{"gene":"PDE3A","run_date":"2026-06-10T05:19:53","timeline":{"discoveries":[{"year":2002,"finding":"Three PDE3A isoforms exist in cardiac myocytes (PDE3A-136, PDE3A-118, PDE3A-94) differing in N-terminal sequence containing membrane-association domains and phosphorylation/activation sites for PKB and PKA. PDE3A-136 contains both membrane-association domains and PKB/PKA sites; PDE3A-118 contains only the downstream membrane-association domain and PKA sites; PDE3A-94 lacks both membrane localization domains and PKB/PKA sites. They are translated from two mRNAs derived from the PDE3A1 gene via alternative transcriptional and post-transcriptional processing.","method":"Antibodies to different regions of PDE3A, Western blotting, in vitro transcription/translation","journal":"The Journal of biological chemistry","confidence":"High","confidence_rationale":"Tier 1-2 / Strong — multiple orthogonal methods (isoform-specific antibodies, in vitro translation, multiple deletion constructs) in a single focused study establishing isoform structure and localization determinants","pmids":["12154085"],"is_preprint":false},{"year":2006,"finding":"PKB/Akt phosphorylates PDE3A and activates its cAMP-hydrolytic activity. Phosphorylation of serines 290-292 is required for PKB/Akt-dependent activation of PDE3A and for PKB/Akt-induced meiotic maturation of both Xenopus and mouse oocytes. Microinjection of constitutively active Myr-Akt into mouse oocytes causes meiotic maturation in a PDE3A-dependent manner.","method":"Cell-free kinase assay with recombinant PKB/Akt and PKA, co-expression in Xenopus oocytes, serine-to-alanine mutagenesis, microinjection of myr-Akt into mouse oocytes, pde3a(-/-) rescue assays","journal":"The EMBO journal","confidence":"High","confidence_rationale":"Tier 1 / Strong — in vitro reconstitution with recombinant proteins, site-directed mutagenesis, and in vivo rescue experiments across two species (Xenopus and mouse)","pmids":["17124499"],"is_preprint":false},{"year":1998,"finding":"PDE3A in rat vascular smooth muscle cells is expressed as a 120 kDa protein found only in the cytosolic fraction, whereas PDE3B is expressed as a 135 kDa protein restricted to the particulate fraction. Prolonged incubation with cAMP-elevating agents (forskolin or 8-bromo-cAMP) produced time-dependent increases in PDE3 activity correlating with increased PDE3A and PDE3B signals and a marked increase in particulate PDE3 activity.","method":"RT-PCR with isoform-specific primers, immunoblotting with PDE3-selective antisera, subcellular fractionation","journal":"British journal of pharmacology","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — reciprocal fractionation plus RT-PCR, single lab, two orthogonal methods","pmids":["9884079"],"is_preprint":false},{"year":2015,"finding":"PDE3A1 forms a multiprotein signalosome in human sarcoplasmic reticulum (SR) with SERCA2, phospholamban (PLB), and AKAP18. PKA phosphorylation of PDE3A increases its cAMP-hydrolytic activity, promotes its association with SERCA2/AKAP18 signalosomes, and modulates PLB phosphorylation and SERCA2 activity. Ser-292/Ser-293, a site unique to PDE3A1, is the principal site regulating interaction with SERCA2. Deletion of the PDE3A1/PDE3A2 N-terminus blocks interactions with SERCA2.","method":"Co-immunoprecipitation of endogenous and recombinant proteins, gel filtration chromatography, PKA phosphorylation assays, serine-to-alanine substitution mutagenesis, N-terminal deletion mutants, immunohistochemical staining, SERCA2 activity assay","journal":"The Journal of biological chemistry","confidence":"High","confidence_rationale":"Tier 1 / Strong — multiple orthogonal methods (co-IP, recombinant protein reconstitution, mutagenesis, enzyme activity assay) in a single rigorous study identifying specific regulatory phosphorylation site","pmids":["25593322"],"is_preprint":false},{"year":2015,"finding":"PDE3A gain-of-function missense mutations (six families) cause autosomal dominant hypertension with brachydactyly. The mutations increase PKA-mediated phosphorylation of PDE3A, resulting in increased cAMP-hydrolytic activity and enhanced cell proliferation in mesenchymal stem cell-derived VSMCs and chondrocytes. Levels of phosphorylated VASP were diminished and PTHrP levels were dysregulated.","method":"In vitro analyses of mesenchymal stem cell-derived VSMCs and chondrocytes, cAMP-hydrolytic activity assays, phosphorylation assays, VASP phosphorylation measurement, PTHrP measurement","journal":"Nature genetics","confidence":"High","confidence_rationale":"Tier 2 / Strong — functional gain-of-function analysis in disease-relevant cell types with multiple biochemical readouts, replicated across six independent families","pmids":["25961942"],"is_preprint":false},{"year":2015,"finding":"DNMDP binding to PDE3A promotes a neomorphic interaction between PDE3A and Schlafen 12 (SLFN12). Co-expression of SLFN12 with PDE3A correlates with cancer cell sensitivity to DNMDP; depletion of either PDE3A or SLFN12 confers DNMDP resistance. PDE3A depletion alone also causes resistance.","method":"Phenotypic compound library screening across 766 cancer cell lines, target deconvolution by predictive chemogenomics, PDE3A depletion (knockdown), SLFN12 depletion, correlation of PDE3A gene expression with compound sensitivity","journal":"Nature chemical biology","confidence":"High","confidence_rationale":"Tier 2 / Strong — large-scale chemogenomic screening, genetic depletion experiments, and direct interaction evidence across multiple cell lines and methods","pmids":["26656089"],"is_preprint":false},{"year":2021,"finding":"PDE3A and SLFN12 form a heterotetramer stabilized by DNMDP binding. Interactions between the C-terminal alpha helix of SLFN12 and residues near the active site of PDE3A are required for complex formation, further stabilized by SLFN12-DNMDP interactions. PDE3A binding activates SLFN12 RNase activity, and this RNase activity is required for DNMDP-induced cytotoxicity.","method":"Cryo-EM structure of PDE3A-SLFN12 complex, mutagenesis of interaction interface, SLFN12 RNase activity assay, cell viability assay with RNase-dead SLFN12 mutants","journal":"Nature communications","confidence":"High","confidence_rationale":"Tier 1 / Strong — cryo-EM structure combined with mutagenesis and functional RNase activity assays in a single rigorous study","pmids":["34272366"],"is_preprint":false},{"year":2021,"finding":"High-resolution cryo-EM structures of PDE3A-SLFN12 complexes with anagrelide, nauclefine, or DNMDP show a butterfly-shaped heterotetramer. Small molecules are packed in a shallow pocket in the catalytic domain of PDE3A, and the resulting compound-modified interface binds the short helix (E552-I558) of SLFN12 through hydrophobic interactions, gluing the two proteins together. SLFN12 blocks protein translation leading to apoptosis.","method":"Cryo-EM structure determination from HeLa cells pre-treated with molecular glues, structure-guided analog synthesis, cell viability and apoptosis assays, tumor xenograft experiments","journal":"Nature communications","confidence":"High","confidence_rationale":"Tier 1 / Strong — high-resolution cryo-EM structure with structure-guided mutagenesis and in vivo xenograft validation","pmids":["34707099"],"is_preprint":false},{"year":2009,"finding":"Platelet agonists (including thrombin via PAR-1) stimulate PKC-dependent phosphorylation of PDE3A on Ser-312, Ser-428, Ser-438, Ser-465, and Ser-492, leading to increased cAMP hydrolysis and 14-3-3 protein binding. This phosphorylation and PDE3A activation required PKC but not PI3K/PKB, mTOR/p70S6K, or ERK/RSK. IGF-1, which activates PI3K/PKB but not PKC, did not regulate PDE3A.","method":"Phosphoproteomics/mass spectrometry mapping of phosphorylation sites, PKC inhibitors and phorbol ester activation, immunoprecipitation of 14-3-3/PDE3A complex, cAMP hydrolysis activity assay, platelet activation assays","journal":"The Journal of biological chemistry","confidence":"High","confidence_rationale":"Tier 2 / Strong — mass spectrometry phosphosite mapping combined with pharmacological pathway dissection and functional activity assays in a single study with multiple orthogonal methods","pmids":["19261611"],"is_preprint":false},{"year":2002,"finding":"PKA stimulates phosphorylation and activation of PDE3A in gastric smooth muscle cells. Sodium nitroprusside (via cGMP) inhibits PDE3 activity and augments cAMP levels; this PDE3 inhibition is reversed by blockade of cGMP synthesis, demonstrating cGMP-mediated inhibition of PDE3A.","method":"RT-PCR and Western blot for PDE3A/PDE3B expression, PDE3A phosphorylation assay with PKA activators and inhibitors (PKI, H-89, KT-5823), PDE3 activity assay, cAMP measurement","journal":"American journal of physiology. Cell physiology","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — biochemical activity and phosphorylation assays in primary smooth muscle cells, single lab, two orthogonal approaches","pmids":["11832336"],"is_preprint":false},{"year":2011,"finding":"PDE3A deletion in murine VSMCs suppresses MAPK signaling via two complementary pathways: PKA-catalyzed inhibitory phosphorylation of Raf-1 (Ser-259) with resulting ERK inhibition, and PKA/CREB-mediated induction of p21, leading to G0/G1 cell cycle arrest. PDE3A-KO VSMCs also showed elevated p53 accumulation, increased MKP-1, lower Cyclin-D1, and reduced Rb phosphorylation. p53 siRNA in 3A-KO VSMCs restored growth without affecting Cyclin-D1/Rb phosphorylation; dominant-negative CREB partially restored growth.","method":"PDE3A-KO mouse-derived VSMCs, serum/PDGF-induced DNA synthesis assay, ERK and Raf-1 phosphorylation analysis, cell cycle analysis, adenoviral overexpression of CREB constructs, p53 siRNA transfection","journal":"The Journal of biological chemistry","confidence":"High","confidence_rationale":"Tier 2 / Strong — genetic KO model with multiple mechanistic interventions (siRNA, adenoviral rescue, pathway-specific inhibitors) in disease-relevant cell type","pmids":["21632535"],"is_preprint":false},{"year":2010,"finding":"PDE3A physically and functionally interacts with CFTR channel at the plasma membrane. PDE3A inhibition generates compartmentalized cAMP that clusters PDE3A and CFTR into plasma membrane microdomains and potentiates CFTR channel function. Actin skeleton disruption reduces PDE3A-CFTR interaction and compromises compartmentalized cAMP signaling and CFTR channel activation.","method":"Co-immunoprecipitation of PDE3A and CFTR, patch-clamp electrophysiology, actin disruption experiments, pig trachea submucosal gland secretion model","journal":"Molecular biology of the cell","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — reciprocal co-IP plus functional electrophysiology in a physiological gland secretion model, single lab","pmids":["20089840"],"is_preprint":false},{"year":2001,"finding":"Mouse oocytes express a soluble form of PDE3A. Full-length recombinant PDE3A partitions to the particulate fraction, while N-terminal truncation forms (Delta 1 and Delta 2) are recovered mostly in the soluble fraction, identifying the N-terminus as the membrane-targeting domain. The Km values for cAMP hydrolysis by truncated forms are similar to those of full-length PDE3A (0.2-0.5 μM).","method":"cDNA cloning from mouse oocyte library, expression in Leydig tumor cells, subcellular fractionation, kinetic analysis, pharmacological profiling of recombinant enzyme vs oocyte PDE","journal":"Biology of reproduction","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — functional expression with deletion constructs and subcellular fractionation, single lab","pmids":["11420239"],"is_preprint":false},{"year":2000,"finding":"Conserved histidines H752, H756, and glutamate E825 in the first metal-binding motif are essential for PDE3A catalytic activity (kcat near zero when mutated to alanine). E866A mutation increases Km for cAMP 11-fold and Ki for cGMP 27-fold, suggesting a role in substrate/inhibitor binding. H836A mutation raises Ki for cGMP 177-fold. cAMP and cGMP binding sites in PDE3A are overlapping but not identical, involving common and different amino acids.","method":"Site-directed mutagenesis, baculovirus/Sf9 expression, kinetic analysis (kcat, Km, Ki determination), metal ion-free assay supplemented with Mn2+, Mg2+, or Co2+","journal":"Blood","confidence":"High","confidence_rationale":"Tier 1 / Moderate — systematic mutagenesis of catalytic residues combined with detailed kinetic analysis, single lab but multiple mutants with orthogonal readouts","pmids":["10828019"],"is_preprint":false},{"year":1996,"finding":"The PDE3A catalytic domain is localized to within amino acid residues 679-1141. Deletion mutants encoding residues 665-1141 and 679-1141 display PDE activity, while those starting at residue 686 or later lose detectable activity.","method":"Deletion mutagenesis, expression in PDE-deficient yeast (Saccharomyces cerevisiae), PDE activity assay, Western blotting","journal":"Blood","confidence":"Medium","confidence_rationale":"Tier 1 / Moderate — systematic deletion mapping in functional yeast expression system, single lab","pmids":["8695850"],"is_preprint":false},{"year":1998,"finding":"Histidine H840 (second histidine in HDXXH motif) is essential for PDE3A catalytic activity (mutation to alanine abolishes activity), likely required for bivalent cation binding. H869A mutation reduces affinity for cAMP and cGMP (4-fold increases in Km and IC50 for cGMP), identifying it as part of the inhibitory binding site. Cysteine C816 (in the 44-aa insert unique to PDE3) is required for proper protein folding.","method":"Site-directed mutagenesis, expression in PDE-deficient yeast, kinetic analysis (kcat, Km, IC50 for cGMP and milrinone), Western blotting","journal":"Archives of biochemistry and biophysics","confidence":"Medium","confidence_rationale":"Tier 1 / Moderate — active-site mutagenesis with kinetic characterization, single lab, systematic approach","pmids":["9826434"],"is_preprint":false},{"year":2013,"finding":"PDE3A1 and PDE3A2 isoforms are selectively phosphorylated through different signaling pathways with distinct functional consequences. Isoproterenol (PKA activation) phosphorylates PDE3A1 at S312 (14-3-3-binding site), while PMA (PKC activation) phosphorylates PDE3A2 at alternative 14-3-3-binding site S428. PDE3A2 activity is stimulated by phosphorylation at S428, whereas PDE3A1 activity is not affected by phosphorylation at either site. The two isoforms have distinct protein interactomes revealed by 2D electrophoresis of co-immunoprecipitated proteins.","method":"FLAG-tagged PDE3A1 and PDE3A2 expression in HEK293 cells, gel filtration chromatography, 2D electrophoresis, co-immunoprecipitation, phospho-specific analysis with isoproterenol and PMA, PDE activity assay","journal":"Proceedings of the National Academy of Sciences of the United States of America","confidence":"High","confidence_rationale":"Tier 2 / Strong — multiple orthogonal methods (gel filtration, co-IP, proteomic analysis, activity assay) in engineered and endogenous human myocardium systems, validated in two cell types","pmids":["24248367"],"is_preprint":false},{"year":2010,"finding":"In PDE3A(-/-) oocytes arrested at G2/M, elevated PKA activity is associated with inactivation of Cdc2 and Plk1, and inhibition of histone H3 (S10) phosphorylation and dephosphorylation of Cdc25B (S323) and Cdc2 (Thr14/Tyr15). PKAc phosphorylates recombinant Plk1 and inhibits Plk1 activity in vitro. PDE3A co-localizes with and co-immunoprecipitates with Plk1 in WT ovary and HeLa cells. PKA inhibitor (Rp-cAMPS) reactivates Plk1 in PDE3A(-/-) oocytes.","method":"PDE3A(-/-) mouse model, co-immunoprecipitation, co-localization imaging, in vitro Plk1 phosphorylation assay with recombinant PKAc, PKA inhibitor rescue experiment","journal":"Cell cycle (Georgetown, Tex.)","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — KO mouse model combined with co-IP, in vitro kinase assay, and pharmacological rescue, single lab","pmids":["21099356"],"is_preprint":false},{"year":2016,"finding":"PDE3A hydrolyzes cUMP with a Km of ~143 μM and Vmax of ~42 μmol/min/mg (low-affinity, high-velocity substrate). For comparison, cAMP is hydrolyzed with Km ~0.7 μM and Vmax ~1.2 μmol/min/mg. The PDE3 inhibitor milrinone inhibits cUMP hydrolysis (Ki = 57 nM).","method":"Enzyme kinetics (Michaelis-Menten analysis), HPLC-tandem mass spectrometry measurement of UMP and AMP formation, milrinone inhibition assay","journal":"Naunyn-Schmiedeberg's archives of pharmacology","confidence":"Medium","confidence_rationale":"Tier 1 / Moderate — in vitro enzyme kinetics with mass spectrometry product detection, single lab","pmids":["27975297"],"is_preprint":false},{"year":2015,"finding":"PDE3A-IBMX-resin chemical proteomics in HeLa cells identified 14-3-3 proteins as PDE3A interactors, and revealed that PDE3A associates with a PP2A complex composed of regulatory, scaffold, and catalytic subunits.","method":"Chemical proteomics with IBMX-based affinity resin, selective competition with cilostamide and papaverine, mass spectrometry identification of co-captured proteins in HeLa cell lysates","journal":"Molecular bioSystems","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — affinity-based chemical proteomics with competitor selectivity validation, single lab","pmids":["26205238"],"is_preprint":false},{"year":2017,"finding":"SFPQ (splicing factor proline and glutamine rich) protein modulates PDE3A mRNA levels and functions as a transcriptional activator of PDE3A. Multiple transcription start sites (TSS1, 2, 3) were identified within the first exon of PDE3A. Serum-induced PDE3A expression was affected by increasing SFPQ binding to the upstream regulatory region, as demonstrated by ChIP-seq.","method":"5'-RACE to map transcription start sites, ChIP-seq for SFPQ binding sites, SFPQ overexpression/knockdown with mRNA measurement, RT-PCR","journal":"Bioscience reports","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — ChIP-seq plus functional expression studies, single lab","pmids":["28743736"],"is_preprint":false},{"year":2019,"finding":"ATF3 transcription factor binds to a 29-nucleotide insertion (INS) in the PDE3A promoter and represses cAMP-dependent promoter activity. The INS also represses a cAMP response element enhancer 61 nt downstream. In failing hearts homozygous for the DEL genotype treated with PDE3 inhibitors, PDE3A1 mRNA and microsomal PDE3 enzyme activity were increased ~1.7-1.8 fold, consistent with derepression of the cAMP response element.","method":"Luciferase reporter assay with cloned PDE3A promoter variants, transcription factor binding analysis (ATF3), RT-PCR of explanted failing LVs, PDE3 enzyme activity measurement","journal":"Journal of the American College of Cardiology","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — reporter assay plus human tissue validation, single lab, two orthogonal methods","pmids":["30871701"],"is_preprint":false},{"year":2020,"finding":"In human pulmonary artery smooth muscle cells (hPASMC), nitric oxide (NO) increases PDE3A protein expression and PDE3 activity via the soluble guanylate cyclase (sGC)-cGMP pathway, leading to decreased cAMP and activation of AMPK. Knockdown of PDE3A with siRNA blunts NO-induced AMPK activation, demonstrating PDE3A as an intermediary between NO/cGMP signaling and AMPK regulation.","method":"siRNA knockdown of PDE3A in hPASMC, Western blotting for AMPK phosphorylation, cAMP measurement, sGC stimulator and inhibitor pharmacology, PDE3 activity assay","journal":"Physiological reports","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — siRNA knockdown with mechanistic pathway dissection using pharmacological tools, single lab","pmids":["32914566"],"is_preprint":false},{"year":2022,"finding":"Cytotoxic PDE3A modulators (molecular glues) promote PDE3A-SLFN12 interaction, increasing SLFN12 protein stability in the cytoplasm and inducing SLFN12 dephosphorylation at Ser-368 and Ser-573. This dephosphorylation is required for cell death. Dephosphorylation promotes the rRNA RNase activity of SLFN12, which is essential for SLFN12's cell-death-inducing function.","method":"Mutational analysis of SLFN12 phosphorylation sites, co-immunoprecipitation, cell death assays, SLFN12 RNase activity assay, protein stability assays","journal":"Cell chemical biology","confidence":"High","confidence_rationale":"Tier 1-2 / Moderate — mutagenesis, RNase assay, co-IP, and functional cell death assays with multiple orthogonal methods in a single study","pmids":["35104454"],"is_preprint":false},{"year":2001,"finding":"A vascular smooth muscle cell-specific PDE3A isoform ('PDE3A2') lacks the N-terminal 145 amino acids present in the myocardial isoform (PDE3A1) and is a product of the same gene, generated pre-translationally. The recombinant protein has a molecular mass of ~131 kDa, consistent with translation from an ATG at nt 436-438 of the myocardial PDE3A coding region.","method":"cDNA cloning from aortic myocytes, RT-PCR, 5'-RACE, RNase protection assay, Sf9 cell expression, Western blotting with region-specific antibodies","journal":"The Biochemical journal","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — multiple molecular techniques to characterize isoform structure and translational origin, single lab","pmids":["11115397"],"is_preprint":false}],"current_model":"PDE3A is a cGMP-inhibited cAMP phosphodiesterase expressed in multiple isoforms (PDE3A1/2/3) that differ in N-terminal length determining membrane association and phosphorylation by PKA, PKC, and PKB/Akt; PKA/PKC phosphorylation at specific serine residues (including Ser-292/293 in PDE3A1) regulates its catalytic activity, subcellular localization, 14-3-3/PP2A binding, and incorporation into SERCA2/AKAP18 signalosomes in cardiac SR; in oocytes, PKB/Akt-mediated phosphorylation at Ser-290-292 activates PDE3A to lower cAMP and enable meiotic resumption, while gain-of-function mutations causing HTNB syndrome hyperactivate PDE3A via increased PKA-mediated phosphorylation, enhancing VSMC proliferation; additionally, certain PDE3A modulators act as molecular glues to induce a PDE3A-SLFN12 heterotetramer wherein the compound-modified PDE3A active site recruits SLFN12's C-terminal helix, activating SLFN12 RNase activity (requiring SLFN12 dephosphorylation) that cleaves rRNA/tRNA to cause cancer cell apoptosis."},"narrative":{"mechanistic_narrative":"PDE3A is a cGMP-inhibited, cAMP-hydrolyzing phosphodiesterase that sets local cyclic-nucleotide tone within signalosomes controlling smooth muscle proliferation, cardiac contractility, oocyte meiosis, and—when pharmacologically subverted—cancer cell death [PMID:25593322, PMID:25961942, PMID:21632535]. The enzyme is expressed as multiple isoforms (PDE3A1/PDE3A2/PDE3A-94 and related forms) generated pre-translationally from a single gene; their differing N-termini contain membrane-association domains that determine soluble versus particulate localization, with N-terminal truncation shifting the enzyme to the cytosol [PMID:12154085, PMID:11420239, PMID:11115397]. Catalysis depends on a metal-binding active site in residues ~679–1141 in which conserved histidines and glutamates (H752, H756, H840, E825) are required for turnover while residues such as E866/H836/H869 govern cAMP and cGMP binding at overlapping but non-identical sites [PMID:10828019, PMID:8695850, PMID:9826434]; the enzyme hydrolyzes cAMP with high affinity and can also turn over cUMP as a low-affinity substrate [PMID:27975297]. PDE3A activity, localization, and partner binding are tuned by phosphorylation: PKA, PKC, and PKB/Akt phosphorylate distinct serines in an isoform-selective manner, creating 14-3-3 binding sites and controlling incorporation into a sarcoplasmic-reticulum SERCA2/AKAP18/phospholamban signalosome where PKA phosphorylation of the PDE3A1-unique Ser-292/293 promotes SERCA2 association and modulates SERCA2 activity [PMID:17124499, PMID:25593322, PMID:19261611, PMID:24248367]. Through compartmentalized cAMP, PDE3A restrains the PKA→Raf-1/ERK and PKA/CREB→p21 axes to permit vascular smooth muscle proliferation, and dominant gain-of-function missense mutations that increase PKA-mediated phosphorylation and cAMP hydrolysis cause autosomal-dominant hypertension with brachydactyly by enhancing VSMC and chondrocyte proliferation [PMID:25961942, PMID:21632535]. In oocytes, PKB/Akt phosphorylation at Ser-290–292 activates PDE3A to lower cAMP and drive meiotic resumption, coupling to Plk1/Cdc2 control [PMID:17124499, PMID:21099356]. PDE3A is also a druggable scaffold: small-molecule 'molecular glues' such as DNMDP occupy a pocket in the PDE3A catalytic domain and create a neomorphic interface that recruits the C-terminal helix of Schlafen 12 (SLFN12) into a butterfly-shaped heterotetramer, activating SLFN12 RNase activity—dependent on SLFN12 dephosphorylation—to block translation and trigger cancer cell apoptosis [PMID:26656089, PMID:34272366, PMID:34707099, PMID:35104454].","teleology":[{"year":1996,"claim":"Defining where catalysis resides was the first step toward understanding PDE3A as an enzyme; deletion mapping localized the catalytic domain to a discrete C-terminal region.","evidence":"Deletion mutagenesis expressed in PDE-deficient yeast with activity assays","pmids":["8695850"],"confidence":"Medium","gaps":["Does not identify catalytic residues","No structural model of the active site"]},{"year":1998,"claim":"To explain catalysis and inhibitor selectivity, active-site residues were tested; specific histidines were shown essential for activity and metal coordination while another residue defined the inhibitory binding site, and a unique cysteine was required for folding.","evidence":"Site-directed mutagenesis in yeast with kinetic analysis of cGMP and milrinone inhibition","pmids":["9826434"],"confidence":"Medium","gaps":["Roles inferred from kinetics without crystal structure","Metal coordination geometry not directly resolved"]},{"year":1998,"claim":"Establishing the cellular context, PDE3A and PDE3B were shown to occupy distinct subcellular compartments in vascular smooth muscle and to be upregulated by sustained cAMP elevation.","evidence":"Isoform-specific RT-PCR, immunoblotting, and subcellular fractionation in rat VSMCs","pmids":["9884079"],"confidence":"Medium","gaps":["Mechanism of cAMP-induced upregulation unresolved","Functional consequence of compartmentalization not defined"]},{"year":2000,"claim":"Extending the active-site model, systematic mutagenesis showed cAMP and cGMP bind overlapping but non-identical residues, explaining how cGMP can act as a competitive inhibitor.","evidence":"Site-directed mutagenesis in Sf9 cells with kcat/Km/Ki determination under defined metal conditions","pmids":["10828019"],"confidence":"High","gaps":["No structural visualization of the dual binding mode","Does not address allosteric regulation by phosphorylation"]},{"year":2001,"claim":"The structural basis of localization was traced to the N-terminus; truncation forms partition to cytosol while retaining catalytic kinetics, and a VSMC-specific isoform lacking the N-terminal 145 residues was shown to arise pre-translationally from the same gene.","evidence":"cDNA cloning, expression with fractionation and kinetics in oocyte and aortic myocyte systems","pmids":["11420239","11115397"],"confidence":"Medium","gaps":["Membrane-targeting sequence not mapped at residue level","Tissue-specific isoform regulation mechanism unclear"]},{"year":2002,"claim":"Isoform architecture was systematically defined, linking distinct N-termini to membrane-association domains and to differential PKA/PKB phosphorylation site content, framing isoforms as functionally specialized.","evidence":"Isoform-specific antibodies, Western blotting, and in vitro transcription/translation in cardiac myocytes","pmids":["12154085"],"confidence":"High","gaps":["Functional consequences of each phospho-site not yet tested","In vivo isoform-specific roles undefined"]},{"year":2002,"claim":"Reciprocal regulation by cyclic nucleotides was demonstrated in smooth muscle: PKA activates PDE3A while cGMP inhibits it, establishing PDE3A as a node integrating cAMP and cGMP signaling.","evidence":"Phosphorylation and activity assays with PKA and cGMP-synthesis modulators in gastric smooth muscle cells","pmids":["11832336"],"confidence":"Medium","gaps":["Phosphosite mediating PKA activation not mapped here","Stoichiometry of cGMP inhibition in cells not quantified"]},{"year":2006,"claim":"A physiological kinase-substrate link was established: PKB/Akt phosphorylation at Ser-290–292 activates PDE3A and is required for oocyte meiotic resumption, connecting growth-factor signaling to cyclic-nucleotide control of meiosis.","evidence":"Cell-free kinase assays, mutagenesis, and myr-Akt microinjection with pde3a(-/-) rescue across Xenopus and mouse oocytes","pmids":["17124499"],"confidence":"High","gaps":["Does not resolve downstream cell-cycle effectors","Relative contribution of Akt vs PKA in vivo unquantified"]},{"year":2009,"claim":"In platelets, agonist signaling was shown to act through PKC—not PI3K/PKB—to phosphorylate multiple PDE3A serines, increasing activity and 14-3-3 binding, demonstrating pathway-selective control of the enzyme.","evidence":"Phosphoproteomic site mapping, pharmacological pathway dissection, co-IP, and activity assays in platelets","pmids":["19261611"],"confidence":"High","gaps":["Functional role of each individual phosphosite not isolated","How 14-3-3 binding alters localization not shown"]},{"year":2010,"claim":"PDE3A was placed within a plasma-membrane microdomain controlling an ion channel, showing it physically and functionally couples to CFTR to generate compartmentalized cAMP dependent on the actin cytoskeleton.","evidence":"Co-IP, patch-clamp, actin disruption, and gland secretion model","pmids":["20089840"],"confidence":"Medium","gaps":["Direct vs scaffold-mediated PDE3A–CFTR interaction unresolved","Adaptor anchoring PDE3A to actin not identified"]},{"year":2010,"claim":"The oocyte arrest phenotype was mechanistically linked downstream: loss of PDE3A elevates PKA, which inactivates Plk1 and Cdc2, and PDE3A co-localizes with Plk1, defining the cell-cycle machinery controlled by PDE3A-regulated cAMP.","evidence":"PDE3A(-/-) oocytes, co-IP, co-localization, in vitro Plk1 phosphorylation, and PKA-inhibitor rescue","pmids":["21099356"],"confidence":"Medium","gaps":["Whether PDE3A–Plk1 interaction is direct unproven","Physiological role of the interaction beyond meiosis unclear"]},{"year":2011,"claim":"The proliferative role of PDE3A in vasculature was mechanistically dissected: deleting PDE3A engages two PKA-dependent brakes (Raf-1/ERK inhibition and CREB/p21/p53 induction) to arrest the cell cycle, explaining how PDE3A-controlled cAMP permits VSMC growth.","evidence":"PDE3A-KO VSMCs with proliferation assays, pathway analysis, CREB constructs, and p53 siRNA","pmids":["21632535"],"confidence":"High","gaps":["Spatial pool of cAMP driving each branch not localized","Relative weight of the two pathways in vivo unquantified"]},{"year":2013,"claim":"Isoform-selective regulation was demonstrated functionally: PKA and PKC phosphorylate distinct sites on PDE3A1 (S312) versus PDE3A2 (S428), with differential activity effects and distinct interactomes, establishing the isoforms as separately wired signaling units.","evidence":"Tagged isoform expression, gel filtration, 2D electrophoresis co-IP, and phospho-specific activity assays in HEK293 and myocardium","pmids":["24248367"],"confidence":"High","gaps":["Identities of isoform-specific interactors largely unresolved","In vivo relevance of S312 14-3-3 binding for PDE3A1 unclear"]},{"year":2015,"claim":"PDE3A was shown to nucleate a cardiac SR signalosome with SERCA2, phospholamban, and AKAP18, with PKA phosphorylation of the PDE3A1-unique Ser-292/293 controlling SERCA2 association and activity, providing a structural basis for local cAMP control of calcium handling.","evidence":"Co-IP, gel filtration, PKA phosphorylation, mutagenesis, N-terminal deletions, and SERCA2 activity assays","pmids":["25593322"],"confidence":"High","gaps":["Stoichiometry and architecture of the signalosome unresolved","Direct vs AKAP-bridged SERCA2 contact not distinguished"]},{"year":2015,"claim":"A direct disease link was established: gain-of-function PDE3A mutations cause autosomal-dominant hypertension with brachydactyly by increasing PKA-mediated phosphorylation and cAMP hydrolysis, driving VSMC and chondrocyte proliferation.","evidence":"Mutation analysis across six families with functional assays in mesenchymal-derived VSMCs and chondrocytes","pmids":["25961942"],"confidence":"High","gaps":["How mutations increase PKA accessibility structurally unknown","Link between VASP/PTHrP dysregulation and brachydactyly incomplete"]},{"year":2015,"claim":"A neomorphic pharmacology was discovered: DNMDP binding to PDE3A creates a gain-of-function interaction with SLFN12, with co-expression of both proteins required for cancer-cell sensitivity, reframing PDE3A as a molecular-glue scaffold for cytotoxicity.","evidence":"Phenotypic screening across 766 cell lines, chemogenomic deconvolution, and PDE3A/SLFN12 depletion","pmids":["26656089"],"confidence":"High","gaps":["Mechanism of SLFN12 activation not yet defined here","Structure of the induced complex not yet resolved"]},{"year":2015,"claim":"Chemical proteomics confirmed endogenous PDE3A partners, identifying 14-3-3 proteins and a PP2A holoenzyme as associated with PDE3A, expanding its regulatory interactome.","evidence":"IBMX-resin affinity capture with competitor selectivity and mass spectrometry in HeLa lysates","pmids":["26205238"],"confidence":"Medium","gaps":["Functional consequence of PP2A association not tested","Direct vs indirect binding not distinguished"]},{"year":2016,"claim":"The substrate scope was broadened: PDE3A hydrolyzes cUMP as a low-affinity, high-velocity substrate sensitive to milrinone, indicating PDE3A activity is not restricted to cAMP/cGMP.","evidence":"Enzyme kinetics with HPLC-MS/MS product detection and milrinone inhibition","pmids":["27975297"],"confidence":"Medium","gaps":["Physiological relevance of cUMP hydrolysis unknown","Cellular cUMP levels not measured"]},{"year":2017,"claim":"Transcriptional control of PDE3A was addressed: SFPQ acts as a transcriptional activator binding upstream regulatory regions to modulate serum-induced PDE3A mRNA, identifying a determinant of PDE3A expression levels.","evidence":"5'-RACE TSS mapping, ChIP-seq, and SFPQ overexpression/knockdown with mRNA measurement","pmids":["28743736"],"confidence":"Medium","gaps":["Whether SFPQ regulation is isoform-selective unclear","Signal coupling serum to SFPQ binding unresolved"]},{"year":2019,"claim":"Promoter-level regulation in heart was defined: ATF3 binds a promoter insertion to repress cAMP-dependent PDE3A transcription, linking a common indel genotype to PDE3A expression and PDE3-inhibitor response in failing hearts.","evidence":"Luciferase reporter assays, ATF3 binding analysis, and RT-PCR/activity in explanted failing left ventricles","pmids":["30871701"],"confidence":"Medium","gaps":["Direct ATF3 occupancy in vivo not shown","Clinical impact of genotype on therapy not established"]},{"year":2020,"claim":"PDE3A was positioned as an intermediary in vascular NO signaling: NO via sGC/cGMP raises PDE3A expression and activity to lower cAMP and activate AMPK, with PDE3A knockdown blunting AMPK activation.","evidence":"siRNA knockdown in hPASMC with cAMP measurement, sGC pharmacology, and AMPK phospho-blotting","pmids":["32914566"],"confidence":"Medium","gaps":["Apparent contrast with direct cGMP inhibition of PDE3A not reconciled","Mechanism of NO-induced PDE3A upregulation unknown"]},{"year":2021,"claim":"The structural mechanism of the molecular-glue effect was solved: cryo-EM of PDE3A–SLFN12 heterotetramers showed compounds packed in a PDE3A catalytic-domain pocket creating an interface that captures the SLFN12 C-terminal helix and activates SLFN12 RNase activity essential for cytotoxicity.","evidence":"Cryo-EM structures with anagrelide/nauclefine/DNMDP, interface mutagenesis, RNase and viability assays, and xenografts","pmids":["34272366","34707099"],"confidence":"High","gaps":["RNA substrate specificity of activated SLFN12 not fully mapped","Why only certain cells are sensitive beyond SLFN12 expression unclear"]},{"year":2022,"claim":"The activation switch downstream of complex formation was identified: glue-induced PDE3A binding stabilizes SLFN12 and drives its dephosphorylation at Ser-368/Ser-573, which is required to unleash its rRNA RNase activity and cell death.","evidence":"SLFN12 phosphosite mutagenesis, co-IP, stability, RNase, and cell-death assays","pmids":["35104454"],"confidence":"High","gaps":["Phosphatase responsible for SLFN12 dephosphorylation unidentified","How PDE3A binding triggers dephosphorylation unresolved"]},{"year":null,"claim":"How the multiple regulatory layers—isoform-specific phosphorylation, signalosome assembly, transcriptional control, and cGMP inhibition—are integrated to shape spatially distinct cAMP pools in a given cell type remains undefined, as does the endogenous physiological role (if any) of the PDE3A–SLFN12 axis.","evidence":"","pmids":[],"confidence":"Medium","gaps":["No full-length multi-isoform structure with phosphorylation states","Endogenous trigger for PDE3A–SLFN12 interaction unknown","Integrated quantitative model of compartmentalized cAMP lacking"]}],"mechanism_profile":{"molecular_activity":[{"term_id":"GO:0016787","term_label":"hydrolase activity","supporting_discovery_ids":[13,18]},{"term_id":"GO:0140098","term_label":"catalytic activity, acting on RNA","supporting_discovery_ids":[13,18]},{"term_id":"GO:0098772","term_label":"molecular function regulator activity","supporting_discovery_ids":[3,6]}],"localization":[{"term_id":"GO:0005829","term_label":"cytosol","supporting_discovery_ids":[2,12]},{"term_id":"GO:0005783","term_label":"endoplasmic reticulum","supporting_discovery_ids":[3]},{"term_id":"GO:0005886","term_label":"plasma membrane","supporting_discovery_ids":[11]}],"pathway":[{"term_id":"R-HSA-162582","term_label":"Signal Transduction","supporting_discovery_ids":[1,3,9]},{"term_id":"R-HSA-1643685","term_label":"Disease","supporting_discovery_ids":[4]},{"term_id":"R-HSA-5357801","term_label":"Programmed Cell Death","supporting_discovery_ids":[6,7,23]},{"term_id":"R-HSA-1640170","term_label":"Cell Cycle","supporting_discovery_ids":[10,17]}],"complexes":["PDE3A1-SERCA2-phospholamban-AKAP18 signalosome","PDE3A-SLFN12 heterotetramer"],"partners":["SLFN12","SERCA2","AKAP18","PHOSPHOLAMBAN","CFTR","PLK1","YWHA (14-3-3)","PPP2 (PP2A)"],"other_free_text":[]}},"prefetch_data":{"uniprot":{"accession":"Q14432","full_name":"cGMP-inhibited 3',5'-cyclic phosphodiesterase 3A","aliases":["Cyclic GMP-inhibited phosphodiesterase A","CGI-PDE A","cGMP-inhibited cAMP phosphodiesterase","cGI-PDE"],"length_aa":1141,"mass_kda":125.0,"function":"Cyclic nucleotide phosphodiesterase with specificity for the second messengers cAMP and cGMP, which are key regulators of many important physiological processes (PubMed:1315035, PubMed:25961942, PubMed:8155697, PubMed:8695850). Also has activity toward cUMP (PubMed:27975297). Independently of its catalytic activity it is part of an E2/17beta-estradiol-induced pro-apoptotic signaling pathway. E2 stabilizes the PDE3A/SLFN12 complex in the cytosol, promoting the dephosphorylation of SLFN12 and activating its pro-apoptotic ribosomal RNA/rRNA ribonuclease activity. This apoptotic pathway might be relevant in tissues with high concentration of E2 and be for instance involved in placenta remodeling (PubMed:31420216, PubMed:34707099)","subcellular_location":"Membrane; Cytoplasm, cytosol","url":"https://www.uniprot.org/uniprotkb/Q14432/entry"},"depmap":{"release":"DepMap","has_data":true,"is_common_essential":false,"resolved_as":"","url":"https://depmap.org/portal/gene/PDE3A","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":[],"url":"https://opencell.sf.czbiohub.org/search/PDE3A","total_profiled":1310},"omim":[{"mim_id":"608742","title":"HYPERTENSION, ESSENTIAL, SUSCEPTIBILITY TO, 4","url":"https://www.omim.org/entry/608742"},{"mim_id":"602047","title":"PHOSPHODIESTERASE 3B; PDE3B","url":"https://www.omim.org/entry/602047"},{"mim_id":"171890","title":"PHOSPHODIESTERASE 1A; PDE1A","url":"https://www.omim.org/entry/171890"},{"mim_id":"123805","title":"PHOSPHODIESTERASE 3A; PDE3A","url":"https://www.omim.org/entry/123805"},{"mim_id":"112410","title":"HYPERTENSION AND BRACHYDACTYLY SYNDROME; HTNB","url":"https://www.omim.org/entry/112410"}],"hpa":{"profiled":true,"resolved_as":"","reliability":"Approved","locations":[{"location":"Plasma membrane","reliability":"Approved"}],"tissue_specificity":"Tissue enhanced","tissue_distribution":"Detected in many","driving_tissues":[{"tissue":"blood vessel","ntpm":19.9},{"tissue":"heart muscle","ntpm":28.0}],"url":"https://www.proteinatlas.org/search/PDE3A"},"hgnc":{"alias_symbol":["CGI-PDE"],"prev_symbol":[]},"alphafold":{"accession":"Q14432","domains":[{"cath_id":"-","chopping":"133-179_193-259","consensus_level":"high","plddt":72.1366,"start":133,"end":259},{"cath_id":"1.10.1300.10","chopping":"683-780_800-957","consensus_level":"high","plddt":94.6516,"start":683,"end":957}],"viewer_url":"https://alphafold.ebi.ac.uk/entry/Q14432","model_url":"https://alphafold.ebi.ac.uk/files/AF-Q14432-F1-model_v6.cif","pae_url":"https://alphafold.ebi.ac.uk/files/AF-Q14432-F1-predicted_aligned_error_v6.png","plddt_mean":60.25},"mouse_models":{"mgi_url":"https://www.informatics.jax.org/marker/summary?nomen=PDE3A","jax_strain_url":"https://www.jax.org/strain/search?query=PDE3A"},"sequence":{"accession":"Q14432","fasta_url":"https://rest.uniprot.org/uniprotkb/Q14432.fasta","uniprot_url":"https://www.uniprot.org/uniprotkb/Q14432/entry","alphafold_viewer_url":"https://alphafold.ebi.ac.uk/entry/Q14432"}},"corpus_meta":[{"pmid":"25961942","id":"PMC_25961942","title":"PDE3A mutations cause autosomal dominant hypertension with brachydactyly.","date":"2015","source":"Nature genetics","url":"https://pubmed.ncbi.nlm.nih.gov/25961942","citation_count":127,"is_preprint":false},{"pmid":"12154085","id":"PMC_12154085","title":"Isoforms of cyclic nucleotide phosphodiesterase PDE3A in cardiac myocytes.","date":"2002","source":"The Journal of biological chemistry","url":"https://pubmed.ncbi.nlm.nih.gov/12154085","citation_count":107,"is_preprint":false},{"pmid":"17124499","id":"PMC_17124499","title":"Protein kinase B/Akt phosphorylation of PDE3A and its role in mammalian oocyte maturation.","date":"2006","source":"The EMBO journal","url":"https://pubmed.ncbi.nlm.nih.gov/17124499","citation_count":101,"is_preprint":false},{"pmid":"9884079","id":"PMC_9884079","title":"Expression of cyclic GMP-inhibited phosphodiesterases 3A and 3B (PDE3A and PDE3B) in rat tissues: differential subcellular localization and regulated expression by cyclic AMP.","date":"1998","source":"British journal of pharmacology","url":"https://pubmed.ncbi.nlm.nih.gov/9884079","citation_count":96,"is_preprint":false},{"pmid":"25593322","id":"PMC_25593322","title":"Regulation of sarcoplasmic reticulum Ca2+ ATPase 2 (SERCA2) activity by phosphodiesterase 3A (PDE3A) in human myocardium: phosphorylation-dependent interaction of PDE3A1 with SERCA2.","date":"2015","source":"The Journal of biological chemistry","url":"https://pubmed.ncbi.nlm.nih.gov/25593322","citation_count":84,"is_preprint":false},{"pmid":"26656089","id":"PMC_26656089","title":"Identification of cancer-cytotoxic modulators of PDE3A by predictive chemogenomics.","date":"2015","source":"Nature chemical biology","url":"https://pubmed.ncbi.nlm.nih.gov/26656089","citation_count":82,"is_preprint":false},{"pmid":"19261611","id":"PMC_19261611","title":"Protein kinase C-mediated phosphorylation and activation of PDE3A regulate cAMP levels in human platelets.","date":"2009","source":"The Journal of biological chemistry","url":"https://pubmed.ncbi.nlm.nih.gov/19261611","citation_count":81,"is_preprint":false},{"pmid":"25877153","id":"PMC_25877153","title":"Targeted disruption of PDE3B, but not PDE3A, protects murine heart from ischemia/reperfusion injury.","date":"2015","source":"Proceedings of the National Academy of Sciences of the United States of America","url":"https://pubmed.ncbi.nlm.nih.gov/25877153","citation_count":74,"is_preprint":false},{"pmid":"34272366","id":"PMC_34272366","title":"Structure of PDE3A-SLFN12 complex reveals requirements for activation of SLFN12 RNase.","date":"2021","source":"Nature communications","url":"https://pubmed.ncbi.nlm.nih.gov/34272366","citation_count":73,"is_preprint":false},{"pmid":"11832336","id":"PMC_11832336","title":"PKA-dependent activation of PDE3A and PDE4 and inhibition of adenylyl cyclase V/VI in smooth muscle.","date":"2002","source":"American journal of physiology. 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reports","url":"https://pubmed.ncbi.nlm.nih.gov/39435735","citation_count":6,"is_preprint":false},{"pmid":"1314573","id":"PMC_1314573","title":"Insulin and isoproterenol induce phosphorylation of the particulate cyclic GMP-inhibited, low Km cyclic AMP phosphodiesterase (cGI PDE) in 3T3-L1 adipocytes.","date":"1992","source":"Biochemical and biophysical research communications","url":"https://pubmed.ncbi.nlm.nih.gov/1314573","citation_count":6,"is_preprint":false},{"pmid":"25493569","id":"PMC_25493569","title":"PDE3A-SLCO1C1 locus is associated with response to anti-tumor necrosis factor therapy in psoriatic arthritis.","date":"2014","source":"Pharmacogenomics","url":"https://pubmed.ncbi.nlm.nih.gov/25493569","citation_count":6,"is_preprint":false},{"pmid":"38001568","id":"PMC_38001568","title":"PDE3A Is a Highly Expressed Therapy Target in Myxoid Liposarcoma.","date":"2023","source":"Cancers","url":"https://pubmed.ncbi.nlm.nih.gov/38001568","citation_count":5,"is_preprint":false},{"pmid":"27765510","id":"PMC_27765510","title":"Synthesis of linear and angular aryl-morpholino-naphth-oxazines, their DNA-PK, PI3K, PDE3A and antiplatelet activity.","date":"2016","source":"Bioorganic & medicinal chemistry letters","url":"https://pubmed.ncbi.nlm.nih.gov/27765510","citation_count":5,"is_preprint":false},{"pmid":"37296663","id":"PMC_37296663","title":"CRISPR/Cas9 Knock-Out in Primary Neonatal and Adult Cardiomyocytes Reveals Distinct cAMP Dynamics Regulation by Various PDE2A and PDE3A Isoforms.","date":"2023","source":"Cells","url":"https://pubmed.ncbi.nlm.nih.gov/37296663","citation_count":4,"is_preprint":false},{"pmid":"31589936","id":"PMC_31589936","title":"PDE3A variant associated with hypertension and brachydactyly syndrome in a patient with ischemic stroke caused by spontaneous intracranial artery dissection: A review of the clinical and molecular genetic features.","date":"2019","source":"European journal of medical genetics","url":"https://pubmed.ncbi.nlm.nih.gov/31589936","citation_count":4,"is_preprint":false},{"pmid":"38244313","id":"PMC_38244313","title":"ALDOA coordinates PDE3A through the β-catenin/ID3 axis to stimulate cancer metastasis and M2 polarization in lung cancer with EGFR mutations.","date":"2024","source":"Biochemical and biophysical research communications","url":"https://pubmed.ncbi.nlm.nih.gov/38244313","citation_count":4,"is_preprint":false},{"pmid":"28838830","id":"PMC_28838830","title":"Synthesis and biological evaluation of 8-aryl-2-morpholino-7-O-substituted benzo[e][1,3]oxazin-4-ones against DNA-PK, PI3K, PDE3A enzymes and platelet aggregation.","date":"2017","source":"Bioorganic & medicinal chemistry","url":"https://pubmed.ncbi.nlm.nih.gov/28838830","citation_count":4,"is_preprint":false},{"pmid":"36979891","id":"PMC_36979891","title":"PDE3A and GSK3B as Atrial Fibrillation Susceptibility Genes in the Chinese Population via Bioinformatics and Genome-Wide Association Analysis.","date":"2023","source":"Biomedicines","url":"https://pubmed.ncbi.nlm.nih.gov/36979891","citation_count":4,"is_preprint":false},{"pmid":"40497949","id":"PMC_40497949","title":"PDE3A as a Therapeutic Target for the Modulation of Compartmentalised Cyclic Nucleotide-Dependent Signalling.","date":"2025","source":"Cells","url":"https://pubmed.ncbi.nlm.nih.gov/40497949","citation_count":2,"is_preprint":false},{"pmid":"32631253","id":"PMC_32631253","title":"Whole-exome sequencing identifies a de novo PDE3A variant causing autosomal dominant hypertension with brachydactyly type E syndrome: a case report.","date":"2020","source":"BMC medical genetics","url":"https://pubmed.ncbi.nlm.nih.gov/32631253","citation_count":2,"is_preprint":false},{"pmid":"40563987","id":"PMC_40563987","title":"IGF2BP3 Modulates mRNA Splicing and Stability to Promote Trophoblast Progression via Interaction with PDE3A and Suppression by miR-196a-5p in Preeclampsia.","date":"2025","source":"Biomedicines","url":"https://pubmed.ncbi.nlm.nih.gov/40563987","citation_count":1,"is_preprint":false},{"pmid":"41726589","id":"PMC_41726589","title":"The Role of PDE3A in Cancer.","date":"2026","source":"ACS omega","url":"https://pubmed.ncbi.nlm.nih.gov/41726589","citation_count":0,"is_preprint":false},{"pmid":"42047795","id":"PMC_42047795","title":"Pan-cancer ex vivo target evaluation of phosphodiesterase 3 A (PDE3A).","date":"2026","source":"Journal of molecular medicine (Berlin, Germany)","url":"https://pubmed.ncbi.nlm.nih.gov/42047795","citation_count":0,"is_preprint":false},{"pmid":"38845116","id":"PMC_38845116","title":"RETRACTION: Lack of MicroRNA-155 Ameliorates Renal Fibrosis by Targeting PDE3A/TGF-β1/Smad Signaling in Mice with Obstructive Nephropathy.","date":"2024","source":"Cell biology international","url":"https://pubmed.ncbi.nlm.nih.gov/38845116","citation_count":0,"is_preprint":false},{"pmid":"41673703","id":"PMC_41673703","title":"AR-mediated YBX3 suppresses oocyte meiotic resumption in polycystic ovary syndrome by attenuating Pde3A and Ccnb1 expression.","date":"2026","source":"Journal of ovarian research","url":"https://pubmed.ncbi.nlm.nih.gov/41673703","citation_count":0,"is_preprint":false},{"pmid":null,"id":"bio_10.1101_2025.04.10.648087","title":"Phosphodiesterase 3A modulators sensitize tumor cells to Bcl-xL and Bcl-2/Bcl-xL inhibitors","date":"2025-04-10","source":"bioRxiv","url":"https://doi.org/10.1101/2025.04.10.648087","citation_count":0,"is_preprint":true},{"pmid":null,"id":"bio_10.1101_2025.03.24.645113","title":"β-aminopropionitrile-induced thoracic aortopathy is refractory to cilostazol and sildenafil in mice","date":"2025-03-27","source":"bioRxiv","url":"https://doi.org/10.1101/2025.03.24.645113","citation_count":0,"is_preprint":true},{"pmid":null,"id":"bio_10.1101_2024.06.27.24309406","title":"Transcriptome- and proteome-wide Mendelian randomization to prioritize therapeutic targets for coronary heart disease","date":"2024-06-28","source":"bioRxiv","url":"https://doi.org/10.1101/2024.06.27.24309406","citation_count":0,"is_preprint":true}],"cost":{"stage1":{"model":"claude-sonnet-4-6","input_tokens":40108,"output_tokens":7485,"usd":0.1163,"stage1_stop_reason":"end_turn"},"stage2":{"model":"claude-opus-4-8","input_tokens":16600,"output_tokens":7295,"usd":0.132688,"stage2_stop_reason":"end_turn"},"total_usd":0.248988,"stage1_batch_id":"msgbatch_013a8chtv3AWyTqv4z4sEF4C","stage2_batch_id":"msgbatch_01AHsuW63vinsvuTgzmQ3n62","note":"batch pricing = 50% of standard"},"stage1_raw":"```json\n{\n  \"discoveries\": [\n    {\n      \"year\": 2002,\n      \"finding\": \"Three PDE3A isoforms exist in cardiac myocytes (PDE3A-136, PDE3A-118, PDE3A-94) differing in N-terminal sequence containing membrane-association domains and phosphorylation/activation sites for PKB and PKA. PDE3A-136 contains both membrane-association domains and PKB/PKA sites; PDE3A-118 contains only the downstream membrane-association domain and PKA sites; PDE3A-94 lacks both membrane localization domains and PKB/PKA sites. They are translated from two mRNAs derived from the PDE3A1 gene via alternative transcriptional and post-transcriptional processing.\",\n      \"method\": \"Antibodies to different regions of PDE3A, Western blotting, in vitro transcription/translation\",\n      \"journal\": \"The Journal of biological chemistry\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1-2 / Strong — multiple orthogonal methods (isoform-specific antibodies, in vitro translation, multiple deletion constructs) in a single focused study establishing isoform structure and localization determinants\",\n      \"pmids\": [\"12154085\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2006,\n      \"finding\": \"PKB/Akt phosphorylates PDE3A and activates its cAMP-hydrolytic activity. Phosphorylation of serines 290-292 is required for PKB/Akt-dependent activation of PDE3A and for PKB/Akt-induced meiotic maturation of both Xenopus and mouse oocytes. Microinjection of constitutively active Myr-Akt into mouse oocytes causes meiotic maturation in a PDE3A-dependent manner.\",\n      \"method\": \"Cell-free kinase assay with recombinant PKB/Akt and PKA, co-expression in Xenopus oocytes, serine-to-alanine mutagenesis, microinjection of myr-Akt into mouse oocytes, pde3a(-/-) rescue assays\",\n      \"journal\": \"The EMBO journal\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 / Strong — in vitro reconstitution with recombinant proteins, site-directed mutagenesis, and in vivo rescue experiments across two species (Xenopus and mouse)\",\n      \"pmids\": [\"17124499\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 1998,\n      \"finding\": \"PDE3A in rat vascular smooth muscle cells is expressed as a 120 kDa protein found only in the cytosolic fraction, whereas PDE3B is expressed as a 135 kDa protein restricted to the particulate fraction. Prolonged incubation with cAMP-elevating agents (forskolin or 8-bromo-cAMP) produced time-dependent increases in PDE3 activity correlating with increased PDE3A and PDE3B signals and a marked increase in particulate PDE3 activity.\",\n      \"method\": \"RT-PCR with isoform-specific primers, immunoblotting with PDE3-selective antisera, subcellular fractionation\",\n      \"journal\": \"British journal of pharmacology\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — reciprocal fractionation plus RT-PCR, single lab, two orthogonal methods\",\n      \"pmids\": [\"9884079\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2015,\n      \"finding\": \"PDE3A1 forms a multiprotein signalosome in human sarcoplasmic reticulum (SR) with SERCA2, phospholamban (PLB), and AKAP18. PKA phosphorylation of PDE3A increases its cAMP-hydrolytic activity, promotes its association with SERCA2/AKAP18 signalosomes, and modulates PLB phosphorylation and SERCA2 activity. Ser-292/Ser-293, a site unique to PDE3A1, is the principal site regulating interaction with SERCA2. Deletion of the PDE3A1/PDE3A2 N-terminus blocks interactions with SERCA2.\",\n      \"method\": \"Co-immunoprecipitation of endogenous and recombinant proteins, gel filtration chromatography, PKA phosphorylation assays, serine-to-alanine substitution mutagenesis, N-terminal deletion mutants, immunohistochemical staining, SERCA2 activity assay\",\n      \"journal\": \"The Journal of biological chemistry\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 / Strong — multiple orthogonal methods (co-IP, recombinant protein reconstitution, mutagenesis, enzyme activity assay) in a single rigorous study identifying specific regulatory phosphorylation site\",\n      \"pmids\": [\"25593322\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2015,\n      \"finding\": \"PDE3A gain-of-function missense mutations (six families) cause autosomal dominant hypertension with brachydactyly. The mutations increase PKA-mediated phosphorylation of PDE3A, resulting in increased cAMP-hydrolytic activity and enhanced cell proliferation in mesenchymal stem cell-derived VSMCs and chondrocytes. Levels of phosphorylated VASP were diminished and PTHrP levels were dysregulated.\",\n      \"method\": \"In vitro analyses of mesenchymal stem cell-derived VSMCs and chondrocytes, cAMP-hydrolytic activity assays, phosphorylation assays, VASP phosphorylation measurement, PTHrP measurement\",\n      \"journal\": \"Nature genetics\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — functional gain-of-function analysis in disease-relevant cell types with multiple biochemical readouts, replicated across six independent families\",\n      \"pmids\": [\"25961942\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2015,\n      \"finding\": \"DNMDP binding to PDE3A promotes a neomorphic interaction between PDE3A and Schlafen 12 (SLFN12). Co-expression of SLFN12 with PDE3A correlates with cancer cell sensitivity to DNMDP; depletion of either PDE3A or SLFN12 confers DNMDP resistance. PDE3A depletion alone also causes resistance.\",\n      \"method\": \"Phenotypic compound library screening across 766 cancer cell lines, target deconvolution by predictive chemogenomics, PDE3A depletion (knockdown), SLFN12 depletion, correlation of PDE3A gene expression with compound sensitivity\",\n      \"journal\": \"Nature chemical biology\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — large-scale chemogenomic screening, genetic depletion experiments, and direct interaction evidence across multiple cell lines and methods\",\n      \"pmids\": [\"26656089\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2021,\n      \"finding\": \"PDE3A and SLFN12 form a heterotetramer stabilized by DNMDP binding. Interactions between the C-terminal alpha helix of SLFN12 and residues near the active site of PDE3A are required for complex formation, further stabilized by SLFN12-DNMDP interactions. PDE3A binding activates SLFN12 RNase activity, and this RNase activity is required for DNMDP-induced cytotoxicity.\",\n      \"method\": \"Cryo-EM structure of PDE3A-SLFN12 complex, mutagenesis of interaction interface, SLFN12 RNase activity assay, cell viability assay with RNase-dead SLFN12 mutants\",\n      \"journal\": \"Nature communications\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 / Strong — cryo-EM structure combined with mutagenesis and functional RNase activity assays in a single rigorous study\",\n      \"pmids\": [\"34272366\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2021,\n      \"finding\": \"High-resolution cryo-EM structures of PDE3A-SLFN12 complexes with anagrelide, nauclefine, or DNMDP show a butterfly-shaped heterotetramer. Small molecules are packed in a shallow pocket in the catalytic domain of PDE3A, and the resulting compound-modified interface binds the short helix (E552-I558) of SLFN12 through hydrophobic interactions, gluing the two proteins together. SLFN12 blocks protein translation leading to apoptosis.\",\n      \"method\": \"Cryo-EM structure determination from HeLa cells pre-treated with molecular glues, structure-guided analog synthesis, cell viability and apoptosis assays, tumor xenograft experiments\",\n      \"journal\": \"Nature communications\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 / Strong — high-resolution cryo-EM structure with structure-guided mutagenesis and in vivo xenograft validation\",\n      \"pmids\": [\"34707099\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2009,\n      \"finding\": \"Platelet agonists (including thrombin via PAR-1) stimulate PKC-dependent phosphorylation of PDE3A on Ser-312, Ser-428, Ser-438, Ser-465, and Ser-492, leading to increased cAMP hydrolysis and 14-3-3 protein binding. This phosphorylation and PDE3A activation required PKC but not PI3K/PKB, mTOR/p70S6K, or ERK/RSK. IGF-1, which activates PI3K/PKB but not PKC, did not regulate PDE3A.\",\n      \"method\": \"Phosphoproteomics/mass spectrometry mapping of phosphorylation sites, PKC inhibitors and phorbol ester activation, immunoprecipitation of 14-3-3/PDE3A complex, cAMP hydrolysis activity assay, platelet activation assays\",\n      \"journal\": \"The Journal of biological chemistry\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — mass spectrometry phosphosite mapping combined with pharmacological pathway dissection and functional activity assays in a single study with multiple orthogonal methods\",\n      \"pmids\": [\"19261611\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2002,\n      \"finding\": \"PKA stimulates phosphorylation and activation of PDE3A in gastric smooth muscle cells. Sodium nitroprusside (via cGMP) inhibits PDE3 activity and augments cAMP levels; this PDE3 inhibition is reversed by blockade of cGMP synthesis, demonstrating cGMP-mediated inhibition of PDE3A.\",\n      \"method\": \"RT-PCR and Western blot for PDE3A/PDE3B expression, PDE3A phosphorylation assay with PKA activators and inhibitors (PKI, H-89, KT-5823), PDE3 activity assay, cAMP measurement\",\n      \"journal\": \"American journal of physiology. Cell physiology\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — biochemical activity and phosphorylation assays in primary smooth muscle cells, single lab, two orthogonal approaches\",\n      \"pmids\": [\"11832336\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2011,\n      \"finding\": \"PDE3A deletion in murine VSMCs suppresses MAPK signaling via two complementary pathways: PKA-catalyzed inhibitory phosphorylation of Raf-1 (Ser-259) with resulting ERK inhibition, and PKA/CREB-mediated induction of p21, leading to G0/G1 cell cycle arrest. PDE3A-KO VSMCs also showed elevated p53 accumulation, increased MKP-1, lower Cyclin-D1, and reduced Rb phosphorylation. p53 siRNA in 3A-KO VSMCs restored growth without affecting Cyclin-D1/Rb phosphorylation; dominant-negative CREB partially restored growth.\",\n      \"method\": \"PDE3A-KO mouse-derived VSMCs, serum/PDGF-induced DNA synthesis assay, ERK and Raf-1 phosphorylation analysis, cell cycle analysis, adenoviral overexpression of CREB constructs, p53 siRNA transfection\",\n      \"journal\": \"The Journal of biological chemistry\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — genetic KO model with multiple mechanistic interventions (siRNA, adenoviral rescue, pathway-specific inhibitors) in disease-relevant cell type\",\n      \"pmids\": [\"21632535\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2010,\n      \"finding\": \"PDE3A physically and functionally interacts with CFTR channel at the plasma membrane. PDE3A inhibition generates compartmentalized cAMP that clusters PDE3A and CFTR into plasma membrane microdomains and potentiates CFTR channel function. Actin skeleton disruption reduces PDE3A-CFTR interaction and compromises compartmentalized cAMP signaling and CFTR channel activation.\",\n      \"method\": \"Co-immunoprecipitation of PDE3A and CFTR, patch-clamp electrophysiology, actin disruption experiments, pig trachea submucosal gland secretion model\",\n      \"journal\": \"Molecular biology of the cell\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — reciprocal co-IP plus functional electrophysiology in a physiological gland secretion model, single lab\",\n      \"pmids\": [\"20089840\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2001,\n      \"finding\": \"Mouse oocytes express a soluble form of PDE3A. Full-length recombinant PDE3A partitions to the particulate fraction, while N-terminal truncation forms (Delta 1 and Delta 2) are recovered mostly in the soluble fraction, identifying the N-terminus as the membrane-targeting domain. The Km values for cAMP hydrolysis by truncated forms are similar to those of full-length PDE3A (0.2-0.5 μM).\",\n      \"method\": \"cDNA cloning from mouse oocyte library, expression in Leydig tumor cells, subcellular fractionation, kinetic analysis, pharmacological profiling of recombinant enzyme vs oocyte PDE\",\n      \"journal\": \"Biology of reproduction\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — functional expression with deletion constructs and subcellular fractionation, single lab\",\n      \"pmids\": [\"11420239\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2000,\n      \"finding\": \"Conserved histidines H752, H756, and glutamate E825 in the first metal-binding motif are essential for PDE3A catalytic activity (kcat near zero when mutated to alanine). E866A mutation increases Km for cAMP 11-fold and Ki for cGMP 27-fold, suggesting a role in substrate/inhibitor binding. H836A mutation raises Ki for cGMP 177-fold. cAMP and cGMP binding sites in PDE3A are overlapping but not identical, involving common and different amino acids.\",\n      \"method\": \"Site-directed mutagenesis, baculovirus/Sf9 expression, kinetic analysis (kcat, Km, Ki determination), metal ion-free assay supplemented with Mn2+, Mg2+, or Co2+\",\n      \"journal\": \"Blood\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 / Moderate — systematic mutagenesis of catalytic residues combined with detailed kinetic analysis, single lab but multiple mutants with orthogonal readouts\",\n      \"pmids\": [\"10828019\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 1996,\n      \"finding\": \"The PDE3A catalytic domain is localized to within amino acid residues 679-1141. Deletion mutants encoding residues 665-1141 and 679-1141 display PDE activity, while those starting at residue 686 or later lose detectable activity.\",\n      \"method\": \"Deletion mutagenesis, expression in PDE-deficient yeast (Saccharomyces cerevisiae), PDE activity assay, Western blotting\",\n      \"journal\": \"Blood\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 1 / Moderate — systematic deletion mapping in functional yeast expression system, single lab\",\n      \"pmids\": [\"8695850\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 1998,\n      \"finding\": \"Histidine H840 (second histidine in HDXXH motif) is essential for PDE3A catalytic activity (mutation to alanine abolishes activity), likely required for bivalent cation binding. H869A mutation reduces affinity for cAMP and cGMP (4-fold increases in Km and IC50 for cGMP), identifying it as part of the inhibitory binding site. Cysteine C816 (in the 44-aa insert unique to PDE3) is required for proper protein folding.\",\n      \"method\": \"Site-directed mutagenesis, expression in PDE-deficient yeast, kinetic analysis (kcat, Km, IC50 for cGMP and milrinone), Western blotting\",\n      \"journal\": \"Archives of biochemistry and biophysics\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 1 / Moderate — active-site mutagenesis with kinetic characterization, single lab, systematic approach\",\n      \"pmids\": [\"9826434\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2013,\n      \"finding\": \"PDE3A1 and PDE3A2 isoforms are selectively phosphorylated through different signaling pathways with distinct functional consequences. Isoproterenol (PKA activation) phosphorylates PDE3A1 at S312 (14-3-3-binding site), while PMA (PKC activation) phosphorylates PDE3A2 at alternative 14-3-3-binding site S428. PDE3A2 activity is stimulated by phosphorylation at S428, whereas PDE3A1 activity is not affected by phosphorylation at either site. The two isoforms have distinct protein interactomes revealed by 2D electrophoresis of co-immunoprecipitated proteins.\",\n      \"method\": \"FLAG-tagged PDE3A1 and PDE3A2 expression in HEK293 cells, gel filtration chromatography, 2D electrophoresis, co-immunoprecipitation, phospho-specific analysis with isoproterenol and PMA, PDE activity assay\",\n      \"journal\": \"Proceedings of the National Academy of Sciences of the United States of America\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — multiple orthogonal methods (gel filtration, co-IP, proteomic analysis, activity assay) in engineered and endogenous human myocardium systems, validated in two cell types\",\n      \"pmids\": [\"24248367\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2010,\n      \"finding\": \"In PDE3A(-/-) oocytes arrested at G2/M, elevated PKA activity is associated with inactivation of Cdc2 and Plk1, and inhibition of histone H3 (S10) phosphorylation and dephosphorylation of Cdc25B (S323) and Cdc2 (Thr14/Tyr15). PKAc phosphorylates recombinant Plk1 and inhibits Plk1 activity in vitro. PDE3A co-localizes with and co-immunoprecipitates with Plk1 in WT ovary and HeLa cells. PKA inhibitor (Rp-cAMPS) reactivates Plk1 in PDE3A(-/-) oocytes.\",\n      \"method\": \"PDE3A(-/-) mouse model, co-immunoprecipitation, co-localization imaging, in vitro Plk1 phosphorylation assay with recombinant PKAc, PKA inhibitor rescue experiment\",\n      \"journal\": \"Cell cycle (Georgetown, Tex.)\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — KO mouse model combined with co-IP, in vitro kinase assay, and pharmacological rescue, single lab\",\n      \"pmids\": [\"21099356\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2016,\n      \"finding\": \"PDE3A hydrolyzes cUMP with a Km of ~143 μM and Vmax of ~42 μmol/min/mg (low-affinity, high-velocity substrate). For comparison, cAMP is hydrolyzed with Km ~0.7 μM and Vmax ~1.2 μmol/min/mg. The PDE3 inhibitor milrinone inhibits cUMP hydrolysis (Ki = 57 nM).\",\n      \"method\": \"Enzyme kinetics (Michaelis-Menten analysis), HPLC-tandem mass spectrometry measurement of UMP and AMP formation, milrinone inhibition assay\",\n      \"journal\": \"Naunyn-Schmiedeberg's archives of pharmacology\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 1 / Moderate — in vitro enzyme kinetics with mass spectrometry product detection, single lab\",\n      \"pmids\": [\"27975297\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2015,\n      \"finding\": \"PDE3A-IBMX-resin chemical proteomics in HeLa cells identified 14-3-3 proteins as PDE3A interactors, and revealed that PDE3A associates with a PP2A complex composed of regulatory, scaffold, and catalytic subunits.\",\n      \"method\": \"Chemical proteomics with IBMX-based affinity resin, selective competition with cilostamide and papaverine, mass spectrometry identification of co-captured proteins in HeLa cell lysates\",\n      \"journal\": \"Molecular bioSystems\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — affinity-based chemical proteomics with competitor selectivity validation, single lab\",\n      \"pmids\": [\"26205238\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2017,\n      \"finding\": \"SFPQ (splicing factor proline and glutamine rich) protein modulates PDE3A mRNA levels and functions as a transcriptional activator of PDE3A. Multiple transcription start sites (TSS1, 2, 3) were identified within the first exon of PDE3A. Serum-induced PDE3A expression was affected by increasing SFPQ binding to the upstream regulatory region, as demonstrated by ChIP-seq.\",\n      \"method\": \"5'-RACE to map transcription start sites, ChIP-seq for SFPQ binding sites, SFPQ overexpression/knockdown with mRNA measurement, RT-PCR\",\n      \"journal\": \"Bioscience reports\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — ChIP-seq plus functional expression studies, single lab\",\n      \"pmids\": [\"28743736\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2019,\n      \"finding\": \"ATF3 transcription factor binds to a 29-nucleotide insertion (INS) in the PDE3A promoter and represses cAMP-dependent promoter activity. The INS also represses a cAMP response element enhancer 61 nt downstream. In failing hearts homozygous for the DEL genotype treated with PDE3 inhibitors, PDE3A1 mRNA and microsomal PDE3 enzyme activity were increased ~1.7-1.8 fold, consistent with derepression of the cAMP response element.\",\n      \"method\": \"Luciferase reporter assay with cloned PDE3A promoter variants, transcription factor binding analysis (ATF3), RT-PCR of explanted failing LVs, PDE3 enzyme activity measurement\",\n      \"journal\": \"Journal of the American College of Cardiology\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — reporter assay plus human tissue validation, single lab, two orthogonal methods\",\n      \"pmids\": [\"30871701\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2020,\n      \"finding\": \"In human pulmonary artery smooth muscle cells (hPASMC), nitric oxide (NO) increases PDE3A protein expression and PDE3 activity via the soluble guanylate cyclase (sGC)-cGMP pathway, leading to decreased cAMP and activation of AMPK. Knockdown of PDE3A with siRNA blunts NO-induced AMPK activation, demonstrating PDE3A as an intermediary between NO/cGMP signaling and AMPK regulation.\",\n      \"method\": \"siRNA knockdown of PDE3A in hPASMC, Western blotting for AMPK phosphorylation, cAMP measurement, sGC stimulator and inhibitor pharmacology, PDE3 activity assay\",\n      \"journal\": \"Physiological reports\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — siRNA knockdown with mechanistic pathway dissection using pharmacological tools, single lab\",\n      \"pmids\": [\"32914566\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2022,\n      \"finding\": \"Cytotoxic PDE3A modulators (molecular glues) promote PDE3A-SLFN12 interaction, increasing SLFN12 protein stability in the cytoplasm and inducing SLFN12 dephosphorylation at Ser-368 and Ser-573. This dephosphorylation is required for cell death. Dephosphorylation promotes the rRNA RNase activity of SLFN12, which is essential for SLFN12's cell-death-inducing function.\",\n      \"method\": \"Mutational analysis of SLFN12 phosphorylation sites, co-immunoprecipitation, cell death assays, SLFN12 RNase activity assay, protein stability assays\",\n      \"journal\": \"Cell chemical biology\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1-2 / Moderate — mutagenesis, RNase assay, co-IP, and functional cell death assays with multiple orthogonal methods in a single study\",\n      \"pmids\": [\"35104454\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2001,\n      \"finding\": \"A vascular smooth muscle cell-specific PDE3A isoform ('PDE3A2') lacks the N-terminal 145 amino acids present in the myocardial isoform (PDE3A1) and is a product of the same gene, generated pre-translationally. The recombinant protein has a molecular mass of ~131 kDa, consistent with translation from an ATG at nt 436-438 of the myocardial PDE3A coding region.\",\n      \"method\": \"cDNA cloning from aortic myocytes, RT-PCR, 5'-RACE, RNase protection assay, Sf9 cell expression, Western blotting with region-specific antibodies\",\n      \"journal\": \"The Biochemical journal\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — multiple molecular techniques to characterize isoform structure and translational origin, single lab\",\n      \"pmids\": [\"11115397\"],\n      \"is_preprint\": false\n    }\n  ],\n  \"current_model\": \"PDE3A is a cGMP-inhibited cAMP phosphodiesterase expressed in multiple isoforms (PDE3A1/2/3) that differ in N-terminal length determining membrane association and phosphorylation by PKA, PKC, and PKB/Akt; PKA/PKC phosphorylation at specific serine residues (including Ser-292/293 in PDE3A1) regulates its catalytic activity, subcellular localization, 14-3-3/PP2A binding, and incorporation into SERCA2/AKAP18 signalosomes in cardiac SR; in oocytes, PKB/Akt-mediated phosphorylation at Ser-290-292 activates PDE3A to lower cAMP and enable meiotic resumption, while gain-of-function mutations causing HTNB syndrome hyperactivate PDE3A via increased PKA-mediated phosphorylation, enhancing VSMC proliferation; additionally, certain PDE3A modulators act as molecular glues to induce a PDE3A-SLFN12 heterotetramer wherein the compound-modified PDE3A active site recruits SLFN12's C-terminal helix, activating SLFN12 RNase activity (requiring SLFN12 dephosphorylation) that cleaves rRNA/tRNA to cause cancer cell apoptosis.\"\n}\n```","stage2_raw":"{\n  \"mechanistic_narrative\": \"PDE3A is a cGMP-inhibited, cAMP-hydrolyzing phosphodiesterase that sets local cyclic-nucleotide tone within signalosomes controlling smooth muscle proliferation, cardiac contractility, oocyte meiosis, and—when pharmacologically subverted—cancer cell death [#3, #4, #10]. The enzyme is expressed as multiple isoforms (PDE3A1/PDE3A2/PDE3A-94 and related forms) generated pre-translationally from a single gene; their differing N-termini contain membrane-association domains that determine soluble versus particulate localization, with N-terminal truncation shifting the enzyme to the cytosol [#0, #12, #24]. Catalysis depends on a metal-binding active site in residues ~679–1141 in which conserved histidines and glutamates (H752, H756, H840, E825) are required for turnover while residues such as E866/H836/H869 govern cAMP and cGMP binding at overlapping but non-identical sites [#13, #14, #15]; the enzyme hydrolyzes cAMP with high affinity and can also turn over cUMP as a low-affinity substrate [#18]. PDE3A activity, localization, and partner binding are tuned by phosphorylation: PKA, PKC, and PKB/Akt phosphorylate distinct serines in an isoform-selective manner, creating 14-3-3 binding sites and controlling incorporation into a sarcoplasmic-reticulum SERCA2/AKAP18/phospholamban signalosome where PKA phosphorylation of the PDE3A1-unique Ser-292/293 promotes SERCA2 association and modulates SERCA2 activity [#1, #3, #8, #16]. Through compartmentalized cAMP, PDE3A restrains the PKA→Raf-1/ERK and PKA/CREB→p21 axes to permit vascular smooth muscle proliferation, and dominant gain-of-function missense mutations that increase PKA-mediated phosphorylation and cAMP hydrolysis cause autosomal-dominant hypertension with brachydactyly by enhancing VSMC and chondrocyte proliferation [#4, #10]. In oocytes, PKB/Akt phosphorylation at Ser-290–292 activates PDE3A to lower cAMP and drive meiotic resumption, coupling to Plk1/Cdc2 control [#1, #17]. PDE3A is also a druggable scaffold: small-molecule 'molecular glues' such as DNMDP occupy a pocket in the PDE3A catalytic domain and create a neomorphic interface that recruits the C-terminal helix of Schlafen 12 (SLFN12) into a butterfly-shaped heterotetramer, activating SLFN12 RNase activity—dependent on SLFN12 dephosphorylation—to block translation and trigger cancer cell apoptosis [#5, #6, #7, #23].\",\n  \"teleology\": [\n    {\n      \"year\": 1996,\n      \"claim\": \"Defining where catalysis resides was the first step toward understanding PDE3A as an enzyme; deletion mapping localized the catalytic domain to a discrete C-terminal region.\",\n      \"evidence\": \"Deletion mutagenesis expressed in PDE-deficient yeast with activity assays\",\n      \"pmids\": [\"8695850\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Does not identify catalytic residues\", \"No structural model of the active site\"]\n    },\n    {\n      \"year\": 1998,\n      \"claim\": \"To explain catalysis and inhibitor selectivity, active-site residues were tested; specific histidines were shown essential for activity and metal coordination while another residue defined the inhibitory binding site, and a unique cysteine was required for folding.\",\n      \"evidence\": \"Site-directed mutagenesis in yeast with kinetic analysis of cGMP and milrinone inhibition\",\n      \"pmids\": [\"9826434\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Roles inferred from kinetics without crystal structure\", \"Metal coordination geometry not directly resolved\"]\n    },\n    {\n      \"year\": 1998,\n      \"claim\": \"Establishing the cellular context, PDE3A and PDE3B were shown to occupy distinct subcellular compartments in vascular smooth muscle and to be upregulated by sustained cAMP elevation.\",\n      \"evidence\": \"Isoform-specific RT-PCR, immunoblotting, and subcellular fractionation in rat VSMCs\",\n      \"pmids\": [\"9884079\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Mechanism of cAMP-induced upregulation unresolved\", \"Functional consequence of compartmentalization not defined\"]\n    },\n    {\n      \"year\": 2000,\n      \"claim\": \"Extending the active-site model, systematic mutagenesis showed cAMP and cGMP bind overlapping but non-identical residues, explaining how cGMP can act as a competitive inhibitor.\",\n      \"evidence\": \"Site-directed mutagenesis in Sf9 cells with kcat/Km/Ki determination under defined metal conditions\",\n      \"pmids\": [\"10828019\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"No structural visualization of the dual binding mode\", \"Does not address allosteric regulation by phosphorylation\"]\n    },\n    {\n      \"year\": 2001,\n      \"claim\": \"The structural basis of localization was traced to the N-terminus; truncation forms partition to cytosol while retaining catalytic kinetics, and a VSMC-specific isoform lacking the N-terminal 145 residues was shown to arise pre-translationally from the same gene.\",\n      \"evidence\": \"cDNA cloning, expression with fractionation and kinetics in oocyte and aortic myocyte systems\",\n      \"pmids\": [\"11420239\", \"11115397\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Membrane-targeting sequence not mapped at residue level\", \"Tissue-specific isoform regulation mechanism unclear\"]\n    },\n    {\n      \"year\": 2002,\n      \"claim\": \"Isoform architecture was systematically defined, linking distinct N-termini to membrane-association domains and to differential PKA/PKB phosphorylation site content, framing isoforms as functionally specialized.\",\n      \"evidence\": \"Isoform-specific antibodies, Western blotting, and in vitro transcription/translation in cardiac myocytes\",\n      \"pmids\": [\"12154085\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Functional consequences of each phospho-site not yet tested\", \"In vivo isoform-specific roles undefined\"]\n    },\n    {\n      \"year\": 2002,\n      \"claim\": \"Reciprocal regulation by cyclic nucleotides was demonstrated in smooth muscle: PKA activates PDE3A while cGMP inhibits it, establishing PDE3A as a node integrating cAMP and cGMP signaling.\",\n      \"evidence\": \"Phosphorylation and activity assays with PKA and cGMP-synthesis modulators in gastric smooth muscle cells\",\n      \"pmids\": [\"11832336\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Phosphosite mediating PKA activation not mapped here\", \"Stoichiometry of cGMP inhibition in cells not quantified\"]\n    },\n    {\n      \"year\": 2006,\n      \"claim\": \"A physiological kinase-substrate link was established: PKB/Akt phosphorylation at Ser-290–292 activates PDE3A and is required for oocyte meiotic resumption, connecting growth-factor signaling to cyclic-nucleotide control of meiosis.\",\n      \"evidence\": \"Cell-free kinase assays, mutagenesis, and myr-Akt microinjection with pde3a(-/-) rescue across Xenopus and mouse oocytes\",\n      \"pmids\": [\"17124499\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Does not resolve downstream cell-cycle effectors\", \"Relative contribution of Akt vs PKA in vivo unquantified\"]\n    },\n    {\n      \"year\": 2009,\n      \"claim\": \"In platelets, agonist signaling was shown to act through PKC—not PI3K/PKB—to phosphorylate multiple PDE3A serines, increasing activity and 14-3-3 binding, demonstrating pathway-selective control of the enzyme.\",\n      \"evidence\": \"Phosphoproteomic site mapping, pharmacological pathway dissection, co-IP, and activity assays in platelets\",\n      \"pmids\": [\"19261611\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Functional role of each individual phosphosite not isolated\", \"How 14-3-3 binding alters localization not shown\"]\n    },\n    {\n      \"year\": 2010,\n      \"claim\": \"PDE3A was placed within a plasma-membrane microdomain controlling an ion channel, showing it physically and functionally couples to CFTR to generate compartmentalized cAMP dependent on the actin cytoskeleton.\",\n      \"evidence\": \"Co-IP, patch-clamp, actin disruption, and gland secretion model\",\n      \"pmids\": [\"20089840\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Direct vs scaffold-mediated PDE3A–CFTR interaction unresolved\", \"Adaptor anchoring PDE3A to actin not identified\"]\n    },\n    {\n      \"year\": 2010,\n      \"claim\": \"The oocyte arrest phenotype was mechanistically linked downstream: loss of PDE3A elevates PKA, which inactivates Plk1 and Cdc2, and PDE3A co-localizes with Plk1, defining the cell-cycle machinery controlled by PDE3A-regulated cAMP.\",\n      \"evidence\": \"PDE3A(-/-) oocytes, co-IP, co-localization, in vitro Plk1 phosphorylation, and PKA-inhibitor rescue\",\n      \"pmids\": [\"21099356\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Whether PDE3A–Plk1 interaction is direct unproven\", \"Physiological role of the interaction beyond meiosis unclear\"]\n    },\n    {\n      \"year\": 2011,\n      \"claim\": \"The proliferative role of PDE3A in vasculature was mechanistically dissected: deleting PDE3A engages two PKA-dependent brakes (Raf-1/ERK inhibition and CREB/p21/p53 induction) to arrest the cell cycle, explaining how PDE3A-controlled cAMP permits VSMC growth.\",\n      \"evidence\": \"PDE3A-KO VSMCs with proliferation assays, pathway analysis, CREB constructs, and p53 siRNA\",\n      \"pmids\": [\"21632535\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Spatial pool of cAMP driving each branch not localized\", \"Relative weight of the two pathways in vivo unquantified\"]\n    },\n    {\n      \"year\": 2013,\n      \"claim\": \"Isoform-selective regulation was demonstrated functionally: PKA and PKC phosphorylate distinct sites on PDE3A1 (S312) versus PDE3A2 (S428), with differential activity effects and distinct interactomes, establishing the isoforms as separately wired signaling units.\",\n      \"evidence\": \"Tagged isoform expression, gel filtration, 2D electrophoresis co-IP, and phospho-specific activity assays in HEK293 and myocardium\",\n      \"pmids\": [\"24248367\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Identities of isoform-specific interactors largely unresolved\", \"In vivo relevance of S312 14-3-3 binding for PDE3A1 unclear\"]\n    },\n    {\n      \"year\": 2015,\n      \"claim\": \"PDE3A was shown to nucleate a cardiac SR signalosome with SERCA2, phospholamban, and AKAP18, with PKA phosphorylation of the PDE3A1-unique Ser-292/293 controlling SERCA2 association and activity, providing a structural basis for local cAMP control of calcium handling.\",\n      \"evidence\": \"Co-IP, gel filtration, PKA phosphorylation, mutagenesis, N-terminal deletions, and SERCA2 activity assays\",\n      \"pmids\": [\"25593322\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Stoichiometry and architecture of the signalosome unresolved\", \"Direct vs AKAP-bridged SERCA2 contact not distinguished\"]\n    },\n    {\n      \"year\": 2015,\n      \"claim\": \"A direct disease link was established: gain-of-function PDE3A mutations cause autosomal-dominant hypertension with brachydactyly by increasing PKA-mediated phosphorylation and cAMP hydrolysis, driving VSMC and chondrocyte proliferation.\",\n      \"evidence\": \"Mutation analysis across six families with functional assays in mesenchymal-derived VSMCs and chondrocytes\",\n      \"pmids\": [\"25961942\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"How mutations increase PKA accessibility structurally unknown\", \"Link between VASP/PTHrP dysregulation and brachydactyly incomplete\"]\n    },\n    {\n      \"year\": 2015,\n      \"claim\": \"A neomorphic pharmacology was discovered: DNMDP binding to PDE3A creates a gain-of-function interaction with SLFN12, with co-expression of both proteins required for cancer-cell sensitivity, reframing PDE3A as a molecular-glue scaffold for cytotoxicity.\",\n      \"evidence\": \"Phenotypic screening across 766 cell lines, chemogenomic deconvolution, and PDE3A/SLFN12 depletion\",\n      \"pmids\": [\"26656089\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Mechanism of SLFN12 activation not yet defined here\", \"Structure of the induced complex not yet resolved\"]\n    },\n    {\n      \"year\": 2015,\n      \"claim\": \"Chemical proteomics confirmed endogenous PDE3A partners, identifying 14-3-3 proteins and a PP2A holoenzyme as associated with PDE3A, expanding its regulatory interactome.\",\n      \"evidence\": \"IBMX-resin affinity capture with competitor selectivity and mass spectrometry in HeLa lysates\",\n      \"pmids\": [\"26205238\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Functional consequence of PP2A association not tested\", \"Direct vs indirect binding not distinguished\"]\n    },\n    {\n      \"year\": 2016,\n      \"claim\": \"The substrate scope was broadened: PDE3A hydrolyzes cUMP as a low-affinity, high-velocity substrate sensitive to milrinone, indicating PDE3A activity is not restricted to cAMP/cGMP.\",\n      \"evidence\": \"Enzyme kinetics with HPLC-MS/MS product detection and milrinone inhibition\",\n      \"pmids\": [\"27975297\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Physiological relevance of cUMP hydrolysis unknown\", \"Cellular cUMP levels not measured\"]\n    },\n    {\n      \"year\": 2017,\n      \"claim\": \"Transcriptional control of PDE3A was addressed: SFPQ acts as a transcriptional activator binding upstream regulatory regions to modulate serum-induced PDE3A mRNA, identifying a determinant of PDE3A expression levels.\",\n      \"evidence\": \"5'-RACE TSS mapping, ChIP-seq, and SFPQ overexpression/knockdown with mRNA measurement\",\n      \"pmids\": [\"28743736\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Whether SFPQ regulation is isoform-selective unclear\", \"Signal coupling serum to SFPQ binding unresolved\"]\n    },\n    {\n      \"year\": 2019,\n      \"claim\": \"Promoter-level regulation in heart was defined: ATF3 binds a promoter insertion to repress cAMP-dependent PDE3A transcription, linking a common indel genotype to PDE3A expression and PDE3-inhibitor response in failing hearts.\",\n      \"evidence\": \"Luciferase reporter assays, ATF3 binding analysis, and RT-PCR/activity in explanted failing left ventricles\",\n      \"pmids\": [\"30871701\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Direct ATF3 occupancy in vivo not shown\", \"Clinical impact of genotype on therapy not established\"]\n    },\n    {\n      \"year\": 2020,\n      \"claim\": \"PDE3A was positioned as an intermediary in vascular NO signaling: NO via sGC/cGMP raises PDE3A expression and activity to lower cAMP and activate AMPK, with PDE3A knockdown blunting AMPK activation.\",\n      \"evidence\": \"siRNA knockdown in hPASMC with cAMP measurement, sGC pharmacology, and AMPK phospho-blotting\",\n      \"pmids\": [\"32914566\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Apparent contrast with direct cGMP inhibition of PDE3A not reconciled\", \"Mechanism of NO-induced PDE3A upregulation unknown\"]\n    },\n    {\n      \"year\": 2021,\n      \"claim\": \"The structural mechanism of the molecular-glue effect was solved: cryo-EM of PDE3A–SLFN12 heterotetramers showed compounds packed in a PDE3A catalytic-domain pocket creating an interface that captures the SLFN12 C-terminal helix and activates SLFN12 RNase activity essential for cytotoxicity.\",\n      \"evidence\": \"Cryo-EM structures with anagrelide/nauclefine/DNMDP, interface mutagenesis, RNase and viability assays, and xenografts\",\n      \"pmids\": [\"34272366\", \"34707099\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"RNA substrate specificity of activated SLFN12 not fully mapped\", \"Why only certain cells are sensitive beyond SLFN12 expression unclear\"]\n    },\n    {\n      \"year\": 2022,\n      \"claim\": \"The activation switch downstream of complex formation was identified: glue-induced PDE3A binding stabilizes SLFN12 and drives its dephosphorylation at Ser-368/Ser-573, which is required to unleash its rRNA RNase activity and cell death.\",\n      \"evidence\": \"SLFN12 phosphosite mutagenesis, co-IP, stability, RNase, and cell-death assays\",\n      \"pmids\": [\"35104454\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Phosphatase responsible for SLFN12 dephosphorylation unidentified\", \"How PDE3A binding triggers dephosphorylation unresolved\"]\n    },\n    {\n      \"year\": null,\n      \"claim\": \"How the multiple regulatory layers—isoform-specific phosphorylation, signalosome assembly, transcriptional control, and cGMP inhibition—are integrated to shape spatially distinct cAMP pools in a given cell type remains undefined, as does the endogenous physiological role (if any) of the PDE3A–SLFN12 axis.\",\n      \"evidence\": \"\",\n      \"pmids\": [],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"No full-length multi-isoform structure with phosphorylation states\", \"Endogenous trigger for PDE3A–SLFN12 interaction unknown\", \"Integrated quantitative model of compartmentalized cAMP lacking\"]\n    }\n  ],\n  \"mechanism_profile\": {\n    \"molecular_activity\": [\n      {\"term_id\": \"GO:0016787\", \"supporting_discovery_ids\": [13, 18]},\n      {\"term_id\": \"GO:0140098\", \"supporting_discovery_ids\": [13, 18]},\n      {\"term_id\": \"GO:0098772\", \"supporting_discovery_ids\": [3, 6]}\n    ],\n    \"localization\": [\n      {\"term_id\": \"GO:0005829\", \"supporting_discovery_ids\": [2, 12]},\n      {\"term_id\": \"GO:0005783\", \"supporting_discovery_ids\": [3]},\n      {\"term_id\": \"GO:0005886\", \"supporting_discovery_ids\": [11]}\n    ],\n    \"pathway\": [\n      {\"term_id\": \"R-HSA-162582\", \"supporting_discovery_ids\": [1, 3, 9]},\n      {\"term_id\": \"R-HSA-1643685\", \"supporting_discovery_ids\": [4]},\n      {\"term_id\": \"R-HSA-5357801\", \"supporting_discovery_ids\": [6, 7, 23]},\n      {\"term_id\": \"R-HSA-1640170\", \"supporting_discovery_ids\": [10, 17]}\n    ],\n    \"complexes\": [\n      \"PDE3A1-SERCA2-phospholamban-AKAP18 signalosome\",\n      \"PDE3A-SLFN12 heterotetramer\"\n    ],\n    \"partners\": [\n      \"SLFN12\",\n      \"SERCA2\",\n      \"AKAP18\",\n      \"phospholamban\",\n      \"CFTR\",\n      \"Plk1\",\n      \"YWHA (14-3-3)\",\n      \"PPP2 (PP2A)\"\n    ],\n    \"other_free_text\": []\n  }\n}","audit_flag":null,"evaluation":{"pairwise":"win","faith_supported":7,"faith_total":7,"faith_pct":100.0}}