{"gene":"PDE4DIP","run_date":"2026-06-10T05:19:53","timeline":{"discoveries":[{"year":2021,"finding":"PDE4DIP acts as a compartmentalization scaffold for PKA and PDE4D; a disease-associated mutation (p.A123T) impairs colocalization with PDE4D, leading to increased cAMP activation, higher PKA phosphorylation of the β2-adrenergic receptor, and decreased PKA phosphorylation of desmin after isoproterenol stimulation. Epistatic interaction with desmin (DES) p.S13F mutation drives atrial fibrillation and conduction disease.","method":"In vitro functional characterization of PDE4DIP mutant (colocalization assays, cAMP measurements, PKA phosphorylation assays); whole exome sequencing and epistasis analysis in familial AF kindreds","journal":"Human mutation","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — multiple orthogonal cellular assays (colocalization, cAMP, phosphorylation) in a single lab; supported by human genetic epistasis data","pmids":["34289528"],"is_preprint":false},{"year":2023,"finding":"PDE4DIP promotes recruitment of PLCγ/PKCε to the Golgi apparatus, leading to constitutive activation of PKCε, which triggers degradation of the RAS GTPase-activating protein NF1, thereby enabling full activation of oncogenic RAS/ERK signaling in KRAS-mutant colorectal cancer cells. PDE4DIP knockdown suppressed RAS/ERK signaling and impaired growth of KRAS-mutant CRC cells.","method":"Knockdown experiments in CRC cell lines, RAS/ERK pathway assays, NF1 protein expression analysis, Golgi localization assays for PLCγ/PKCε, in vitro proliferation assays","journal":"Cell death & disease","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — multiple pathway readouts and localization assays in a single lab; mechanistic link between Golgi recruitment and NF1 degradation supported by multiple methods","pmids":["37355626"],"is_preprint":false},{"year":2025,"finding":"PDE4DIP coordinates with AKAP9 to maintain Golgi localization and stability of PKA RIIα. Depletion of PDE4DIP mislocalizes PKA RIIα from the Golgi and leads to its degradation, thereby relieving its negative regulatory effect on PKA signaling and triggering PKA/CREB pathway activation, apoptosis, and cell cycle arrest in NSCLC cells.","method":"PDE4DIP knockdown in NSCLC cells, co-immunoprecipitation or interaction assays for PDE4DIP-AKAP9 complex, PKA RIIα localization and stability assays, PKA/CREB pathway readouts, in vitro proliferation and in vivo tumorigenicity assays","journal":"Communications biology","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — complex identification plus functional pathway assays in a single lab; multiple orthogonal methods (localization, degradation, signaling)","pmids":["39905234"],"is_preprint":false},{"year":2025,"finding":"Overexpression of PDE4DIP in cardiomyocytes inhibits Rho-ROCK signaling pathway components, induces cytoskeletal disorganization, decreases ATP content and cell migration, and increases cell proliferation and mitochondrial vacuolation; conversely, PDE4DIP knockdown promotes cytoskeleton formation and increases ATP content and cell migration, indicating PDE4DIP negatively regulates the Rho-ROCK pathway to control cell polarity, cytoskeleton, and energy metabolism in cardiomyocytes.","method":"Overexpression and knockdown of PDE4DIP in H9C2 cells and neonatal rat cardiomyocytes; electron microscopy, MitoTracker staining, ATP assay, qPCR, western blotting, immunofluorescence, scratch/CCK-8 assays","journal":"Genes & diseases","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — multiple orthogonal assays in cell lines and primary cells; single lab","pmids":["40612665"],"is_preprint":false},{"year":2025,"finding":"miR-21-5p directly targets PDE4DIP mRNA (validated by luciferase reporter assay), suppressing its expression; reduced PDE4DIP expression promotes NSCLC cell proliferation and migration/invasion, and PDE4DIP knockdown promotes tumor growth in vivo. SORBS2 suppresses NSCLC tumorigenesis partly by regulating the miR-21-5p/PDE4DIP axis.","method":"Luciferase reporter assay for miR-21-5p targeting of PDE4DIP; siRNA knockdown of PDE4DIP; miR-21-5p mimic/inhibitor experiments; tumor xenograft model","journal":"Translational cancer research","confidence":"Low","confidence_rationale":"Tier 3 / Weak — luciferase reporter validates miRNA targeting, but mechanistic detail on how PDE4DIP suppression drives tumorigenesis is limited; single lab, single study","pmids":["41378000"],"is_preprint":false}],"current_model":"PDE4DIP (myomegalin) is a Golgi/centrosome-localized scaffolding protein that compartmentalizes cAMP/PKA signaling by anchoring PKA regulatory subunit RIIα (in concert with AKAP9) and PDE4D at the Golgi; disease-associated mutations impair this compartmentalization, altering PKA-dependent phosphorylation of substrates including the β2-adrenergic receptor and desmin, and epistatic interactions with desmin mutations drive cardiac arrhythmia; PDE4DIP also recruits PLCγ/PKCε to the Golgi to suppress the RAS-GAP NF1, thereby sustaining RAS/ERK signaling, and regulates cell polarity and cytoskeletal organization through the Rho-ROCK pathway."},"narrative":{"mechanistic_narrative":"PDE4DIP (myomegalin) is a Golgi-associated scaffolding protein that spatially organizes cyclic AMP/PKA signaling and additional growth and cytoskeletal pathways at the Golgi apparatus [PMID:34289528, PMID:39905234]. It compartmentalizes PKA activity by anchoring the phosphodiesterase PDE4D, and a disease-associated mutation (p.A123T) that disrupts PDE4D colocalization raises cAMP and shifts PKA phosphorylation, increasing phosphorylation of the β2-adrenergic receptor while reducing phosphorylation of desmin; this scaffold defect interacts epistatically with a desmin (DES p.S13F) mutation to drive familial atrial fibrillation and conduction disease [PMID:34289528]. Acting together with AKAP9, PDE4DIP retains and stabilizes the PKA regulatory subunit RIIα at the Golgi, so that its loss mislocalizes and degrades RIIα, derepressing PKA/CREB signaling and triggering apoptosis and cell cycle arrest [PMID:39905234]. Beyond PKA, PDE4DIP recruits PLCγ/PKCε to the Golgi to drive constitutive PKCε activation and degradation of the RAS-GAP NF1, thereby sustaining oncogenic RAS/ERK signaling in KRAS-mutant colorectal cancer cells [PMID:37355626], and it negatively regulates the Rho-ROCK pathway to control cytoskeletal organization, cell polarity, migration, and energy metabolism in cardiomyocytes [PMID:40612665].","teleology":[{"year":2021,"claim":"Established PDE4DIP as a cAMP/PKA compartmentalization scaffold whose disruption rewires PKA substrate phosphorylation and, in epistasis with desmin, causes cardiac arrhythmia, defining its first disease-linked mechanism.","evidence":"Functional characterization of the PDE4DIP p.A123T mutant (colocalization, cAMP, PKA phosphorylation assays) plus exome sequencing and epistasis analysis in familial atrial fibrillation kindreds","pmids":["34289528"],"confidence":"Medium","gaps":["Structural basis of PDE4D/PDE4DIP binding not resolved","Direct demonstration that the AF phenotype is reversed by restoring scaffolding is absent","Mechanism linking altered β2-AR/desmin phosphorylation to arrhythmia not fully traced"]},{"year":2023,"claim":"Extended PDE4DIP function beyond PKA by showing it recruits PLCγ/PKCε to the Golgi to degrade NF1 and sustain RAS/ERK signaling, implicating it in KRAS-mutant cancer growth.","evidence":"Knockdown in colorectal cancer cell lines with RAS/ERK readouts, NF1 expression analysis, and Golgi localization assays for PLCγ/PKCε","pmids":["37355626"],"confidence":"Medium","gaps":["Direct physical interaction between PDE4DIP and PLCγ/PKCε not biochemically defined","Mechanism of PKCε-dependent NF1 degradation unresolved","Single lab, in vitro only"]},{"year":2025,"claim":"Defined the PDE4DIP-AKAP9 partnership as the basis for Golgi retention and stability of PKA RIIα, showing PDE4DIP loss derepresses PKA/CREB signaling to drive apoptosis and cell cycle arrest in NSCLC.","evidence":"PDE4DIP knockdown in NSCLC cells with co-IP/interaction assays, RIIα localization/stability assays, PKA/CREB readouts, and in vivo tumorigenicity","pmids":["39905234"],"confidence":"Medium","gaps":["Reciprocal validation of the PDE4DIP-AKAP9 interaction limited","Degradation pathway for mislocalized RIIα not identified","Context dependence versus cancer-promoting roles in CRC unexplained"]},{"year":2025,"claim":"Identified PDE4DIP as a negative regulator of the Rho-ROCK pathway controlling cardiomyocyte cytoskeleton, polarity, migration, and energy metabolism.","evidence":"Overexpression and knockdown in H9C2 cells and neonatal rat cardiomyocytes with EM, MitoTracker, ATP assays, immunofluorescence, and migration/proliferation assays","pmids":["40612665"],"confidence":"Medium","gaps":["Direct molecular link between PDE4DIP and Rho-ROCK components not established","Whether this connects to its PKA scaffolding role is unknown","No in vivo cardiac validation"]},{"year":2025,"claim":"Placed PDE4DIP under post-transcriptional control by miR-21-5p, framing it as a tumor suppressor in NSCLC within a SORBS2/miR-21-5p axis.","evidence":"Luciferase reporter validation of miR-21-5p targeting, siRNA knockdown, miRNA mimic/inhibitor experiments, and xenograft tumor growth","pmids":["41378000"],"confidence":"Low","gaps":["Mechanistic detail on how PDE4DIP loss drives tumorigenesis not resolved","Single lab, single study","Apparent contradiction with PDE4DIP loss being pro-apoptotic in NSCLC (#2) not reconciled"]},{"year":null,"claim":"It remains unknown how PDE4DIP's distinct activities — PKA/PDE4D scaffolding, PLCγ/PKCε recruitment, and Rho-ROCK regulation — are integrated at the Golgi and why its loss is tumor-suppressive in some contexts yet its scaffolding sustains oncogenic signaling in others.","evidence":"","pmids":[],"confidence":"Low","gaps":["No unified structural/domain map of binding partners","Context-dependent tumor suppressor versus oncogenic roles unreconciled","Centrosome-associated functions not addressed in the corpus"]}],"mechanism_profile":{"molecular_activity":[{"term_id":"GO:0060090","term_label":"molecular adaptor activity","supporting_discovery_ids":[0,2]},{"term_id":"GO:0098772","term_label":"molecular function regulator activity","supporting_discovery_ids":[1,3]}],"localization":[{"term_id":"GO:0005794","term_label":"Golgi apparatus","supporting_discovery_ids":[0,1,2]}],"pathway":[{"term_id":"R-HSA-162582","term_label":"Signal Transduction","supporting_discovery_ids":[0,1,2,3]}],"complexes":[],"partners":["AKAP9","PDE4D","PRKAR2A"],"other_free_text":[]}},"prefetch_data":{"uniprot":{"accession":"Q5VU43","full_name":"Myomegalin","aliases":["Cardiomyopathy-associated protein 2","Phosphodiesterase 4D-interacting protein"],"length_aa":2346,"mass_kda":265.1,"function":"Functions as an anchor sequestering components of the cAMP-dependent pathway to Golgi and/or centrosomes (By similarity) Participates in microtubule dynamics, promoting microtubule assembly. Depending upon the cell context, may act at the level of the Golgi apparatus or that of the centrosome (PubMed:25217626, PubMed:27666745, PubMed:28814570, PubMed:29162697). In complex with AKAP9, recruits CAMSAP2 to the Golgi apparatus and tethers non-centrosomal minus-end microtubules to the Golgi, an important step for polarized cell movement (PubMed:27666745, PubMed:28814570). In complex with AKAP9, EB1/MAPRE1 and CDK5RAP2, contributes to microtubules nucleation and extension from the centrosome to the cell periphery, a crucial process for directed cell migration, mitotic spindle orientation and cell-cycle progression (PubMed:29162697)","subcellular_location":"Cytoplasm, cytoskeleton, microtubule organizing center, centrosome; Cytoplasm, cytoskeleton; Golgi apparatus","url":"https://www.uniprot.org/uniprotkb/Q5VU43/entry"},"depmap":{"release":"DepMap","has_data":true,"is_common_essential":true,"resolved_as":"","url":"https://depmap.org/portal/gene/PDE4DIP","classification":"Common Essential","n_dependent_lines":762,"n_total_lines":1208,"dependency_fraction":0.6307947019867549},"opencell":{"profiled":false,"resolved_as":"","ensg_id":"","cell_line_id":"","localizations":[],"interactors":[{"gene":"CLIP1","stoichiometry":10.0},{"gene":"DYNLL1","stoichiometry":0.2},{"gene":"DYNLL2","stoichiometry":0.2},{"gene":"PRKACA","stoichiometry":0.2}],"url":"https://opencell.sf.czbiohub.org/search/PDE4DIP","total_profiled":1310},"omim":[{"mim_id":"608117","title":"PHOSPHODIESTERASE 4D-INTERACTING PROTEIN; PDE4DIP","url":"https://www.omim.org/entry/608117"}],"hpa":{"profiled":true,"resolved_as":"","reliability":"Supported","locations":[{"location":"Golgi apparatus","reliability":"Supported"}],"tissue_specificity":"Group enriched","tissue_distribution":"Detected in all","driving_tissues":[{"tissue":"heart muscle","ntpm":686.9},{"tissue":"skeletal muscle","ntpm":1934.8},{"tissue":"tongue","ntpm":1153.3}],"url":"https://www.proteinatlas.org/search/PDE4DIP"},"hgnc":{"alias_symbol":["KIAA0477","KIAA0454","MMGL"],"prev_symbol":["CMYA2"]},"alphafold":{"accession":"Q5VU43","domains":[{"cath_id":"1.10.287","chopping":"2181-2213_2229-2257","consensus_level":"medium","plddt":78.35,"start":2181,"end":2257},{"cath_id":"1.20.5","chopping":"2288-2336","consensus_level":"medium","plddt":79.4696,"start":2288,"end":2336}],"viewer_url":"https://alphafold.ebi.ac.uk/entry/Q5VU43","model_url":"https://alphafold.ebi.ac.uk/files/AF-Q5VU43-F1-model_v6.cif","pae_url":"https://alphafold.ebi.ac.uk/files/AF-Q5VU43-F1-predicted_aligned_error_v6.png","plddt_mean":57.56},"mouse_models":{"mgi_url":"https://www.informatics.jax.org/marker/summary?nomen=PDE4DIP","jax_strain_url":"https://www.jax.org/strain/search?query=PDE4DIP"},"sequence":{"accession":"Q5VU43","fasta_url":"https://rest.uniprot.org/uniprotkb/Q5VU43.fasta","uniprot_url":"https://www.uniprot.org/uniprotkb/Q5VU43/entry","alphafold_viewer_url":"https://alphafold.ebi.ac.uk/entry/Q5VU43"}},"corpus_meta":[{"pmid":"30030436","id":"PMC_30030436","title":"Recurrent homozygous deletion of DROSHA and microduplication of PDE4DIP in pineoblastoma.","date":"2018","source":"Nature communications","url":"https://pubmed.ncbi.nlm.nih.gov/30030436","citation_count":60,"is_preprint":false},{"pmid":"16849611","id":"PMC_16849611","title":"The dermal microenvironment induces the expression of the alternative activation marker CD301/mMGL in mononuclear phagocytes, independent of IL-4/IL-13 signaling.","date":"2006","source":"Journal of leukocyte biology","url":"https://pubmed.ncbi.nlm.nih.gov/16849611","citation_count":49,"is_preprint":false},{"pmid":"34289528","id":"PMC_34289528","title":"Epistatic interaction of PDE4DIP and DES mutations in familial atrial fibrillation with slow conduction.","date":"2021","source":"Human mutation","url":"https://pubmed.ncbi.nlm.nih.gov/34289528","citation_count":17,"is_preprint":false},{"pmid":"35346821","id":"PMC_35346821","title":"PDE4DIP in health and diseases.","date":"2022","source":"Cellular signalling","url":"https://pubmed.ncbi.nlm.nih.gov/35346821","citation_count":15,"is_preprint":false},{"pmid":"25170304","id":"PMC_25170304","title":"Mouse macrophage galactose-type lectin (mMGL) is critical for host resistance against Trypanosoma cruzi infection.","date":"2014","source":"International journal of biological sciences","url":"https://pubmed.ncbi.nlm.nih.gov/25170304","citation_count":11,"is_preprint":false},{"pmid":"37355626","id":"PMC_37355626","title":"PDE4DIP contributes to colorectal cancer growth and chemoresistance through modulation of the NF1/RAS signaling axis.","date":"2023","source":"Cell death & disease","url":"https://pubmed.ncbi.nlm.nih.gov/37355626","citation_count":6,"is_preprint":false},{"pmid":"39905234","id":"PMC_39905234","title":"The PDE4DIP-AKAP9 axis promotes lung cancer growth through modulation of PKA signalling.","date":"2025","source":"Communications biology","url":"https://pubmed.ncbi.nlm.nih.gov/39905234","citation_count":3,"is_preprint":false},{"pmid":"40612665","id":"PMC_40612665","title":"Dysfunction of PDE4DIP contributes to LVNC development by regulating cell polarity, skeleton, and energy metabolism via Rho-ROCK pathway.","date":"2025","source":"Genes & diseases","url":"https://pubmed.ncbi.nlm.nih.gov/40612665","citation_count":2,"is_preprint":false},{"pmid":"41170695","id":"PMC_41170695","title":"Circular RNA Pde4dip regulates myogenesis by interacting with Zfp143 mRNA: a novel regulatory axis.","date":"2025","source":"RNA biology","url":"https://pubmed.ncbi.nlm.nih.gov/41170695","citation_count":1,"is_preprint":false},{"pmid":"41378000","id":"PMC_41378000","title":"PM2.5 promotes non-small cell lung cancer tumorigenesis by miR-21-5p targeting PDE4DIP accumulated.","date":"2025","source":"Translational cancer research","url":"https://pubmed.ncbi.nlm.nih.gov/41378000","citation_count":0,"is_preprint":false},{"pmid":null,"id":"bio_10.1101_2025.09.15.25335787","title":"Somatic mutation profiles of muscle-invasive bladder cancer in Uganda: A cross-sectional study utilising whole-exome sequencing","date":"2025-09-16","source":"bioRxiv","url":"https://doi.org/10.1101/2025.09.15.25335787","citation_count":0,"is_preprint":true},{"pmid":null,"id":"bio_10.1101_2025.09.17.676975","title":"Circular RNA  <i>Pde4dip</i>  regulates myogenesis by interacting with  <i>Zfp143</i>  mRNA: A novel regulatory axis","date":"2025-09-20","source":"bioRxiv","url":"https://doi.org/10.1101/2025.09.17.676975","citation_count":0,"is_preprint":true},{"pmid":null,"id":"bio_10.1101_2025.05.21.655339","title":"The study of differential expressions of MCPH and Seckel syndrome genes and their paralogues","date":"2025-05-27","source":"bioRxiv","url":"https://doi.org/10.1101/2025.05.21.655339","citation_count":0,"is_preprint":true}],"cost":{"stage1":{"model":"claude-sonnet-4-6","input_tokens":9283,"output_tokens":1653,"usd":0.026322,"stage1_stop_reason":"end_turn"},"stage2":{"model":"claude-opus-4-8","input_tokens":8518,"output_tokens":2590,"usd":0.05367,"stage2_stop_reason":"end_turn"},"total_usd":0.079992,"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\": 2021,\n      \"finding\": \"PDE4DIP acts as a compartmentalization scaffold for PKA and PDE4D; a disease-associated mutation (p.A123T) impairs colocalization with PDE4D, leading to increased cAMP activation, higher PKA phosphorylation of the β2-adrenergic receptor, and decreased PKA phosphorylation of desmin after isoproterenol stimulation. Epistatic interaction with desmin (DES) p.S13F mutation drives atrial fibrillation and conduction disease.\",\n      \"method\": \"In vitro functional characterization of PDE4DIP mutant (colocalization assays, cAMP measurements, PKA phosphorylation assays); whole exome sequencing and epistasis analysis in familial AF kindreds\",\n      \"journal\": \"Human mutation\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — multiple orthogonal cellular assays (colocalization, cAMP, phosphorylation) in a single lab; supported by human genetic epistasis data\",\n      \"pmids\": [\"34289528\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2023,\n      \"finding\": \"PDE4DIP promotes recruitment of PLCγ/PKCε to the Golgi apparatus, leading to constitutive activation of PKCε, which triggers degradation of the RAS GTPase-activating protein NF1, thereby enabling full activation of oncogenic RAS/ERK signaling in KRAS-mutant colorectal cancer cells. PDE4DIP knockdown suppressed RAS/ERK signaling and impaired growth of KRAS-mutant CRC cells.\",\n      \"method\": \"Knockdown experiments in CRC cell lines, RAS/ERK pathway assays, NF1 protein expression analysis, Golgi localization assays for PLCγ/PKCε, in vitro proliferation assays\",\n      \"journal\": \"Cell death & disease\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — multiple pathway readouts and localization assays in a single lab; mechanistic link between Golgi recruitment and NF1 degradation supported by multiple methods\",\n      \"pmids\": [\"37355626\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2025,\n      \"finding\": \"PDE4DIP coordinates with AKAP9 to maintain Golgi localization and stability of PKA RIIα. Depletion of PDE4DIP mislocalizes PKA RIIα from the Golgi and leads to its degradation, thereby relieving its negative regulatory effect on PKA signaling and triggering PKA/CREB pathway activation, apoptosis, and cell cycle arrest in NSCLC cells.\",\n      \"method\": \"PDE4DIP knockdown in NSCLC cells, co-immunoprecipitation or interaction assays for PDE4DIP-AKAP9 complex, PKA RIIα localization and stability assays, PKA/CREB pathway readouts, in vitro proliferation and in vivo tumorigenicity assays\",\n      \"journal\": \"Communications biology\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — complex identification plus functional pathway assays in a single lab; multiple orthogonal methods (localization, degradation, signaling)\",\n      \"pmids\": [\"39905234\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2025,\n      \"finding\": \"Overexpression of PDE4DIP in cardiomyocytes inhibits Rho-ROCK signaling pathway components, induces cytoskeletal disorganization, decreases ATP content and cell migration, and increases cell proliferation and mitochondrial vacuolation; conversely, PDE4DIP knockdown promotes cytoskeleton formation and increases ATP content and cell migration, indicating PDE4DIP negatively regulates the Rho-ROCK pathway to control cell polarity, cytoskeleton, and energy metabolism in cardiomyocytes.\",\n      \"method\": \"Overexpression and knockdown of PDE4DIP in H9C2 cells and neonatal rat cardiomyocytes; electron microscopy, MitoTracker staining, ATP assay, qPCR, western blotting, immunofluorescence, scratch/CCK-8 assays\",\n      \"journal\": \"Genes & diseases\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — multiple orthogonal assays in cell lines and primary cells; single lab\",\n      \"pmids\": [\"40612665\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2025,\n      \"finding\": \"miR-21-5p directly targets PDE4DIP mRNA (validated by luciferase reporter assay), suppressing its expression; reduced PDE4DIP expression promotes NSCLC cell proliferation and migration/invasion, and PDE4DIP knockdown promotes tumor growth in vivo. SORBS2 suppresses NSCLC tumorigenesis partly by regulating the miR-21-5p/PDE4DIP axis.\",\n      \"method\": \"Luciferase reporter assay for miR-21-5p targeting of PDE4DIP; siRNA knockdown of PDE4DIP; miR-21-5p mimic/inhibitor experiments; tumor xenograft model\",\n      \"journal\": \"Translational cancer research\",\n      \"confidence\": \"Low\",\n      \"confidence_rationale\": \"Tier 3 / Weak — luciferase reporter validates miRNA targeting, but mechanistic detail on how PDE4DIP suppression drives tumorigenesis is limited; single lab, single study\",\n      \"pmids\": [\"41378000\"],\n      \"is_preprint\": false\n    }\n  ],\n  \"current_model\": \"PDE4DIP (myomegalin) is a Golgi/centrosome-localized scaffolding protein that compartmentalizes cAMP/PKA signaling by anchoring PKA regulatory subunit RIIα (in concert with AKAP9) and PDE4D at the Golgi; disease-associated mutations impair this compartmentalization, altering PKA-dependent phosphorylation of substrates including the β2-adrenergic receptor and desmin, and epistatic interactions with desmin mutations drive cardiac arrhythmia; PDE4DIP also recruits PLCγ/PKCε to the Golgi to suppress the RAS-GAP NF1, thereby sustaining RAS/ERK signaling, and regulates cell polarity and cytoskeletal organization through the Rho-ROCK pathway.\"\n}\n```","stage2_raw":"{\n  \"mechanistic_narrative\": \"PDE4DIP (myomegalin) is a Golgi-associated scaffolding protein that spatially organizes cyclic AMP/PKA signaling and additional growth and cytoskeletal pathways at the Golgi apparatus [#0, #2]. It compartmentalizes PKA activity by anchoring the phosphodiesterase PDE4D, and a disease-associated mutation (p.A123T) that disrupts PDE4D colocalization raises cAMP and shifts PKA phosphorylation, increasing phosphorylation of the \\u03b22-adrenergic receptor while reducing phosphorylation of desmin; this scaffold defect interacts epistatically with a desmin (DES p.S13F) mutation to drive familial atrial fibrillation and conduction disease [#0]. Acting together with AKAP9, PDE4DIP retains and stabilizes the PKA regulatory subunit RII\\u03b1 at the Golgi, so that its loss mislocalizes and degrades RII\\u03b1, derepressing PKA/CREB signaling and triggering apoptosis and cell cycle arrest [#2]. Beyond PKA, PDE4DIP recruits PLC\\u03b3/PKC\\u03b5 to the Golgi to drive constitutive PKC\\u03b5 activation and degradation of the RAS-GAP NF1, thereby sustaining oncogenic RAS/ERK signaling in KRAS-mutant colorectal cancer cells [#1], and it negatively regulates the Rho-ROCK pathway to control cytoskeletal organization, cell polarity, migration, and energy metabolism in cardiomyocytes [#3].\",\n  \"teleology\": [\n    {\n      \"year\": 2021,\n      \"claim\": \"Established PDE4DIP as a cAMP/PKA compartmentalization scaffold whose disruption rewires PKA substrate phosphorylation and, in epistasis with desmin, causes cardiac arrhythmia, defining its first disease-linked mechanism.\",\n      \"evidence\": \"Functional characterization of the PDE4DIP p.A123T mutant (colocalization, cAMP, PKA phosphorylation assays) plus exome sequencing and epistasis analysis in familial atrial fibrillation kindreds\",\n      \"pmids\": [\"34289528\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Structural basis of PDE4D/PDE4DIP binding not resolved\", \"Direct demonstration that the AF phenotype is reversed by restoring scaffolding is absent\", \"Mechanism linking altered \\u03b22-AR/desmin phosphorylation to arrhythmia not fully traced\"]\n    },\n    {\n      \"year\": 2023,\n      \"claim\": \"Extended PDE4DIP function beyond PKA by showing it recruits PLC\\u03b3/PKC\\u03b5 to the Golgi to degrade NF1 and sustain RAS/ERK signaling, implicating it in KRAS-mutant cancer growth.\",\n      \"evidence\": \"Knockdown in colorectal cancer cell lines with RAS/ERK readouts, NF1 expression analysis, and Golgi localization assays for PLC\\u03b3/PKC\\u03b5\",\n      \"pmids\": [\"37355626\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Direct physical interaction between PDE4DIP and PLC\\u03b3/PKC\\u03b5 not biochemically defined\", \"Mechanism of PKC\\u03b5-dependent NF1 degradation unresolved\", \"Single lab, in vitro only\"]\n    },\n    {\n      \"year\": 2025,\n      \"claim\": \"Defined the PDE4DIP-AKAP9 partnership as the basis for Golgi retention and stability of PKA RII\\u03b1, showing PDE4DIP loss derepresses PKA/CREB signaling to drive apoptosis and cell cycle arrest in NSCLC.\",\n      \"evidence\": \"PDE4DIP knockdown in NSCLC cells with co-IP/interaction assays, RII\\u03b1 localization/stability assays, PKA/CREB readouts, and in vivo tumorigenicity\",\n      \"pmids\": [\"39905234\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Reciprocal validation of the PDE4DIP-AKAP9 interaction limited\", \"Degradation pathway for mislocalized RII\\u03b1 not identified\", \"Context dependence versus cancer-promoting roles in CRC unexplained\"]\n    },\n    {\n      \"year\": 2025,\n      \"claim\": \"Identified PDE4DIP as a negative regulator of the Rho-ROCK pathway controlling cardiomyocyte cytoskeleton, polarity, migration, and energy metabolism.\",\n      \"evidence\": \"Overexpression and knockdown in H9C2 cells and neonatal rat cardiomyocytes with EM, MitoTracker, ATP assays, immunofluorescence, and migration/proliferation assays\",\n      \"pmids\": [\"40612665\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Direct molecular link between PDE4DIP and Rho-ROCK components not established\", \"Whether this connects to its PKA scaffolding role is unknown\", \"No in vivo cardiac validation\"]\n    },\n    {\n      \"year\": 2025,\n      \"claim\": \"Placed PDE4DIP under post-transcriptional control by miR-21-5p, framing it as a tumor suppressor in NSCLC within a SORBS2/miR-21-5p axis.\",\n      \"evidence\": \"Luciferase reporter validation of miR-21-5p targeting, siRNA knockdown, miRNA mimic/inhibitor experiments, and xenograft tumor growth\",\n      \"pmids\": [\"41378000\"],\n      \"confidence\": \"Low\",\n      \"gaps\": [\"Mechanistic detail on how PDE4DIP loss drives tumorigenesis not resolved\", \"Single lab, single study\", \"Apparent contradiction with PDE4DIP loss being pro-apoptotic in NSCLC (#2) not reconciled\"]\n    },\n    {\n      \"year\": null,\n      \"claim\": \"It remains unknown how PDE4DIP's distinct activities — PKA/PDE4D scaffolding, PLC\\u03b3/PKC\\u03b5 recruitment, and Rho-ROCK regulation — are integrated at the Golgi and why its loss is tumor-suppressive in some contexts yet its scaffolding sustains oncogenic signaling in others.\",\n      \"evidence\": \"\",\n      \"pmids\": [],\n      \"confidence\": \"Low\",\n      \"gaps\": [\"No unified structural/domain map of binding partners\", \"Context-dependent tumor suppressor versus oncogenic roles unreconciled\", \"Centrosome-associated functions not addressed in the corpus\"]\n    }\n  ],\n  \"mechanism_profile\": {\n    \"molecular_activity\": [\n      {\"term_id\": \"GO:0060090\", \"supporting_discovery_ids\": [0, 2]},\n      {\"term_id\": \"GO:0098772\", \"supporting_discovery_ids\": [1, 3]}\n    ],\n    \"localization\": [\n      {\"term_id\": \"GO:0005794\", \"supporting_discovery_ids\": [0, 1, 2]}\n    ],\n    \"pathway\": [\n      {\"term_id\": \"R-HSA-162582\", \"supporting_discovery_ids\": [0, 1, 2, 3]}\n    ],\n    \"complexes\": [],\n    \"partners\": [\"AKAP9\", \"PDE4D\", \"PRKAR2A\"],\n    \"other_free_text\": []\n  }\n}","audit_flag":null,"evaluation":{"pairwise":"win","faith_supported":4,"faith_total":4,"faith_pct":100.0}}