pmids":["29761841"],"is_preprint":false},{"year":2018,"finding":"In neural cells, FOXG1 regulates PRKAR2B expression both transcriptionally and posttranscriptionally: FOXG1 affects biogenesis of miR-200b/a/429 by interacting with the RNA helicase DDX5/p68 and recruiting it to the DROSHA microprocessor complex; elevated miR-200 represses PRKAR2B mRNA, and increased PRKAR2B protein attenuates PKA activity at postsynaptic sites, potentially contributing to neuronal dysfunction in FOXG1 syndrome.","method":"Genome-wide small RNA sequencing, quantitative proteomics, RNA-Seq, coimmunoprecipitation (FOXG1-DDX5-DROSHA), miR-200 overexpression in N2a cells","journal":"Molecular neurobiology","confidence":"Medium","confidence_rationale":"Tier 2 — multiple orthogonal methods (proteomics, RNA-Seq, Co-IP) in single lab","pmids":["30539330"],"is_preprint":false},{"year":2018,"finding":"In mouse oocytes, PRKAR2B is most highly expressed at metaphase I (MI) and is required for normal oocyte maturation; RNAi-mediated knockdown of Prkar2b causes MI-stage arrest with abnormal spindle formation and chromosome aggregation, and reduces expression of other PKA family members (except Prkaca) and the majority of pentose phosphate pathway (PPP) factors.","method":"RNAi microinjection, immunofluorescence, time-lapse video microscopy, qRT-PCR, immunohistochemistry","journal":"Cellular physiology and biochemistry","confidence":"Medium","confidence_rationale":"Tier 2 — direct loss-of-function in oocytes with spindle/chromosome and metabolic phenotype readouts, single lab","pmids":["29518769"],"is_preprint":false},{"year":2020,"finding":"PRKAR2B promotes aerobic glycolysis (Warburg effect) in prostate cancer cells by increasing HIF-1α protein levels; HIF-1α in turn transcriptionally induces PRKAR2B expression (as shown by luciferase reporter and chromatin immunoprecipitation), forming a positive feedback loop; PRKAR2B-mediated tumor growth is largely abolished by glycolytic inhibitor 2-DG, galactose replacement, or HIF-1α knockdown.","method":"Loss- and gain-of-function, Western blotting, real-time qPCR, luciferase reporter assay, chromatin immunoprecipitation, glucose consumption/lactate/ECAR measurements, in vivo tumor growth","journal":"Cell proliferation","confidence":"Medium","confidence_rationale":"Tier 2 — multiple orthogonal methods including ChIP and functional metabolic readouts, single lab","pmids":["33025691"],"is_preprint":false},{"year":2020,"finding":"miR-200b-3p and miR-200c-3p directly repress PRKAR2B expression in prostate cancer cells and are downregulated in metastatic CRPC; the transcription factor XBP1 directly drives PRKAR2B transcription; rescue experiments show that PRKAR2B mediates the proliferative and anti-apoptotic effects of miR-200b-3p/200c-3p suppression and XBP1 activity.","method":"miRNA target validation, luciferase reporter, qPCR, Western blotting, siRNA knockdown rescue assays, ChIP","journal":"Biomedicine & pharmacotherapy","confidence":"Medium","confidence_rationale":"Tier 2 — luciferase validation and rescue experiments, multiple orthogonal methods, single lab","pmids":["31986411"],"is_preprint":false},{"year":2020,"finding":"SARS-CoV-2 proteins physically associate with PRKAR2B as part of the human protein interaction network; PRKAR2B was identified as a host protein that physically interacts with SARS-CoV-2 proteins by affinity-purification mass spectrometry in human cells.","method":"Affinity purification mass spectrometry (AP-MS) in HEK293 cells expressing tagged SARS-CoV-2 proteins","journal":"Nature","confidence":"Low","confidence_rationale":"Tier 3 — large-scale AP-MS screen; PRKAR2B is one of many hits, no functional follow-up specific to PRKAR2B","pmids":["32353859"],"is_preprint":false},{"year":2021,"finding":"BioPlex 3.0 large-scale AP-MS interaction network identifies protein-protein interactions involving PRKAR2B in HEK293T and HCT116 cells, placing PRKAR2B within defined protein communities consistent with PKA signaling complexes.","method":"Affinity purification mass spectrometry (AP-MS) across 10,128 human proteins","journal":"Cell","confidence":"Low","confidence_rationale":"Tier 3 — large-scale interactome screen; PRKAR2B interactions identified but not individually validated","pmids":["33961781"],"is_preprint":false},{"year":2022,"finding":"In Theileria annulata-infected bovine leukocytes and Plasmodium falciparum-infected red blood cells, infection-induced upregulation of miR-34c-3p represses PRKAR2B expression at the mRNA level, leading to increased PKA catalytic activity independent of cAMP flux; this cAMP-independent PKA activation enhances the tumorigenic, disseminating phenotype of infected macrophages and improves parasite fitness.","method":"miRNA target validation (luciferase reporter, qRT-PCR), miR-34c-3p overexpression and inhibition, PKA activity assays, functional invasion/dissemination assays","journal":"mSphere","confidence":"Medium","confidence_rationale":"Tier 2 — luciferase reporter validation plus PKA activity assays and functional phenotype, single lab","pmids":["36847534"],"is_preprint":false},{"year":2023,"finding":"MAPKAPK2 (MK2) regulates PRKAR2B mRNA stability in head and neck squamous cell carcinoma (HNSCC); MK2 knockdown reduces PRKAR2B transcript levels, and transcript turnover studies indicate MK2 controls PRKAR2B mRNA stability via its 3'-UTR.","method":"NGS transcriptome profiling, MK2 knockdown, 3'-UTR filtering, nCounter gene expression assay, immunohistochemistry, transcript stability assays","journal":"Computational and structural biotechnology journal","confidence":"Medium","confidence_rationale":"Tier 2 — multiple orthogonal methods including transcript turnover assays and IHC validation, single lab","pmids":["36817960"],"is_preprint":false},{"year":2025,"finding":"In porcine adipocytes, the circular RNA circSAMD4A promotes adipogenic differentiation by competitively binding miR-127, thereby alleviating miR-127-mediated repression of PRKAR2B and enhancing PRKAR2B expression and lipid accumulation.","method":"RNA sequencing, circRNA/miRNA functional assays, luciferase reporter, lipid accumulation assays","journal":"Animal science journal","confidence":"Low","confidence_rationale":"Tier 3 — single lab, luciferase reporter for interaction but limited mechanistic follow-up on PRKAR2B's downstream role","pmids":["40589305"],"is_preprint":false},{"year":2025,"finding":"In diabetic kidney disease (DKD), miR-3147 (upregulated in glomerular mesangial cells under high glucose) targets PRKAR2B mRNA and represses its expression, promoting mesangial cell proliferation and early-stage apoptosis under high glucose conditions.","method":"miRNA-Seq, luciferase reporter validation, miR-3147 overexpression in mesangial cells, cell viability and apoptosis assays","journal":"Renal failure","confidence":"Low","confidence_rationale":"Tier 3 — luciferase reporter plus cellular phenotype, single study, limited mechanistic depth on PRKAR2B's downstream effectors","pmids":["40571682"],"is_preprint":false},{"year":2026,"finding":"In pancreatic ductal adenocarcinoma (PDAC), the transcription factor HHEX transcriptionally represses PRKAR2B expression; downregulation of HHEX reduces PRKAR2B, relieving inhibition on PKA catalytic activity; a high-glucose microenvironment further promotes cAMP production to activate PKA, which then upregulates hexokinase 2 (HK2) to enhance glycolysis and metastasis; glycolysis inhibition blocks metastasis driven by this axis.","method":"Loss- and gain-of-function (HHEX, PRKAR2B), ChIP/transcription factor binding assays, PKA activity assays, HK2 expression analysis, in vivo high-glucose/glycolysis inhibition experiments","journal":"iScience","confidence":"Medium","confidence_rationale":"Tier 2 — multiple orthogonal methods including transcription factor binding, kinase activity, and in vivo rescue, single lab","pmids":["41704777"],"is_preprint":false}],"current_model":"PRKAR2B (RIIβ), the type II-beta regulatory subunit of PKA, inhibits PKA catalytic activity by occupying the substrate-binding site until cAMP binding triggers its release; it is anchored to specific subcellular locations (e.g., sarcoplasmic reticulum via mAKAP, membrane channels via yotiao) by AKAPs including dual-specific D-AKAP2; its expression is regulated upstream by transcription factors (HIF-1α, XBP1, HHEX, FOXG1) and miRNAs (miR-200b/c, miR-127, miR-34c-3p, miR-3147), and its levels are post-transcriptionally controlled by MAPKAPK2-mediated mRNA stability; in cancer contexts, PRKAR2B drives glycolysis via a HIF-1α feedback loop and HHEX-PKA-HK2 axis, promotes metastasis through Wnt/β-catenin-induced EMT, and regulates cell cycle progression; in oocytes, it is required for spindle formation and meiotic progression."},"narrative":{"teleology":[{"year":1990,"claim":"Establishing the core mechanism by which PRKAR2B inhibits PKA: the autoinhibitory domain of RIIβ occupies the catalytic subunit's substrate-binding site, and cAMP binding releases this inhibition, providing the foundational biochemical framework for all subsequent studies of PRKAR2B function.","evidence":"Biochemical reconstitution with recombinant proteins, peptide-binding assays, and mutagenesis","pmids":["2165385"],"confidence":"High","gaps":["Structural details of the RIIβ–catalytic subunit interface at atomic resolution were not resolved","Isoform-specific differences between RIIβ and RIIα in autoinhibition kinetics were not addressed"]},{"year":1997,"claim":"Discovery that AKAPs provide subcellular targeting of PRKAR2B: D-AKAP2 was identified as a dual-specificity anchoring protein binding the N-terminal dimerization domain of both RI and RII subunits, establishing the principle that PRKAR2B is compartmentalized through protein–protein interactions.","evidence":"Yeast two-hybrid screen and coprecipitation assays with D-AKAP2 and PKA regulatory subunits","pmids":["9326583"],"confidence":"High","gaps":["Endogenous tissue localization of D-AKAP2–PRKAR2B complexes was not demonstrated","Functional consequences of disrupting D-AKAP2–PRKAR2B interaction in vivo were not tested"]},{"year":2002,"claim":"PRKAR2B-containing PKA was shown to be tethered to specific ion channels and cardiac receptors via distinct AKAPs (mAKAP at RyR2, yotiao at KCNQ1), demonstrating that AKAP-mediated compartmentalization of PKA enables spatially restricted phosphorylation of cardiac substrates with direct physiological and disease consequences.","evidence":"Cosedimentation, coimmunoprecipitation, functional channel recordings (RyR2), and mutagenesis of yotiao–KCNQ1 interaction including an LQTS-associated mutation","pmids":["10830164","11799244"],"confidence":"High","gaps":["Whether PRKAR2B specifically (versus RIIα) is the dominant regulatory subunit at these cardiac complexes was not resolved","Direct structural characterization of AKAP–RIIβ–catalytic subunit ternary complexes was lacking"]},{"year":2014,"claim":"PRKAR2B depletion in adrenocortical carcinoma cells revealed that loss of RIIβ activates PKA and cross-activates MEK/ERK and NF-κB pathways, accelerates cell cycle progression, and induces compensatory upregulation of PRKAR1A, establishing PRKAR2B as a context-dependent tumor suppressive brake on proliferative signaling.","evidence":"siRNA knockdown in H295R cells with Western blotting, flow cytometry, and signaling pathway analysis","pmids":["25268545"],"confidence":"Medium","gaps":["Mechanisms underlying compensatory PRKAR1A upregulation upon PRKAR2B loss were not elucidated","In vivo relevance of these findings was not tested","Whether NF-κB activation is a direct or indirect consequence of PKA derepression was unclear"]},{"year":2018,"claim":"In prostate cancer, PRKAR2B was shown to promote tumor metastasis through activation of Wnt/β-catenin signaling and consequent EMT, and its expression is regulated by the FOXG1–miR-200 axis in neural cells, revealing that PRKAR2B functions as a pro-oncogenic and context-specific signaling node whose abundance is tightly controlled by miRNA-mediated repression.","evidence":"Gain/loss-of-function with Wnt inhibitor rescue and in vivo metastasis model (prostate cancer); multi-omics (small RNA-Seq, proteomics, Co-IP of FOXG1–DDX5–DROSHA) in neural cells","pmids":["29761841","30539330","28008150"],"confidence":"Medium","gaps":["The molecular mechanism by which PRKAR2B activates Wnt/β-catenin signaling is unknown","Whether FOXG1-mediated miR-200 regulation of PRKAR2B operates in cancer contexts was not tested","Direct physical interaction between PRKAR2B and Wnt pathway components was not demonstrated"]},{"year":2018,"claim":"PRKAR2B was established as essential for meiotic progression in oocytes: knockdown caused MI arrest with abnormal spindle formation and chromosome aggregation, linking PKA regulation to cell division machinery beyond mitosis.","evidence":"RNAi microinjection in mouse oocytes with immunofluorescence, time-lapse microscopy, and qRT-PCR","pmids":["29518769"],"confidence":"Medium","gaps":["Whether the spindle defect results from PKA hyperactivation or loss of a non-catalytic scaffolding role of PRKAR2B was not distinguished","Downstream PKA substrates mediating spindle assembly in oocytes were not identified"]},{"year":2020,"claim":"A HIF-1α–PRKAR2B positive feedback loop was demonstrated in prostate cancer: PRKAR2B stabilizes HIF-1α protein, which transcriptionally induces PRKAR2B, driving aerobic glycolysis; simultaneously, XBP1 was identified as a direct transcriptional activator of PRKAR2B, and miR-200b/c as direct repressors, revealing multilayered transcriptional and post-transcriptional control of PRKAR2B abundance in cancer metabolism.","evidence":"ChIP, luciferase reporters, metabolic flux measurements (glucose consumption, ECAR), in vivo tumor growth with glycolysis inhibitor rescue; miRNA target validation and rescue assays","pmids":["33025691","31986411"],"confidence":"Medium","gaps":["The mechanism by which PRKAR2B stabilizes HIF-1α protein is unknown","Whether the HIF-1α–PRKAR2B loop operates independently of canonical PKA catalytic activity was not resolved","Relative contributions of XBP1 versus HIF-1α to PRKAR2B transcription in different tumor types were not compared"]},{"year":2022,"claim":"Parasite-induced miR-34c-3p was shown to repress PRKAR2B in infected leukocytes, providing cAMP-independent PKA activation that enhances dissemination — demonstrating that host PRKAR2B levels are exploited by intracellular pathogens to hijack PKA signaling.","evidence":"Luciferase reporter validation, miR-34c-3p overexpression/inhibition, PKA activity assays, functional invasion assays in Theileria-infected bovine macrophages","pmids":["36847534"],"confidence":"Medium","gaps":["Whether PRKAR2B repression alone is sufficient to explain cAMP-independent PKA activation was not formally shown","Applicability to human infections beyond Theileria and Plasmodium was not tested"]},{"year":2023,"claim":"MAPKAPK2 (MK2) was identified as a post-transcriptional regulator of PRKAR2B mRNA stability via its 3′-UTR in head and neck cancer, adding a kinase-mediated mRNA stabilization layer to the regulatory circuitry controlling PRKAR2B abundance.","evidence":"MK2 knockdown, transcript turnover assays, 3′-UTR analysis, nCounter gene expression assay in HNSCC cells","pmids":["36817960"],"confidence":"Medium","gaps":["The RNA-binding protein intermediary between MK2 and PRKAR2B 3′-UTR was not identified","Whether MK2-mediated PRKAR2B stabilization affects PKA activity in HNSCC was not measured"]},{"year":2025,"claim":"The HHEX–PRKAR2B–PKA–HK2 axis was delineated in pancreatic cancer: HHEX transcriptionally represses PRKAR2B, relieving PKA catalytic inhibition; under high glucose, elevated cAMP further activates PKA, which upregulates hexokinase 2 to drive glycolysis and metastasis, establishing a metabolic signaling cascade centered on PRKAR2B.","evidence":"ChIP, gain/loss-of-function of HHEX and PRKAR2B, PKA activity assays, in vivo high-glucose and glycolysis inhibition experiments in PDAC models","pmids":["41704777"],"confidence":"Medium","gaps":["Whether PKA directly phosphorylates HK2 or regulates it transcriptionally was not determined","The generalizability of the HHEX–PRKAR2B axis beyond PDAC is unknown"]},{"year":null,"claim":"Key open questions remain: (1) the structural basis for isoform-specific (RIIβ versus RIIα) AKAP selectivity and catalytic subunit regulation; (2) the molecular mechanism by which PRKAR2B influences Wnt/β-catenin and HIF-1α signaling independently of canonical PKA kinase activity; (3) direct identification of PKA substrates downstream of PRKAR2B in oocyte meiosis and spindle assembly.","evidence":"","pmids":[],"confidence":"Low","gaps":["No high-resolution structure of full-length RIIβ in complex with AKAPs and catalytic subunits","Non-canonical (kinase-independent) functions of PRKAR2B remain poorly characterized","Genetic models (knockout mice) for PRKAR2B have not been extensively phenotyped across tissues in the timeline"]}],"mechanism_profile":{"molecular_activity":[{"term_id":"GO:0098772","term_label":"molecular function regulator activity","supporting_discovery_ids":[0,4,13,17]}],"localization":[{"term_id":"GO:0005829","term_label":"cytosol","supporting_discovery_ids":[0,4]},{"term_id":"GO:0005886","term_label":"plasma membrane","supporting_discovery_ids":[2,3]}],"pathway":[{"term_id":"R-HSA-162582","term_label":"Signal Transduction","supporting_discovery_ids":[0,1,2,3,4,13,17]},{"term_id":"R-HSA-1430728","term_label":"Metabolism","supporting_discovery_ids":[9,17]},{"term_id":"R-HSA-1640170","term_label":"Cell Cycle","supporting_discovery_ids":[4,5,8]}],"complexes":["PKA holoenzyme (type II)","mAKAP-RyR2 macromolecular complex","yotiao-KCNQ1 signaling complex"],"partners":["PRKACA","AKAP10","AKAP6","AKAP9","HIF1A","HHEX","XBP1","DDX5"],"other_free_text":[]},"mechanistic_narrative":"PRKAR2B is the type II-beta regulatory subunit of cAMP-dependent protein kinase (PKA), serving as a key negative regulator of PKA catalytic activity by occupying the substrate-binding site of catalytic subunits until cAMP binding triggers their release [PMID:2165385]. PRKAR2B is compartmentalized to specific subcellular signaling domains through A-kinase anchoring proteins (AKAPs) including D-AKAP2, mAKAP (at the sarcoplasmic reticulum/ryanodine receptor RyR2 complex), and yotiao (at KCNQ1 ion channels), enabling spatially restricted PKA signaling that controls cardiac excitation-contraction coupling and ion channel modulation [PMID:9326583, PMID:10830164, PMID:11799244]. PRKAR2B expression is regulated transcriptionally by HIF-1α, XBP1, HHEX, and FOXG1, and post-transcriptionally by multiple miRNAs (miR-200b/c, miR-34c-3p, miR-127, miR-3147) and MAPKAPK2-mediated mRNA stabilization; in cancer contexts, PRKAR2B promotes aerobic glycolysis through a HIF-1α positive feedback loop and an HHEX–PKA–HK2 axis, and drives metastasis via Wnt/β-catenin-induced epithelial-mesenchymal transition [PMID:33025691, PMID:41704777, PMID:29761841, PMID:36817960]. In oocytes, PRKAR2B is required for normal meiotic spindle assembly and progression through metaphase I [PMID:29518769]."},"prefetch_data":{"uniprot":{"accession":"P31323","full_name":"cAMP-dependent protein kinase type II-beta regulatory subunit","aliases":[],"length_aa":418,"mass_kda":46.3,"function":"Regulatory subunit of the cAMP-dependent protein kinases involved in cAMP signaling in cells. Type II regulatory chains mediate membrane association by binding to anchoring proteins, including the MAP2 kinase","subcellular_location":"Cytoplasm; Cell membrane","url":"https://www.uniprot.org/uniprotkb/P31323/entry"},"depmap":{"release":"DepMap","has_data":true,"is_common_essential":false,"resolved_as":"","url":"https://depmap.org/portal/gene/PRKAR2B","classification":"Not Classified","n_dependent_lines":0,"n_total_lines":1208,"dependency_fraction":0.0},"opencell":{"profiled":false,"resolved_as":"","ensg_id":"","cell_line_id":"","localizations":[],"interactors":[{"gene":"PRKACA","stoichiometry":4.0}],"url":"https://opencell.sf.czbiohub.org/search/PRKAR2B","total_profiled":1310},"omim":[{"mim_id":"615876","title":"RADIAL SPOKE HEAD 3; RSPH3","url":"https://www.omim.org/entry/615876"},{"mim_id":"609910","title":"CILIA- AND FLAGELLA-ASSOCIATED PROTEIN 91; CFAP91","url":"https://www.omim.org/entry/609910"},{"mim_id":"605824","title":"POPEYE DOMAIN-CONTAINING PROTEIN 3; POPDC3","url":"https://www.omim.org/entry/605824"},{"mim_id":"605823","title":"POPEYE DOMAIN-CONTAINING PROTEIN 2; POPDC2","url":"https://www.omim.org/entry/605823"},{"mim_id":"604694","title":"A-KINASE ANCHOR PROTEIN 10; AKAP10","url":"https://www.omim.org/entry/604694"}],"hpa":{"profiled":true,"resolved_as":"","reliability":"Approved","locations":[{"location":"Golgi apparatus","reliability":"Approved"},{"location":"Centrosome","reliability":"Approved"},{"location":"Basal body","reliability":"Approved"},{"location":"Cytosol","reliability":"Approved"}],"tissue_specificity":"Tissue enhanced","tissue_distribution":"Detected in many","driving_tissues":[{"tissue":"adipose tissue","ntpm":159.6}],"url":"https://www.proteinatlas.org/search/PRKAR2B"},"hgnc":{"alias_symbol":[],"prev_symbol":["PRKAR2"]},"alphafold":{"accession":"P31323","domains":[{"cath_id":"2.60.120.10","chopping":"138-253","consensus_level":"high","plddt":90.4461,"start":138,"end":253},{"cath_id":"2.60.120.10","chopping":"274-406","consensus_level":"high","plddt":86.7686,"start":274,"end":406}],"viewer_url":"https://alphafold.ebi.ac.uk/entry/P31323","model_url":"https://alphafold.ebi.ac.uk/files/AF-P31323-F1-model_v6.cif","pae_url":"https://alphafold.ebi.ac.uk/files/AF-P31323-F1-predicted_aligned_error_v6.png","plddt_mean":78.69},"mouse_models":{"mgi_url":"https://www.informatics.jax.org/marker/summary?nomen=PRKAR2B","jax_strain_url":"https://www.jax.org/strain/search?query=PRKAR2B"},"sequence":{"accession":"P31323","fasta_url":"https://rest.uniprot.org/uniprotkb/P31323.fasta","uniprot_url":"https://www.uniprot.org/uniprotkb/P31323/entry","alphafold_viewer_url":"https://alphafold.ebi.ac.uk/entry/P31323"}},"corpus_meta":[{"pmid":"33025691","id":"PMC_33025691","title":"PRKAR2B-HIF-1α loop promotes aerobic glycolysis and tumour growth in prostate cancer.","date":"2020","source":"Cell proliferation","url":"https://pubmed.ncbi.nlm.nih.gov/33025691","citation_count":44,"is_preprint":false,"source_track":"pubmed_title"},{"pmid":"29761841","id":"PMC_29761841","title":"PRKAR2B promotes prostate cancer metastasis by activating Wnt/β-catenin and inducing epithelial-mesenchymal transition.","date":"2018","source":"Journal of cellular biochemistry","url":"https://pubmed.ncbi.nlm.nih.gov/29761841","citation_count":31,"is_preprint":false,"source_track":"pubmed_title"},{"pmid":"31986411","id":"PMC_31986411","title":"Transcriptional regulation of PRKAR2B by miR-200b-3p/200c-3p and XBP1 in human prostate cancer.","date":"2020","source":"Biomedicine & pharmacotherapy = Biomedecine & pharmacotherapie","url":"https://pubmed.ncbi.nlm.nih.gov/31986411","citation_count":27,"is_preprint":false,"source_track":"pubmed_title"},{"pmid":"30539330","id":"PMC_30539330","title":"FOXG1 Regulates PRKAR2B Transcriptionally and Posttranscriptionally via miR200 in the Adult Hippocampus.","date":"2018","source":"Molecular neurobiology","url":"https://pubmed.ncbi.nlm.nih.gov/30539330","citation_count":18,"is_preprint":false,"source_track":"pubmed_title"},{"pmid":"25268545","id":"PMC_25268545","title":"Comparison of the effects of PRKAR1A and PRKAR2B depletion on signaling pathways, cell growth, and cell cycle control of adrenocortical cells.","date":"2014","source":"Hormone and metabolic research = Hormon- und Stoffwechselforschung = Hormones et metabolisme","url":"https://pubmed.ncbi.nlm.nih.gov/25268545","citation_count":18,"is_preprint":false,"source_track":"pubmed_title"},{"pmid":"28008150","id":"PMC_28008150","title":"PRKAR2B plays an oncogenic role in the castration-resistant prostate cancer.","date":"2017","source":"Oncotarget","url":"https://pubmed.ncbi.nlm.nih.gov/28008150","citation_count":17,"is_preprint":false,"source_track":"pubmed_title"},{"pmid":"29518769","id":"PMC_29518769","title":"Knockdown of PRKAR2B Results in the Failure of Oocyte Maturation.","date":"2018","source":"Cellular physiology and biochemistry : international journal of experimental cellular physiology, biochemistry, and pharmacology","url":"https://pubmed.ncbi.nlm.nih.gov/29518769","citation_count":16,"is_preprint":false,"source_track":"pubmed_title"},{"pmid":"36847534","id":"PMC_36847534","title":"miR-34c-3p Regulates Protein Kinase A Activity Independent of cAMP by Dicing prkar2b Transcripts in Theileria annulata-Infected Leukocytes.","date":"2023","source":"mSphere","url":"https://pubmed.ncbi.nlm.nih.gov/36847534","citation_count":8,"is_preprint":false,"source_track":"pubmed_title"},{"pmid":"24737441","id":"PMC_24737441","title":"Protein kinase cAMP-dependent regulatory type II beta (PRKAR2B) gene variants in antipsychotic-induced weight gain.","date":"2014","source":"Human psychopharmacology","url":"https://pubmed.ncbi.nlm.nih.gov/24737441","citation_count":8,"is_preprint":false,"source_track":"pubmed_title"},{"pmid":"36817960","id":"PMC_36817960","title":"MAPKAPK2-centric transcriptome profiling reveals its major role in governing molecular crosstalk of IGFBP2, MUC4, and PRKAR2B during HNSCC pathogenesis.","date":"2023","source":"Computational and structural biotechnology journal","url":"https://pubmed.ncbi.nlm.nih.gov/36817960","citation_count":6,"is_preprint":false,"source_track":"pubmed_title"},{"pmid":"35524977","id":"PMC_35524977","title":"Long noncoding RNA TDRG1 aggravates doxorubicin-induced cardiomyopathy by binding with miR-873-5p to upregulate PRKAR2.","date":"2022","source":"Environmental toxicology","url":"https://pubmed.ncbi.nlm.nih.gov/35524977","citation_count":5,"is_preprint":false,"source_track":"pubmed_title"},{"pmid":"35730470","id":"PMC_35730470","title":"Long non-coding RNA TDRG1 aggravates colorectal cancer stemness by binding with miR-873-5p to upregulate PRKAR2.","date":"2022","source":"Environmental toxicology","url":"https://pubmed.ncbi.nlm.nih.gov/35730470","citation_count":3,"is_preprint":false,"source_track":"pubmed_title"},{"pmid":"40589305","id":"PMC_40589305","title":"ceRNA Profiling Reveals circSAMD4A Promoted Porcine Adipocytes Differentiation via Targeting miR-127/PRKAR2B.","date":"2025","source":"Animal science journal = Nihon chikusan Gakkaiho","url":"https://pubmed.ncbi.nlm.nih.gov/40589305","citation_count":1,"is_preprint":false,"source_track":"pubmed_title"},{"pmid":"40571682","id":"PMC_40571682","title":"Glomerular mesangial derived extracellular vesicles deteriorate diabetic kidney disease via miR-3147/PRKAR2B axis.","date":"2025","source":"Renal failure","url":"https://pubmed.ncbi.nlm.nih.gov/40571682","citation_count":0,"is_preprint":false,"source_track":"pubmed_title"},{"pmid":"41704777","id":"PMC_41704777","title":"HHEX-PRKAR2B axis-mediated PKA activation drives glucose metabolism-dependent progression of pancreatic ductal adenocarcinoma.","date":"2026","source":"iScience","url":"https://pubmed.ncbi.nlm.nih.gov/41704777","citation_count":0,"is_preprint":false,"source_track":"pubmed_title"},{"pmid":"32353859","id":"PMC_32353859","title":"A SARS-CoV-2 protein interaction map reveals targets for drug repurposing.","date":"2020","source":"Nature","url":"https://pubmed.ncbi.nlm.nih.gov/32353859","citation_count":3411,"is_preprint":false,"source_track":"gene2pubmed"},{"pmid":"10830164","id":"PMC_10830164","title":"PKA phosphorylation dissociates FKBP12.6 from the calcium release channel (ryanodine receptor): defective regulation in failing hearts.","date":"2000","source":"Cell","url":"https://pubmed.ncbi.nlm.nih.gov/10830164","citation_count":1641,"is_preprint":false,"source_track":"gene2pubmed"},{"pmid":"12477932","id":"PMC_12477932","title":"Generation and initial analysis of more than 15,000 full-length human and mouse cDNA sequences.","date":"2002","source":"Proceedings of the National Academy of Sciences of the United States of America","url":"https://pubmed.ncbi.nlm.nih.gov/12477932","citation_count":1479,"is_preprint":false,"source_track":"gene2pubmed"},{"pmid":"26186194","id":"PMC_26186194","title":"The BioPlex Network: A Systematic Exploration of the Human Interactome.","date":"2015","source":"Cell","url":"https://pubmed.ncbi.nlm.nih.gov/26186194","citation_count":1118,"is_preprint":false,"source_track":"gene2pubmed"},{"pmid":"28514442","id":"PMC_28514442","title":"Architecture of the human interactome defines protein communities and disease networks.","date":"2017","source":"Nature","url":"https://pubmed.ncbi.nlm.nih.gov/28514442","citation_count":1085,"is_preprint":false,"source_track":"gene2pubmed"},{"pmid":"2165385","id":"PMC_2165385","title":"cAMP-dependent protein kinase: framework for a diverse family of regulatory enzymes.","date":"1990","source":"Annual review of biochemistry","url":"https://pubmed.ncbi.nlm.nih.gov/2165385","citation_count":1019,"is_preprint":false,"source_track":"gene2pubmed"},{"pmid":"26496610","id":"PMC_26496610","title":"A human interactome in three quantitative dimensions organized by stoichiometries and abundances.","date":"2015","source":"Cell","url":"https://pubmed.ncbi.nlm.nih.gov/26496610","citation_count":1015,"is_preprint":false,"source_track":"gene2pubmed"},{"pmid":"25416956","id":"PMC_25416956","title":"A proteome-scale map of the human interactome network.","date":"2014","source":"Cell","url":"https://pubmed.ncbi.nlm.nih.gov/25416956","citation_count":977,"is_preprint":false,"source_track":"gene2pubmed"},{"pmid":"32296183","id":"PMC_32296183","title":"A reference map of the human binary protein interactome.","date":"2020","source":"Nature","url":"https://pubmed.ncbi.nlm.nih.gov/32296183","citation_count":849,"is_preprint":false,"source_track":"gene2pubmed"},{"pmid":"11076863","id":"PMC_11076863","title":"DNA cloning using in vitro site-specific recombination.","date":"2000","source":"Genome research","url":"https://pubmed.ncbi.nlm.nih.gov/11076863","citation_count":815,"is_preprint":false,"source_track":"gene2pubmed"},{"pmid":"33961781","id":"PMC_33961781","title":"Dual proteome-scale networks reveal cell-specific remodeling of the human interactome.","date":"2021","source":"Cell","url":"https://pubmed.ncbi.nlm.nih.gov/33961781","citation_count":705,"is_preprint":false,"source_track":"gene2pubmed"},{"pmid":"21873635","id":"PMC_21873635","title":"Phylogenetic-based propagation of functional annotations within the Gene Ontology consortium.","date":"2011","source":"Briefings in bioinformatics","url":"https://pubmed.ncbi.nlm.nih.gov/21873635","citation_count":656,"is_preprint":false,"source_track":"gene2pubmed"},{"pmid":"12626323","id":"PMC_12626323","title":"Glucagon and regulation of glucose metabolism.","date":"2003","source":"American journal of physiology. Endocrinology and metabolism","url":"https://pubmed.ncbi.nlm.nih.gov/12626323","citation_count":635,"is_preprint":false,"source_track":"gene2pubmed"},{"pmid":"11799244","id":"PMC_11799244","title":"Requirement of a macromolecular signaling complex for beta adrenergic receptor modulation of the KCNQ1-KCNE1 potassium channel.","date":"2002","source":"Science (New York, N.Y.)","url":"https://pubmed.ncbi.nlm.nih.gov/11799244","citation_count":591,"is_preprint":false,"source_track":"gene2pubmed"},{"pmid":"33060197","id":"PMC_33060197","title":"Comparative host-coronavirus protein interaction networks reveal pan-viral disease mechanisms.","date":"2020","source":"Science (New York, N.Y.)","url":"https://pubmed.ncbi.nlm.nih.gov/33060197","citation_count":564,"is_preprint":false,"source_track":"gene2pubmed"},{"pmid":"35271311","id":"PMC_35271311","title":"OpenCell: Endogenous tagging for the cartography of human cellular organization.","date":"2022","source":"Science (New York, N.Y.)","url":"https://pubmed.ncbi.nlm.nih.gov/35271311","citation_count":432,"is_preprint":false,"source_track":"gene2pubmed"},{"pmid":"7790358","id":"PMC_7790358","title":"Cell cycle regulation of the activity and subcellular localization of Plk1, a human protein kinase implicated in mitotic spindle function.","date":"1995","source":"The Journal of cell biology","url":"https://pubmed.ncbi.nlm.nih.gov/7790358","citation_count":427,"is_preprint":false,"source_track":"gene2pubmed"},{"pmid":"26871637","id":"PMC_26871637","title":"Widespread Expansion of Protein Interaction Capabilities by Alternative Splicing.","date":"2016","source":"Cell","url":"https://pubmed.ncbi.nlm.nih.gov/26871637","citation_count":423,"is_preprint":false,"source_track":"gene2pubmed"},{"pmid":"34079125","id":"PMC_34079125","title":"A proximity-dependent biotinylation map of a human cell.","date":"2021","source":"Nature","url":"https://pubmed.ncbi.nlm.nih.gov/34079125","citation_count":339,"is_preprint":false,"source_track":"gene2pubmed"},{"pmid":"21399614","id":"PMC_21399614","title":"Novel asymmetrically localizing components of human centrosomes identified by complementary proteomics methods.","date":"2011","source":"The EMBO journal","url":"https://pubmed.ncbi.nlm.nih.gov/21399614","citation_count":265,"is_preprint":false,"source_track":"gene2pubmed"},{"pmid":"35063084","id":"PMC_35063084","title":"Tau interactome maps synaptic and mitochondrial processes associated with neurodegeneration.","date":"2022","source":"Cell","url":"https://pubmed.ncbi.nlm.nih.gov/35063084","citation_count":256,"is_preprint":false,"source_track":"gene2pubmed"},{"pmid":"12852856","id":"PMC_12852856","title":"Polo-like kinase 1 regulates Nlp, a centrosome protein involved in microtubule nucleation.","date":"2003","source":"Developmental cell","url":"https://pubmed.ncbi.nlm.nih.gov/12852856","citation_count":216,"is_preprint":false,"source_track":"gene2pubmed"},{"pmid":"29568061","id":"PMC_29568061","title":"An AP-MS- and BioID-compatible MAC-tag enables comprehensive mapping of protein interactions and subcellular localizations.","date":"2018","source":"Nature communications","url":"https://pubmed.ncbi.nlm.nih.gov/29568061","citation_count":201,"is_preprint":false,"source_track":"gene2pubmed"},{"pmid":"9326583","id":"PMC_9326583","title":"D-AKAP2, a novel protein kinase A anchoring protein with a putative RGS domain.","date":"1997","source":"Proceedings of the National Academy of Sciences of the United States of America","url":"https://pubmed.ncbi.nlm.nih.gov/9326583","citation_count":198,"is_preprint":false,"source_track":"gene2pubmed"},{"pmid":"12221128","id":"PMC_12221128","title":"Centrosomal proteins CG-NAP and kendrin provide microtubule nucleation sites by anchoring gamma-tubulin ring complex.","date":"2002","source":"Molecular biology of the cell","url":"https://pubmed.ncbi.nlm.nih.gov/12221128","citation_count":190,"is_preprint":false,"source_track":"gene2pubmed"},{"pmid":"12853948","id":"PMC_12853948","title":"The DNA sequence of human chromosome 7.","date":"2003","source":"Nature","url":"https://pubmed.ncbi.nlm.nih.gov/12853948","citation_count":188,"is_preprint":false,"source_track":"gene2pubmed"},{"pmid":"9278385","id":"PMC_9278385","title":"The Tat protein of HIV-1 induces tumor necrosis factor-alpha production. Implications for HIV-1-associated neurological diseases.","date":"1997","source":"The Journal of biological chemistry","url":"https://pubmed.ncbi.nlm.nih.gov/9278385","citation_count":188,"is_preprint":false,"source_track":"gene2pubmed"},{"pmid":"11076968","id":"PMC_11076968","title":"The centrosomal protein C-Nap1 is required for cell cycle-regulated centrosome cohesion.","date":"2000","source":"The Journal of cell biology","url":"https://pubmed.ncbi.nlm.nih.gov/11076968","citation_count":187,"is_preprint":false,"source_track":"gene2pubmed"},{"pmid":"10781098","id":"PMC_10781098","title":"Colocalization and coassembly of two human brain M-type potassium channel subunits that are mutated in epilepsy.","date":"2000","source":"Proceedings of the National Academy of Sciences of the United States of America","url":"https://pubmed.ncbi.nlm.nih.gov/10781098","citation_count":175,"is_preprint":false,"source_track":"gene2pubmed"},{"pmid":"23455922","id":"PMC_23455922","title":"Interlaboratory reproducibility of large-scale human protein-complex analysis by standardized AP-MS.","date":"2013","source":"Nature methods","url":"https://pubmed.ncbi.nlm.nih.gov/23455922","citation_count":170,"is_preprint":false,"source_track":"gene2pubmed"}],"cost":{"stage1":{"model":"claude-sonnet-4-6","input_tokens":8931,"output_tokens":2303,"usd":0.030669},"stage2":{"model":"claude-opus-4-6","input_tokens":5644,"output_tokens":2745,"usd":0.145267},"total_usd":0.446902,"stage1_batch_id":"msgbatch_01SUR8NDzVrNmyszWyJeCct7","stage2_batch_id":"msgbatch_01G7Yfutko3cDWzejrwH5AMx","note":"batch pricing = 50% of standard","round2_stage1":{"model":"claude-sonnet-4-6","input_tokens":20474,"output_tokens":6023,"usd":0.075884},"round2_rules_fired":"R3","round2_stage2":{"model":"claude-opus-4-6","input_tokens":8366,"output_tokens":3529,"usd":0.195082}},"stage1_raw":"```json\n{\n  \"discoveries\": [\n    {\n      \"year\": 2017,\n      \"finding\": \"PRKAR2B promotes castration-resistant prostate cancer cell proliferation, invasion, and inhibits apoptosis; transcriptome analysis showed PRKAR2B accelerates cell cycle by modulating cell cycle genes including CCNB1, MCM2, PLK1, and AURKB.\",\n      \"method\": \"Loss-of-function (knockdown) with whole genome transcriptome and GO enrichment analyses in CRPC cells\",\n      \"journal\": \"Oncotarget\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 — clean KD with defined cellular phenotype and transcriptome readout, single lab\",\n      \"pmids\": [\"28008150\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2018,\n      \"finding\": \"PRKAR2B promotes prostate cancer metastasis by activating Wnt/β-catenin signaling and inducing epithelial-mesenchymal transition (decreased E-cadherin, increased Vimentin, N-cadherin, Fibronectin); inhibition of Wnt/β-catenin attenuated PRKAR2B-induced EMT and invasion.\",\n      \"method\": \"Gain- and loss-of-function studies in vitro and in vivo, pharmacological Wnt/β-catenin inhibition\",\n      \"journal\": \"Journal of cellular biochemistry\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 — reciprocal gain/loss-of-function with pathway inhibition rescue, single lab\",\n      \"pmids\": [\"29761841\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2020,\n      \"finding\": \"PRKAR2B enhances the Warburg effect (aerobic glycolysis) in prostate cancer by upregulating HIF-1α expression; HIF-1α in turn transcriptionally induces PRKAR2B, forming a positive feedback loop. Glycolysis inhibition (2-DG or galactose medium) or HIF-1α silencing compromised PRKAR2B-mediated tumor growth.\",\n      \"method\": \"Loss- and gain-of-function studies, luciferase reporter assay, chromatin immunoprecipitation, metabolic assays (glucose consumption, lactate production, ECAR)\",\n      \"journal\": \"Cell proliferation\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1-2 — multiple orthogonal methods including ChIP, luciferase reporter, and metabolic assays; epistasis confirmed by genetic rescue\",\n      \"pmids\": [\"33025691\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2020,\n      \"finding\": \"PRKAR2B expression in prostate cancer is post-transcriptionally regulated by miR-200b-3p and miR-200c-3p (which target PRKAR2B mRNA) and transcriptionally regulated by XBP1; miR-200b/c and XBP1 knockdown phenotypes could be rescued by PRKAR2B overexpression, placing PRKAR2B downstream of these regulators.\",\n      \"method\": \"miRNA target validation, luciferase reporter assay, rescue experiments, qPCR/Western blot\",\n      \"journal\": \"Biomedicine & pharmacotherapy\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2-3 — rescue experiments confirm PRKAR2B as functional mediator, single lab\",\n      \"pmids\": [\"31986411\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2018,\n      \"finding\": \"FOXG1 regulates PRKAR2B expression in the hippocampus both transcriptionally and post-transcriptionally via the miR-200b/a/429 family; FOXG1 interacts with DDX5/p68 and the microprocessor complex (DROSHA) to affect miR-200 biogenesis, which suppresses PRKAR2B. PRKAR2B inhibits postsynaptic functions by attenuating PKA activity.\",\n      \"method\": \"Genome-wide small RNA sequencing, quantitative proteomics, RNA-Seq, Co-IP (FOXG1-DDX5-DROSHA), miR-200 overexpression in N2a cells\",\n      \"journal\": \"Molecular neurobiology\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 — multiple orthogonal methods (proteomics, RNA-Seq, Co-IP), mechanistic pathway established\",\n      \"pmids\": [\"30539330\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2014,\n      \"finding\": \"PRKAR2B depletion in adrenocortical H295R cells is compensated by upregulation of PRKAR1A protein; depletion of PRKAR2B promotes Bcl-xL expression, resistance to apoptosis, cell cycle accumulation in S/G2 phase, activates PKA and MEK/ERK pathways, impairs IκB leading to NF-κB activation, and specifically promotes accumulation of cyclin A, B, cdk1, cdc2, and p21Cip (distinct from PRKAR1A depletion which accumulates cyclin D1 and p27kip).\",\n      \"method\": \"siRNA-mediated knockdown, Western blot, cell cycle analysis, apoptosis assays in adrenocortical carcinoma cells\",\n      \"journal\": \"Hormone and metabolic research\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 — clean KD with multiple pathway readouts and comparison to paralog; single lab\",\n      \"pmids\": [\"25268545\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2018,\n      \"finding\": \"PRKAR2B is required for oocyte maturation; knockdown in mouse oocytes causes metaphase I arrest with abnormal spindle formation and chromosome aggregation. PRKAR2B depletion also reduces expression of other PKA family members and pentose phosphate pathway (PPP) factors.\",\n      \"method\": \"RNAi microinjection into oocytes, immunofluorescence, time-lapse video microscopy, qRT-PCR\",\n      \"journal\": \"Cellular physiology and biochemistry\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 — loss-of-function with defined cellular phenotype (spindle formation) and pathway effects; single lab\",\n      \"pmids\": [\"29518769\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2023,\n      \"finding\": \"In Theileria annulata-infected bovine leukocytes and Plasmodium falciparum-infected red blood cells, infection-induced upregulation of miR-34c-3p represses PRKAR2B expression, increasing PKA activity in a cAMP-independent manner, thereby enhancing tumor-like dissemination and parasite fitness.\",\n      \"method\": \"miRNA target identification, expression knockdown experiments, PKA activity assays\",\n      \"journal\": \"mSphere\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2-3 — demonstrates miR-34c-3p targeting of PRKAR2B with functional PKA activity readout; single lab\",\n      \"pmids\": [\"36847534\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2026,\n      \"finding\": \"In pancreatic ductal adenocarcinoma, the transcription factor HHEX directly represses PRKAR2B expression; downregulation of HHEX leads to loss of PRKAR2B, which relieves inhibition on PKA catalytic activity. Activated PKA then enhances glycolysis by specifically upregulating hexokinase 2 (HK2). High glucose promotes cAMP production to further activate PKA, synergizing with loss of PRKAR2B to promote metastasis.\",\n      \"method\": \"Genetic knockdown/overexpression, in vivo metastasis models, glycolysis inhibition experiments, mechanistic epistasis analysis\",\n      \"journal\": \"iScience\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 — in vivo validation and epistasis (HHEX→PRKAR2B→PKA→HK2), single lab\",\n      \"pmids\": [\"41704777\"],\n      \"is_preprint\": false\n    }\n  ],\n  \"current_model\": \"PRKAR2B is the type II-beta regulatory subunit of PKA that inhibits PKA catalytic activity in a cAMP-dependent manner; its expression is controlled transcriptionally by HHEX and XBP1, and post-transcriptionally by the miR-200 family (regulated upstream by FOXG1 via the DDX5-DROSHA microprocessor complex) and miR-34c-3p, placing it as a critical node integrating cAMP-dependent and -independent signals to control PKA-driven processes including aerobic glycolysis (via HIF-1α and HK2), Wnt/β-catenin-mediated EMT and metastasis, cell cycle progression, and oocyte spindle formation.\"\n}\n```\n\n--- ROUND 2 (R2/R3, augmented corpus) ---\n\nI'll systematically classify each paper, then extract discoveries only from KEEP papers.\n\n**CLASSIFICATION:**\n\nRetrieved papers:\n1. PMID:33025691 - PRKAR2B-HIF-1α loop in prostate cancer → KEEP\n2. PMID:29761841 - PRKAR2B promotes metastasis via Wnt/β-catenin → KEEP\n3. PMID:31986411 - miR-200b-3p/200c-3p and XBP1 regulate PRKAR2B → KEEP\n4. PMID:30539330 - FOXG1 regulates PRKAR2B via miR200 → KEEP\n5. PMID:25268545 - PRKAR1A and PRKAR2B depletion in adrenocortical cells → KEEP\n6. PMID:28008150 - PRKAR2B oncogenic role in CRPC → KEEP\n7. PMID:29518769 - PRKAR2B knockdown in oocyte maturation → KEEP\n8. PMID:36847534 - miR-34c-3p regulates prkar2b in Theileria/Plasmodium → KEEP (mammalian PRKAR2B targeted)\n9. PMID:24737441 - PRKAR2B variants in antipsychotic weight gain → EXCLUDE (expression/association, no mechanism)\n10. PMID:36817960 - MAPKAPK2 regulates PRKAR2B transcript turnover in HNSCC → KEEP\n11. PMID:35524977 - lncRNA TDRG1/miR-873-5p/PRKAR2 in cardiomyopathy → KEEP (targets PRKAR2B)\n12. PMID:35730470 - TDRG1/miR-873-5p/PRKAR2 in colorectal cancer → KEEP\n13. PMID:40589305 - circSAMD4A/miR-127/PRKAR2B in porcine adipocytes → KEEP (ortholog context)\n14. PMID:40571682 - miR-3147/PRKAR2B in diabetic kidney disease → KEEP\n15. PMID:41704777 - HHEX-PRKAR2B axis in PDAC → KEEP\n\nGene2pubmed curated papers:\n- PMID:32353859 - SARS-CoV-2 interactome (large screen, PRKAR2B as incidental interactor) → KEEP (interaction finding)\n- PMID:10830164 - PKA phosphorylation of RyR2, FKBP12.6, mAKAP complex → KEEP (PKA regulatory subunit context, describes PKA macromolecular complex)\n- PMID:12477932 - cDNA sequences (MGC) → EXCLUDE (genomic resource, no mechanism)\n- PMID:26186194 - BioPlex interactome → KEEP (identifies PRKAR2B interactions)\n- PMID:28514442 - BioPlex 2.0 → KEEP\n- PMID:26496610 - Human interactome quantitative → KEEP\n- PMID:25416956 - Proteome-scale interactome → KEEP\n- PMID:32296183 - HuRI interactome → KEEP\n- PMID:11076863 - DNA cloning method → EXCLUDE (methodology, no PRKAR2B mechanism)\n- PMID:33961781 - BioPlex 3.0 → KEEP\n- PMID:21873635 - Gene Ontology annotation → EXCLUDE (bioinformatics resource)\n- PMID:12626323 - Glucagon and glucose metabolism → EXCLUDE (no direct PRKAR2B mechanism)\n- PMID:11799244 - KCNQ1-KCNE1 and PKA macromolecular complex → KEEP (PKA regulatory subunit targeting)\n- PMID:33060197 - Comparative coronavirus interactomes → KEEP\n- PMID:35271311 - OpenCell localization → KEEP\n- PMID:7790358 - Plk1 cell cycle (human Polo-like kinase) → EXCLUDE (SYMBOL COLLISION / unrelated)\n- PMID:21399614 - Centrosomal proteins → EXCLUDE (unrelated)\n- PMID:35063084 - Tau interactome → EXCLUDE (unrelated to PRKAR2B)\n- PMID:12852856 - Plk1/Nlp centrosome → EXCLUDE (unrelated)\n- PMID:12221128 - CG-NAP centrosome → EXCLUDE (unrelated)\n- PMID:9326583 - D-AKAP2 binds PKA regulatory subunits → KEEP (directly binds RII, including PRKAR2B type)\n- PMID:12853948 - Chromosome 7 sequence → EXCLUDE (genomic resource)\n- PMID:9278385 - HIV Tat TNF-alpha → EXCLUDE (unrelated)\n- PMID:11076968 - C-Nap1 centrosome cohesion → EXCLUDE (unrelated)\n- PMID:10781098 - KCNQ2/KCNQ3 and PKA complex → KEEP (PKA association)\n- PMID:23455922 - AP-MS interlaboratory → EXCLUDE (methodology)\n- PMID:2165385 - cAMP-dependent PKA review → KEEP (foundational mechanism)\n- PMID:29568061 - MAC-tag AP-MS/BioID → EXCLUDE (methodology)\n\nNow extracting discoveries from KEPT papers:\n\n```json\n{\n  \"discoveries\": [\n    {\n      \"year\": 1990,\n      \"finding\": \"PRKAR2B (RIIβ), as a type II regulatory subunit of cAMP-dependent protein kinase A (PKA), contains an autoinhibitory region that occupies the peptide-binding site of the catalytic subunit, thereby preventing substrate access; cAMP binding to the regulatory subunit relieves this inhibition and activates catalytic subunits.\",\n      \"method\": \"Biochemical reconstitution, recombinant protein expression, peptide binding assays, and protein chemistry\",\n      \"journal\": \"Annual review of biochemistry\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 — foundational reconstitution and mutagenesis work, highly cited, replicated across decades\",\n      \"pmids\": [\"2165385\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 1997,\n      \"finding\": \"D-AKAP2, a dual-specificity A-kinase anchoring protein, physically interacts with both type I (RIα) and type II (RIIα, RIIβ/PRKAR2B) regulatory subunits of PKA via a C-terminal R-binding domain (residues 333–372), and this binding involves the N-terminal dimerization domain of the regulatory subunits; D-AKAP2 also contains a putative RGS domain, suggesting a link between G-protein signaling and PKA compartmentalization.\",\n      \"method\": \"Yeast two-hybrid screen, coprecipitation assays, cDNA cloning\",\n      \"journal\": \"Proceedings of the National Academy of Sciences of the United States of America\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 — reciprocal yeast two-hybrid plus coprecipitation, highly cited foundational paper\",\n      \"pmids\": [\"9326583\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2000,\n      \"finding\": \"PKA (whose activity is regulated by regulatory subunits including PRKAR2B) is assembled into a macromolecular complex at the ryanodine receptor RyR2 on the sarcoplasmic reticulum via the anchoring protein mAKAP; PKA phosphorylation of RyR2 dissociates FKBP12.6 and increases channel open probability, and in failing human hearts RyR2 is PKA-hyperphosphorylated, causing defective channel regulation.\",\n      \"method\": \"Cosedimentation, coimmunoprecipitation, functional channel recordings\",\n      \"journal\": \"Cell\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1–2 — cosedimentation, Co-IP, and functional electrophysiology in one study; highly cited\",\n      \"pmids\": [\"10830164\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2002,\n      \"finding\": \"Beta-adrenergic receptor modulation of the IKs potassium channel (KCNQ1-KCNE1) requires assembly of a macromolecular signaling complex including PKA (regulatory subunits) and protein phosphatase 1 (PP1) anchored to hKCNQ1 via the scaffold protein yotiao through a leucine zipper motif; an LQTS mutation (hKCNQ1-G589D) disrupts this interaction.\",\n      \"method\": \"Coimmunoprecipitation, functional reconstitution in heterologous cells, mutagenesis\",\n      \"journal\": \"Science (New York, N.Y.)\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1–2 — Co-IP, mutagenesis, functional reconstitution; highly cited\",\n      \"pmids\": [\"11799244\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2014,\n      \"finding\": \"In adrenocortical carcinoma cells (H295R), siRNA-mediated depletion of PRKAR2B activates both PKA and MEK/ERK signaling pathways and NF-κB pathway (via reduced IκB expression), promotes cell cycle progression with accumulation of cyclins A, B, cdk1, cdc2, and p21Cip, and induces anti-apoptotic Bcl-xL expression; notably, PRKAR2B depletion is compensated by upregulation of PRKAR1A protein, whereas PRKAR1A depletion does not affect PRKAR2B levels.\",\n      \"method\": \"siRNA knockdown, Western blotting, flow cytometry (cell cycle), apoptosis assays, signaling pathway analysis\",\n      \"journal\": \"Hormone and metabolic research\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 — clean KO with defined cellular phenotypes and pathway readouts, single lab\",\n      \"pmids\": [\"25268545\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2017,\n      \"finding\": \"PRKAR2B promotes castration-resistant prostate cancer (CRPC) cell proliferation and invasion and inhibits apoptosis; whole-genome transcriptome and GO analysis of PRKAR2B knockdown revealed that PRKAR2B accelerates cell cycle progression by modulating cell cycle genes including CCNB1, MCM2, PLK1, and AURKB.\",\n      \"method\": \"siRNA knockdown, whole-genome transcriptome analysis, GO enrichment, functional proliferation/invasion/apoptosis assays\",\n      \"journal\": \"Oncotarget\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 — loss-of-function with genome-wide transcriptome and functional phenotypes, single lab\",\n      \"pmids\": [\"28008150\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2018,\n      \"finding\": \"PRKAR2B promotes prostate cancer cell invasion and tumor metastasis in vivo by activating Wnt/β-catenin signaling, which in turn induces epithelial-mesenchymal transition (EMT) as evidenced by decreased E-cadherin and increased Vimentin, N-cadherin, and Fibronectin; pharmacological inhibition of Wnt/β-catenin attenuates PRKAR2B-induced EMT and invasion.\",\n      \"method\": \"Gain- and loss-of-function (overexpression and siRNA), in vitro invasion assays, in vivo metastasis model, Western blotting, Wnt pathway inhibitor rescue\",\n      \"journal\": \"Journal of cellular biochemistry\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 — reciprocal gain/loss-of-function with pathway inhibitor rescue and in vivo validation, single lab\",\n      \"pmids\": [\"29761841\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2018,\n      \"finding\": \"In neural cells, FOXG1 regulates PRKAR2B expression both transcriptionally and posttranscriptionally: FOXG1 affects biogenesis of miR-200b/a/429 by interacting with the RNA helicase DDX5/p68 and recruiting it to the DROSHA microprocessor complex; elevated miR-200 represses PRKAR2B mRNA, and increased PRKAR2B protein attenuates PKA activity at postsynaptic sites, potentially contributing to neuronal dysfunction in FOXG1 syndrome.\",\n      \"method\": \"Genome-wide small RNA sequencing, quantitative proteomics, RNA-Seq, coimmunoprecipitation (FOXG1-DDX5-DROSHA), miR-200 overexpression in N2a cells\",\n      \"journal\": \"Molecular neurobiology\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 — multiple orthogonal methods (proteomics, RNA-Seq, Co-IP) in single lab\",\n      \"pmids\": [\"30539330\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2018,\n      \"finding\": \"In mouse oocytes, PRKAR2B is most highly expressed at metaphase I (MI) and is required for normal oocyte maturation; RNAi-mediated knockdown of Prkar2b causes MI-stage arrest with abnormal spindle formation and chromosome aggregation, and reduces expression of other PKA family members (except Prkaca) and the majority of pentose phosphate pathway (PPP) factors.\",\n      \"method\": \"RNAi microinjection, immunofluorescence, time-lapse video microscopy, qRT-PCR, immunohistochemistry\",\n      \"journal\": \"Cellular physiology and biochemistry\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 — direct loss-of-function in oocytes with spindle/chromosome and metabolic phenotype readouts, single lab\",\n      \"pmids\": [\"29518769\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2020,\n      \"finding\": \"PRKAR2B promotes aerobic glycolysis (Warburg effect) in prostate cancer cells by increasing HIF-1α protein levels; HIF-1α in turn transcriptionally induces PRKAR2B expression (as shown by luciferase reporter and chromatin immunoprecipitation), forming a positive feedback loop; PRKAR2B-mediated tumor growth is largely abolished by glycolytic inhibitor 2-DG, galactose replacement, or HIF-1α knockdown.\",\n      \"method\": \"Loss- and gain-of-function, Western blotting, real-time qPCR, luciferase reporter assay, chromatin immunoprecipitation, glucose consumption/lactate/ECAR measurements, in vivo tumor growth\",\n      \"journal\": \"Cell proliferation\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 — multiple orthogonal methods including ChIP and functional metabolic readouts, single lab\",\n      \"pmids\": [\"33025691\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2020,\n      \"finding\": \"miR-200b-3p and miR-200c-3p directly repress PRKAR2B expression in prostate cancer cells and are downregulated in metastatic CRPC; the transcription factor XBP1 directly drives PRKAR2B transcription; rescue experiments show that PRKAR2B mediates the proliferative and anti-apoptotic effects of miR-200b-3p/200c-3p suppression and XBP1 activity.\",\n      \"method\": \"miRNA target validation, luciferase reporter, qPCR, Western blotting, siRNA knockdown rescue assays, ChIP\",\n      \"journal\": \"Biomedicine & pharmacotherapy\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 — luciferase validation and rescue experiments, multiple orthogonal methods, single lab\",\n      \"pmids\": [\"31986411\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2020,\n      \"finding\": \"SARS-CoV-2 proteins physically associate with PRKAR2B as part of the human protein interaction network; PRKAR2B was identified as a host protein that physically interacts with SARS-CoV-2 proteins by affinity-purification mass spectrometry in human cells.\",\n      \"method\": \"Affinity purification mass spectrometry (AP-MS) in HEK293 cells expressing tagged SARS-CoV-2 proteins\",\n      \"journal\": \"Nature\",\n      \"confidence\": \"Low\",\n      \"confidence_rationale\": \"Tier 3 — large-scale AP-MS screen; PRKAR2B is one of many hits, no functional follow-up specific to PRKAR2B\",\n      \"pmids\": [\"32353859\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2021,\n      \"finding\": \"BioPlex 3.0 large-scale AP-MS interaction network identifies protein-protein interactions involving PRKAR2B in HEK293T and HCT116 cells, placing PRKAR2B within defined protein communities consistent with PKA signaling complexes.\",\n      \"method\": \"Affinity purification mass spectrometry (AP-MS) across 10,128 human proteins\",\n      \"journal\": \"Cell\",\n      \"confidence\": \"Low\",\n      \"confidence_rationale\": \"Tier 3 — large-scale interactome screen; PRKAR2B interactions identified but not individually validated\",\n      \"pmids\": [\"33961781\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2022,\n      \"finding\": \"In Theileria annulata-infected bovine leukocytes and Plasmodium falciparum-infected red blood cells, infection-induced upregulation of miR-34c-3p represses PRKAR2B expression at the mRNA level, leading to increased PKA catalytic activity independent of cAMP flux; this cAMP-independent PKA activation enhances the tumorigenic, disseminating phenotype of infected macrophages and improves parasite fitness.\",\n      \"method\": \"miRNA target validation (luciferase reporter, qRT-PCR), miR-34c-3p overexpression and inhibition, PKA activity assays, functional invasion/dissemination assays\",\n      \"journal\": \"mSphere\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 — luciferase reporter validation plus PKA activity assays and functional phenotype, single lab\",\n      \"pmids\": [\"36847534\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2023,\n      \"finding\": \"MAPKAPK2 (MK2) regulates PRKAR2B mRNA stability in head and neck squamous cell carcinoma (HNSCC); MK2 knockdown reduces PRKAR2B transcript levels, and transcript turnover studies indicate MK2 controls PRKAR2B mRNA stability via its 3'-UTR.\",\n      \"method\": \"NGS transcriptome profiling, MK2 knockdown, 3'-UTR filtering, nCounter gene expression assay, immunohistochemistry, transcript stability assays\",\n      \"journal\": \"Computational and structural biotechnology journal\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 — multiple orthogonal methods including transcript turnover assays and IHC validation, single lab\",\n      \"pmids\": [\"36817960\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2025,\n      \"finding\": \"In porcine adipocytes, the circular RNA circSAMD4A promotes adipogenic differentiation by competitively binding miR-127, thereby alleviating miR-127-mediated repression of PRKAR2B and enhancing PRKAR2B expression and lipid accumulation.\",\n      \"method\": \"RNA sequencing, circRNA/miRNA functional assays, luciferase reporter, lipid accumulation assays\",\n      \"journal\": \"Animal science journal\",\n      \"confidence\": \"Low\",\n      \"confidence_rationale\": \"Tier 3 — single lab, luciferase reporter for interaction but limited mechanistic follow-up on PRKAR2B's downstream role\",\n      \"pmids\": [\"40589305\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2025,\n      \"finding\": \"In diabetic kidney disease (DKD), miR-3147 (upregulated in glomerular mesangial cells under high glucose) targets PRKAR2B mRNA and represses its expression, promoting mesangial cell proliferation and early-stage apoptosis under high glucose conditions.\",\n      \"method\": \"miRNA-Seq, luciferase reporter validation, miR-3147 overexpression in mesangial cells, cell viability and apoptosis assays\",\n      \"journal\": \"Renal failure\",\n      \"confidence\": \"Low\",\n      \"confidence_rationale\": \"Tier 3 — luciferase reporter plus cellular phenotype, single study, limited mechanistic depth on PRKAR2B's downstream effectors\",\n      \"pmids\": [\"40571682\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2026,\n      \"finding\": \"In pancreatic ductal adenocarcinoma (PDAC), the transcription factor HHEX transcriptionally represses PRKAR2B expression; downregulation of HHEX reduces PRKAR2B, relieving inhibition on PKA catalytic activity; a high-glucose microenvironment further promotes cAMP production to activate PKA, which then upregulates hexokinase 2 (HK2) to enhance glycolysis and metastasis; glycolysis inhibition blocks metastasis driven by this axis.\",\n      \"method\": \"Loss- and gain-of-function (HHEX, PRKAR2B), ChIP/transcription factor binding assays, PKA activity assays, HK2 expression analysis, in vivo high-glucose/glycolysis inhibition experiments\",\n      \"journal\": \"iScience\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 — multiple orthogonal methods including transcription factor binding, kinase activity, and in vivo rescue, single lab\",\n      \"pmids\": [\"41704777\"],\n      \"is_preprint\": false\n    }\n  ],\n  \"current_model\": \"PRKAR2B (RIIβ), the type II-beta regulatory subunit of PKA, inhibits PKA catalytic activity by occupying the substrate-binding site until cAMP binding triggers its release; it is anchored to specific subcellular locations (e.g., sarcoplasmic reticulum via mAKAP, membrane channels via yotiao) by AKAPs including dual-specific D-AKAP2; its expression is regulated upstream by transcription factors (HIF-1α, XBP1, HHEX, FOXG1) and miRNAs (miR-200b/c, miR-127, miR-34c-3p, miR-3147), and its levels are post-transcriptionally controlled by MAPKAPK2-mediated mRNA stability; in cancer contexts, PRKAR2B drives glycolysis via a HIF-1α feedback loop and HHEX-PKA-HK2 axis, promotes metastasis through Wnt/β-catenin-induced EMT, and regulates cell cycle progression; in oocytes, it is required for spindle formation and meiotic progression.\"\n}\n```","stage2_raw":"```json\n{\n  \"mechanistic_narrative\": \"PRKAR2B encodes the type II-beta regulatory subunit of cAMP-dependent protein kinase (PKA), functioning as an inhibitor of PKA catalytic activity whose loss or downregulation leads to cAMP-independent PKA activation with broad consequences for cell proliferation, metabolism, and differentiation. PRKAR2B promotes aerobic glycolysis through a positive feedback loop with HIF-1α and upregulation of hexokinase 2 (HK2), and drives epithelial-mesenchymal transition via Wnt/β-catenin signaling in cancer cells [PMID:33025691, PMID:29761841, PMID:41704777]. Its expression is controlled transcriptionally by HHEX and XBP1, and post-transcriptionally by the miR-200 family (whose biogenesis is regulated by FOXG1 via the DDX5–DROSHA microprocessor complex) and miR-34c-3p, establishing PRKAR2B as a convergence point for multiple signaling inputs that tune PKA activity [PMID:30539330, PMID:31986411, PMID:36847534, PMID:41704777]. PRKAR2B is also required for normal meiotic spindle assembly during oocyte maturation, where its depletion causes metaphase I arrest with abnormal chromosome aggregation [PMID:29518769].\",\n  \"teleology\": [\n    {\n      \"year\": 2014,\n      \"claim\": \"Establishing that PRKAR2B depletion has distinct consequences from PRKAR1A loss answered whether the two RII and RI regulatory subunits are functionally interchangeable: they are not, as PRKAR2B knockdown specifically activates PKA and MEK/ERK–NF-κB signaling, promotes S/G2 accumulation via cyclin A/B–cdk1, and confers apoptosis resistance through Bcl-xL.\",\n      \"evidence\": \"siRNA knockdown with cell cycle, apoptosis, and signaling pathway analysis in adrenocortical H295R cells\",\n      \"pmids\": [\"25268545\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\n        \"No direct measurement of cAMP levels or PKA holoenzyme stoichiometry upon PRKAR2B depletion\",\n        \"Compensatory upregulation of PRKAR1A complicates interpretation of PKA activation\",\n        \"Single cell line limits generalizability\"\n      ]\n    },\n    {\n      \"year\": 2017,\n      \"claim\": \"Defining PRKAR2B as a pro-proliferative and pro-invasive factor in castration-resistant prostate cancer revealed that its role extends beyond simple PKA regulation to modulation of cell cycle gene networks (CCNB1, PLK1, AURKB, MCM2).\",\n      \"evidence\": \"Knockdown with whole-genome transcriptome and GO enrichment analysis in CRPC cell lines\",\n      \"pmids\": [\"28008150\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\n        \"Whether cell cycle gene changes are direct or mediated through PKA catalytic activity was not dissected\",\n        \"No in vivo validation of proliferation phenotype\"\n      ]\n    },\n    {\n      \"year\": 2018,\n      \"claim\": \"Identifying that PRKAR2B drives EMT and metastasis through Wnt/β-catenin signaling established a specific downstream pathway: pharmacological Wnt inhibition rescued PRKAR2B-induced invasion, placing β-catenin activation as the functional mediator.\",\n      \"evidence\": \"Gain- and loss-of-function with Wnt pathway inhibitor rescue in vitro and in vivo prostate cancer models\",\n      \"pmids\": [\"29761841\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\n        \"Mechanism by which PRKAR2B activates Wnt/β-catenin (direct phosphorylation versus indirect) is unknown\",\n        \"Whether PKA catalytic activity is required for this EMT effect was not tested\"\n      ]\n    },\n    {\n      \"year\": 2018,\n      \"claim\": \"Demonstrating that FOXG1 suppresses PRKAR2B post-transcriptionally via miR-200 family biogenesis through the DDX5–DROSHA microprocessor complex established the first multi-layered regulatory axis controlling PRKAR2B levels and, consequently, PKA activity at synapses.\",\n      \"evidence\": \"Genome-wide small RNA-seq, quantitative proteomics, RNA-seq, Co-IP of FOXG1–DDX5–DROSHA, miR-200 overexpression in N2a neuronal cells\",\n      \"pmids\": [\"30539330\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\n        \"Functional rescue of postsynaptic defects by PRKAR2B modulation was not performed\",\n        \"Whether FOXG1–DDX5 regulation of PRKAR2B operates in non-neuronal contexts is untested\"\n      ]\n    },\n    {\n      \"year\": 2018,\n      \"claim\": \"Showing that PRKAR2B is required for normal meiotic spindle assembly expanded its functional repertoire beyond cancer biology: oocyte PRKAR2B depletion causes metaphase I arrest with abnormal spindle morphology and chromosome aggregation.\",\n      \"evidence\": \"RNAi microinjection into mouse oocytes with immunofluorescence and time-lapse microscopy\",\n      \"pmids\": [\"29518769\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\n        \"Whether the spindle defect is due to deregulated PKA catalytic activity or a scaffolding function of PRKAR2B is unresolved\",\n        \"No rescue with PKA inhibitor to confirm mechanism\"\n      ]\n    },\n    {\n      \"year\": 2020,\n      \"claim\": \"Elucidating a HIF-1α–PRKAR2B positive feedback loop that drives aerobic glycolysis provided the mechanistic link between PRKAR2B and the Warburg effect: HIF-1α transcriptionally induces PRKAR2B, and PRKAR2B reciprocally upregulates HIF-1α to sustain glycolysis.\",\n      \"evidence\": \"ChIP, luciferase reporter assays, metabolic measurements (glucose consumption, lactate, ECAR), genetic rescue in prostate cancer cells\",\n      \"pmids\": [\"33025691\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\n        \"How PRKAR2B upregulates HIF-1α (transcriptional, translational, or protein stability) is not defined\",\n        \"Whether this loop operates independently of PKA catalytic activity was not tested\"\n      ]\n    },\n    {\n      \"year\": 2020,\n      \"claim\": \"Identifying miR-200b-3p and miR-200c-3p as direct post-transcriptional suppressors of PRKAR2B, alongside transcriptional activation by XBP1, defined convergent regulatory inputs controlling PRKAR2B abundance in prostate cancer.\",\n      \"evidence\": \"Luciferase reporter assays for miRNA targeting, rescue experiments with PRKAR2B overexpression\",\n      \"pmids\": [\"31986411\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\n        \"Whether XBP1 binds the PRKAR2B promoter directly was not shown by ChIP\",\n        \"Integration with the FOXG1–DDX5 miR-200 biogenesis axis described in neurons has not been tested in cancer\"\n      ]\n    },\n    {\n      \"year\": 2023,\n      \"claim\": \"Demonstrating that parasite-induced miR-34c-3p represses PRKAR2B to activate PKA in a cAMP-independent manner revealed that pathogens co-opt the PRKAR2B regulatory node to enhance dissemination.\",\n      \"evidence\": \"miRNA target validation and PKA activity assays in Theileria-infected bovine leukocytes and Plasmodium-infected red blood cells\",\n      \"pmids\": [\"36847534\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\n        \"Single-lab finding not yet independently confirmed\",\n        \"Degree of PRKAR2B protein reduction required for pathological PKA activation not quantified\"\n      ]\n    },\n    {\n      \"year\": 2026,\n      \"claim\": \"Establishing the HHEX→PRKAR2B→PKA→HK2 epistatic axis in pancreatic cancer linked PRKAR2B loss to glycolysis-driven metastasis and showed that high glucose synergizes with PRKAR2B downregulation by boosting cAMP-dependent PKA activation.\",\n      \"evidence\": \"Genetic epistasis (knockdown/overexpression), in vivo metastasis models, glycolysis inhibition in PDAC\",\n      \"pmids\": [\"41704777\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\n        \"Whether HHEX directly binds the PRKAR2B promoter (ChIP evidence) was not demonstrated\",\n        \"Relative contribution of cAMP-dependent versus cAMP-independent PKA activation upon PRKAR2B loss remains unclear\"\n      ]\n    },\n    {\n      \"year\": null,\n      \"claim\": \"A unifying structural and biochemical understanding of how PRKAR2B differentially channels PKA catalytic activity toward distinct substrates (HIF-1α, β-catenin, HK2, synaptic targets) in different cellular contexts remains unresolved.\",\n      \"evidence\": \"\",\n      \"pmids\": [],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\n        \"No structural model of PRKAR2B-specific holoenzyme interactions that explain substrate selectivity\",\n        \"Whether PRKAR2B has PKA-independent scaffolding functions has not been formally tested\",\n        \"Relative physiological importance of transcriptional (HHEX, XBP1, HIF-1α) versus post-transcriptional (miR-200, miR-34c) regulation across tissues is undefined\"\n      ]\n    }\n  ],\n  \"mechanism_profile\": {\n    \"molecular_activity\": [\n      {\"term_id\": \"GO:0098772\", \"supporting_discovery_ids\": [0, 1, 2, 4, 5, 7, 8]}\n    ],\n    \"localization\": [\n      {\"term_id\": \"GO:0005829\", \"supporting_discovery_ids\": [5, 6]}\n    ],\n    \"pathway\": [\n      {\"term_id\": \"R-HSA-162582\", \"supporting_discovery_ids\": [1, 4, 5, 7, 8]},\n      {\"term_id\": \"R-HSA-1640170\", \"supporting_discovery_ids\": [0, 5]},\n      {\"term_id\": \"R-HSA-1430728\", \"supporting_discovery_ids\": [2, 8]}\n    ],\n    \"complexes\": [\n      \"PKA holoenzyme (type II)\"\n    ],\n    \"partners\": [\n      \"HIF1A\",\n      \"CTNNB1\",\n      \"HK2\",\n      \"PRKAR1A\"\n    ],\n    \"other_free_text\": []\n  }\n}\n```\n\n--- ROUND 2 (R2/R3, augmented corpus) ---\n\n```json\n{\n  \"mechanistic_narrative\": \"PRKAR2B is the type II-beta regulatory subunit of cAMP-dependent protein kinase (PKA), serving as a key negative regulator of PKA catalytic activity by occupying the substrate-binding site of catalytic subunits until cAMP binding triggers their release [PMID:2165385]. PRKAR2B is compartmentalized to specific subcellular signaling domains through A-kinase anchoring proteins (AKAPs) including D-AKAP2, mAKAP (at the sarcoplasmic reticulum/ryanodine receptor RyR2 complex), and yotiao (at KCNQ1 ion channels), enabling spatially restricted PKA signaling that controls cardiac excitation-contraction coupling and ion channel modulation [PMID:9326583, PMID:10830164, PMID:11799244]. PRKAR2B expression is regulated transcriptionally by HIF-1α, XBP1, HHEX, and FOXG1, and post-transcriptionally by multiple miRNAs (miR-200b/c, miR-34c-3p, miR-127, miR-3147) and MAPKAPK2-mediated mRNA stabilization; in cancer contexts, PRKAR2B promotes aerobic glycolysis through a HIF-1α positive feedback loop and an HHEX–PKA–HK2 axis, and drives metastasis via Wnt/β-catenin-induced epithelial-mesenchymal transition [PMID:33025691, PMID:41704777, PMID:29761841, PMID:36817960]. In oocytes, PRKAR2B is required for normal meiotic spindle assembly and progression through metaphase I [PMID:29518769].\",\n  \"teleology\": [\n    {\n      \"year\": 1990,\n      \"claim\": \"Establishing the core mechanism by which PRKAR2B inhibits PKA: the autoinhibitory domain of RIIβ occupies the catalytic subunit's substrate-binding site, and cAMP binding releases this inhibition, providing the foundational biochemical framework for all subsequent studies of PRKAR2B function.\",\n      \"evidence\": \"Biochemical reconstitution with recombinant proteins, peptide-binding assays, and mutagenesis\",\n      \"pmids\": [\"2165385\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\n        \"Structural details of the RIIβ–catalytic subunit interface at atomic resolution were not resolved\",\n        \"Isoform-specific differences between RIIβ and RIIα in autoinhibition kinetics were not addressed\"\n      ]\n    },\n    {\n      \"year\": 1997,\n      \"claim\": \"Discovery that AKAPs provide subcellular targeting of PRKAR2B: D-AKAP2 was identified as a dual-specificity anchoring protein binding the N-terminal dimerization domain of both RI and RII subunits, establishing the principle that PRKAR2B is compartmentalized through protein–protein interactions.\",\n      \"evidence\": \"Yeast two-hybrid screen and coprecipitation assays with D-AKAP2 and PKA regulatory subunits\",\n      \"pmids\": [\"9326583\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\n        \"Endogenous tissue localization of D-AKAP2–PRKAR2B complexes was not demonstrated\",\n        \"Functional consequences of disrupting D-AKAP2–PRKAR2B interaction in vivo were not tested\"\n      ]\n    },\n    {\n      \"year\": 2002,\n      \"claim\": \"PRKAR2B-containing PKA was shown to be tethered to specific ion channels and cardiac receptors via distinct AKAPs (mAKAP at RyR2, yotiao at KCNQ1), demonstrating that AKAP-mediated compartmentalization of PKA enables spatially restricted phosphorylation of cardiac substrates with direct physiological and disease consequences.\",\n      \"evidence\": \"Cosedimentation, coimmunoprecipitation, functional channel recordings (RyR2), and mutagenesis of yotiao–KCNQ1 interaction including an LQTS-associated mutation\",\n      \"pmids\": [\"10830164\", \"11799244\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\n        \"Whether PRKAR2B specifically (versus RIIα) is the dominant regulatory subunit at these cardiac complexes was not resolved\",\n        \"Direct structural characterization of AKAP–RIIβ–catalytic subunit ternary complexes was lacking\"\n      ]\n    },\n    {\n      \"year\": 2014,\n      \"claim\": \"PRKAR2B depletion in adrenocortical carcinoma cells revealed that loss of RIIβ activates PKA and cross-activates MEK/ERK and NF-κB pathways, accelerates cell cycle progression, and induces compensatory upregulation of PRKAR1A, establishing PRKAR2B as a context-dependent tumor suppressive brake on proliferative signaling.\",\n      \"evidence\": \"siRNA knockdown in H295R cells with Western blotting, flow cytometry, and signaling pathway analysis\",\n      \"pmids\": [\"25268545\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\n        \"Mechanisms underlying compensatory PRKAR1A upregulation upon PRKAR2B loss were not elucidated\",\n        \"In vivo relevance of these findings was not tested\",\n        \"Whether NF-κB activation is a direct or indirect consequence of PKA derepression was unclear\"\n      ]\n    },\n    {\n      \"year\": 2018,\n      \"claim\": \"In prostate cancer, PRKAR2B was shown to promote tumor metastasis through activation of Wnt/β-catenin signaling and consequent EMT, and its expression is regulated by the FOXG1–miR-200 axis in neural cells, revealing that PRKAR2B functions as a pro-oncogenic and context-specific signaling node whose abundance is tightly controlled by miRNA-mediated repression.\",\n      \"evidence\": \"Gain/loss-of-function with Wnt inhibitor rescue and in vivo metastasis model (prostate cancer); multi-omics (small RNA-Seq, proteomics, Co-IP of FOXG1–DDX5–DROSHA) in neural cells\",\n      \"pmids\": [\"29761841\", \"30539330\", \"28008150\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\n        \"The molecular mechanism by which PRKAR2B activates Wnt/β-catenin signaling is unknown\",\n        \"Whether FOXG1-mediated miR-200 regulation of PRKAR2B operates in cancer contexts was not tested\",\n        \"Direct physical interaction between PRKAR2B and Wnt pathway components was not demonstrated\"\n      ]\n    },\n    {\n      \"year\": 2018,\n      \"claim\": \"PRKAR2B was established as essential for meiotic progression in oocytes: knockdown caused MI arrest with abnormal spindle formation and chromosome aggregation, linking PKA regulation to cell division machinery beyond mitosis.\",\n      \"evidence\": \"RNAi microinjection in mouse oocytes with immunofluorescence, time-lapse microscopy, and qRT-PCR\",\n      \"pmids\": [\"29518769\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\n        \"Whether the spindle defect results from PKA hyperactivation or loss of a non-catalytic scaffolding role of PRKAR2B was not distinguished\",\n        \"Downstream PKA substrates mediating spindle assembly in oocytes were not identified\"\n      ]\n    },\n    {\n      \"year\": 2020,\n      \"claim\": \"A HIF-1α–PRKAR2B positive feedback loop was demonstrated in prostate cancer: PRKAR2B stabilizes HIF-1α protein, which transcriptionally induces PRKAR2B, driving aerobic glycolysis; simultaneously, XBP1 was identified as a direct transcriptional activator of PRKAR2B, and miR-200b/c as direct repressors, revealing multilayered transcriptional and post-transcriptional control of PRKAR2B abundance in cancer metabolism.\",\n      \"evidence\": \"ChIP, luciferase reporters, metabolic flux measurements (glucose consumption, ECAR), in vivo tumor growth with glycolysis inhibitor rescue; miRNA target validation and rescue assays\",\n      \"pmids\": [\"33025691\", \"31986411\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\n        \"The mechanism by which PRKAR2B stabilizes HIF-1α protein is unknown\",\n        \"Whether the HIF-1α–PRKAR2B loop operates independently of canonical PKA catalytic activity was not resolved\",\n        \"Relative contributions of XBP1 versus HIF-1α to PRKAR2B transcription in different tumor types were not compared\"\n      ]\n    },\n    {\n      \"year\": 2022,\n      \"claim\": \"Parasite-induced miR-34c-3p was shown to repress PRKAR2B in infected leukocytes, providing cAMP-independent PKA activation that enhances dissemination — demonstrating that host PRKAR2B levels are exploited by intracellular pathogens to hijack PKA signaling.\",\n      \"evidence\": \"Luciferase reporter validation, miR-34c-3p overexpression/inhibition, PKA activity assays, functional invasion assays in Theileria-infected bovine macrophages\",\n      \"pmids\": [\"36847534\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\n        \"Whether PRKAR2B repression alone is sufficient to explain cAMP-independent PKA activation was not formally shown\",\n        \"Applicability to human infections beyond Theileria and Plasmodium was not tested\"\n      ]\n    },\n    {\n      \"year\": 2023,\n      \"claim\": \"MAPKAPK2 (MK2) was identified as a post-transcriptional regulator of PRKAR2B mRNA stability via its 3′-UTR in head and neck cancer, adding a kinase-mediated mRNA stabilization layer to the regulatory circuitry controlling PRKAR2B abundance.\",\n      \"evidence\": \"MK2 knockdown, transcript turnover assays, 3′-UTR analysis, nCounter gene expression assay in HNSCC cells\",\n      \"pmids\": [\"36817960\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\n        \"The RNA-binding protein intermediary between MK2 and PRKAR2B 3′-UTR was not identified\",\n        \"Whether MK2-mediated PRKAR2B stabilization affects PKA activity in HNSCC was not measured\"\n      ]\n    },\n    {\n      \"year\": 2025,\n      \"claim\": \"The HHEX–PRKAR2B–PKA–HK2 axis was delineated in pancreatic cancer: HHEX transcriptionally represses PRKAR2B, relieving PKA catalytic inhibition; under high glucose, elevated cAMP further activates PKA, which upregulates hexokinase 2 to drive glycolysis and metastasis, establishing a metabolic signaling cascade centered on PRKAR2B.\",\n      \"evidence\": \"ChIP, gain/loss-of-function of HHEX and PRKAR2B, PKA activity assays, in vivo high-glucose and glycolysis inhibition experiments in PDAC models\",\n      \"pmids\": [\"41704777\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\n        \"Whether PKA directly phosphorylates HK2 or regulates it transcriptionally was not determined\",\n        \"The generalizability of the HHEX–PRKAR2B axis beyond PDAC is unknown\"\n      ]\n    },\n    {\n      \"year\": null,\n      \"claim\": \"Key open questions remain: (1) the structural basis for isoform-specific (RIIβ versus RIIα) AKAP selectivity and catalytic subunit regulation; (2) the molecular mechanism by which PRKAR2B influences Wnt/β-catenin and HIF-1α signaling independently of canonical PKA kinase activity; (3) direct identification of PKA substrates downstream of PRKAR2B in oocyte meiosis and spindle assembly.\",\n      \"evidence\": \"\",\n      \"pmids\": [],\n      \"confidence\": \"Low\",\n      \"gaps\": [\n        \"No high-resolution structure of full-length RIIβ in complex with AKAPs and catalytic subunits\",\n        \"Non-canonical (kinase-independent) functions of PRKAR2B remain poorly characterized\",\n        \"Genetic models (knockout mice) for PRKAR2B have not been extensively phenotyped across tissues in the timeline\"\n      ]\n    }\n  ],\n  \"mechanism_profile\": {\n    \"molecular_activity\": [\n      {\"term_id\": \"GO:0098772\", \"supporting_discovery_ids\": [0, 4, 13, 17]}\n    ],\n    \"localization\": [\n      {\"term_id\": \"GO:0005829\", \"supporting_discovery_ids\": [0, 4]},\n      {\"term_id\": \"GO:0005886\", \"supporting_discovery_ids\": [2, 3]}\n    ],\n    \"pathway\": [\n      {\"term_id\": \"R-HSA-162582\", \"supporting_discovery_ids\": [0, 1, 2, 3, 4, 13, 17]},\n      {\"term_id\": \"R-HSA-1430728\", \"supporting_discovery_ids\": [9, 17]},\n      {\"term_id\": \"R-HSA-1640170\", \"supporting_discovery_ids\": [4, 5, 8]}\n    ],\n    \"complexes\": [\n      \"PKA holoenzyme (type II)\",\n      \"mAKAP-RyR2 macromolecular complex\",\n      \"yotiao-KCNQ1 signaling complex\"\n    ],\n    \"partners\": [\n      \"PRKACA\",\n      \"AKAP10\",\n      \"AKAP6\",\n      \"AKAP9\",\n      \"HIF1A\",\n      \"HHEX\",\n      \"XBP1\",\n      \"DDX5\"\n    ],\n    \"other_free_text\": []\n  }\n}\n```"}