{"gene":"PRKRA","run_date":"2026-06-10T06:43:35","timeline":{"discoveries":[{"year":2020,"finding":"Five DYT16 substitution mutations in PACT/PRKRA cause stronger PACT-PACT homodimerization interactions and enhanced PKR activation, leading to dysregulation of the integrated stress response (ISR) and increased apoptosis in patient-derived lymphoblasts. In the absence of stress, PACT and PKR are both bound and inhibited by TRBP; under stress, inhibitory PACT-TRBP and PKR-TRBP interactions dissociate, enabling pro-apoptotic PACT-PACT and PACT-PKR interactions. The flavonoid luteolin disrupts PACT-PKR interactions and rescues the enhanced ER-stress sensitivity.","method":"Biochemical interaction assays (co-immunoprecipitation), PKR kinase activation assays, eIF2α phosphorylation measurement, apoptosis assays in DYT16 patient-derived lymphoblasts, luteolin rescue experiments","journal":"Neurobiology of disease","confidence":"High","confidence_rationale":"Tier 2 / Strong — reciprocal co-IP, kinase activity assays, patient-derived cells, multiple orthogonal methods, replicated across several DYT16 mutations in one rigorous study","pmids":["33049316"],"is_preprint":false},{"year":2019,"finding":"A frameshift (FS) DYT16 mutation in PACT produces a truncated protein that loses its ability to bind dsRNA and to interact directly with PKR, but retains the ability to interact with PACT itself and with the PKR-inhibitory protein TRBP. When expressed in mammalian cells, the truncated protein aggregates and triggers caspase-dependent apoptosis both in a PKR/PACT-dependent and independent manner. Interaction of the FS mutant with TRBP displaces PACT from the TRBP-PACT complex, resulting in PKR activation and apoptosis.","method":"In vitro dsRNA-binding assay, co-immunoprecipitation of mutant PACT with PKR and TRBP, fluorescent fusion protein aggregation imaging in mammalian cells, caspase activation assays","journal":"Journal of cellular biochemistry","confidence":"High","confidence_rationale":"Tier 2 / Moderate — multiple orthogonal methods (binding assay, co-IP, live imaging, caspase assay) in a single focused study","pmids":["31246344"],"is_preprint":false},{"year":2024,"finding":"A frameshift mutation in the murine Prkra gene (Prkralear-5J) produces a truncated PACT/RAX protein that retains its ability to interact with PKR but inhibits PKR activation, resulting in reduced eIF2α phosphorylation in the cerebellum and Purkinje neurons. Homozygous mutant mice show abnormal cerebellar development and severe lack of Purkinje neuron dendritic arborization, establishing PACT-mediated PKR activation and eIF2α phosphorylation as required for normal cerebellar development.","method":"Biochemical co-IP (PACT-PKR interaction), PKR kinase activity assays, eIF2α phosphorylation measurement by western blot, histological analysis of cerebellar development, Purkinje neuron morphology assessment in Prkralear-5J homozygous mice","journal":"Disease models & mechanisms","confidence":"High","confidence_rationale":"Tier 2 / Moderate — in vivo mouse model with multiple orthogonal biochemical and histological methods in a single focused study","pmids":["39512178"],"is_preprint":false},{"year":2025,"finding":"Prkra dimer (via its dimerized dsRNA-binding domain 3) acts as the genuine dsRNA sensor in pluripotent cells (zebrafish embryos and mouse embryonic stem cells) in the absence of an active interferon system. Upon dsRNA binding, activated Prkra dimer sequesters eIF2 complexes away from the translation machinery, inhibiting global protein synthesis in a PKR-independent manner. This mechanism restricts RNA virus replication in zebrafish embryos and compensates for PKR function in differentiated cells.","method":"dsRNA binding assays, eIF2 complex pull-down/sequestration assays, global translation measurements in zebrafish embryos and mouse ES cells, PKR-independent epistasis experiments, virus replication assays","journal":"Molecular cell","confidence":"High","confidence_rationale":"Tier 1-2 / Moderate — in vitro binding/sequestration reconstitution, multiple model systems (zebrafish, mouse ES cells), orthogonal functional readouts (translation, virus replication)","pmids":["40280134"],"is_preprint":false},{"year":2025,"finding":"N1-methylpseudouridine (m1Ψ) modification of IVT mRNA significantly reduces its binding affinity to the Prkra dimer, thereby preventing Prkra-mediated global translation repression in early zebrafish embryos (pluripotent cells). Unmodified IVT mRNA dsRNA by-products activate Prkra to induce cell necrosis and delay maternal-zygotic transition by reducing global translation efficiency.","method":"Binding affinity assays between m1Ψ-modified dsRNA and Prkra dimer, global translation efficiency measurements, cell viability and MZT assays in zebrafish embryos with modified/unmodified IVT mRNA","journal":"Nucleic acids research","confidence":"High","confidence_rationale":"Tier 1-2 / Moderate — direct binding affinity measurement, functional translation and viability assays, mechanistic link to Prkra established in vivo","pmids":["41099713"],"is_preprint":false},{"year":2011,"finding":"A missense mutation (Serine 130 to Proline) in the second RNA-binding domain of mouse Prkra (RAX/PACT) disrupts dsRNA binding without affecting mRNA expression, but significantly lowers steady-state protein levels in the brain. Homozygous rep mice display defects in ear development, growth, craniofacial development, and ovarian structure, establishing the dsRNA-binding function of Prkra as important for multiple developmental processes.","method":"Chemical mutagenesis, co-segregation mapping, dsRNA binding assay in vitro, western blot for protein levels, histological phenotype analysis of ear, skull, and ovary in homozygous mice","journal":"PloS one","confidence":"High","confidence_rationale":"Tier 1-2 / Moderate — direct in vitro dsRNA binding assay with defined point mutation, in vivo developmental phenotype, multiple orthogonal methods","pmids":["22194846"],"is_preprint":false},{"year":2022,"finding":"The DYT-PRKRA P222L mutation in PACT augments PACT's ability to induce IFN-β in response to dsRNA via the RIG-I signaling pathway. Basal expression of IFN-β and interferon-stimulated genes (ISGs) is higher in DYT-PRKRA patient cells, and IFN-β and ISGs are induced to higher levels in DYT-PRKRA cells following dsRNA stimulation, demonstrating that P222L enhances PACT's role in type I IFN induction.","method":"IFN-β reporter assays, qRT-PCR for ISG expression, dsRNA stimulation of DYT-PRKRA patient-derived cells and controls","journal":"Biomolecules","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — patient-derived cell model with functional assays (reporter and gene expression), single lab but two orthogonal readouts","pmids":["35625640"],"is_preprint":false},{"year":2023,"finding":"Luteolin, a plant flavonoid previously identified as an inhibitor of the PACT-PKR interaction by high-throughput screening, markedly disrupts pathological PACT-PKR interactions in DYT-PRKRA cells (carrying enhanced PACT-PKR interaction mutations) and protects these cells against apoptosis.","method":"PACT-PKR interaction assays (co-IP), apoptosis assays in DYT-PRKRA patient-derived cells treated with luteolin","journal":"Frontiers in pharmacology","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — co-IP interaction disruption assay and functional apoptosis readout in patient-derived cells, single lab","pmids":["36874028"],"is_preprint":false},{"year":2011,"finding":"PRKRA (PACT) is a direct target gene of liver-specific miR-122. miR-122 and siRNA-mediated knockdown of PRKRA both facilitate the accumulation of newly synthesized miRNAs (but do not detectably affect endogenous miRNA levels), implicating PRKRA in regulation of miRNA biogenesis, consistent with its known role as a Dicer-interacting protein.","method":"Affinity purification with biotinylated synthetic miR-122, microarray analysis of pulled-down RNAs, qRT-PCR validation, siRNA knockdown of PRKRA with miRNA quantification","journal":"Nucleic acids research","confidence":"Medium","confidence_rationale":"Tier 2-3 / Moderate — affinity purification plus functional siRNA knockdown with miRNA readout, single lab, two orthogonal approaches","pmids":["21937511"],"is_preprint":false},{"year":2018,"finding":"PRKRA/PACT promotes chemoresistance in mucinous ovarian cancer (MOC) via its interaction with Dicer, which regulates expression of miR-515-3p. miR-515-3p, in turn, increases sensitivity to oxaliplatin by targeting AXL. PRKRA knockdown combined with oxaliplatin produced significant antitumor effects in orthotopic mouse MOC models.","method":"siRNA kinome screen, orthotopic mouse model, siRNA knockdown of PRKRA, miR-515-3p expression analysis, AXL targeting validation","journal":"Molecular cancer therapeutics","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — in vivo orthotopic model, siRNA KD, mechanistic pathway from PACT–Dicer–miR-515-3p–AXL, single lab","pmids":["30305341"],"is_preprint":false},{"year":2020,"finding":"PACT/PRKRA interacts with the transcription factor DMRT1 (identified by immunoprecipitation from Xenopus testis followed by MS/MS), and significantly enhances DMRT1-driven transcriptional activity in transfected 293T cells. p53 represses DMRT1 activity and strongly attenuates the enhancement conferred by PACT/PRKRA.","method":"Co-immunoprecipitation from Xenopus testes with anti-DMRT1 antibody, MS/MS identification of interactors, luciferase reporter assay in 293T cells, in situ hybridization for Pact/Prkra mRNA in tadpole gonads","journal":"Genetics and molecular biology","confidence":"Medium","confidence_rationale":"Tier 3 / Moderate — co-IP plus reporter assay, single lab, two orthogonal approaches but limited mechanistic depth","pmids":["32251494"],"is_preprint":false},{"year":2023,"finding":"PRKRA upregulates the transcription of MMP1 via the NF-κB pathway in pancreatic cancer cells. ChIP and dual-luciferase reporter assays demonstrated that the NF-κB subunit P65 binds to the MMP1 promoter downstream of PRKRA. PRKRA knockout decreased organoid proliferation, while overexpression enhanced xenograft growth and chemoresistance.","method":"siRNA/CRISPR knockdown and lentiviral overexpression, transcriptome sequencing, ChIP assay for P65 binding to MMP1 promoter, dual-luciferase reporter assay, xenograft mouse model, organoid culture","journal":"Heliyon","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — ChIP and reporter assay for direct mechanistic link, in vivo xenograft, single lab with multiple orthogonal methods","pmids":["37484321"],"is_preprint":false},{"year":2025,"finding":"PRKRA knockdown in hepatic cell lines (HepG2, HuH7) increases intracellular total cholesterol and decreases LDL uptake, while PRKRA overexpression has the opposite effect. Mechanistically, reduced PRKRA levels are associated with HMGCS1 upregulation (increased cholesterol biosynthesis) and LDLR downregulation (reduced LDL uptake), as revealed by transcriptome sequencing.","method":"siRNA knockdown and overexpression in HepG2/HuH7 cells, intracellular cholesterol measurement, Dil-LDL uptake assay, transcriptome sequencing","journal":"Lipids in health and disease","confidence":"Low","confidence_rationale":"Tier 3 / Weak — single lab, overexpression/KD phenotype with transcriptomics but no direct mechanistic link established between PRKRA and cholesterol pathway enzymes","pmids":["40349061"],"is_preprint":false}],"current_model":"PRKRA/PACT is a dsRNA-binding protein that, upon stress-induced homodimerization (via its third dsRNA-binding domain), directly activates the protein kinase PKR through a physical interaction, leading to eIF2α phosphorylation and global translation inhibition as part of the integrated stress response; in pluripotent cells lacking active PKR/interferon signaling, PRKRA dimers can also sequester eIF2 complexes to inhibit translation in a PKR-independent manner. In unstressed cells, PRKRA is held inactive by the inhibitory protein TRBP; DYT-PRKRA dystonia mutations enhance PACT-PACT and PACT-PKR interactions, dysregulating the ISR and promoting apoptosis, including in cerebellar Purkinje neurons. PRKRA also participates in innate immunity by facilitating type I IFN induction via RIG-I signaling, in miRNA biogenesis via interaction with Dicer, and in transcriptional regulation by modulating DMRT1 activity."},"narrative":{"mechanistic_narrative":"PRKRA (PACT/RAX) is a double-stranded RNA-binding protein that functions as a central activator of the integrated stress response (ISR), coupling cellular stress to translational control [PMID:33049316, PMID:40280134]. Upon stress, PACT undergoes homodimerization through its third dsRNA-binding domain and physically engages the protein kinase PKR, driving PKR activation and downstream eIF2α phosphorylation; in unstressed cells PACT and PKR are held inactive in complexes with the inhibitory protein TRBP, and stress dissociates these inhibitory interactions to license pro-apoptotic PACT-PACT and PACT-PKR contacts [PMID:33049316]. In pluripotent cells lacking an active interferon/PKR system, the PACT dimer itself acts as the genuine dsRNA sensor and represses global protein synthesis in a PKR-independent manner by sequestering eIF2 complexes away from the translation machinery, a mechanism that restricts RNA virus replication; this dsRNA sensing depends on binding affinity, since m1ψ modification of dsRNA reduces PACT binding and relieves translational repression [PMID:40280134, PMID:41099713]. PACT-mediated PKR activation and eIF2α phosphorylation are required for normal cerebellar development and Purkinje neuron dendritic arborization in vivo, and dsRNA-binding-disrupting mutations cause broad developmental defects [PMID:39512178, PMID:22194846]. DYT-PRKRA (DYT16) dystonia is caused by PRKRA mutations that strengthen PACT-PACT and PACT-PKR interactions, dysregulating the ISR and promoting caspase-dependent apoptosis; a frameshift mutant that loses dsRNA and PKR binding but retains TRBP binding displaces PACT from TRBP to activate PKR, and a separate mutation augments dsRNA-triggered IFN-β induction via RIG-I signaling [PMID:33049316, PMID:31246344, PMID:35625640]. The flavonoid luteolin disrupts pathological PACT-PKR interactions and protects DYT-PRKRA cells from apoptosis [PMID:33049316, PMID:36874028]. Beyond stress signaling, PACT contributes to miRNA biogenesis through interaction with Dicer [PMID:21937511, PMID:30305341], modulates DMRT1-driven transcription [PMID:32251494], and acts as a transcriptional regulator of MMP1 via NF-κB in cancer contexts [PMID:37484321].","teleology":[{"year":2011,"claim":"Establishing that PACT's dsRNA-binding function is physiologically required addressed whether this biochemical activity has organismal consequences beyond cell-based assays.","evidence":"Point mutation (S130P) in the second RNA-binding domain of mouse Prkra, in vitro dsRNA binding assay and developmental phenotyping of homozygous mice","pmids":["22194846"],"confidence":"High","gaps":["Did not resolve which downstream effector (PKR vs eIF2 sequestration) mediates the developmental phenotypes","Lowered steady-state protein levels confound interpretation of the binding defect"]},{"year":2011,"claim":"Identifying PRKRA as a miR-122 target and a regulator of newly synthesized miRNA accumulation extended PACT's role from stress signaling into miRNA biogenesis via its Dicer association.","evidence":"Affinity purification with biotinylated miR-122, microarray and qRT-PCR, plus siRNA knockdown of PRKRA with miRNA quantification","pmids":["21937511"],"confidence":"Medium","gaps":["Effect seen only on newly synthesized, not endogenous steady-state, miRNAs","Direct biochemical role within the Dicer complex not dissected"]},{"year":2018,"claim":"Linking PACT-Dicer-mediated miRNA regulation to chemoresistance showed the pathway has pathological consequences in cancer.","evidence":"siRNA kinome screen, PRKRA knockdown, miR-515-3p/AXL analysis, orthotopic mouse mucinous ovarian cancer model","pmids":["30305341"],"confidence":"Medium","gaps":["Whether the chemoresistance effect requires PACT's dsRNA/PKR functions is unaddressed","Direct PACT-Dicer binding not re-validated here"]},{"year":2019,"claim":"Dissecting a DYT16 frameshift mutant clarified how a PACT variant lacking dsRNA and PKR binding can still drive disease, implicating TRBP displacement as the toxic mechanism.","evidence":"In vitro dsRNA binding, co-IP of mutant with PKR/TRBP, aggregation imaging and caspase assays in mammalian cells","pmids":["31246344"],"confidence":"High","gaps":["Relative contributions of PKR-dependent vs independent apoptosis not quantified","Aggregation toxicity mechanism not separated from TRBP displacement"]},{"year":2020,"claim":"Demonstrating that DYT16 missense mutations strengthen PACT-PACT and PACT-PKR interactions to dysregulate the ISR provided the unifying molecular mechanism for the dystonia and a druggable target.","evidence":"Reciprocal co-IP, PKR kinase and eIF2α phosphorylation assays, apoptosis assays in patient-derived lymphoblasts, luteolin rescue","pmids":["33049316"],"confidence":"High","gaps":["Connection from lymphoblast ISR phenotype to neuronal pathology not directly shown","Stoichiometry of the TRBP-PACT-PKR switch not structurally defined"]},{"year":2020,"claim":"Identifying PACT as a DMRT1 co-activator antagonized by p53 placed PACT in transcriptional control of gonadal gene expression.","evidence":"Co-IP from Xenopus testis with MS/MS, luciferase reporter assays in 293T, in situ hybridization in tadpole gonads","pmids":["32251494"],"confidence":"Medium","gaps":["Direct vs indirect PACT-DMRT1 binding not distinguished","No demonstration of endogenous target gene regulation"]},{"year":2022,"claim":"Showing the P222L mutation augments dsRNA-induced IFN-β via RIG-I extended DYT-PRKRA pathology into innate immune dysregulation.","evidence":"IFN-β reporter assays and ISG qRT-PCR after dsRNA stimulation in patient-derived cells","pmids":["35625640"],"confidence":"Medium","gaps":["Mechanism by which PACT engages RIG-I not biochemically defined","Relationship between IFN induction and the PKR/ISR axis unresolved"]},{"year":2023,"claim":"Confirming luteolin disrupts pathological PACT-PKR interactions and rescues apoptosis advanced a candidate therapeutic strategy for DYT-PRKRA.","evidence":"Co-IP interaction-disruption and apoptosis assays in DYT-PRKRA patient-derived cells","pmids":["36874028"],"confidence":"Medium","gaps":["No in vivo efficacy or neuronal rescue shown","Binding site/selectivity of luteolin not defined"]},{"year":2023,"claim":"Demonstrating PRKRA drives MMP1 transcription through NF-κB/P65 revealed a transcriptional, pro-tumorigenic role in pancreatic cancer.","evidence":"Knockdown/overexpression, transcriptome sequencing, ChIP and dual-luciferase for P65-MMP1 promoter, xenograft and organoid models","pmids":["37484321"],"confidence":"Medium","gaps":["How PRKRA activates NF-κB upstream is not established","Link to PACT's canonical dsRNA/PKR functions unexplored"]},{"year":2024,"claim":"An in vivo mouse frameshift model established that PACT-mediated PKR activation and eIF2α phosphorylation are required for cerebellar development and Purkinje neuron arborization, connecting the molecular switch to neurodevelopmental phenotype.","evidence":"Co-IP, PKR kinase and eIF2α phosphorylation assays, cerebellar histology and Purkinje morphology in Prkralear-5J mice","pmids":["39512178"],"confidence":"High","gaps":["Cell-autonomous vs non-autonomous requirement in Purkinje neurons not resolved","Whether human DYT16 acts through the same developmental mechanism unclear"]},{"year":2025,"claim":"Defining PACT dimers as the genuine dsRNA sensor that sequesters eIF2 in PKR-deficient pluripotent cells revealed a PKR-independent translational-control mechanism and antiviral function.","evidence":"dsRNA binding and eIF2 sequestration assays, global translation and virus replication measurements in zebrafish embryos and mouse ES cells, PKR-independent epistasis","pmids":["40280134"],"confidence":"High","gaps":["Structural basis of eIF2 sequestration by the PACT dimer not defined","Whether this mechanism operates in differentiated human cells unaddressed"]},{"year":2025,"claim":"Showing m1ψ modification reduces dsRNA binding to PACT and relieves translational repression linked PACT sensing to mRNA therapeutic design and embryonic mRNA toxicity.","evidence":"Binding affinity assays of m1ψ-dsRNA to Prkra dimer, translation efficiency and viability/MZT assays in zebrafish embryos","pmids":["41099713"],"confidence":"High","gaps":["Molecular determinants of m1ψ-mediated affinity loss not mapped","Applicability to mammalian/human pluripotent systems untested"]},{"year":2025,"claim":"A hepatic cholesterol-handling phenotype hinted at a role for PRKRA in lipid metabolism via HMGCS1 and LDLR regulation.","evidence":"siRNA knockdown/overexpression in HepG2/HuH7, cholesterol and Dil-LDL uptake assays, transcriptome sequencing","pmids":["40349061"],"confidence":"Low","gaps":["No direct mechanistic link between PRKRA and cholesterol pathway enzymes established","Single-lab cell-line phenotype without in vivo validation"]},{"year":null,"claim":"How PACT's distinct activities — PKR-dependent ISR activation, PKR-independent eIF2 sequestration, RIG-I/IFN induction, Dicer-coupled miRNA biogenesis, and NF-κB/DMRT1 transcriptional roles — are partitioned and coordinated within a single cell remains unresolved.","evidence":"","pmids":[],"confidence":"Low","gaps":["No structural model of the TRBP-PACT-PKR regulatory switch","Tissue- and cell-state-specific selection among PACT's functions undefined","Direct mechanism of PACT-driven NF-κB and RIG-I activation unknown"]}],"mechanism_profile":{"molecular_activity":[{"term_id":"GO:0003723","term_label":"RNA binding","supporting_discovery_ids":[1,3,4,5]},{"term_id":"GO:0098772","term_label":"molecular function regulator activity","supporting_discovery_ids":[0,2,3]},{"term_id":"GO:0140110","term_label":"transcription regulator activity","supporting_discovery_ids":[10,11]},{"term_id":"GO:0140313","term_label":"molecular sequestering activity","supporting_discovery_ids":[3]}],"localization":[{"term_id":"GO:0005829","term_label":"cytosol","supporting_discovery_ids":[1]}],"pathway":[{"term_id":"R-HSA-8953897","term_label":"Cellular responses to stimuli","supporting_discovery_ids":[0,3]},{"term_id":"R-HSA-168256","term_label":"Immune System","supporting_discovery_ids":[6]},{"term_id":"R-HSA-8953854","term_label":"Metabolism of RNA","supporting_discovery_ids":[8,9]},{"term_id":"R-HSA-392499","term_label":"Metabolism of proteins","supporting_discovery_ids":[3,4]}],"complexes":[],"partners":["EIF2AK2","TARBP2","DICER1","DMRT1","RELA"],"other_free_text":[]}},"prefetch_data":{"uniprot":{"accession":"O75569","full_name":"Interferon-inducible double-stranded RNA-dependent protein kinase activator A","aliases":["PKR-associated protein X","PKR-associating protein X","Protein activator of the interferon-induced protein kinase","Protein kinase, interferon-inducible double-stranded RNA-dependent activator"],"length_aa":313,"mass_kda":34.4,"function":"Activates EIF2AK2/PKR in the absence of double-stranded RNA (dsRNA), leading to phosphorylation of EIF2S1/EFI2-alpha and inhibition of translation and induction of apoptosis. Required for siRNA production by DICER1 and for subsequent siRNA-mediated post-transcriptional gene silencing. Does not seem to be required for processing of pre-miRNA to miRNA by DICER1. Promotes UBC9-p53/TP53 association and sumoylation and phosphorylation of p53/TP53 at 'Lys-386' at 'Ser-392' respectively and enhances its activity in a EIF2AK2/PKR-dependent manner (By similarity). May function as regulator of gastric epithelial differentiation (By similarity)","subcellular_location":"Cytoplasm, perinuclear region; Cytoplasm","url":"https://www.uniprot.org/uniprotkb/O75569/entry"},"depmap":{"release":"DepMap","has_data":true,"is_common_essential":true,"resolved_as":"","url":"https://depmap.org/portal/gene/PRKRA","classification":"Common Essential","n_dependent_lines":818,"n_total_lines":1208,"dependency_fraction":0.6771523178807947},"opencell":{"profiled":false,"resolved_as":"","ensg_id":"","cell_line_id":"","localizations":[],"interactors":[{"gene":"DHX9","stoichiometry":0.2},{"gene":"DRG1","stoichiometry":0.2},{"gene":"ILF3","stoichiometry":0.2},{"gene":"LAMP1","stoichiometry":0.2},{"gene":"NPM1","stoichiometry":0.2},{"gene":"SRP68","stoichiometry":0.2}],"url":"https://opencell.sf.czbiohub.org/search/PRKRA","total_profiled":1310},"omim":[{"mim_id":"621027","title":"CHOLESTEROL-INDUCED REGULATOR OF METABOLISM RNA, NONCODING; CHROMR","url":"https://www.omim.org/entry/621027"},{"mim_id":"612067","title":"DYSTONIA 16; DYT16","url":"https://www.omim.org/entry/612067"},{"mim_id":"609631","title":"RNA SENSOR RIGI; RIGI","url":"https://www.omim.org/entry/609631"},{"mim_id":"606252","title":"TIR DOMAIN-CONTAINING ADAPTOR PROTEIN; TIRAP","url":"https://www.omim.org/entry/606252"},{"mim_id":"603424","title":"PROTEIN KINASE, INTERFERON-INDUCIBLE DOUBLE-STRANDED RNA-DEPENDENT ACTIVATOR; PRKRA","url":"https://www.omim.org/entry/603424"}],"hpa":{"profiled":true,"resolved_as":"","reliability":"Supported","locations":[{"location":"Cytosol","reliability":"Supported"},{"location":"Nucleoplasm","reliability":"Additional"}],"tissue_specificity":"Low tissue specificity","tissue_distribution":"Detected in all","driving_tissues":[],"url":"https://www.proteinatlas.org/search/PRKRA"},"hgnc":{"alias_symbol":["PACT","RAX","HSD14","DYT16"],"prev_symbol":[]},"alphafold":{"accession":"O75569","domains":[{"cath_id":"3.30.160.20","chopping":"22-102","consensus_level":"high","plddt":80.5304,"start":22,"end":102},{"cath_id":"3.30.160.20","chopping":"126-193","consensus_level":"high","plddt":87.5303,"start":126,"end":193},{"cath_id":"3.30.160.20","chopping":"214-310","consensus_level":"high","plddt":88.92,"start":214,"end":310}],"viewer_url":"https://alphafold.ebi.ac.uk/entry/O75569","model_url":"https://alphafold.ebi.ac.uk/files/AF-O75569-F1-model_v6.cif","pae_url":"https://alphafold.ebi.ac.uk/files/AF-O75569-F1-predicted_aligned_error_v6.png","plddt_mean":75.44},"mouse_models":{"mgi_url":"https://www.informatics.jax.org/marker/summary?nomen=PRKRA","jax_strain_url":"https://www.jax.org/strain/search?query=PRKRA"},"sequence":{"accession":"O75569","fasta_url":"https://rest.uniprot.org/uniprotkb/O75569.fasta","uniprot_url":"https://www.uniprot.org/uniprotkb/O75569/entry","alphafold_viewer_url":"https://alphafold.ebi.ac.uk/entry/O75569"}},"corpus_meta":[{"pmid":"18243799","id":"PMC_18243799","title":"DYT16, a novel young-onset dystonia-parkinsonism disorder: identification of a segregating mutation in the stress-response protein PRKRA.","date":"2008","source":"The Lancet. Neurology","url":"https://pubmed.ncbi.nlm.nih.gov/18243799","citation_count":163,"is_preprint":false},{"pmid":"25142429","id":"PMC_25142429","title":"DYT16 revisited: exome sequencing identifies PRKRA mutations in a European dystonia family.","date":"2014","source":"Movement disorders : official journal of the Movement Disorder Society","url":"https://pubmed.ncbi.nlm.nih.gov/25142429","citation_count":40,"is_preprint":false},{"pmid":"21937511","id":"PMC_21937511","title":"Hepato-specific microRNA-122 facilitates accumulation of newly synthesized miRNA through regulating PRKRA.","date":"2011","source":"Nucleic acids research","url":"https://pubmed.ncbi.nlm.nih.gov/21937511","citation_count":33,"is_preprint":false},{"pmid":"30305341","id":"PMC_30305341","title":"PRKRA/PACT Expression Promotes Chemoresistance of Mucinous Ovarian Cancer.","date":"2018","source":"Molecular cancer therapeutics","url":"https://pubmed.ncbi.nlm.nih.gov/30305341","citation_count":27,"is_preprint":false},{"pmid":"33049316","id":"PMC_33049316","title":"Dystonia 16 (DYT16) mutations in PACT cause dysregulated PKR activation and eIF2α signaling leading to a compromised stress response.","date":"2020","source":"Neurobiology of disease","url":"https://pubmed.ncbi.nlm.nih.gov/33049316","citation_count":27,"is_preprint":false},{"pmid":"29279192","id":"PMC_29279192","title":"The prevalence of PRKRA mutations in idiopathic dystonia.","date":"2017","source":"Parkinsonism & related disorders","url":"https://pubmed.ncbi.nlm.nih.gov/29279192","citation_count":25,"is_preprint":false},{"pmid":"22842711","id":"PMC_22842711","title":"DYT16: the original cases.","date":"2012","source":"Journal of neurology, neurosurgery, and psychiatry","url":"https://pubmed.ncbi.nlm.nih.gov/22842711","citation_count":18,"is_preprint":false},{"pmid":"31246344","id":"PMC_31246344","title":"A truncated PACT protein resulting from a frameshift mutation reported in movement disorder DYT16 triggers caspase activation and apoptosis.","date":"2019","source":"Journal of cellular biochemistry","url":"https://pubmed.ncbi.nlm.nih.gov/31246344","citation_count":15,"is_preprint":false},{"pmid":"22194846","id":"PMC_22194846","title":"Missense mutation in the second RNA binding domain reveals a role for Prkra (PACT/RAX) during skull development.","date":"2011","source":"PloS one","url":"https://pubmed.ncbi.nlm.nih.gov/22194846","citation_count":15,"is_preprint":false},{"pmid":"35035655","id":"PMC_35035655","title":"Novel lncRNA AL033381.2 Promotes Hepatocellular Carcinoma Progression by Upregulating PRKRA Expression.","date":"2022","source":"Oxidative medicine and cellular longevity","url":"https://pubmed.ncbi.nlm.nih.gov/35035655","citation_count":11,"is_preprint":false},{"pmid":"37484321","id":"PMC_37484321","title":"PRKRA promotes pancreatic cancer progression by upregulating MMP1 transcription via the NF-κB pathway.","date":"2023","source":"Heliyon","url":"https://pubmed.ncbi.nlm.nih.gov/37484321","citation_count":10,"is_preprint":false},{"pmid":"29859505","id":"PMC_29859505","title":"Structure-based design and profiling of novel 17β-HSD14 inhibitors.","date":"2018","source":"European journal of medicinal chemistry","url":"https://pubmed.ncbi.nlm.nih.gov/29859505","citation_count":10,"is_preprint":false},{"pmid":"30836176","id":"PMC_30836176","title":"Mutational and structural studies uncover crucial amino acids determining activity and stability of 17β-HSD14.","date":"2019","source":"The Journal of steroid biochemistry and molecular biology","url":"https://pubmed.ncbi.nlm.nih.gov/30836176","citation_count":10,"is_preprint":false},{"pmid":"19578509","id":"PMC_19578509","title":"DICER1 and PRKRA in Colon Adenocarcinoma.","date":"2008","source":"Biomarker 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genetics","url":"https://pubmed.ncbi.nlm.nih.gov/36186440","citation_count":6,"is_preprint":false},{"pmid":"40280134","id":"PMC_40280134","title":"Prkra dimer senses double-stranded RNAs to dictate global translation efficiency.","date":"2025","source":"Molecular cell","url":"https://pubmed.ncbi.nlm.nih.gov/40280134","citation_count":5,"is_preprint":false},{"pmid":"36874028","id":"PMC_36874028","title":"Luteolin protects DYT-PRKRA cells from apoptosis by suppressing PKR activation.","date":"2023","source":"Frontiers in pharmacology","url":"https://pubmed.ncbi.nlm.nih.gov/36874028","citation_count":5,"is_preprint":false},{"pmid":"28263879","id":"PMC_28263879","title":"Ctenopharyngodon idella IRF2 and ATF4 down-regulate the transcriptional level of PRKRA.","date":"2017","source":"Fish & shellfish immunology","url":"https://pubmed.ncbi.nlm.nih.gov/28263879","citation_count":5,"is_preprint":false},{"pmid":"35165239","id":"PMC_35165239","title":"Prkra Mutation Alters circRNA Expression During Embryonic External Ear Development.","date":"2022","source":"The Journal of craniofacial surgery","url":"https://pubmed.ncbi.nlm.nih.gov/35165239","citation_count":4,"is_preprint":false},{"pmid":"35625640","id":"PMC_35625640","title":"DYT-PRKRA Mutation P222L Enhances PACT's Stimulatory Activity on Type I Interferon Induction.","date":"2022","source":"Biomolecules","url":"https://pubmed.ncbi.nlm.nih.gov/35625640","citation_count":3,"is_preprint":false},{"pmid":"39512178","id":"PMC_39512178","title":"Mutation in Prkra results in cerebellar abnormality and reduced eIF2α phosphorylation in a model of DYT-PRKRA.","date":"2024","source":"Disease models & mechanisms","url":"https://pubmed.ncbi.nlm.nih.gov/39512178","citation_count":3,"is_preprint":false},{"pmid":"35968958","id":"PMC_35968958","title":"Point Mutation in Prkra Alters miRNA Expression During Embryonic External Ear Development.","date":"2022","source":"The Journal of craniofacial 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disease","url":"https://pubmed.ncbi.nlm.nih.gov/40349061","citation_count":0,"is_preprint":false},{"pmid":"40879515","id":"PMC_40879515","title":"A Homozygous c.74A>G Variant in PRKRA Causes DYT-PRKRA: Extensive Familial Segregation and a Variant of Uncertain Significance (VUS) Reclassification.","date":"2025","source":"Movement disorders : official journal of the Movement Disorder Society","url":"https://pubmed.ncbi.nlm.nih.gov/40879515","citation_count":0,"is_preprint":false},{"pmid":"37810563","id":"PMC_37810563","title":"Retracted: Novel lncRNA AL033381.2 Promotes Hepatocellular Carcinoma Progression by Upregulating PRKRA Expression.","date":"2023","source":"Oxidative medicine and cellular longevity","url":"https://pubmed.ncbi.nlm.nih.gov/37810563","citation_count":0,"is_preprint":false},{"pmid":null,"id":"bio_10.1101_2025.11.04.25339446","title":"Loss of function and structural variants in the  <i>PRKRA</i>  synaptic gene link mild cognitive impairment and 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stronger PACT-PACT homodimerization interactions and enhanced PKR activation, leading to dysregulation of the integrated stress response (ISR) and increased apoptosis in patient-derived lymphoblasts. In the absence of stress, PACT and PKR are both bound and inhibited by TRBP; under stress, inhibitory PACT-TRBP and PKR-TRBP interactions dissociate, enabling pro-apoptotic PACT-PACT and PACT-PKR interactions. The flavonoid luteolin disrupts PACT-PKR interactions and rescues the enhanced ER-stress sensitivity.\",\n      \"method\": \"Biochemical interaction assays (co-immunoprecipitation), PKR kinase activation assays, eIF2α phosphorylation measurement, apoptosis assays in DYT16 patient-derived lymphoblasts, luteolin rescue experiments\",\n      \"journal\": \"Neurobiology of disease\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — reciprocal co-IP, kinase activity assays, patient-derived cells, multiple orthogonal methods, replicated across several DYT16 mutations in one rigorous study\",\n      \"pmids\": [\"33049316\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2019,\n      \"finding\": \"A frameshift (FS) DYT16 mutation in PACT produces a truncated protein that loses its ability to bind dsRNA and to interact directly with PKR, but retains the ability to interact with PACT itself and with the PKR-inhibitory protein TRBP. When expressed in mammalian cells, the truncated protein aggregates and triggers caspase-dependent apoptosis both in a PKR/PACT-dependent and independent manner. Interaction of the FS mutant with TRBP displaces PACT from the TRBP-PACT complex, resulting in PKR activation and apoptosis.\",\n      \"method\": \"In vitro dsRNA-binding assay, co-immunoprecipitation of mutant PACT with PKR and TRBP, fluorescent fusion protein aggregation imaging in mammalian cells, caspase activation assays\",\n      \"journal\": \"Journal of cellular biochemistry\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — multiple orthogonal methods (binding assay, co-IP, live imaging, caspase assay) in a single focused study\",\n      \"pmids\": [\"31246344\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2024,\n      \"finding\": \"A frameshift mutation in the murine Prkra gene (Prkralear-5J) produces a truncated PACT/RAX protein that retains its ability to interact with PKR but inhibits PKR activation, resulting in reduced eIF2α phosphorylation in the cerebellum and Purkinje neurons. Homozygous mutant mice show abnormal cerebellar development and severe lack of Purkinje neuron dendritic arborization, establishing PACT-mediated PKR activation and eIF2α phosphorylation as required for normal cerebellar development.\",\n      \"method\": \"Biochemical co-IP (PACT-PKR interaction), PKR kinase activity assays, eIF2α phosphorylation measurement by western blot, histological analysis of cerebellar development, Purkinje neuron morphology assessment in Prkralear-5J homozygous mice\",\n      \"journal\": \"Disease models & mechanisms\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — in vivo mouse model with multiple orthogonal biochemical and histological methods in a single focused study\",\n      \"pmids\": [\"39512178\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2025,\n      \"finding\": \"Prkra dimer (via its dimerized dsRNA-binding domain 3) acts as the genuine dsRNA sensor in pluripotent cells (zebrafish embryos and mouse embryonic stem cells) in the absence of an active interferon system. Upon dsRNA binding, activated Prkra dimer sequesters eIF2 complexes away from the translation machinery, inhibiting global protein synthesis in a PKR-independent manner. This mechanism restricts RNA virus replication in zebrafish embryos and compensates for PKR function in differentiated cells.\",\n      \"method\": \"dsRNA binding assays, eIF2 complex pull-down/sequestration assays, global translation measurements in zebrafish embryos and mouse ES cells, PKR-independent epistasis experiments, virus replication assays\",\n      \"journal\": \"Molecular cell\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1-2 / Moderate — in vitro binding/sequestration reconstitution, multiple model systems (zebrafish, mouse ES cells), orthogonal functional readouts (translation, virus replication)\",\n      \"pmids\": [\"40280134\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2025,\n      \"finding\": \"N1-methylpseudouridine (m1Ψ) modification of IVT mRNA significantly reduces its binding affinity to the Prkra dimer, thereby preventing Prkra-mediated global translation repression in early zebrafish embryos (pluripotent cells). Unmodified IVT mRNA dsRNA by-products activate Prkra to induce cell necrosis and delay maternal-zygotic transition by reducing global translation efficiency.\",\n      \"method\": \"Binding affinity assays between m1Ψ-modified dsRNA and Prkra dimer, global translation efficiency measurements, cell viability and MZT assays in zebrafish embryos with modified/unmodified IVT mRNA\",\n      \"journal\": \"Nucleic acids research\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1-2 / Moderate — direct binding affinity measurement, functional translation and viability assays, mechanistic link to Prkra established in vivo\",\n      \"pmids\": [\"41099713\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2011,\n      \"finding\": \"A missense mutation (Serine 130 to Proline) in the second RNA-binding domain of mouse Prkra (RAX/PACT) disrupts dsRNA binding without affecting mRNA expression, but significantly lowers steady-state protein levels in the brain. Homozygous rep mice display defects in ear development, growth, craniofacial development, and ovarian structure, establishing the dsRNA-binding function of Prkra as important for multiple developmental processes.\",\n      \"method\": \"Chemical mutagenesis, co-segregation mapping, dsRNA binding assay in vitro, western blot for protein levels, histological phenotype analysis of ear, skull, and ovary in homozygous mice\",\n      \"journal\": \"PloS one\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1-2 / Moderate — direct in vitro dsRNA binding assay with defined point mutation, in vivo developmental phenotype, multiple orthogonal methods\",\n      \"pmids\": [\"22194846\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2022,\n      \"finding\": \"The DYT-PRKRA P222L mutation in PACT augments PACT's ability to induce IFN-β in response to dsRNA via the RIG-I signaling pathway. Basal expression of IFN-β and interferon-stimulated genes (ISGs) is higher in DYT-PRKRA patient cells, and IFN-β and ISGs are induced to higher levels in DYT-PRKRA cells following dsRNA stimulation, demonstrating that P222L enhances PACT's role in type I IFN induction.\",\n      \"method\": \"IFN-β reporter assays, qRT-PCR for ISG expression, dsRNA stimulation of DYT-PRKRA patient-derived cells and controls\",\n      \"journal\": \"Biomolecules\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — patient-derived cell model with functional assays (reporter and gene expression), single lab but two orthogonal readouts\",\n      \"pmids\": [\"35625640\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2023,\n      \"finding\": \"Luteolin, a plant flavonoid previously identified as an inhibitor of the PACT-PKR interaction by high-throughput screening, markedly disrupts pathological PACT-PKR interactions in DYT-PRKRA cells (carrying enhanced PACT-PKR interaction mutations) and protects these cells against apoptosis.\",\n      \"method\": \"PACT-PKR interaction assays (co-IP), apoptosis assays in DYT-PRKRA patient-derived cells treated with luteolin\",\n      \"journal\": \"Frontiers in pharmacology\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — co-IP interaction disruption assay and functional apoptosis readout in patient-derived cells, single lab\",\n      \"pmids\": [\"36874028\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2011,\n      \"finding\": \"PRKRA (PACT) is a direct target gene of liver-specific miR-122. miR-122 and siRNA-mediated knockdown of PRKRA both facilitate the accumulation of newly synthesized miRNAs (but do not detectably affect endogenous miRNA levels), implicating PRKRA in regulation of miRNA biogenesis, consistent with its known role as a Dicer-interacting protein.\",\n      \"method\": \"Affinity purification with biotinylated synthetic miR-122, microarray analysis of pulled-down RNAs, qRT-PCR validation, siRNA knockdown of PRKRA with miRNA quantification\",\n      \"journal\": \"Nucleic acids research\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2-3 / Moderate — affinity purification plus functional siRNA knockdown with miRNA readout, single lab, two orthogonal approaches\",\n      \"pmids\": [\"21937511\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2018,\n      \"finding\": \"PRKRA/PACT promotes chemoresistance in mucinous ovarian cancer (MOC) via its interaction with Dicer, which regulates expression of miR-515-3p. miR-515-3p, in turn, increases sensitivity to oxaliplatin by targeting AXL. PRKRA knockdown combined with oxaliplatin produced significant antitumor effects in orthotopic mouse MOC models.\",\n      \"method\": \"siRNA kinome screen, orthotopic mouse model, siRNA knockdown of PRKRA, miR-515-3p expression analysis, AXL targeting validation\",\n      \"journal\": \"Molecular cancer therapeutics\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — in vivo orthotopic model, siRNA KD, mechanistic pathway from PACT–Dicer–miR-515-3p–AXL, single lab\",\n      \"pmids\": [\"30305341\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2020,\n      \"finding\": \"PACT/PRKRA interacts with the transcription factor DMRT1 (identified by immunoprecipitation from Xenopus testis followed by MS/MS), and significantly enhances DMRT1-driven transcriptional activity in transfected 293T cells. p53 represses DMRT1 activity and strongly attenuates the enhancement conferred by PACT/PRKRA.\",\n      \"method\": \"Co-immunoprecipitation from Xenopus testes with anti-DMRT1 antibody, MS/MS identification of interactors, luciferase reporter assay in 293T cells, in situ hybridization for Pact/Prkra mRNA in tadpole gonads\",\n      \"journal\": \"Genetics and molecular biology\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 3 / Moderate — co-IP plus reporter assay, single lab, two orthogonal approaches but limited mechanistic depth\",\n      \"pmids\": [\"32251494\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2023,\n      \"finding\": \"PRKRA upregulates the transcription of MMP1 via the NF-κB pathway in pancreatic cancer cells. ChIP and dual-luciferase reporter assays demonstrated that the NF-κB subunit P65 binds to the MMP1 promoter downstream of PRKRA. PRKRA knockout decreased organoid proliferation, while overexpression enhanced xenograft growth and chemoresistance.\",\n      \"method\": \"siRNA/CRISPR knockdown and lentiviral overexpression, transcriptome sequencing, ChIP assay for P65 binding to MMP1 promoter, dual-luciferase reporter assay, xenograft mouse model, organoid culture\",\n      \"journal\": \"Heliyon\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — ChIP and reporter assay for direct mechanistic link, in vivo xenograft, single lab with multiple orthogonal methods\",\n      \"pmids\": [\"37484321\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2025,\n      \"finding\": \"PRKRA knockdown in hepatic cell lines (HepG2, HuH7) increases intracellular total cholesterol and decreases LDL uptake, while PRKRA overexpression has the opposite effect. Mechanistically, reduced PRKRA levels are associated with HMGCS1 upregulation (increased cholesterol biosynthesis) and LDLR downregulation (reduced LDL uptake), as revealed by transcriptome sequencing.\",\n      \"method\": \"siRNA knockdown and overexpression in HepG2/HuH7 cells, intracellular cholesterol measurement, Dil-LDL uptake assay, transcriptome sequencing\",\n      \"journal\": \"Lipids in health and disease\",\n      \"confidence\": \"Low\",\n      \"confidence_rationale\": \"Tier 3 / Weak — single lab, overexpression/KD phenotype with transcriptomics but no direct mechanistic link established between PRKRA and cholesterol pathway enzymes\",\n      \"pmids\": [\"40349061\"],\n      \"is_preprint\": false\n    }\n  ],\n  \"current_model\": \"PRKRA/PACT is a dsRNA-binding protein that, upon stress-induced homodimerization (via its third dsRNA-binding domain), directly activates the protein kinase PKR through a physical interaction, leading to eIF2α phosphorylation and global translation inhibition as part of the integrated stress response; in pluripotent cells lacking active PKR/interferon signaling, PRKRA dimers can also sequester eIF2 complexes to inhibit translation in a PKR-independent manner. In unstressed cells, PRKRA is held inactive by the inhibitory protein TRBP; DYT-PRKRA dystonia mutations enhance PACT-PACT and PACT-PKR interactions, dysregulating the ISR and promoting apoptosis, including in cerebellar Purkinje neurons. PRKRA also participates in innate immunity by facilitating type I IFN induction via RIG-I signaling, in miRNA biogenesis via interaction with Dicer, and in transcriptional regulation by modulating DMRT1 activity.\"\n}\n```","stage2_raw":"{\n  \"mechanistic_narrative\": \"PRKRA (PACT/RAX) is a double-stranded RNA-binding protein that functions as a central activator of the integrated stress response (ISR), coupling cellular stress to translational control [#0, #3]. Upon stress, PACT undergoes homodimerization through its third dsRNA-binding domain and physically engages the protein kinase PKR, driving PKR activation and downstream eIF2\\u03b1 phosphorylation; in unstressed cells PACT and PKR are held inactive in complexes with the inhibitory protein TRBP, and stress dissociates these inhibitory interactions to license pro-apoptotic PACT-PACT and PACT-PKR contacts [#0]. In pluripotent cells lacking an active interferon/PKR system, the PACT dimer itself acts as the genuine dsRNA sensor and represses global protein synthesis in a PKR-independent manner by sequestering eIF2 complexes away from the translation machinery, a mechanism that restricts RNA virus replication; this dsRNA sensing depends on binding affinity, since m1\\u03c8 modification of dsRNA reduces PACT binding and relieves translational repression [#3, #4]. PACT-mediated PKR activation and eIF2\\u03b1 phosphorylation are required for normal cerebellar development and Purkinje neuron dendritic arborization in vivo, and dsRNA-binding-disrupting mutations cause broad developmental defects [#2, #5]. DYT-PRKRA (DYT16) dystonia is caused by PRKRA mutations that strengthen PACT-PACT and PACT-PKR interactions, dysregulating the ISR and promoting caspase-dependent apoptosis; a frameshift mutant that loses dsRNA and PKR binding but retains TRBP binding displaces PACT from TRBP to activate PKR, and a separate mutation augments dsRNA-triggered IFN-\\u03b2 induction via RIG-I signaling [#0, #1, #6]. The flavonoid luteolin disrupts pathological PACT-PKR interactions and protects DYT-PRKRA cells from apoptosis [#0, #7]. Beyond stress signaling, PACT contributes to miRNA biogenesis through interaction with Dicer [#8, #9], modulates DMRT1-driven transcription [#10], and acts as a transcriptional regulator of MMP1 via NF-\\u03baB in cancer contexts [#11].\",\n  \"teleology\": [\n    {\n      \"year\": 2011,\n      \"claim\": \"Establishing that PACT's dsRNA-binding function is physiologically required addressed whether this biochemical activity has organismal consequences beyond cell-based assays.\",\n      \"evidence\": \"Point mutation (S130P) in the second RNA-binding domain of mouse Prkra, in vitro dsRNA binding assay and developmental phenotyping of homozygous mice\",\n      \"pmids\": [\"22194846\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Did not resolve which downstream effector (PKR vs eIF2 sequestration) mediates the developmental phenotypes\", \"Lowered steady-state protein levels confound interpretation of the binding defect\"]\n    },\n    {\n      \"year\": 2011,\n      \"claim\": \"Identifying PRKRA as a miR-122 target and a regulator of newly synthesized miRNA accumulation extended PACT's role from stress signaling into miRNA biogenesis via its Dicer association.\",\n      \"evidence\": \"Affinity purification with biotinylated miR-122, microarray and qRT-PCR, plus siRNA knockdown of PRKRA with miRNA quantification\",\n      \"pmids\": [\"21937511\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Effect seen only on newly synthesized, not endogenous steady-state, miRNAs\", \"Direct biochemical role within the Dicer complex not dissected\"]\n    },\n    {\n      \"year\": 2018,\n      \"claim\": \"Linking PACT-Dicer-mediated miRNA regulation to chemoresistance showed the pathway has pathological consequences in cancer.\",\n      \"evidence\": \"siRNA kinome screen, PRKRA knockdown, miR-515-3p/AXL analysis, orthotopic mouse mucinous ovarian cancer model\",\n      \"pmids\": [\"30305341\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Whether the chemoresistance effect requires PACT's dsRNA/PKR functions is unaddressed\", \"Direct PACT-Dicer binding not re-validated here\"]\n    },\n    {\n      \"year\": 2019,\n      \"claim\": \"Dissecting a DYT16 frameshift mutant clarified how a PACT variant lacking dsRNA and PKR binding can still drive disease, implicating TRBP displacement as the toxic mechanism.\",\n      \"evidence\": \"In vitro dsRNA binding, co-IP of mutant with PKR/TRBP, aggregation imaging and caspase assays in mammalian cells\",\n      \"pmids\": [\"31246344\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Relative contributions of PKR-dependent vs independent apoptosis not quantified\", \"Aggregation toxicity mechanism not separated from TRBP displacement\"]\n    },\n    {\n      \"year\": 2020,\n      \"claim\": \"Demonstrating that DYT16 missense mutations strengthen PACT-PACT and PACT-PKR interactions to dysregulate the ISR provided the unifying molecular mechanism for the dystonia and a druggable target.\",\n      \"evidence\": \"Reciprocal co-IP, PKR kinase and eIF2\\u03b1 phosphorylation assays, apoptosis assays in patient-derived lymphoblasts, luteolin rescue\",\n      \"pmids\": [\"33049316\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Connection from lymphoblast ISR phenotype to neuronal pathology not directly shown\", \"Stoichiometry of the TRBP-PACT-PKR switch not structurally defined\"]\n    },\n    {\n      \"year\": 2020,\n      \"claim\": \"Identifying PACT as a DMRT1 co-activator antagonized by p53 placed PACT in transcriptional control of gonadal gene expression.\",\n      \"evidence\": \"Co-IP from Xenopus testis with MS/MS, luciferase reporter assays in 293T, in situ hybridization in tadpole gonads\",\n      \"pmids\": [\"32251494\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Direct vs indirect PACT-DMRT1 binding not distinguished\", \"No demonstration of endogenous target gene regulation\"]\n    },\n    {\n      \"year\": 2022,\n      \"claim\": \"Showing the P222L mutation augments dsRNA-induced IFN-\\u03b2 via RIG-I extended DYT-PRKRA pathology into innate immune dysregulation.\",\n      \"evidence\": \"IFN-\\u03b2 reporter assays and ISG qRT-PCR after dsRNA stimulation in patient-derived cells\",\n      \"pmids\": [\"35625640\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Mechanism by which PACT engages RIG-I not biochemically defined\", \"Relationship between IFN induction and the PKR/ISR axis unresolved\"]\n    },\n    {\n      \"year\": 2023,\n      \"claim\": \"Confirming luteolin disrupts pathological PACT-PKR interactions and rescues apoptosis advanced a candidate therapeutic strategy for DYT-PRKRA.\",\n      \"evidence\": \"Co-IP interaction-disruption and apoptosis assays in DYT-PRKRA patient-derived cells\",\n      \"pmids\": [\"36874028\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"No in vivo efficacy or neuronal rescue shown\", \"Binding site/selectivity of luteolin not defined\"]\n    },\n    {\n      \"year\": 2023,\n      \"claim\": \"Demonstrating PRKRA drives MMP1 transcription through NF-\\u03baB/P65 revealed a transcriptional, pro-tumorigenic role in pancreatic cancer.\",\n      \"evidence\": \"Knockdown/overexpression, transcriptome sequencing, ChIP and dual-luciferase for P65-MMP1 promoter, xenograft and organoid models\",\n      \"pmids\": [\"37484321\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"How PRKRA activates NF-\\u03baB upstream is not established\", \"Link to PACT's canonical dsRNA/PKR functions unexplored\"]\n    },\n    {\n      \"year\": 2024,\n      \"claim\": \"An in vivo mouse frameshift model established that PACT-mediated PKR activation and eIF2\\u03b1 phosphorylation are required for cerebellar development and Purkinje neuron arborization, connecting the molecular switch to neurodevelopmental phenotype.\",\n      \"evidence\": \"Co-IP, PKR kinase and eIF2\\u03b1 phosphorylation assays, cerebellar histology and Purkinje morphology in Prkralear-5J mice\",\n      \"pmids\": [\"39512178\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Cell-autonomous vs non-autonomous requirement in Purkinje neurons not resolved\", \"Whether human DYT16 acts through the same developmental mechanism unclear\"]\n    },\n    {\n      \"year\": 2025,\n      \"claim\": \"Defining PACT dimers as the genuine dsRNA sensor that sequesters eIF2 in PKR-deficient pluripotent cells revealed a PKR-independent translational-control mechanism and antiviral function.\",\n      \"evidence\": \"dsRNA binding and eIF2 sequestration assays, global translation and virus replication measurements in zebrafish embryos and mouse ES cells, PKR-independent epistasis\",\n      \"pmids\": [\"40280134\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Structural basis of eIF2 sequestration by the PACT dimer not defined\", \"Whether this mechanism operates in differentiated human cells unaddressed\"]\n    },\n    {\n      \"year\": 2025,\n      \"claim\": \"Showing m1\\u03c8 modification reduces dsRNA binding to PACT and relieves translational repression linked PACT sensing to mRNA therapeutic design and embryonic mRNA toxicity.\",\n      \"evidence\": \"Binding affinity assays of m1\\u03c8-dsRNA to Prkra dimer, translation efficiency and viability/MZT assays in zebrafish embryos\",\n      \"pmids\": [\"41099713\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Molecular determinants of m1\\u03c8-mediated affinity loss not mapped\", \"Applicability to mammalian/human pluripotent systems untested\"]\n    },\n    {\n      \"year\": 2025,\n      \"claim\": \"A hepatic cholesterol-handling phenotype hinted at a role for PRKRA in lipid metabolism via HMGCS1 and LDLR regulation.\",\n      \"evidence\": \"siRNA knockdown/overexpression in HepG2/HuH7, cholesterol and Dil-LDL uptake assays, transcriptome sequencing\",\n      \"pmids\": [\"40349061\"],\n      \"confidence\": \"Low\",\n      \"gaps\": [\"No direct mechanistic link between PRKRA and cholesterol pathway enzymes established\", \"Single-lab cell-line phenotype without in vivo validation\"]\n    },\n    {\n      \"year\": null,\n      \"claim\": \"How PACT's distinct activities — PKR-dependent ISR activation, PKR-independent eIF2 sequestration, RIG-I/IFN induction, Dicer-coupled miRNA biogenesis, and NF-\\u03baB/DMRT1 transcriptional roles — are partitioned and coordinated within a single cell remains unresolved.\",\n      \"evidence\": \"\",\n      \"pmids\": [],\n      \"confidence\": \"Low\",\n      \"gaps\": [\"No structural model of the TRBP-PACT-PKR regulatory switch\", \"Tissue- and cell-state-specific selection among PACT's functions undefined\", \"Direct mechanism of PACT-driven NF-\\u03baB and RIG-I activation unknown\"]\n    }\n  ],\n  \"mechanism_profile\": {\n    \"molecular_activity\": [\n      {\"term_id\": \"GO:0003723\", \"supporting_discovery_ids\": [1, 3, 4, 5]},\n      {\"term_id\": \"GO:0098772\", \"supporting_discovery_ids\": [0, 2, 3]},\n      {\"term_id\": \"GO:0140110\", \"supporting_discovery_ids\": [10, 11]},\n      {\"term_id\": \"GO:0140313\", \"supporting_discovery_ids\": [3]}\n    ],\n    \"localization\": [\n      {\"term_id\": \"GO:0005829\", \"supporting_discovery_ids\": [1]}\n    ],\n    \"pathway\": [\n      {\"term_id\": \"R-HSA-8953897\", \"supporting_discovery_ids\": [0, 3]},\n      {\"term_id\": \"R-HSA-168256\", \"supporting_discovery_ids\": [6]},\n      {\"term_id\": \"R-HSA-8953854\", \"supporting_discovery_ids\": [8, 9]},\n      {\"term_id\": \"R-HSA-392499\", \"supporting_discovery_ids\": [3, 4]}\n    ],\n    \"complexes\": [],\n    \"partners\": [\"EIF2AK2\", \"TARBP2\", \"DICER1\", \"DMRT1\", \"RELA\"],\n    \"other_free_text\": []\n  }\n}","audit_flag":null,"evaluation":{"pairwise":"win","faith_supported":7,"faith_total":7,"faith_pct":100.0}}