{"gene":"ADCY8","run_date":"2026-06-09T22:02:41","timeline":{"discoveries":[{"year":2012,"finding":"AC8 directly binds Orai1 (the pore component of store-operated Ca2+ channels) via their amino termini; this protein-protein interaction coordinates subcellular changes in both Ca2+ and cAMP at the AC8-Orai1 microdomain, enabling Ca2+ entry through Orai1 to stimulate AC8-dependent cAMP synthesis.","method":"Co-immunoprecipitation, GST pulldown, high-resolution FRET-based biosensors targeted to AC8 and Orai1 microdomains, live-cell imaging","journal":"Science signaling","confidence":"High","confidence_rationale":"Tier 2 / Strong — reciprocal protein interaction confirmed by multiple orthogonal methods (pulldown, Co-IP, targeted biosensors) with functional validation of the interaction's role in cAMP dynamics","pmids":["22494970"],"is_preprint":false},{"year":2010,"finding":"AC8 directly associates with AKAP79/150; this interaction limits the sensitivity of AC8 to intracellular Ca2+ events, demonstrated in HEK293 cells overexpressing both proteins and confirmed in endogenous systems (pancreatic insulin-secreting cells and hippocampal neurons).","method":"Co-immunoprecipitation, high-resolution live-cell imaging, endogenous system validation","journal":"The Journal of biological chemistry","confidence":"High","confidence_rationale":"Tier 2 / Strong — reciprocal Co-IP confirmed, functional consequence (attenuated Ca2+ sensitivity of AC8) shown by live imaging, replicated in multiple endogenous cell types","pmids":["20410303"],"is_preprint":false},{"year":2012,"finding":"AKAP79 recruits PKA to AC8, and PKA directly phosphorylates AC8 at Ser-112 on its N-terminus (identified by site-directed mutagenesis), providing negative feedback that reduces the on-rate of cAMP production during Ca2+ oscillations; non-phosphorylatable AC8 mutants are insensitive to this AKAP79-PKA-mediated dampening.","method":"Site-directed mutagenesis (Ser-112), live-cell cAMP biosensors, experimentally imposed Ca2+ oscillations, co-immunoprecipitation","journal":"Journal of cell science","confidence":"High","confidence_rationale":"Tier 1 / Moderate — site-directed mutagenesis identifies specific phosphorylation site, functional consequence confirmed by live biosensor imaging with Ca2+ oscillation protocol, single lab but multiple orthogonal approaches","pmids":["22976297"],"is_preprint":false},{"year":2005,"finding":"The catalytic subunit of protein phosphatase 2A (PP2AC) and its scaffolding subunit (PP2AA) directly bind the N-terminus of AC8; GST-fusion pulldowns show PP2AC is catalytically active within this complex; Ca2+/calmodulin binding to the AC8 N-terminus antagonizes PP2AC association; both PP2AC and AC8 co-localize in lipid rafts.","method":"Yeast two-hybrid screen, GST-fusion protein pulldown from HEK293 and mouse forebrain membranes, phosphatase activity assay, lipid raft fractionation","journal":"Molecular pharmacology","confidence":"High","confidence_rationale":"Tier 1 / Moderate — yeast two-hybrid identification confirmed by GST pulldown from native tissue, enzymatic activity measured, competitive antagonism with CaM demonstrated, single lab with multiple orthogonal methods","pmids":["16258073"],"is_preprint":false},{"year":2024,"finding":"Cryo-EM structure of bovine AC8 bound to stimulatory Gαs protein and forskolin at 3.5 Å resolution reveals the architecture of ordered AC8 domains; structural proteomics (LiP-MS and XL-MS) identifies contact sites between AC8 and CaM, Gαs, and Gβγ, and infers conformational changes induced by these regulators; the captured state does not favour tight nucleotide binding despite resolved forskolin density; the extracellular surface features a negatively charged pocket as a potential interactor site.","method":"Cryo-EM (3.5 Å), limited proteolysis-mass spectrometry (LiP-MS), crosslinking mass spectrometry (XL-MS)","journal":"EMBO reports","confidence":"High","confidence_rationale":"Tier 1 / Moderate — near-atomic resolution cryo-EM structure combined with two independent structural proteomics methods (LiP-MS and XL-MS), rigorous single study","pmids":["38351373"],"is_preprint":false},{"year":2019,"finding":"AC8 is processed with complex N-glycans and traffics through lipid rafts en route to the plasma membrane; AC8 undergoes a dynamic interaction with caveolin-1 that affects AC8 processing, targeting, and responsiveness in plasma membrane lipid rafts; cytoskeletal integrity is required to maintain the AC8 microdomain.","method":"Site-directed mutagenesis, pharmacological disruption, live-cell imaging, biochemical fractionation","journal":"The Journal of membrane biology","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — biochemical fractionation and live-cell imaging with mutagenesis confirm trafficking route and caveolin-1 interaction, single lab","pmids":["30746562"],"is_preprint":false},{"year":2003,"finding":"Cardiac-directed expression of human AC8 in transgenic mice leads to increased cAMP-PDE activity (particularly PDE4 and PDE1 isoforms), creating strong compartmentation of cAMP that selectively activates sarcoplasmic reticulum Ca2+ uptake but shields L-type Ca2+ channels from the elevated cAMP, preventing Ca2+ overload.","method":"Transgenic mouse model (AC8TG), PDE isoform activity assays, L-type Ca2+ current recordings (patch-clamp), contractility measurements","journal":"FASEB journal","confidence":"High","confidence_rationale":"Tier 2 / Strong — genetic model with direct biochemical PDE assays and electrophysiological recordings, findings consistent across two related papers from same group","pmids":["12890691","12206999"],"is_preprint":false},{"year":2010,"finding":"ADCY8 (calmodulin-activated adenylyl cyclase) is cell-autonomously required in retinal neurons for normal midline crossing in zebrafish; knockdown of ADCY8 makes retinal axons insensitive to SDF1 (which normally antagonizes slit-mediated repulsion via cAMP signaling) and induces ipsilateral misprojections.","method":"Antisense morpholino knockdown in zebrafish, in vivo axon tracing, epistasis with slit signaling pathway","journal":"The Journal of neuroscience","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — cell-autonomous requirement demonstrated by morpholino knockdown with defined axon pathfinding phenotype and pathway epistasis, single lab, ortholog study","pmids":["20505109"],"is_preprint":false},{"year":2012,"finding":"Notch pathway activation (via Notch target genes Hrt1 and Hrt3) attenuates IL-1β-induced de novo AC8 expression in vascular smooth muscle cells (VSMCs) undergoing trans-differentiation; inhibition of Notch amplifies IL-1β-driven AC8 upregulation and VSMC trans-differentiation phenotype; this was confirmed in an in vivo rat carotid balloon-injury model of restenosis.","method":"Notch pathway pharmacological inhibition/activation, overexpression of Hrt1/Hrt3, in vivo carotid balloon-injury model, qPCR/western blotting","journal":"The Journal of biological chemistry","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — in vitro gain- and loss-of-function with pathway intermediates confirmed in vivo, single lab","pmids":["22613711"],"is_preprint":false},{"year":2025,"finding":"CRISPR-Cas9 deletion of ADCY8 (AC8) in U87MG glioma cells causes system-wide remodeling of the mitochondrial proteome, shifting metabolic balance from glycolysis toward oxidative phosphorylation (increased oxygen consumption, elevated TCA cycle flux, decreased glycolytic flux), indicating that AC8-mediated transcriptional regulation suppresses mitochondrial oxidative metabolism in these cancer cells.","method":"CRISPR-Cas9 knockout, quantitative proteomics, oxygen consumption measurement, metabolic flux analysis (TCA cycle and glycolysis)","journal":"Biochimica et biophysica acta. Bioenergetics","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — clean CRISPR KO with multiple orthogonal metabolic readouts, single lab, single study","pmids":["40669556"],"is_preprint":false},{"year":2025,"finding":"Adcy8 knockout mice show impaired lipolysis in adipose tissue with reduced cAMP levels and decreased phosphorylation of lipolytic enzymes (via the cAMP-PKA pathway); forskolin-enhanced lipolysis observed in wild-type mice is abrogated in Adcy8-/- mice, establishing AC8 as the mediator of cAMP-PKA-dependent lipolysis in adipose tissue.","method":"Adcy8 knockout mouse model (normal and high-fat diet), cAMP measurement, phosphorylation assays of lipolytic enzymes, forskolin stimulation experiment","journal":"Biochimica et biophysica acta. Molecular and cell biology of lipids","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — genetic KO with direct biochemical readouts and pharmacological rescue experiment, single lab","pmids":["40527393"],"is_preprint":false},{"year":2024,"finding":"In TGAC8 mice (cardiac-specific AC8 overexpression), chronic adenylyl cyclase activation leads to cell-autonomous RelA-mediated NF-κB signaling in cardiomyocytes via calcium-PKA signaling; this drives non-cell-autonomous proinflammatory signaling in cardiac endothelial and smooth muscle cells, expansion of myocardial immune cells, and elevated serum inflammatory cytokines, preceding cardiac fibrosis.","method":"Cardiac-specific transgenic mouse model, NF-κB pathway activation assays, PKA inhibition, cell-type-specific analysis, cytokine measurement","journal":"GeroScience","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — genetic model with mechanistic pathway (Ca2+/PKA/RelA) identified and pharmacological confirmation, single lab","pmids":["38499959"],"is_preprint":false},{"year":2021,"finding":"In breast cancer cells, overexpression of AC8 shifts the AC8-Orai1α stoichiometry in favor of AC8, impairing PKA-dependent Orai1α inactivation (which normally occurs via phosphorylation at serine-34 of Orai1α by PKA activated downstream of the AC8-Orai1 complex), thereby contributing to enhanced store-operated Ca2+ entry in triple-negative breast cancer cells.","method":"Functional analysis of AC8-Orai1 interaction in breast cancer cell lines, Ca2+ entry measurements, PKA phosphorylation assays (cited in review of experimental findings)","journal":"Cells","confidence":"Low","confidence_rationale":"Tier 3 / Weak — review/synthesis paper summarizing mechanistic findings; primary experiments cited but not fully described in this abstract; mechanism of Orai1α Ser-34 phosphorylation is attributed to prior work","pmids":["34070268"],"is_preprint":false},{"year":2024,"finding":"In atrial myocytes, lysosomal Ca2+ release via the NAADP pathway contributes to α-adrenergic (phenylephrine)-stimulated cAMP production through activation of Ca2+-sensitive AC1 and AC8; double knockout of Adcy1 and Adcy8 in mice reduces positive chronotropic and inotropic responses to phenylephrine, Ca2+ transient amplitude, and cytosolic cAMP levels in response to phenylephrine.","method":"Adcy1/Adcy8 double-knockout mouse model, NAADP pathway inhibitors (BZ-194, SAN4825, Bafilomycin A1), cAMP biosensors in neonatal atrial myocytes, Ca2+ transient measurements","journal":"bioRxiv","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — genetic double-KO model with pharmacological dissection and multiple readouts, preprint not yet peer-reviewed","pmids":["bio_10.1101_2024.11.25.625232"],"is_preprint":true}],"current_model":"ADCY8 (AC8) is a transmembrane adenylyl cyclase that converts ATP to cAMP in response to Ca2+/calmodulin stimulation; it forms a direct complex with Orai1 (via N-terminal interaction) to couple store-operated Ca2+ entry to cAMP synthesis, is scaffolded by AKAP79/150 which recruits PKA to phosphorylate AC8 at Ser-112 providing negative feedback, binds the PP2A core dimer (antagonized by Ca2+/calmodulin) at its N-terminus, traffics to plasma membrane lipid rafts via complex N-glycosylation and caveolin-1 interaction, and is structurally defined by a cryo-EM structure showing Gαs- and CaM-binding interfaces; in physiological contexts AC8 regulates cardiac contractility, adipose lipolysis via cAMP-PKA, axonal pathfinding, lysosomal Ca2+-dependent atrial adrenergic responses, and metabolic reprogramming in cancer cells."},"narrative":{"mechanistic_narrative":"ADCY8 (AC8) is a Ca2+/calmodulin-stimulated transmembrane adenylyl cyclase that integrates local Ca2+ signals into compartmentalized cAMP synthesis at plasma-membrane microdomains [PMID:22494970, PMID:16258073]. It is physically coupled to store-operated Ca2+ entry through a direct N-terminal interaction with the Orai1 channel pore, so that Ca2+ entering via Orai1 drives AC8-dependent cAMP production within a shared AC8-Orai1 microdomain [PMID:22494970]. AC8 activity is shaped by a regulatory scaffold: AKAP79/150 binds AC8 and limits its sensitivity to intracellular Ca2+, and the AKAP-recruited PKA phosphorylates AC8 at Ser-112 on its N-terminus to provide negative feedback that slows cAMP production during Ca2+ oscillations [PMID:20410303, PMID:22976297]. The same N-terminus binds a catalytically active PP2A core dimer in a manner antagonized by Ca2+/calmodulin, and the enzyme is processed with complex N-glycans and trafficked through lipid rafts via a dynamic caveolin-1 interaction that requires cytoskeletal integrity [PMID:16258073, PMID:30746562]. A cryo-EM structure of AC8 bound to Gαs and forskolin, together with structural proteomics, defines the ordered domain architecture and the contact interfaces for CaM, Gαs, and Gβγ [PMID:38351373]. Through cAMP-PKA signaling AC8 governs diverse physiological outputs: it mediates cAMP-PKA-dependent lipolysis in adipose tissue [PMID:40527393], shapes compartmentalized cardiac cAMP that selectively tunes sarcoplasmic reticulum Ca2+ uptake while shielding L-type Ca2+ channels [PMID:12890691, PMID:12206999], cooperates with AC1 to couple lysosomal NAADP-driven Ca2+ release to α-adrenergic chronotropic and inotropic responses in atrial myocytes [PMID:bio_10.1101_2024.11.25.625232], and is cell-autonomously required in retinal neurons for cAMP-dependent axonal midline crossing [PMID:20505109].","teleology":[{"year":2003,"claim":"Established that AC8-generated cAMP is spatially compartmentalized rather than diffuse, explaining how a single cyclase can selectively tune some Ca2+ handling pathways without causing global Ca2+ overload.","evidence":"Cardiac-directed AC8 transgenic mice with PDE isoform activity assays, patch-clamp L-type Ca2+ recordings and contractility measurements","pmids":["12890691","12206999"],"confidence":"High","gaps":["Did not resolve the molecular scaffolds enforcing the cAMP compartment","PDE coupling specificity to AC8 not structurally defined"]},{"year":2005,"claim":"Identified PP2A as a direct N-terminal AC8 partner antagonized by Ca2+/calmodulin, revealing a phosphatase arm in AC8 microdomain regulation and placing AC8 in lipid rafts.","evidence":"Yeast two-hybrid screen with GST pulldown from native forebrain membranes, phosphatase activity assay, and lipid raft fractionation","pmids":["16258073"],"confidence":"High","gaps":["Substrates dephosphorylated by AC8-bound PP2A not identified","Functional consequence of CaM-PP2A competition on cAMP output not quantified"]},{"year":2010,"claim":"Showed AKAP79/150 directly tunes down AC8's Ca2+ sensitivity, identifying a scaffold-based set-point control over Ca2+-to-cAMP coupling, validated in endogenous secretory and neuronal cells.","evidence":"Co-immunoprecipitation and live-cell imaging in HEK293 plus endogenous insulin-secreting and hippocampal neuron systems","pmids":["20410303"],"confidence":"High","gaps":["Did not yet define the PKA phosphorylation event mediating feedback","Stoichiometry of the AKAP-AC8 complex unknown"]},{"year":2010,"claim":"Demonstrated a cell-autonomous developmental role for ADCY8 in cAMP-dependent retinal axon guidance, extending its function beyond secretory and cardiac contexts.","evidence":"Morpholino knockdown in zebrafish with in vivo axon tracing and epistasis against slit/SDF1 signaling","pmids":["20505109"],"confidence":"Medium","gaps":["Ortholog knockdown; mammalian requirement not tested","Direct biochemical link between AC8 cAMP and slit responsiveness not shown"]},{"year":2012,"claim":"Resolved the direct AC8-Orai1 interaction, establishing the physical basis by which store-operated Ca2+ entry is converted into local cAMP.","evidence":"Co-IP, GST pulldown, and microdomain-targeted FRET biosensors with live-cell imaging","pmids":["22494970"],"confidence":"High","gaps":["Stoichiometry of AC8-Orai1 in native cells not defined","Structural interface of the N-terminal interaction unresolved"]},{"year":2012,"claim":"Pinpointed Ser-112 as the PKA phosphosite mediating AKAP79-dependent negative feedback, completing the local feedback loop that dampens cAMP during Ca2+ oscillations.","evidence":"Site-directed mutagenesis with imposed Ca2+ oscillations and live-cell cAMP biosensors plus Co-IP","pmids":["22976297"],"confidence":"High","gaps":["Single lab; in vivo physiological role of Ser-112 phosphorylation untested","Kinetics of phosphorylation/dephosphorylation cycling not measured"]},{"year":2012,"claim":"Showed AC8 expression is transcriptionally controlled, with Notch signaling restraining IL-1β-driven AC8 induction during vascular smooth muscle trans-differentiation.","evidence":"Notch pharmacological modulation and Hrt1/Hrt3 overexpression in VSMCs with an in vivo rat carotid balloon-injury model","pmids":["22613711"],"confidence":"Medium","gaps":["Direct Notch-target binding at the ADCY8 locus not demonstrated","cAMP-dependent mechanism downstream of AC8 in VSMCs not defined"]},{"year":2019,"claim":"Defined the trafficking and microdomain maintenance route of AC8, linking complex N-glycosylation, caveolin-1, and cytoskeletal integrity to AC8 plasma-membrane targeting and responsiveness.","evidence":"Site-directed mutagenesis, pharmacological disruption, biochemical fractionation and live-cell imaging","pmids":["30746562"],"confidence":"Medium","gaps":["Single lab; caveolin-1 interaction interface not mapped","Whether trafficking defects alter Ca2+-cAMP coupling in vivo unknown"]},{"year":2024,"claim":"Provided the first near-atomic AC8 architecture and mapped the regulatory contact surfaces for Gαs, CaM, and Gβγ, giving a structural framework for its allosteric control.","evidence":"3.5 Å cryo-EM of bovine AC8 with Gαs and forskolin, integrated with LiP-MS and XL-MS structural proteomics","pmids":["38351373"],"confidence":"High","gaps":["Captured state did not favour tight nucleotide binding, leaving the catalytic conformation undefined","Identity of the negatively charged extracellular pocket interactor unknown","N-terminal regulatory region not resolved"]},{"year":2024,"claim":"Connected chronic AC8 activation to inflammatory remodeling, showing cardiac cAMP overdrive triggers cell-autonomous RelA/NF-κB and non-cell-autonomous proinflammatory signaling preceding fibrosis.","evidence":"Cardiac-specific TGAC8 transgenic mice with NF-κB assays, PKA inhibition, cell-type-specific analysis and cytokine measurement","pmids":["38499959"],"confidence":"Medium","gaps":["Gain-of-function model; relevance to physiological AC8 levels unclear","Mechanism linking PKA to RelA activation not fully defined"]},{"year":2024,"claim":"Linked lysosomal NAADP-driven Ca2+ release to AC8/AC1 activation in atrial α-adrenergic responses, expanding the Ca2+ sources that feed AC8.","evidence":"Adcy1/Adcy8 double-knockout mice with NAADP-pathway inhibitors, atrial cAMP biosensors and Ca2+ transient measurements (preprint)","pmids":["bio_10.1101_2024.11.25.625232"],"confidence":"Medium","gaps":["Preprint, not peer-reviewed","Relative contributions of AC1 vs AC8 not separated","Direct AC8-lysosomal coupling mechanism unresolved"]},{"year":2025,"claim":"Established AC8 as the obligate cyclase for cAMP-PKA-dependent adipose lipolysis using genetic loss-of-function with pharmacological rescue.","evidence":"Adcy8 knockout mice on normal and high-fat diet with cAMP measurement, lipolytic enzyme phosphorylation assays and forskolin stimulation","pmids":["40527393"],"confidence":"Medium","gaps":["Single lab; upstream activator of adipose AC8 not defined","Tissue-autonomy versus systemic effects not fully dissected"]},{"year":2025,"claim":"Revealed a transcriptional/metabolic function in cancer, where AC8 loss reprograms the mitochondrial proteome and shifts cells from glycolysis to oxidative phosphorylation.","evidence":"CRISPR-Cas9 knockout in U87MG glioma cells with quantitative proteomics, oxygen consumption and TCA/glycolytic flux analysis","pmids":["40669556"],"confidence":"Medium","gaps":["Mechanism by which AC8 controls mitochondrial gene/protein expression not defined","Single cell line; generality across cancers untested","cAMP-dependence of the metabolic effect not demonstrated"]},{"year":null,"claim":"How the structurally defined AC8 catalytic and N-terminal regulatory architecture is dynamically organized within the Orai1/AKAP79/PP2A microdomain to control cAMP kinetics in native tissues remains unresolved.","evidence":"","pmids":[],"confidence":"Medium","gaps":["Catalytically competent AC8 conformation not captured","Native-tissue stoichiometry of the AC8 signaling complex unknown","Mechanism coupling AC8 to transcriptional/metabolic outputs undefined"]}],"mechanism_profile":{"molecular_activity":[{"term_id":"GO:0009975","term_label":"cyclase activity","supporting_discovery_ids":[4,6,10]},{"term_id":"GO:0016740","term_label":"transferase activity","supporting_discovery_ids":[4]}],"localization":[{"term_id":"GO:0005886","term_label":"plasma membrane","supporting_discovery_ids":[0,5]},{"term_id":"GO:0005856","term_label":"cytoskeleton","supporting_discovery_ids":[5]}],"pathway":[{"term_id":"R-HSA-162582","term_label":"Signal Transduction","supporting_discovery_ids":[0,2,6]},{"term_id":"R-HSA-1430728","term_label":"Metabolism","supporting_discovery_ids":[9,10]}],"complexes":[],"partners":["ORAI1","AKAP5","PRKACA","PPP2CA","PPP2R1A","GNAS","CAV1"],"other_free_text":[]}},"prefetch_data":{"uniprot":{"accession":"P40145","full_name":"Adenylate cyclase type 8","aliases":["ATP pyrophosphate-lyase 8","Adenylate cyclase type VIII","Adenylyl cyclase 8","AC8","Ca(2+)/calmodulin-activated adenylyl cyclase"],"length_aa":1251,"mass_kda":140.1,"function":"Catalyzes the formation of cAMP in response to calcium entry leadings to cAMP signaling activation that affect processes suche as synaptic plasticity and insulin secretion. Plays a role in many brain functions, such as learning, memory, drug addiction, and anxiety modulation through regulation of synaptic plasticity by modulating long-term memory and long-term potentiation (LTP) through CREB transcription factor activity modulation. Plays a central role in insulin secretion by controlling glucose homeostasis through glucagon-like peptide 1 and glucose signaling pathway and maintains insulin secretion through calcium-dependent PKA activation leading to vesicle pool replenishment. Also, allows PTGER3 to induce potentiation of PTGER4-mediated PLA2 secretion by switching from a negative to a positive regulation, during the IL1B induced-dedifferentiation of smooth muscle cells","subcellular_location":"Cell membrane; Basolateral cell membrane; Apical cell membrane; Synapse; Cell projection, dendrite; Cell projection, axon; Presynaptic cell membrane; Postsynaptic density; Membrane raft; Membrane, coated pit; Cytoplasmic vesicle, clathrin-coated vesicle membrane; Membrane, caveola","url":"https://www.uniprot.org/uniprotkb/P40145/entry"},"depmap":{"release":"DepMap","has_data":true,"is_common_essential":false,"resolved_as":"","url":"https://depmap.org/portal/gene/ADCY8","classification":"Not Classified","n_dependent_lines":3,"n_total_lines":1208,"dependency_fraction":0.0024834437086092716},"opencell":{"profiled":false,"resolved_as":"","ensg_id":"","cell_line_id":"","localizations":[],"interactors":[],"url":"https://opencell.sf.czbiohub.org/search/ADCY8","total_profiled":1310},"omim":[{"mim_id":"602123","title":"CALCIUM/CALMODULIN-DEPENDENT PROTEIN KINASE II-GAMMA; CAMK2G","url":"https://www.omim.org/entry/602123"},{"mim_id":"601115","title":"GLUTAMATE RECEPTOR, METABOTROPIC, 3; GRM3","url":"https://www.omim.org/entry/601115"},{"mim_id":"600163","title":"SODIUM VOLTAGE-GATED CHANNEL, ALPHA SUBUNIT 5; SCN5A","url":"https://www.omim.org/entry/600163"},{"mim_id":"176960","title":"PROTEIN KINASE C, ALPHA; PRKCA","url":"https://www.omim.org/entry/176960"},{"mim_id":"176893","title":"PROTEIN KINASE, cAMP-DEPENDENT, CATALYTIC, GAMMA; PRKACG","url":"https://www.omim.org/entry/176893"}],"hpa":{"profiled":true,"resolved_as":"","reliability":"Approved","locations":[{"location":"Plasma membrane","reliability":"Approved"},{"location":"Cytosol","reliability":"Approved"},{"location":"Nucleoplasm","reliability":"Additional"}],"tissue_specificity":"Group enriched","tissue_distribution":"Detected in some","driving_tissues":[{"tissue":"brain","ntpm":8.0},{"tissue":"epididymis","ntpm":21.5}],"url":"https://www.proteinatlas.org/search/ADCY8"},"hgnc":{"alias_symbol":["HBAC1","AC8"],"prev_symbol":["ADCY3"]},"alphafold":{"accession":"P40145","domains":[{"cath_id":"-","chopping":"163-358_709-808_827-888_903-935","consensus_level":"medium","plddt":85.276,"start":163,"end":935},{"cath_id":"3.30.70.1230","chopping":"406-596","consensus_level":"medium","plddt":87.0935,"start":406,"end":596},{"cath_id":"3.30.70.1230","chopping":"968-1181_1189-1208","consensus_level":"medium","plddt":81.4919,"start":968,"end":1208}],"viewer_url":"https://alphafold.ebi.ac.uk/entry/P40145","model_url":"https://alphafold.ebi.ac.uk/files/AF-P40145-F1-model_v6.cif","pae_url":"https://alphafold.ebi.ac.uk/files/AF-P40145-F1-predicted_aligned_error_v6.png","plddt_mean":71.19},"mouse_models":{"mgi_url":"https://www.informatics.jax.org/marker/summary?nomen=ADCY8","jax_strain_url":"https://www.jax.org/strain/search?query=ADCY8"},"sequence":{"accession":"P40145","fasta_url":"https://rest.uniprot.org/uniprotkb/P40145.fasta","uniprot_url":"https://www.uniprot.org/uniprotkb/P40145/entry","alphafold_viewer_url":"https://alphafold.ebi.ac.uk/entry/P40145"}},"corpus_meta":[{"pmid":"22494970","id":"PMC_22494970","title":"Direct binding between Orai1 and AC8 mediates dynamic interplay between Ca2+ and cAMP signaling.","date":"2012","source":"Science signaling","url":"https://pubmed.ncbi.nlm.nih.gov/22494970","citation_count":111,"is_preprint":false},{"pmid":"20410303","id":"PMC_20410303","title":"AKAP79/150 interacts with AC8 and regulates Ca2+-dependent cAMP synthesis in pancreatic and neuronal systems.","date":"2010","source":"The Journal of biological chemistry","url":"https://pubmed.ncbi.nlm.nih.gov/20410303","citation_count":66,"is_preprint":false},{"pmid":"12890691","id":"PMC_12890691","title":"Cyclic AMP compartmentation due to increased cAMP-phosphodiesterase activity in transgenic mice with a cardiac-directed expression of the human adenylyl cyclase type 8 (AC8).","date":"2003","source":"FASEB journal : official publication of the Federation of American Societies for Experimental Biology","url":"https://pubmed.ncbi.nlm.nih.gov/12890691","citation_count":58,"is_preprint":false},{"pmid":"29522173","id":"PMC_29522173","title":"Loss of cardiac Wnt/β-catenin signalling in desmoplakin-deficient AC8 zebrafish models is rescuable by genetic and pharmacological intervention.","date":"2018","source":"Cardiovascular research","url":"https://pubmed.ncbi.nlm.nih.gov/29522173","citation_count":47,"is_preprint":false},{"pmid":"19691954","id":"PMC_19691954","title":"Interspecies trait genetics reveals association of Adcy8 with mouse avoidance behavior and a human mood disorder.","date":"2009","source":"Biological psychiatry","url":"https://pubmed.ncbi.nlm.nih.gov/19691954","citation_count":46,"is_preprint":false},{"pmid":"16258073","id":"PMC_16258073","title":"A direct interaction between the N terminus of adenylyl cyclase AC8 and the catalytic subunit of protein phosphatase 2A.","date":"2005","source":"Molecular 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by an AC8-AKAP79-PKA signalling complex.","date":"2012","source":"Journal of cell science","url":"https://pubmed.ncbi.nlm.nih.gov/22976297","citation_count":30,"is_preprint":false},{"pmid":"20505109","id":"PMC_20505109","title":"The calmodulin-stimulated adenylate cyclase ADCY8 sets the sensitivity of zebrafish retinal axons to midline repellents and is required for normal midline crossing.","date":"2010","source":"The Journal of neuroscience : the official journal of the Society for Neuroscience","url":"https://pubmed.ncbi.nlm.nih.gov/20505109","citation_count":29,"is_preprint":false},{"pmid":"23702564","id":"PMC_23702564","title":"1H NMR-based metabolomics studies of urine reveal differences between type 1 diabetic patients with high and low HbAc1 values.","date":"2013","source":"Journal of pharmaceutical and biomedical analysis","url":"https://pubmed.ncbi.nlm.nih.gov/23702564","citation_count":27,"is_preprint":false},{"pmid":"27651839","id":"PMC_27651839","title":"Molecular Pap smear: HPV genotype and DNA methylation of ADCY8, CDH8, and ZNF582 as an integrated biomarker for high-grade cervical cytology.","date":"2016","source":"Clinical epigenetics","url":"https://pubmed.ncbi.nlm.nih.gov/27651839","citation_count":26,"is_preprint":false},{"pmid":"22613711","id":"PMC_22613711","title":"The Notch pathway attenuates interleukin 1β (IL1β)-mediated induction of adenylyl cyclase 8 (AC8) expression during vascular smooth muscle cell (VSMC) trans-differentiation.","date":"2012","source":"The Journal of biological chemistry","url":"https://pubmed.ncbi.nlm.nih.gov/22613711","citation_count":20,"is_preprint":false},{"pmid":"36515265","id":"PMC_36515265","title":"A remarkable adaptive paradigm of heart performance and protection emerges in response to marked cardiac-specific overexpression of ADCY8.","date":"2022","source":"eLife","url":"https://pubmed.ncbi.nlm.nih.gov/36515265","citation_count":19,"is_preprint":false},{"pmid":"38351373","id":"PMC_38351373","title":"Regulatory sites of CaM-sensitive adenylyl cyclase AC8 revealed by cryo-EM and structural proteomics.","date":"2024","source":"EMBO reports","url":"https://pubmed.ncbi.nlm.nih.gov/38351373","citation_count":14,"is_preprint":false},{"pmid":"35005298","id":"PMC_35005298","title":"Evaluation of calcium-sensitive adenylyl cyclase AC1 and AC8 mRNA expression in the anterior cingulate cortex of mice with spared nerve injury neuropathy.","date":"2021","source":"Neurobiology of pain (Cambridge, Mass.)","url":"https://pubmed.ncbi.nlm.nih.gov/35005298","citation_count":9,"is_preprint":false},{"pmid":"33178175","id":"PMC_33178175","title":"Molecular Pap Smear: Validation of HPV Genotype and Host Methylation Profiles of ADCY8, CDH8, and ZNF582 as a Predictor of Cervical Cytopathology.","date":"2020","source":"Frontiers in microbiology","url":"https://pubmed.ncbi.nlm.nih.gov/33178175","citation_count":8,"is_preprint":false},{"pmid":"30746562","id":"PMC_30746562","title":"Structural and Functional Determinants of AC8 Trafficking, Targeting and Responsiveness in Lipid Raft Microdomains.","date":"2019","source":"The Journal of membrane biology","url":"https://pubmed.ncbi.nlm.nih.gov/30746562","citation_count":7,"is_preprint":false},{"pmid":"34070268","id":"PMC_34070268","title":"The Orai1-AC8 Interplay: How Breast Cancer Cells Escape from Orai1 Channel Inactivation.","date":"2021","source":"Cells","url":"https://pubmed.ncbi.nlm.nih.gov/34070268","citation_count":6,"is_preprint":false},{"pmid":"38499959","id":"PMC_38499959","title":"RelA-mediated signaling connects adaptation to chronic cardiomyocyte stress with myocardial and systemic inflammation in the ADCY8 model of accelerated aging.","date":"2024","source":"GeroScience","url":"https://pubmed.ncbi.nlm.nih.gov/38499959","citation_count":6,"is_preprint":false},{"pmid":"25055061","id":"PMC_25055061","title":"Evaluation of biocompatibility of the AC8 peptide and its potential use as a drug carrier.","date":"2014","source":"Molecular pharmaceutics","url":"https://pubmed.ncbi.nlm.nih.gov/25055061","citation_count":5,"is_preprint":false},{"pmid":"36384395","id":"PMC_36384395","title":"Polymorphism in ovine ADCY8 gene and its association with residual feed intake in Hu sheep.","date":"2022","source":"Animal biotechnology","url":"https://pubmed.ncbi.nlm.nih.gov/36384395","citation_count":4,"is_preprint":false},{"pmid":"22305930","id":"PMC_22305930","title":"The AC8 IgG3 monoclonal anti-cholesterol antibody modulates uptake and presentation of antigens for T cell activation.","date":"2012","source":"Immunology letters","url":"https://pubmed.ncbi.nlm.nih.gov/22305930","citation_count":2,"is_preprint":false},{"pmid":"40527393","id":"PMC_40527393","title":"Adcy8 deficiency contributes to impaired lipolysis and an increased prevalence of obesity in mice.","date":"2025","source":"Biochimica et biophysica acta. Molecular and cell biology of lipids","url":"https://pubmed.ncbi.nlm.nih.gov/40527393","citation_count":1,"is_preprint":false},{"pmid":"40669556","id":"PMC_40669556","title":"Deletion of AC8 in glioma cells elevates oxidative phosphorylation by system-wide remodeling of the mitochondrial proteome.","date":"2025","source":"Biochimica et biophysica acta. Bioenergetics","url":"https://pubmed.ncbi.nlm.nih.gov/40669556","citation_count":0,"is_preprint":false},{"pmid":null,"id":"bio_10.1101_2024.11.25.625232","title":"Lysosomal calcium signalling contributes to the acute α-adrenergic response via calcium-stimulated adenylyl cyclase 1 and 8","date":"2024-11-26","source":"bioRxiv","url":"https://doi.org/10.1101/2024.11.25.625232","citation_count":0,"is_preprint":true}],"cost":{"stage1":{"model":"claude-sonnet-4-6","input_tokens":15601,"output_tokens":3854,"usd":0.052306,"stage1_stop_reason":"end_turn"},"stage2":{"model":"claude-opus-4-8","input_tokens":11843,"output_tokens":4513,"usd":0.08602,"stage2_stop_reason":"end_turn"},"total_usd":0.138326,"stage1_batch_id":"msgbatch_0179Z2pxRYBsXi2xADneafRw","stage2_batch_id":"msgbatch_01LaY9ZaVdgjWArcZo9eqQE5","note":"batch pricing = 50% of standard"},"stage1_raw":"```json\n{\n  \"discoveries\": [\n    {\n      \"year\": 2012,\n      \"finding\": \"AC8 directly binds Orai1 (the pore component of store-operated Ca2+ channels) via their amino termini; this protein-protein interaction coordinates subcellular changes in both Ca2+ and cAMP at the AC8-Orai1 microdomain, enabling Ca2+ entry through Orai1 to stimulate AC8-dependent cAMP synthesis.\",\n      \"method\": \"Co-immunoprecipitation, GST pulldown, high-resolution FRET-based biosensors targeted to AC8 and Orai1 microdomains, live-cell imaging\",\n      \"journal\": \"Science signaling\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — reciprocal protein interaction confirmed by multiple orthogonal methods (pulldown, Co-IP, targeted biosensors) with functional validation of the interaction's role in cAMP dynamics\",\n      \"pmids\": [\"22494970\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2010,\n      \"finding\": \"AC8 directly associates with AKAP79/150; this interaction limits the sensitivity of AC8 to intracellular Ca2+ events, demonstrated in HEK293 cells overexpressing both proteins and confirmed in endogenous systems (pancreatic insulin-secreting cells and hippocampal neurons).\",\n      \"method\": \"Co-immunoprecipitation, high-resolution live-cell imaging, endogenous system validation\",\n      \"journal\": \"The Journal of biological chemistry\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — reciprocal Co-IP confirmed, functional consequence (attenuated Ca2+ sensitivity of AC8) shown by live imaging, replicated in multiple endogenous cell types\",\n      \"pmids\": [\"20410303\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2012,\n      \"finding\": \"AKAP79 recruits PKA to AC8, and PKA directly phosphorylates AC8 at Ser-112 on its N-terminus (identified by site-directed mutagenesis), providing negative feedback that reduces the on-rate of cAMP production during Ca2+ oscillations; non-phosphorylatable AC8 mutants are insensitive to this AKAP79-PKA-mediated dampening.\",\n      \"method\": \"Site-directed mutagenesis (Ser-112), live-cell cAMP biosensors, experimentally imposed Ca2+ oscillations, co-immunoprecipitation\",\n      \"journal\": \"Journal of cell science\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 / Moderate — site-directed mutagenesis identifies specific phosphorylation site, functional consequence confirmed by live biosensor imaging with Ca2+ oscillation protocol, single lab but multiple orthogonal approaches\",\n      \"pmids\": [\"22976297\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2005,\n      \"finding\": \"The catalytic subunit of protein phosphatase 2A (PP2AC) and its scaffolding subunit (PP2AA) directly bind the N-terminus of AC8; GST-fusion pulldowns show PP2AC is catalytically active within this complex; Ca2+/calmodulin binding to the AC8 N-terminus antagonizes PP2AC association; both PP2AC and AC8 co-localize in lipid rafts.\",\n      \"method\": \"Yeast two-hybrid screen, GST-fusion protein pulldown from HEK293 and mouse forebrain membranes, phosphatase activity assay, lipid raft fractionation\",\n      \"journal\": \"Molecular pharmacology\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 / Moderate — yeast two-hybrid identification confirmed by GST pulldown from native tissue, enzymatic activity measured, competitive antagonism with CaM demonstrated, single lab with multiple orthogonal methods\",\n      \"pmids\": [\"16258073\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2024,\n      \"finding\": \"Cryo-EM structure of bovine AC8 bound to stimulatory Gαs protein and forskolin at 3.5 Å resolution reveals the architecture of ordered AC8 domains; structural proteomics (LiP-MS and XL-MS) identifies contact sites between AC8 and CaM, Gαs, and Gβγ, and infers conformational changes induced by these regulators; the captured state does not favour tight nucleotide binding despite resolved forskolin density; the extracellular surface features a negatively charged pocket as a potential interactor site.\",\n      \"method\": \"Cryo-EM (3.5 Å), limited proteolysis-mass spectrometry (LiP-MS), crosslinking mass spectrometry (XL-MS)\",\n      \"journal\": \"EMBO reports\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 / Moderate — near-atomic resolution cryo-EM structure combined with two independent structural proteomics methods (LiP-MS and XL-MS), rigorous single study\",\n      \"pmids\": [\"38351373\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2019,\n      \"finding\": \"AC8 is processed with complex N-glycans and traffics through lipid rafts en route to the plasma membrane; AC8 undergoes a dynamic interaction with caveolin-1 that affects AC8 processing, targeting, and responsiveness in plasma membrane lipid rafts; cytoskeletal integrity is required to maintain the AC8 microdomain.\",\n      \"method\": \"Site-directed mutagenesis, pharmacological disruption, live-cell imaging, biochemical fractionation\",\n      \"journal\": \"The Journal of membrane biology\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — biochemical fractionation and live-cell imaging with mutagenesis confirm trafficking route and caveolin-1 interaction, single lab\",\n      \"pmids\": [\"30746562\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2003,\n      \"finding\": \"Cardiac-directed expression of human AC8 in transgenic mice leads to increased cAMP-PDE activity (particularly PDE4 and PDE1 isoforms), creating strong compartmentation of cAMP that selectively activates sarcoplasmic reticulum Ca2+ uptake but shields L-type Ca2+ channels from the elevated cAMP, preventing Ca2+ overload.\",\n      \"method\": \"Transgenic mouse model (AC8TG), PDE isoform activity assays, L-type Ca2+ current recordings (patch-clamp), contractility measurements\",\n      \"journal\": \"FASEB journal\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — genetic model with direct biochemical PDE assays and electrophysiological recordings, findings consistent across two related papers from same group\",\n      \"pmids\": [\"12890691\", \"12206999\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2010,\n      \"finding\": \"ADCY8 (calmodulin-activated adenylyl cyclase) is cell-autonomously required in retinal neurons for normal midline crossing in zebrafish; knockdown of ADCY8 makes retinal axons insensitive to SDF1 (which normally antagonizes slit-mediated repulsion via cAMP signaling) and induces ipsilateral misprojections.\",\n      \"method\": \"Antisense morpholino knockdown in zebrafish, in vivo axon tracing, epistasis with slit signaling pathway\",\n      \"journal\": \"The Journal of neuroscience\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — cell-autonomous requirement demonstrated by morpholino knockdown with defined axon pathfinding phenotype and pathway epistasis, single lab, ortholog study\",\n      \"pmids\": [\"20505109\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2012,\n      \"finding\": \"Notch pathway activation (via Notch target genes Hrt1 and Hrt3) attenuates IL-1β-induced de novo AC8 expression in vascular smooth muscle cells (VSMCs) undergoing trans-differentiation; inhibition of Notch amplifies IL-1β-driven AC8 upregulation and VSMC trans-differentiation phenotype; this was confirmed in an in vivo rat carotid balloon-injury model of restenosis.\",\n      \"method\": \"Notch pathway pharmacological inhibition/activation, overexpression of Hrt1/Hrt3, in vivo carotid balloon-injury model, qPCR/western blotting\",\n      \"journal\": \"The Journal of biological chemistry\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — in vitro gain- and loss-of-function with pathway intermediates confirmed in vivo, single lab\",\n      \"pmids\": [\"22613711\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2025,\n      \"finding\": \"CRISPR-Cas9 deletion of ADCY8 (AC8) in U87MG glioma cells causes system-wide remodeling of the mitochondrial proteome, shifting metabolic balance from glycolysis toward oxidative phosphorylation (increased oxygen consumption, elevated TCA cycle flux, decreased glycolytic flux), indicating that AC8-mediated transcriptional regulation suppresses mitochondrial oxidative metabolism in these cancer cells.\",\n      \"method\": \"CRISPR-Cas9 knockout, quantitative proteomics, oxygen consumption measurement, metabolic flux analysis (TCA cycle and glycolysis)\",\n      \"journal\": \"Biochimica et biophysica acta. Bioenergetics\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — clean CRISPR KO with multiple orthogonal metabolic readouts, single lab, single study\",\n      \"pmids\": [\"40669556\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2025,\n      \"finding\": \"Adcy8 knockout mice show impaired lipolysis in adipose tissue with reduced cAMP levels and decreased phosphorylation of lipolytic enzymes (via the cAMP-PKA pathway); forskolin-enhanced lipolysis observed in wild-type mice is abrogated in Adcy8-/- mice, establishing AC8 as the mediator of cAMP-PKA-dependent lipolysis in adipose tissue.\",\n      \"method\": \"Adcy8 knockout mouse model (normal and high-fat diet), cAMP measurement, phosphorylation assays of lipolytic enzymes, forskolin stimulation experiment\",\n      \"journal\": \"Biochimica et biophysica acta. Molecular and cell biology of lipids\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — genetic KO with direct biochemical readouts and pharmacological rescue experiment, single lab\",\n      \"pmids\": [\"40527393\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2024,\n      \"finding\": \"In TGAC8 mice (cardiac-specific AC8 overexpression), chronic adenylyl cyclase activation leads to cell-autonomous RelA-mediated NF-κB signaling in cardiomyocytes via calcium-PKA signaling; this drives non-cell-autonomous proinflammatory signaling in cardiac endothelial and smooth muscle cells, expansion of myocardial immune cells, and elevated serum inflammatory cytokines, preceding cardiac fibrosis.\",\n      \"method\": \"Cardiac-specific transgenic mouse model, NF-κB pathway activation assays, PKA inhibition, cell-type-specific analysis, cytokine measurement\",\n      \"journal\": \"GeroScience\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — genetic model with mechanistic pathway (Ca2+/PKA/RelA) identified and pharmacological confirmation, single lab\",\n      \"pmids\": [\"38499959\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2021,\n      \"finding\": \"In breast cancer cells, overexpression of AC8 shifts the AC8-Orai1α stoichiometry in favor of AC8, impairing PKA-dependent Orai1α inactivation (which normally occurs via phosphorylation at serine-34 of Orai1α by PKA activated downstream of the AC8-Orai1 complex), thereby contributing to enhanced store-operated Ca2+ entry in triple-negative breast cancer cells.\",\n      \"method\": \"Functional analysis of AC8-Orai1 interaction in breast cancer cell lines, Ca2+ entry measurements, PKA phosphorylation assays (cited in review of experimental findings)\",\n      \"journal\": \"Cells\",\n      \"confidence\": \"Low\",\n      \"confidence_rationale\": \"Tier 3 / Weak — review/synthesis paper summarizing mechanistic findings; primary experiments cited but not fully described in this abstract; mechanism of Orai1α Ser-34 phosphorylation is attributed to prior work\",\n      \"pmids\": [\"34070268\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2024,\n      \"finding\": \"In atrial myocytes, lysosomal Ca2+ release via the NAADP pathway contributes to α-adrenergic (phenylephrine)-stimulated cAMP production through activation of Ca2+-sensitive AC1 and AC8; double knockout of Adcy1 and Adcy8 in mice reduces positive chronotropic and inotropic responses to phenylephrine, Ca2+ transient amplitude, and cytosolic cAMP levels in response to phenylephrine.\",\n      \"method\": \"Adcy1/Adcy8 double-knockout mouse model, NAADP pathway inhibitors (BZ-194, SAN4825, Bafilomycin A1), cAMP biosensors in neonatal atrial myocytes, Ca2+ transient measurements\",\n      \"journal\": \"bioRxiv\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — genetic double-KO model with pharmacological dissection and multiple readouts, preprint not yet peer-reviewed\",\n      \"pmids\": [\"bio_10.1101_2024.11.25.625232\"],\n      \"is_preprint\": true\n    }\n  ],\n  \"current_model\": \"ADCY8 (AC8) is a transmembrane adenylyl cyclase that converts ATP to cAMP in response to Ca2+/calmodulin stimulation; it forms a direct complex with Orai1 (via N-terminal interaction) to couple store-operated Ca2+ entry to cAMP synthesis, is scaffolded by AKAP79/150 which recruits PKA to phosphorylate AC8 at Ser-112 providing negative feedback, binds the PP2A core dimer (antagonized by Ca2+/calmodulin) at its N-terminus, traffics to plasma membrane lipid rafts via complex N-glycosylation and caveolin-1 interaction, and is structurally defined by a cryo-EM structure showing Gαs- and CaM-binding interfaces; in physiological contexts AC8 regulates cardiac contractility, adipose lipolysis via cAMP-PKA, axonal pathfinding, lysosomal Ca2+-dependent atrial adrenergic responses, and metabolic reprogramming in cancer cells.\"\n}\n```","stage2_raw":"{\n  \"mechanistic_narrative\": \"ADCY8 (AC8) is a Ca2+/calmodulin-stimulated transmembrane adenylyl cyclase that integrates local Ca2+ signals into compartmentalized cAMP synthesis at plasma-membrane microdomains [#0, #3]. It is physically coupled to store-operated Ca2+ entry through a direct N-terminal interaction with the Orai1 channel pore, so that Ca2+ entering via Orai1 drives AC8-dependent cAMP production within a shared AC8-Orai1 microdomain [#0]. AC8 activity is shaped by a regulatory scaffold: AKAP79/150 binds AC8 and limits its sensitivity to intracellular Ca2+, and the AKAP-recruited PKA phosphorylates AC8 at Ser-112 on its N-terminus to provide negative feedback that slows cAMP production during Ca2+ oscillations [#1, #2]. The same N-terminus binds a catalytically active PP2A core dimer in a manner antagonized by Ca2+/calmodulin, and the enzyme is processed with complex N-glycans and trafficked through lipid rafts via a dynamic caveolin-1 interaction that requires cytoskeletal integrity [#3, #5]. A cryo-EM structure of AC8 bound to G\\u03b1s and forskolin, together with structural proteomics, defines the ordered domain architecture and the contact interfaces for CaM, G\\u03b1s, and G\\u03b2\\u03b3 [#4]. Through cAMP-PKA signaling AC8 governs diverse physiological outputs: it mediates cAMP-PKA-dependent lipolysis in adipose tissue [#10], shapes compartmentalized cardiac cAMP that selectively tunes sarcoplasmic reticulum Ca2+ uptake while shielding L-type Ca2+ channels [#6], cooperates with AC1 to couple lysosomal NAADP-driven Ca2+ release to \\u03b1-adrenergic chronotropic and inotropic responses in atrial myocytes [#13], and is cell-autonomously required in retinal neurons for cAMP-dependent axonal midline crossing [#7].\",\n  \"teleology\": [\n    {\n      \"year\": 2003,\n      \"claim\": \"Established that AC8-generated cAMP is spatially compartmentalized rather than diffuse, explaining how a single cyclase can selectively tune some Ca2+ handling pathways without causing global Ca2+ overload.\",\n      \"evidence\": \"Cardiac-directed AC8 transgenic mice with PDE isoform activity assays, patch-clamp L-type Ca2+ recordings and contractility measurements\",\n      \"pmids\": [\"12890691\", \"12206999\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Did not resolve the molecular scaffolds enforcing the cAMP compartment\", \"PDE coupling specificity to AC8 not structurally defined\"]\n    },\n    {\n      \"year\": 2005,\n      \"claim\": \"Identified PP2A as a direct N-terminal AC8 partner antagonized by Ca2+/calmodulin, revealing a phosphatase arm in AC8 microdomain regulation and placing AC8 in lipid rafts.\",\n      \"evidence\": \"Yeast two-hybrid screen with GST pulldown from native forebrain membranes, phosphatase activity assay, and lipid raft fractionation\",\n      \"pmids\": [\"16258073\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Substrates dephosphorylated by AC8-bound PP2A not identified\", \"Functional consequence of CaM-PP2A competition on cAMP output not quantified\"]\n    },\n    {\n      \"year\": 2010,\n      \"claim\": \"Showed AKAP79/150 directly tunes down AC8's Ca2+ sensitivity, identifying a scaffold-based set-point control over Ca2+-to-cAMP coupling, validated in endogenous secretory and neuronal cells.\",\n      \"evidence\": \"Co-immunoprecipitation and live-cell imaging in HEK293 plus endogenous insulin-secreting and hippocampal neuron systems\",\n      \"pmids\": [\"20410303\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Did not yet define the PKA phosphorylation event mediating feedback\", \"Stoichiometry of the AKAP-AC8 complex unknown\"]\n    },\n    {\n      \"year\": 2010,\n      \"claim\": \"Demonstrated a cell-autonomous developmental role for ADCY8 in cAMP-dependent retinal axon guidance, extending its function beyond secretory and cardiac contexts.\",\n      \"evidence\": \"Morpholino knockdown in zebrafish with in vivo axon tracing and epistasis against slit/SDF1 signaling\",\n      \"pmids\": [\"20505109\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Ortholog knockdown; mammalian requirement not tested\", \"Direct biochemical link between AC8 cAMP and slit responsiveness not shown\"]\n    },\n    {\n      \"year\": 2012,\n      \"claim\": \"Resolved the direct AC8-Orai1 interaction, establishing the physical basis by which store-operated Ca2+ entry is converted into local cAMP.\",\n      \"evidence\": \"Co-IP, GST pulldown, and microdomain-targeted FRET biosensors with live-cell imaging\",\n      \"pmids\": [\"22494970\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Stoichiometry of AC8-Orai1 in native cells not defined\", \"Structural interface of the N-terminal interaction unresolved\"]\n    },\n    {\n      \"year\": 2012,\n      \"claim\": \"Pinpointed Ser-112 as the PKA phosphosite mediating AKAP79-dependent negative feedback, completing the local feedback loop that dampens cAMP during Ca2+ oscillations.\",\n      \"evidence\": \"Site-directed mutagenesis with imposed Ca2+ oscillations and live-cell cAMP biosensors plus Co-IP\",\n      \"pmids\": [\"22976297\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Single lab; in vivo physiological role of Ser-112 phosphorylation untested\", \"Kinetics of phosphorylation/dephosphorylation cycling not measured\"]\n    },\n    {\n      \"year\": 2012,\n      \"claim\": \"Showed AC8 expression is transcriptionally controlled, with Notch signaling restraining IL-1\\u03b2-driven AC8 induction during vascular smooth muscle trans-differentiation.\",\n      \"evidence\": \"Notch pharmacological modulation and Hrt1/Hrt3 overexpression in VSMCs with an in vivo rat carotid balloon-injury model\",\n      \"pmids\": [\"22613711\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Direct Notch-target binding at the ADCY8 locus not demonstrated\", \"cAMP-dependent mechanism downstream of AC8 in VSMCs not defined\"]\n    },\n    {\n      \"year\": 2019,\n      \"claim\": \"Defined the trafficking and microdomain maintenance route of AC8, linking complex N-glycosylation, caveolin-1, and cytoskeletal integrity to AC8 plasma-membrane targeting and responsiveness.\",\n      \"evidence\": \"Site-directed mutagenesis, pharmacological disruption, biochemical fractionation and live-cell imaging\",\n      \"pmids\": [\"30746562\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Single lab; caveolin-1 interaction interface not mapped\", \"Whether trafficking defects alter Ca2+-cAMP coupling in vivo unknown\"]\n    },\n    {\n      \"year\": 2024,\n      \"claim\": \"Provided the first near-atomic AC8 architecture and mapped the regulatory contact surfaces for G\\u03b1s, CaM, and G\\u03b2\\u03b3, giving a structural framework for its allosteric control.\",\n      \"evidence\": \"3.5 \\u00c5 cryo-EM of bovine AC8 with G\\u03b1s and forskolin, integrated with LiP-MS and XL-MS structural proteomics\",\n      \"pmids\": [\"38351373\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Captured state did not favour tight nucleotide binding, leaving the catalytic conformation undefined\", \"Identity of the negatively charged extracellular pocket interactor unknown\", \"N-terminal regulatory region not resolved\"]\n    },\n    {\n      \"year\": 2024,\n      \"claim\": \"Connected chronic AC8 activation to inflammatory remodeling, showing cardiac cAMP overdrive triggers cell-autonomous RelA/NF-\\u03baB and non-cell-autonomous proinflammatory signaling preceding fibrosis.\",\n      \"evidence\": \"Cardiac-specific TGAC8 transgenic mice with NF-\\u03baB assays, PKA inhibition, cell-type-specific analysis and cytokine measurement\",\n      \"pmids\": [\"38499959\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Gain-of-function model; relevance to physiological AC8 levels unclear\", \"Mechanism linking PKA to RelA activation not fully defined\"]\n    },\n    {\n      \"year\": 2024,\n      \"claim\": \"Linked lysosomal NAADP-driven Ca2+ release to AC8/AC1 activation in atrial \\u03b1-adrenergic responses, expanding the Ca2+ sources that feed AC8.\",\n      \"evidence\": \"Adcy1/Adcy8 double-knockout mice with NAADP-pathway inhibitors, atrial cAMP biosensors and Ca2+ transient measurements (preprint)\",\n      \"pmids\": [\"bio_10.1101_2024.11.25.625232\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Preprint, not peer-reviewed\", \"Relative contributions of AC1 vs AC8 not separated\", \"Direct AC8-lysosomal coupling mechanism unresolved\"]\n    },\n    {\n      \"year\": 2025,\n      \"claim\": \"Established AC8 as the obligate cyclase for cAMP-PKA-dependent adipose lipolysis using genetic loss-of-function with pharmacological rescue.\",\n      \"evidence\": \"Adcy8 knockout mice on normal and high-fat diet with cAMP measurement, lipolytic enzyme phosphorylation assays and forskolin stimulation\",\n      \"pmids\": [\"40527393\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Single lab; upstream activator of adipose AC8 not defined\", \"Tissue-autonomy versus systemic effects not fully dissected\"]\n    },\n    {\n      \"year\": 2025,\n      \"claim\": \"Revealed a transcriptional/metabolic function in cancer, where AC8 loss reprograms the mitochondrial proteome and shifts cells from glycolysis to oxidative phosphorylation.\",\n      \"evidence\": \"CRISPR-Cas9 knockout in U87MG glioma cells with quantitative proteomics, oxygen consumption and TCA/glycolytic flux analysis\",\n      \"pmids\": [\"40669556\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Mechanism by which AC8 controls mitochondrial gene/protein expression not defined\", \"Single cell line; generality across cancers untested\", \"cAMP-dependence of the metabolic effect not demonstrated\"]\n    },\n    {\n      \"year\": null,\n      \"claim\": \"How the structurally defined AC8 catalytic and N-terminal regulatory architecture is dynamically organized within the Orai1/AKAP79/PP2A microdomain to control cAMP kinetics in native tissues remains unresolved.\",\n      \"evidence\": \"\",\n      \"pmids\": [],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Catalytically competent AC8 conformation not captured\", \"Native-tissue stoichiometry of the AC8 signaling complex unknown\", \"Mechanism coupling AC8 to transcriptional/metabolic outputs undefined\"]\n    }\n  ],\n  \"mechanism_profile\": {\n    \"molecular_activity\": [\n      {\"term_id\": \"GO:0009975\", \"supporting_discovery_ids\": [4, 6, 10]},\n      {\"term_id\": \"GO:0016740\", \"supporting_discovery_ids\": [4]}\n    ],\n    \"localization\": [\n      {\"term_id\": \"GO:0005886\", \"supporting_discovery_ids\": [0, 5]},\n      {\"term_id\": \"GO:0005856\", \"supporting_discovery_ids\": [5]}\n    ],\n    \"pathway\": [\n      {\"term_id\": \"R-HSA-162582\", \"supporting_discovery_ids\": [0, 2, 6]},\n      {\"term_id\": \"R-HSA-1430728\", \"supporting_discovery_ids\": [9, 10]}\n    ],\n    \"complexes\": [],\n    \"partners\": [\"ORAI1\", \"AKAP5\", \"PRKACA\", \"PPP2CA\", \"PPP2R1A\", \"GNAS\", \"CAV1\"],\n    \"other_free_text\": []\n  }\n}","audit_flag":null,"evaluation":{"pairwise":"win","faith_supported":6,"faith_total":6,"faith_pct":100.0}}