{"gene":"GRSF1","run_date":"2026-06-10T01:55:21","timeline":{"discoveries":[{"year":1994,"finding":"GRSF1 is a cytoplasmic poly(A)+ mRNA binding protein that interacts with a conserved G-rich RNA element. It contains three RNA recognition motifs and two auxiliary domains, and was localized to the cytoplasm by indirect immunofluorescence. In vivo UV cross-linking demonstrated GRSF1 is bound to poly(A)+ mRNA in living human cells.","method":"Northwestern screening, immunofluorescence, in vivo UV cross-linking, Western blot","journal":"Nucleic acids research","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — direct localization by immunofluorescence, RNA binding confirmed by UV cross-linking, single lab with multiple orthogonal methods","pmids":["8036161"],"is_preprint":false},{"year":1999,"finding":"GRSF1 specifically binds the 5' UTR of influenza virus NP mRNA and acts as a positive translational regulator. Recombinant GRSF1 stimulated translation of NP 5'UTR-driven templates in cell-free translation systems; depletion of GRSF1 from HeLa extracts reduced translation, which was restored upon reconstitution.","method":"Yeast three-hybrid system, gel shift assays, cell-free translation assays, HeLa extract depletion/reconstitution","journal":"Proceedings of the National Academy of Sciences of the United States of America","confidence":"High","confidence_rationale":"Tier 1 / Strong — in vitro reconstitution with depletion and add-back, multiple orthogonal methods (yeast three-hybrid, gel shift, cell-free translation)","pmids":["10359774"],"is_preprint":false},{"year":2002,"finding":"The RNA binding activity of GRSF1 maps to RRM2 (amino acids 194–275), and the GRSF1 RNA binding site on influenza NP and NS1 5'UTRs is the sequence AGGGU. Deletion of the Ala-rich region in addition to RRM1 increased translational activation ~4-fold over wild-type. GRSF1 functions by selectively recruiting cellular and viral mRNAs containing 5'UTR GRSF1 binding sites to polyribosomes via interactions with cellular proteins.","method":"GST-GRSF1 deletion mutants, in vitro translation assays, polysome fractionation, cDNA microarray","journal":"Journal of virology","confidence":"High","confidence_rationale":"Tier 1 / Strong — domain mapping by mutagenesis, RNA binding site mapping, in vitro functional assay, polysome fractionation; single lab but multiple orthogonal methods","pmids":["12239318"],"is_preprint":false},{"year":2013,"finding":"A mitochondrial isoform of GRSF1 accumulates in discrete foci (mitochondrial RNA granules) in the mitochondrial matrix, where it interacts with RNase P and is required for processing of both classical and tRNA-less RNA precursors. Loss of GRSF1 causes abnormal cleavage of primary RNA transcripts, decreased expression of mitochondrially encoded proteins, and mitochondrial dysfunction.","method":"Immunofluorescence/subcellular fractionation, Co-immunoprecipitation (GRSF1–RNase P), RNA processing assays in GRSF1-depleted cells","journal":"Cell metabolism","confidence":"High","confidence_rationale":"Tier 2 / Strong — reciprocal Co-IP, direct localization, loss-of-function with defined RNA processing phenotype; highly cited, multiple orthogonal methods","pmids":["23473034"],"is_preprint":false},{"year":2014,"finding":"GRSF1 promotes translation of the SNARE protein Use1 by binding to G-repeats in the alternatively spliced 5'UTR of Use1 mRNA, and this is required for expansion of erythroblasts. Knockdown of either Grsf1 or Use1 abrogated erythroblast expansion.","method":"RNA band shift assays, reporter translation assays, siRNA knockdown, erythroblast expansion assays","journal":"PloS one","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — RNA binding confirmed by band shift, reporter assays with functional readout, single lab","pmids":["25184340"],"is_preprint":false},{"year":2015,"finding":"GRSF1 mediates miR-346-dependent upregulation of hTERT by binding to the miR-346 middle sequence motif (CCGCAU) in the 'bulge loop' formed when miR-346 is bound to the hTERT 3'UTR, facilitating ribosome recruitment in an AGO2-independent manner. Replacement of miR-138's middle sequence with that of miR-346 switches the outcome to GRSF1-dependent upregulation.","method":"RNA immunoprecipitation, reporter assays, ribosome recruitment assays, miRNA sequence swap experiments","journal":"Scientific reports","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — RIP, reporter assays, mechanistic follow-up with sequence swap; single lab, multiple methods","pmids":["26507454"],"is_preprint":false},{"year":2016,"finding":"GRSF1 binds the nuclear DNA-encoded lncRNA RMRP after its import into mitochondria and increases RMRP abundance in the matrix. Loss of GRSF1 lowers mitochondrial RMRP levels, suppresses oxygen consumption rates, and modestly reduces mitochondrial DNA replication priming.","method":"Affinity RNA pull-down followed by mass spectrometry, RIP, siRNA knockdown, oxygen consumption measurement","journal":"Genes & development","confidence":"High","confidence_rationale":"Tier 2 / Strong — RNA pulldown-MS, RIP, functional knockdown with multiple phenotypic readouts; well-cited, multiple orthogonal methods","pmids":["27198227"],"is_preprint":false},{"year":2017,"finding":"GRSF1 requires the simultaneous presence of all three qRRM (quasi-RNA recognition motif) domains for high-affinity RNA binding (KD ~0.5 µM for full-length protein). Deletion of any single qRRM impairs binding; deletion of the acidic auxiliary domain improves binding, suggesting a regulatory role; deletion of the Ala-rich domain does not affect RNA binding. Isolated individual qRRM domains have negligible RNA-binding affinity.","method":"Recombinant protein expression, quantitative RNA electrophoretic mobility shift assays (EMSA) with truncation mutants","journal":"Biochimica et biophysica acta. General subjects","confidence":"High","confidence_rationale":"Tier 1 / Moderate — in vitro reconstitution with systematic deletion mutants and quantitative binding constants; single lab, rigorous biochemical domain mapping","pmids":["29288125"],"is_preprint":false},{"year":2018,"finding":"GRSF1 loss impairs mitochondrial respiration (respiratory complexes I and IV) and increases ROS, leading to DNA damage, growth suppression, and a senescent phenotype with elevated IL6. Mechanistically, mTOR is activated downstream of oxidative stress, which activates NF-κB to induce IL6 gene transcription and a pro-inflammatory program.","method":"GRSF1 siRNA knockdown, respiratory complex assays, ROS measurement, immunoblotting, NF-κB/mTOR pathway analysis","journal":"Nucleic acids research","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — loss-of-function with defined molecular pathway (mTOR→NF-κB→IL6), multiple assays; single lab","pmids":["30753671"],"is_preprint":false},{"year":2018,"finding":"GRSF1 levels decline in senescent cells through reduced protein stability (not at mRNA level). Lowering GRSF1 causes mitochondrial stress, elevated superoxide, increased DNA damage, diminished proliferation, increased SA-β-gal activity, and elevated IL6 production/secretion.","method":"Protein stability assays, GRSF1 knockdown, ROS measurement, SA-β-gal assay, IL6 ELISA","journal":"Aging","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — loss-of-function with defined senescence phenotype and protein stability measurement; single lab, multiple readouts","pmids":["30086537"],"is_preprint":false},{"year":2018,"finding":"GRSF1 together with the mitochondrial degradosome (SUV3-PNPase complex) restricts mitochondrial antisense RNA (including G-quadruplex-forming species). GRSF1 acts as a G-quadruplex-melting co-factor enabling degradation of antisense mtRNAs by the SUV3-PNPase complex.","method":"Genetic/biochemical characterization of antisense mtRNA levels upon depletion of complex components","journal":"Molecular & cellular oncology","confidence":"Medium","confidence_rationale":"Tier 2 / Weak — mechanistic placement of GRSF1 as co-factor in mtRNA surveillance pathway, single lab review/commentary paper with experimental basis described","pmids":["30525095"],"is_preprint":false},{"year":2019,"finding":"GRSF1 inhibits myoblast differentiation by directly targeting mitochondrial GPX4 mRNA, promoting GPX4 expression which reduces ROS levels; reduction in mitochondrial ROS is necessary for myogenic differentiation. Loss of GRSF1 promotes differentiation by reducing GPX4 and increasing ROS.","method":"siRNA knockdown, ROS measurement, myogenic differentiation assays in vitro and in vivo","journal":"Experimental cell research","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — loss-of-function with defined molecular target (GPX4) and ROS readout, both in vitro and in vivo; single lab","pmids":["31085189"],"is_preprint":false},{"year":2021,"finding":"GRSF1 directly binds GUUU motifs within the 3'UTR of YY1 mRNA (region 2663-2847) to enhance YY1 mRNA stability. YY1 in turn feeds back to promote GRSF1 expression by binding the GRSF1 promoter. GRSF1 and miR-30e-5p competitively regulate YY1 by binding the same 3'UTR region.","method":"RNA immunoprecipitation, luciferase reporter assays, RNA pull-down, ChIP assay, shRNA knockdown","journal":"Journal of experimental & clinical cancer research : CR","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — RIP, RNA pulldown, ChIP, reporter assays with defined binding motif; single lab, multiple orthogonal methods","pmids":["34998399"],"is_preprint":false},{"year":2022,"finding":"GRSF1 directly upregulates GPX4 at the translational level in cardiomyocytes. Knockdown of GRSF1 increased sensitivity to ferroptosis and impaired the cardioprotective effect of geniposide in oxidative-stressed cardiomyocytes.","method":"siRNA knockdown, translation assays, ferroptosis assays, in vivo myocardial infarction model","journal":"Frontiers in pharmacology","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — loss-of-function with defined molecular target (GPX4 translation), both in vitro and in vivo; single lab","pmids":["35600863"],"is_preprint":false},{"year":2022,"finding":"Host adaptive mutations in the 2009 pH1N1 PA gene enhance cytosolic accumulation and translation efficiency of viral mRNAs via GRSF1. Mutations to the GRSF1 binding site in viral NP mRNA 5'UTR, as well as GRSF1 knockdown, reduced cytosolic mRNA accumulation and translation efficiency.","method":"Quantitative translation/transcription assays, GRSF1 knockdown, GRSF1 binding site mutagenesis","journal":"Communications biology","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — binding site mutagenesis and knockdown with quantitative functional readouts; single lab, two orthogonal approaches","pmids":["36253464"],"is_preprint":false},{"year":2023,"finding":"GRSF1 directly interacts with G-tracts in the coding region (CDS) of FGA, FGB, and FGG mRNAs via its qRRM2 domain and decreases their stability, thereby reducing fibrinogen expression and attenuating hypercoagulability. Overexpression of GRSF1 in old mice liver decreased plasma fibrinogen and reduced hypercoagulability; knockdown in young mice increased fibrinogen and promoted coagulation.","method":"RNA immunoprecipitation, RNA pull-down, domain deletion mutants, in vivo overexpression/knockdown mouse liver models, coagulation assays","journal":"Cell death & disease","confidence":"High","confidence_rationale":"Tier 2 / Strong — RIP, RNA pulldown with domain mapping, in vivo gain- and loss-of-function with quantitative phenotypic readouts; single lab but multiple orthogonal methods","pmids":["37923734"],"is_preprint":false},{"year":2024,"finding":"GRSF1 is important for nuclear export of influenza A virus NP mRNAs as well as their translation. Mutation of the GRSF1 binding site in the NP mRNA 5'UTR reduced NP protein production, cytosolic accumulation of NP mRNA, and attenuated viral growth in mammalian cells.","method":"Recombinant virus rescue with GRSF1 binding site mutation, NP protein/mRNA quantification, in vitro mRNA translation assay","journal":"Viruses","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — site-directed mutagenesis in viral context with defined molecular phenotype; single lab, multiple readouts","pmids":["39066299"],"is_preprint":false},{"year":2024,"finding":"GRSF1 interacts with SOD2 mRNA in granulosa cells (demonstrated by RNA immunoprecipitation), and knockdown of SOD2 reverses the protective effects of GRSF1 overexpression on mitochondrial function, indicating GRSF1 modulates oxidative stress through regulating SOD2.","method":"RNA immunoprecipitation, siRNA knockdown, mitochondrial function assays","journal":"Reproduction (Cambridge, England)","confidence":"Low","confidence_rationale":"Tier 3 / Weak — single RIP experiment plus epistasis by SOD2 knockdown; single lab, limited mechanistic depth in abstract","pmids":["38819377"],"is_preprint":false},{"year":2025,"finding":"GRSF1 promotes translation of COX1 mRNA in mitochondria. miR-19-3p suppresses GRSF1 expression; loss of GRSF1 reduces COX1 protein levels, impairs mitochondrial function, and aggravates neuronal injury after subarachnoid haemorrhage.","method":"Lentiviral overexpression/knockdown in neurons and rat SAH model, miR-19-3p mimic/inhibitor, COX1 protein quantification","journal":"Stroke and vascular neurology","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — gain- and loss-of-function in vitro and in vivo with defined molecular target (COX1 mRNA translation); single lab","pmids":["39266212"],"is_preprint":false},{"year":2026,"finding":"GRSF1 maintains cardiac BCAA homeostasis by directly binding G-tracts in the coding region of BCKDHB mRNA through its qRRM domain, promoting BCKDHB mRNA stability and increasing BCKDHB protein expression. Cardiomyocyte-specific GRSF1 deletion led to dilated cardiomyopathy and heart failure; overexpression attenuated pressure-overload heart failure. Functional recovery by GRSF1 overexpression was blocked by cardiac-specific BCKDHB deletion, establishing epistasis.","method":"Cardiomyocyte-specific conditional KO and overexpression mice, metabolomics, GRSF1 qRRM mutant mice, BCKDHB cardiac-specific KO epistasis, mRNA stability assays","journal":"Circulation","confidence":"High","confidence_rationale":"Tier 2 / Strong — genetic epistasis (double KO), domain-specific mutant, in vivo gain and loss of function, metabolomics; multiple orthogonal methods in single rigorous study","pmids":["41487100"],"is_preprint":false},{"year":2026,"finding":"LINC00942 interacts with GRSF1 and facilitates binding of GRSF1 to complex I mRNA in mitochondria, enhancing translation efficiency of complex I subunits, increasing complex I protein levels and mitochondrial oxidative phosphorylation activity, while suppressing ferroptosis in hepatocellular carcinoma cells.","method":"RNA pull-down with mass spectrometry (GRSF1 interaction), RIP, complex I activity assays, ferroptosis assays","journal":"Science China. Life sciences","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — RNA pulldown-MS for interaction, RIP, functional enzymatic assays; single lab","pmids":["41530642"],"is_preprint":false},{"year":2025,"finding":"Super-resolution STED nanoscopy (smFISH-STED) revealed spatial relationships between distinct mitochondrial mRNA species and GRSF1 as an RNA granule marker protein, demonstrating adaptive changes in mRNA distribution and quantity in challenged mammalian cells.","method":"smFISH combined with STED and MINFLUX super-resolution microscopy","journal":"bioRxiv","confidence":"Medium","confidence_rationale":"Tier 2 / Weak — direct super-resolution localization with functional context; single study, preprint, novel imaging approach","pmids":["bio_10.1101_2025.01.23.634455"],"is_preprint":true}],"current_model":"GRSF1 is a multi-compartment RNA-binding protein (cytoplasm, nucleus, and mitochondrial matrix) that uses three cooperative qRRM domains to bind G-rich/G-quadruplex-containing RNA sequences; in mitochondria it localizes to RNA granules, interacts with RNase P to process primary mt-RNA transcripts, facilitates translation of complex I and other mt-encoded proteins (including COX1), promotes stability or translation of specific nuclear-encoded mRNAs (BCKDHB, GPX4, Use1, fibrinogen subunits), and co-operates with the SUV3-PNPase degradosome to restrict antisense mtRNAs, collectively maintaining mitochondrial homeostasis and suppressing ROS-driven senescence and ferroptosis."},"narrative":{"mechanistic_narrative":"GRSF1 is a multi-compartment quasi-RRM RNA-binding protein that recognizes G-rich/G-quadruplex RNA elements and uses this activity to control the translation and stability of select mRNAs in both the cytoplasm and the mitochondrial matrix [PMID:8036161, PMID:29288125]. High-affinity binding requires the cooperative action of all three qRRM domains, with isolated domains binding negligibly and the acidic auxiliary domain acting as a negative regulator [PMID:29288125]; the RRM2/qRRM2 module mediates sequence-specific recognition of motifs such as AGGGU and G-tracts in target transcripts [PMID:12239318, PMID:37923734]. In the cytoplasm, GRSF1 selectively recruits mRNAs bearing 5'UTR G-rich sites to polyribosomes to activate translation, a function exploited by influenza A virus to promote nuclear export, cytosolic accumulation, and translation of NP and other viral mRNAs [PMID:10359774, PMID:12239318, PMID:39066299, PMID:36253464]. GRSF1 also regulates endogenous transcripts by binding G-repeats or G-tracts to either enhance translation (Use1) [PMID:25184340] or modulate mRNA stability—stabilizing YY1 via 3'UTR GUUU motifs [PMID:34998399] while destabilizing fibrinogen FGA/FGB/FGG mRNAs through coding-region G-tracts to attenuate hypercoagulability [PMID:37923734]. A mitochondrial isoform concentrates in RNA granules where it interacts with RNase P to process primary mt-RNA transcripts and supports expression of mitochondrially encoded proteins including COX1 and complex I subunits [PMID:23473034, PMID:39266212, PMID:41530642]; it imports and stabilizes the lncRNA RMRP in the matrix and, as a G-quadruplex-melting cofactor, partners with the SUV3-PNPase degradosome to restrict antisense mtRNAs [PMID:27198227, PMID:30525095]. Through these activities GRSF1 sustains respiratory chain function and limits ROS, such that its loss drives oxidative stress, an mTOR–NF-κB–IL6 senescence program, and ferroptosis, while its translational promotion of antioxidant targets GPX4 and BCKDHB-dependent BCAA metabolism protects cardiomyocytes [PMID:30753671, PMID:30086537, PMID:31085189, PMID:35600863, PMID:41487100].","teleology":[{"year":1994,"claim":"Established GRSF1 as a cytoplasmic poly(A)+ mRNA-binding protein recognizing a conserved G-rich RNA element, defining its core molecular activity.","evidence":"Northwestern screening, immunofluorescence, and in vivo UV cross-linking in human cells","pmids":["8036161"],"confidence":"Medium","gaps":["No functional consequence of binding established","Target mRNAs unidentified","Binding specificity not mapped to domains"]},{"year":1999,"claim":"Showed GRSF1 is a positive translational regulator, answering whether its RNA binding has a functional output by demonstrating it stimulates translation of influenza NP mRNA via the 5'UTR.","evidence":"Yeast three-hybrid, gel shift, and cell-free translation with depletion/reconstitution of HeLa extracts","pmids":["10359774"],"confidence":"High","gaps":["Mechanism of polysome recruitment not resolved","Endogenous cellular targets not yet identified"]},{"year":2002,"claim":"Mapped the RNA-binding activity to RRM2 and the recognition site to AGGGU, and showed GRSF1 acts by recruiting target mRNAs to polyribosomes, linking sequence specificity to mechanism.","evidence":"GST-GRSF1 deletion mutants, in vitro translation, polysome fractionation, cDNA microarray","pmids":["12239318"],"confidence":"High","gaps":["Identity of cooperating cellular proteins not defined","Broader endogenous target set not characterized"]},{"year":2013,"claim":"Revealed a mitochondrial pool of GRSF1 in RNA granules that interacts with RNase P and is required for primary transcript processing, establishing an organellar role distinct from its cytoplasmic translation function.","evidence":"Subcellular fractionation/immunofluorescence, reciprocal Co-IP with RNase P, RNA processing assays in depleted cells","pmids":["23473034"],"confidence":"High","gaps":["How GRSF1 directs RNase P specificity unclear","Granule assembly mechanism unknown"]},{"year":2014,"claim":"Extended the translational activator role to an endogenous physiological target, Use1, showing GRSF1 binding to alternatively spliced 5'UTR G-repeats is required for erythroblast expansion.","evidence":"RNA band shift, reporter translation assays, siRNA knockdown, erythroblast expansion assays","pmids":["25184340"],"confidence":"Medium","gaps":["Single physiological context","No structural basis for G-repeat recognition"]},{"year":2015,"claim":"Implicated GRSF1 in miRNA-directed translational upregulation, showing it reads a CCGCAU motif in a miR-346/hTERT bulge loop to recruit ribosomes independently of AGO2.","evidence":"RNA immunoprecipitation, reporter assays, ribosome recruitment, miRNA sequence-swap experiments","pmids":["26507454"],"confidence":"Medium","gaps":["Generality of the miRNA-bulge mechanism unknown","Direct binding to bulge structure not structurally resolved"]},{"year":2016,"claim":"Defined GRSF1 as a chaperone for the imported lncRNA RMRP within mitochondria, linking it to mitochondrial DNA replication priming and respiration.","evidence":"Affinity RNA pull-down/MS, RIP, siRNA knockdown, oxygen consumption measurement","pmids":["27198227"],"confidence":"High","gaps":["Functional fate of RMRP downstream of GRSF1 not fully resolved","Modest replication-priming effect mechanistically unexplained"]},{"year":2017,"claim":"Defined the biochemical architecture of RNA recognition, showing all three qRRM domains act cooperatively for high-affinity binding and the acidic domain is a negative regulator.","evidence":"Recombinant protein, quantitative EMSA with systematic truncation mutants","pmids":["29288125"],"confidence":"High","gaps":["No atomic structure of the qRRM-RNA complex","How the acidic domain regulates binding unknown"]},{"year":2018,"claim":"Connected GRSF1 loss to oxidative stress and senescence, defining an mTOR→NF-κB→IL6 axis downstream of respiratory complex I/IV impairment, and showed GRSF1 itself is destabilized in senescence.","evidence":"siRNA knockdown, respiratory complex and ROS assays, NF-κB/mTOR pathway analysis, protein stability assays, SA-β-gal, IL6 ELISA","pmids":["30753671","30086537"],"confidence":"Medium","gaps":["Protease/pathway destabilizing GRSF1 in senescence unidentified","Direct mt targets driving complex I/IV defect not fully enumerated"]},{"year":2018,"claim":"Placed GRSF1 in mitochondrial RNA surveillance as a G-quadruplex-melting cofactor enabling SUV3-PNPase degradation of antisense mtRNAs.","evidence":"Biochemical/genetic characterization of antisense mtRNA upon component depletion","pmids":["30525095"],"confidence":"Medium","gaps":["Direct demonstration of G-quadruplex melting activity limited","Commentary-level experimental detail"]},{"year":2019,"claim":"Linked GRSF1 to redox-controlled differentiation by showing it promotes mitochondrial GPX4 expression to suppress ROS and inhibit myogenic differentiation.","evidence":"siRNA knockdown, ROS measurement, myogenic differentiation assays in vitro and in vivo","pmids":["31085189"],"confidence":"Medium","gaps":["Direct binding mode to GPX4 mRNA not mapped here","Whether effect is translational or stability not distinguished"]},{"year":2021,"claim":"Demonstrated GRSF1 stabilizes YY1 mRNA via 3'UTR GUUU motifs in a feedback loop competing with miR-30e-5p, expanding its role to mRNA stability regulation in cancer.","evidence":"RIP, luciferase reporters, RNA pull-down, ChIP, shRNA knockdown","pmids":["34998399"],"confidence":"Medium","gaps":["Mechanism of stabilization (decay machinery) not defined","Single cancer context"]},{"year":2022,"claim":"Showed GRSF1 directly upregulates GPX4 translationally to protect cardiomyocytes from ferroptosis, mechanistically anchoring the antioxidant/anti-ferroptosis role.","evidence":"siRNA knockdown, translation assays, ferroptosis assays, in vivo myocardial infarction model","pmids":["35600863"],"confidence":"Medium","gaps":["GPX4 mRNA binding site not mapped","Relationship to mitochondrial vs cytoplasmic GPX4 pools unclear"]},{"year":2022,"claim":"Established GRSF1's role in viral mRNA cytosolic accumulation and translation as a host-adaptation target, with PA mutations enhancing GRSF1-dependent NP mRNA handling.","evidence":"Quantitative translation/transcription assays, GRSF1 knockdown, binding-site mutagenesis","pmids":["36253464"],"confidence":"Medium","gaps":["Mechanistic link between PA mutations and GRSF1 engagement indirect","Step (export vs translation) not yet separated here"]},{"year":2023,"claim":"Showed GRSF1 destabilizes fibrinogen FGA/FGB/FGG mRNAs via qRRM2 binding to coding-region G-tracts, demonstrating a destabilizing (not just activating) output with in vivo coagulation consequences.","evidence":"RIP, RNA pull-down, domain-deletion mutants, in vivo liver gain/loss-of-function, coagulation assays","pmids":["37923734"],"confidence":"High","gaps":["Decay machinery recruited by GRSF1 not identified","Determinants of activating vs destabilizing outcomes unknown"]},{"year":2024,"claim":"Separated GRSF1's contribution to influenza NP mRNA nuclear export from its translational role, using recombinant virus with binding-site mutations.","evidence":"Recombinant virus rescue with binding-site mutation, NP protein/mRNA quantification, in vitro translation","pmids":["39066299"],"confidence":"Medium","gaps":["Export machinery partners of GRSF1 not defined","How one binding site mediates two steps unclear"]},{"year":2024,"claim":"Added SOD2 mRNA as a putative GRSF1 target linking it to oxidative stress control in granulosa cells via epistasis.","evidence":"RNA immunoprecipitation, siRNA knockdown, mitochondrial function assays","pmids":["38819377"],"confidence":"Low","gaps":["Single RIP without binding-site mapping or reciprocal validation","Whether GRSF1 affects SOD2 translation or stability not shown"]},{"year":2025,"claim":"Demonstrated GRSF1 promotes mitochondrial COX1 mRNA translation and is suppressed by miR-19-3p, linking it to neuronal protection after subarachnoid haemorrhage.","evidence":"Lentiviral overexpression/knockdown in neurons and rat SAH model, miR-19-3p mimic/inhibitor, COX1 quantification","pmids":["39266212"],"confidence":"Medium","gaps":["Direct COX1 mRNA binding by GRSF1 not mapped","Mechanism of translational enhancement unresolved"]},{"year":2026,"claim":"Established a definitive genetic role for GRSF1 in cardiac metabolism, showing qRRM-dependent stabilization of BCKDHB mRNA maintains BCAA homeostasis and protects against heart failure, with double-KO epistasis.","evidence":"Cardiomyocyte-specific conditional KO and overexpression mice, qRRM mutant mice, BCKDHB double-KO epistasis, metabolomics, mRNA stability assays","pmids":["41487100"],"confidence":"High","gaps":["Decay pathway controlling BCKDHB mRNA not defined","Relationship to GRSF1's mitochondrial functions in heart unclear"]},{"year":2026,"claim":"Identified LINC00942 as an RNA cofactor that bridges GRSF1 to complex I mRNAs to enhance their translation and suppress ferroptosis, revealing lncRNA-guided target selection.","evidence":"RNA pull-down/MS, RIP, complex I activity assays, ferroptosis assays in HCC cells","pmids":["41530642"],"confidence":"Medium","gaps":["How LINC00942 confers complex I mRNA specificity unclear","Generality beyond HCC unknown"]},{"year":null,"claim":"How GRSF1 switches between translational activation, mRNA stabilization, and mRNA destabilization on different G-rich targets, and what decay/recruitment machinery it engages, remains unresolved.","evidence":"","pmids":[],"confidence":"Medium","gaps":["No atomic structure of qRRM-RNA complexes resolving target discrimination","Decay and translation machinery partners not identified","Determinants of activating vs destabilizing outcomes unknown"]}],"mechanism_profile":{"molecular_activity":[{"term_id":"GO:0003723","term_label":"RNA binding","supporting_discovery_ids":[0,1,2,7,12,15,19]},{"term_id":"GO:0045182","term_label":"translation regulator activity","supporting_discovery_ids":[1,2,4,18,20]},{"term_id":"GO:0098772","term_label":"molecular function regulator activity","supporting_discovery_ids":[12,15,19]}],"localization":[{"term_id":"GO:0005829","term_label":"cytosol","supporting_discovery_ids":[0]},{"term_id":"GO:0005739","term_label":"mitochondrion","supporting_discovery_ids":[3,6,18,21]},{"term_id":"GO:0005634","term_label":"nucleus","supporting_discovery_ids":[16]}],"pathway":[{"term_id":"R-HSA-8953854","term_label":"Metabolism of RNA","supporting_discovery_ids":[3,6,10]},{"term_id":"R-HSA-392499","term_label":"Metabolism of proteins","supporting_discovery_ids":[1,2,4,18,20]},{"term_id":"R-HSA-1430728","term_label":"Metabolism","supporting_discovery_ids":[8,18,19,20]},{"term_id":"R-HSA-5357801","term_label":"Programmed Cell Death","supporting_discovery_ids":[11,13,20]}],"complexes":["mitochondrial RNA granule","SUV3-PNPase degradosome"],"partners":["RNASEP","SUV3","PNPASE","RMRP","LINC00942"],"other_free_text":[]}},"prefetch_data":{"uniprot":{"accession":"Q12849","full_name":"G-rich sequence factor 1","aliases":[],"length_aa":480,"mass_kda":53.1,"function":"Regulator of post-transcriptional mitochondrial gene expression, required for assembly of the mitochondrial ribosome and for recruitment of mRNA and lncRNA. Binds RNAs containing the 14 base G-rich element. Preferentially binds RNAs transcribed from three contiguous genes on the light strand of mtDNA, the ND6 mRNA, and the long non-coding RNAs for MT-CYB and MT-ND5, each of which contains multiple consensus binding sequences (PubMed:23473033, PubMed:23473034, PubMed:29967381). Involved in the degradosome-mediated decay of non-coding mitochondrial transcripts (MT-ncRNA) and tRNA-like molecules (PubMed:29967381). Acts by unwinding G-quadruplex RNA structures in MT-ncRNA, thus facilitating their degradation by the degradosome (PubMed:29967381). G-quadruplexes (G4) are non-canonical 4 stranded structures formed by transcripts from the light strand of mtDNA (PubMed:29967381)","subcellular_location":"Cytoplasm","url":"https://www.uniprot.org/uniprotkb/Q12849/entry"},"depmap":{"release":"DepMap","has_data":true,"is_common_essential":false,"resolved_as":"","url":"https://depmap.org/portal/gene/GRSF1","classification":"Not Classified","n_dependent_lines":320,"n_total_lines":1208,"dependency_fraction":0.26490066225165565},"opencell":{"profiled":false,"resolved_as":"","ensg_id":"","cell_line_id":"","localizations":[],"interactors":[{"gene":"RAN","stoichiometry":0.2},{"gene":"RPS6KA3","stoichiometry":0.2}],"url":"https://opencell.sf.czbiohub.org/search/GRSF1","total_profiled":1310},"omim":[{"mim_id":"604851","title":"G-RICH RNA SEQUENCE-BINDING FACTOR 1; GRSF1","url":"https://www.omim.org/entry/604851"},{"mim_id":"138322","title":"GLUTATHIONE PEROXIDASE 4; GPX4","url":"https://www.omim.org/entry/138322"}],"hpa":{"profiled":true,"resolved_as":"","reliability":"Enhanced","locations":[{"location":"Mitochondria","reliability":"Enhanced"}],"tissue_specificity":"Tissue enhanced","tissue_distribution":"Detected in all","driving_tissues":[{"tissue":"skeletal muscle","ntpm":242.1}],"url":"https://www.proteinatlas.org/search/GRSF1"},"hgnc":{"alias_symbol":[],"prev_symbol":[]},"alphafold":{"accession":"Q12849","domains":[{"cath_id":"3.30.70.330","chopping":"152-244","consensus_level":"high","plddt":81.6971,"start":152,"end":244},{"cath_id":"3.30.70.330","chopping":"252-334","consensus_level":"high","plddt":85.2114,"start":252,"end":334},{"cath_id":"3.30.70.330","chopping":"403-475","consensus_level":"high","plddt":90.0663,"start":403,"end":475}],"viewer_url":"https://alphafold.ebi.ac.uk/entry/Q12849","model_url":"https://alphafold.ebi.ac.uk/files/AF-Q12849-F1-model_v6.cif","pae_url":"https://alphafold.ebi.ac.uk/files/AF-Q12849-F1-predicted_aligned_error_v6.png","plddt_mean":65.56},"mouse_models":{"mgi_url":"https://www.informatics.jax.org/marker/summary?nomen=GRSF1","jax_strain_url":"https://www.jax.org/strain/search?query=GRSF1"},"sequence":{"accession":"Q12849","fasta_url":"https://rest.uniprot.org/uniprotkb/Q12849.fasta","uniprot_url":"https://www.uniprot.org/uniprotkb/Q12849/entry","alphafold_viewer_url":"https://alphafold.ebi.ac.uk/entry/Q12849"}},"corpus_meta":[{"pmid":"23473034","id":"PMC_23473034","title":"GRSF1 regulates RNA processing in mitochondrial RNA granules.","date":"2013","source":"Cell metabolism","url":"https://pubmed.ncbi.nlm.nih.gov/23473034","citation_count":198,"is_preprint":false},{"pmid":"27198227","id":"PMC_27198227","title":"HuR and GRSF1 modulate the nuclear export and mitochondrial localization of the lncRNA RMRP.","date":"2016","source":"Genes & development","url":"https://pubmed.ncbi.nlm.nih.gov/27198227","citation_count":196,"is_preprint":false},{"pmid":"26507454","id":"PMC_26507454","title":"miR-346 and miR-138 competitively regulate hTERT in GRSF1- and AGO2-dependent manners, respectively.","date":"2015","source":"Scientific reports","url":"https://pubmed.ncbi.nlm.nih.gov/26507454","citation_count":74,"is_preprint":false},{"pmid":"30394198","id":"PMC_30394198","title":"GRSF1-mediated MIR-G-1 promotes malignant behavior and nuclear autophagy by directly upregulating TMED5 and LMNB1 in cervical cancer cells.","date":"2018","source":"Autophagy","url":"https://pubmed.ncbi.nlm.nih.gov/30394198","citation_count":73,"is_preprint":false},{"pmid":"10359774","id":"PMC_10359774","title":"Regulation of eukaryotic protein synthesis: selective influenza viral mRNA translation is mediated by the cellular RNA-binding protein GRSF-1.","date":"1999","source":"Proceedings of the National Academy of Sciences of the United States of America","url":"https://pubmed.ncbi.nlm.nih.gov/10359774","citation_count":71,"is_preprint":false},{"pmid":"31474757","id":"PMC_31474757","title":"A novel miRNA identified in GRSF1 complex drives the metastasis via the PIK3R3/AKT/NF-κB and TIMP3/MMP9 pathways in cervical cancer cells.","date":"2019","source":"Cell death & disease","url":"https://pubmed.ncbi.nlm.nih.gov/31474757","citation_count":54,"is_preprint":false},{"pmid":"8036161","id":"PMC_8036161","title":"GRSF-1: a poly(A)+ mRNA binding protein which interacts with a conserved G-rich element.","date":"1994","source":"Nucleic acids research","url":"https://pubmed.ncbi.nlm.nih.gov/8036161","citation_count":50,"is_preprint":false},{"pmid":"12239318","id":"PMC_12239318","title":"Selective translation of eukaryotic mRNAs: functional molecular analysis of GRSF-1, a positive regulator of influenza virus protein synthesis.","date":"2002","source":"Journal of virology","url":"https://pubmed.ncbi.nlm.nih.gov/12239318","citation_count":48,"is_preprint":false},{"pmid":"35600863","id":"PMC_35600863","title":"Geniposide Possesses the Protective Effect on Myocardial Injury by Inhibiting Oxidative Stress and Ferroptosis via Activation of the Grsf1/GPx4 Axis.","date":"2022","source":"Frontiers in pharmacology","url":"https://pubmed.ncbi.nlm.nih.gov/35600863","citation_count":44,"is_preprint":false},{"pmid":"30753671","id":"PMC_30753671","title":"Loss of RNA-binding protein GRSF1 activates mTOR to elicit a proinflammatory transcriptional program.","date":"2019","source":"Nucleic acids research","url":"https://pubmed.ncbi.nlm.nih.gov/30753671","citation_count":28,"is_preprint":false},{"pmid":"34998399","id":"PMC_34998399","title":"The RNA-binding protein GRSF1 promotes hepatocarcinogenesis via competitively binding to YY1 mRNA with miR-30e-5p.","date":"2022","source":"Journal of experimental & clinical cancer research : CR","url":"https://pubmed.ncbi.nlm.nih.gov/34998399","citation_count":23,"is_preprint":false},{"pmid":"30086537","id":"PMC_30086537","title":"GRSF1 suppresses cell senescence.","date":"2018","source":"Aging","url":"https://pubmed.ncbi.nlm.nih.gov/30086537","citation_count":21,"is_preprint":false},{"pmid":"25184340","id":"PMC_25184340","title":"Grsf1-induced translation of the SNARE protein Use1 is required for expansion of the erythroid compartment.","date":"2014","source":"PloS one","url":"https://pubmed.ncbi.nlm.nih.gov/25184340","citation_count":21,"is_preprint":false},{"pmid":"30525095","id":"PMC_30525095","title":"Controlling the mitochondrial antisense - role of the SUV3-PNPase complex and its co-factor GRSF1 in mitochondrial RNA surveillance.","date":"2018","source":"Molecular & cellular oncology","url":"https://pubmed.ncbi.nlm.nih.gov/30525095","citation_count":19,"is_preprint":false},{"pmid":"31085189","id":"PMC_31085189","title":"Guanine-rich RNA binding protein GRSF1 inhibits myoblast differentiation through repressing mitochondrial ROS production.","date":"2019","source":"Experimental cell research","url":"https://pubmed.ncbi.nlm.nih.gov/31085189","citation_count":18,"is_preprint":false},{"pmid":"30944385","id":"PMC_30944385","title":"GRSF1 is an age-related regulator of senescence.","date":"2019","source":"Scientific reports","url":"https://pubmed.ncbi.nlm.nih.gov/30944385","citation_count":16,"is_preprint":false},{"pmid":"33813277","id":"PMC_33813277","title":"GRSF1 promotes tumorigenesis and EMT-mediated metastasis through PI3K/AKT pathway in gastric cancer.","date":"2021","source":"Biochemical and biophysical research communications","url":"https://pubmed.ncbi.nlm.nih.gov/33813277","citation_count":14,"is_preprint":false},{"pmid":"33713675","id":"PMC_33713675","title":"Expression Regulation, Protein Chemistry and Functional Biology of the Guanine-Rich Sequence Binding Factor 1 (GRSF1).","date":"2021","source":"Journal of molecular biology","url":"https://pubmed.ncbi.nlm.nih.gov/33713675","citation_count":13,"is_preprint":false},{"pmid":"36253464","id":"PMC_36253464","title":"Host adaptive mutations in the 2009 H1N1 pandemic influenza A virus PA gene regulate translation efficiency of viral mRNAs via GRSF1.","date":"2022","source":"Communications biology","url":"https://pubmed.ncbi.nlm.nih.gov/36253464","citation_count":11,"is_preprint":false},{"pmid":"36120303","id":"PMC_36120303","title":"Xiao-Yao-San protects against anti-tuberculosis drug-induced liver injury by regulating Grsf1 in the mitochondrial oxidative stress pathway.","date":"2022","source":"Frontiers in pharmacology","url":"https://pubmed.ncbi.nlm.nih.gov/36120303","citation_count":11,"is_preprint":false},{"pmid":"37923734","id":"PMC_37923734","title":"GRSF1 antagonizes age-associated hypercoagulability via modulation of fibrinogen mRNA stability.","date":"2023","source":"Cell death & disease","url":"https://pubmed.ncbi.nlm.nih.gov/37923734","citation_count":10,"is_preprint":false},{"pmid":"29288125","id":"PMC_29288125","title":"Functional characterization of isolated RNA-binding domains of the GRSF1 protein.","date":"2017","source":"Biochimica et biophysica acta. General subjects","url":"https://pubmed.ncbi.nlm.nih.gov/29288125","citation_count":8,"is_preprint":false},{"pmid":"35509860","id":"PMC_35509860","title":"lncRNA GHET1 Promotes the Progression of Triple-Negative Breast Cancer via Regulation of miR-377-3p/GRSF1 Signaling Axis.","date":"2022","source":"Computational and mathematical methods in medicine","url":"https://pubmed.ncbi.nlm.nih.gov/35509860","citation_count":8,"is_preprint":false},{"pmid":"29366917","id":"PMC_29366917","title":"Functional characterization of naturally occurring genetic variations of the human guanine-rich RNA sequence binding factor 1 (GRSF1).","date":"2018","source":"Biochimica et biophysica acta. General subjects","url":"https://pubmed.ncbi.nlm.nih.gov/29366917","citation_count":8,"is_preprint":false},{"pmid":"34078750","id":"PMC_34078750","title":"GRSF1 deficiency in skeletal muscle reduces endurance in aged mice.","date":"2021","source":"Aging","url":"https://pubmed.ncbi.nlm.nih.gov/34078750","citation_count":6,"is_preprint":false},{"pmid":"38819377","id":"PMC_38819377","title":"GRSF1 deficiency attenuates mitochondrial function in aging granulosa cells.","date":"2024","source":"Reproduction (Cambridge, England)","url":"https://pubmed.ncbi.nlm.nih.gov/38819377","citation_count":6,"is_preprint":false},{"pmid":"37861894","id":"PMC_37861894","title":"Anti-aging Factor GRSF1 Attenuates Cerebral Ischemia-Reperfusion Injury in Mice by Inhibiting GPX4-Mediated Ferroptosis.","date":"2023","source":"Molecular neurobiology","url":"https://pubmed.ncbi.nlm.nih.gov/37861894","citation_count":6,"is_preprint":false},{"pmid":"36494688","id":"PMC_36494688","title":"Male guanine-rich RNA sequence binding factor 1 knockout mice (Grsf1-/-) gain less body weight during adolescence and adulthood.","date":"2022","source":"Cell & bioscience","url":"https://pubmed.ncbi.nlm.nih.gov/36494688","citation_count":5,"is_preprint":false},{"pmid":"40722682","id":"PMC_40722682","title":"Duodenal Adenocarcinoma Is Characterized by Acidity, High Infiltration of Macrophage, and Activated Linc01559-GRSF1 Axis.","date":"2025","source":"Biomedicines","url":"https://pubmed.ncbi.nlm.nih.gov/40722682","citation_count":2,"is_preprint":false},{"pmid":"41487100","id":"PMC_41487100","title":"GRSF1 Protects Against Heart Failure by Maintaining BCAA Homeostasis.","date":"2026","source":"Circulation","url":"https://pubmed.ncbi.nlm.nih.gov/41487100","citation_count":1,"is_preprint":false},{"pmid":"39066299","id":"PMC_39066299","title":"Functional Analysis of GRSF1 in the Nuclear Export and Translation of Influenza A Virus mRNAs.","date":"2024","source":"Viruses","url":"https://pubmed.ncbi.nlm.nih.gov/39066299","citation_count":1,"is_preprint":false},{"pmid":"41530642","id":"PMC_41530642","title":"Mitochondrial LINC00942 activates complex I and inhibits ferroptosis through interacting with GRSF1 in liver cancer.","date":"2026","source":"Science China. Life sciences","url":"https://pubmed.ncbi.nlm.nih.gov/41530642","citation_count":1,"is_preprint":false},{"pmid":"40813599","id":"PMC_40813599","title":"GRSF1 loss in THP-1 macrophages promotes senescence-associated transcription in neighboring fibroblasts.","date":"2025","source":"Scientific reports","url":"https://pubmed.ncbi.nlm.nih.gov/40813599","citation_count":0,"is_preprint":false},{"pmid":"39266212","id":"PMC_39266212","title":"miR-19-3p/GRSF1/COX1 axis attenuates early brain injury via maintaining mitochondrial function after subarachnoid haemorrhage.","date":"2025","source":"Stroke and vascular neurology","url":"https://pubmed.ncbi.nlm.nih.gov/39266212","citation_count":0,"is_preprint":false},{"pmid":"41665976","id":"PMC_41665976","title":"BACH2 alleviates immune checkpoint inhibitors-induced cardiac pyroptosis via transcriptionally promoting GRSF1.","date":"2026","source":"Clinical and translational medicine","url":"https://pubmed.ncbi.nlm.nih.gov/41665976","citation_count":0,"is_preprint":false},{"pmid":"42035548","id":"PMC_42035548","title":"METTL3-mediated m6A modification of Smad3 affects ferroptosis in septic acute lung injury by mediating GRSF1/GPX4.","date":"2026","source":"International immunopharmacology","url":"https://pubmed.ncbi.nlm.nih.gov/42035548","citation_count":0,"is_preprint":false},{"pmid":null,"id":"bio_10.1101_2025.01.23.634455","title":"Super-resolution microscopy of mitochondrial mRNAs","date":"2025-01-24","source":"bioRxiv","url":"https://doi.org/10.1101/2025.01.23.634455","citation_count":0,"is_preprint":true}],"cost":{"stage1":{"model":"claude-sonnet-4-6","input_tokens":20098,"output_tokens":5387,"usd":0.07055,"stage1_stop_reason":"end_turn"},"stage2":{"model":"claude-opus-4-8","input_tokens":13916,"output_tokens":5853,"usd":0.107953,"stage2_stop_reason":"end_turn"},"total_usd":0.178503,"stage1_batch_id":"msgbatch_01DUPACZi7AAWwuZiUjseQF4","stage2_batch_id":"msgbatch_018yt7chE3f48PEFtDwtj6AE","note":"batch pricing = 50% of standard"},"stage1_raw":"```json\n{\n  \"discoveries\": [\n    {\n      \"year\": 1994,\n      \"finding\": \"GRSF1 is a cytoplasmic poly(A)+ mRNA binding protein that interacts with a conserved G-rich RNA element. It contains three RNA recognition motifs and two auxiliary domains, and was localized to the cytoplasm by indirect immunofluorescence. In vivo UV cross-linking demonstrated GRSF1 is bound to poly(A)+ mRNA in living human cells.\",\n      \"method\": \"Northwestern screening, immunofluorescence, in vivo UV cross-linking, Western blot\",\n      \"journal\": \"Nucleic acids research\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — direct localization by immunofluorescence, RNA binding confirmed by UV cross-linking, single lab with multiple orthogonal methods\",\n      \"pmids\": [\"8036161\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 1999,\n      \"finding\": \"GRSF1 specifically binds the 5' UTR of influenza virus NP mRNA and acts as a positive translational regulator. Recombinant GRSF1 stimulated translation of NP 5'UTR-driven templates in cell-free translation systems; depletion of GRSF1 from HeLa extracts reduced translation, which was restored upon reconstitution.\",\n      \"method\": \"Yeast three-hybrid system, gel shift assays, cell-free translation assays, HeLa extract depletion/reconstitution\",\n      \"journal\": \"Proceedings of the National Academy of Sciences of the United States of America\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 / Strong — in vitro reconstitution with depletion and add-back, multiple orthogonal methods (yeast three-hybrid, gel shift, cell-free translation)\",\n      \"pmids\": [\"10359774\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2002,\n      \"finding\": \"The RNA binding activity of GRSF1 maps to RRM2 (amino acids 194–275), and the GRSF1 RNA binding site on influenza NP and NS1 5'UTRs is the sequence AGGGU. Deletion of the Ala-rich region in addition to RRM1 increased translational activation ~4-fold over wild-type. GRSF1 functions by selectively recruiting cellular and viral mRNAs containing 5'UTR GRSF1 binding sites to polyribosomes via interactions with cellular proteins.\",\n      \"method\": \"GST-GRSF1 deletion mutants, in vitro translation assays, polysome fractionation, cDNA microarray\",\n      \"journal\": \"Journal of virology\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 / Strong — domain mapping by mutagenesis, RNA binding site mapping, in vitro functional assay, polysome fractionation; single lab but multiple orthogonal methods\",\n      \"pmids\": [\"12239318\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2013,\n      \"finding\": \"A mitochondrial isoform of GRSF1 accumulates in discrete foci (mitochondrial RNA granules) in the mitochondrial matrix, where it interacts with RNase P and is required for processing of both classical and tRNA-less RNA precursors. Loss of GRSF1 causes abnormal cleavage of primary RNA transcripts, decreased expression of mitochondrially encoded proteins, and mitochondrial dysfunction.\",\n      \"method\": \"Immunofluorescence/subcellular fractionation, Co-immunoprecipitation (GRSF1–RNase P), RNA processing assays in GRSF1-depleted cells\",\n      \"journal\": \"Cell metabolism\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — reciprocal Co-IP, direct localization, loss-of-function with defined RNA processing phenotype; highly cited, multiple orthogonal methods\",\n      \"pmids\": [\"23473034\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2014,\n      \"finding\": \"GRSF1 promotes translation of the SNARE protein Use1 by binding to G-repeats in the alternatively spliced 5'UTR of Use1 mRNA, and this is required for expansion of erythroblasts. Knockdown of either Grsf1 or Use1 abrogated erythroblast expansion.\",\n      \"method\": \"RNA band shift assays, reporter translation assays, siRNA knockdown, erythroblast expansion assays\",\n      \"journal\": \"PloS one\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — RNA binding confirmed by band shift, reporter assays with functional readout, single lab\",\n      \"pmids\": [\"25184340\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2015,\n      \"finding\": \"GRSF1 mediates miR-346-dependent upregulation of hTERT by binding to the miR-346 middle sequence motif (CCGCAU) in the 'bulge loop' formed when miR-346 is bound to the hTERT 3'UTR, facilitating ribosome recruitment in an AGO2-independent manner. Replacement of miR-138's middle sequence with that of miR-346 switches the outcome to GRSF1-dependent upregulation.\",\n      \"method\": \"RNA immunoprecipitation, reporter assays, ribosome recruitment assays, miRNA sequence swap experiments\",\n      \"journal\": \"Scientific reports\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — RIP, reporter assays, mechanistic follow-up with sequence swap; single lab, multiple methods\",\n      \"pmids\": [\"26507454\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2016,\n      \"finding\": \"GRSF1 binds the nuclear DNA-encoded lncRNA RMRP after its import into mitochondria and increases RMRP abundance in the matrix. Loss of GRSF1 lowers mitochondrial RMRP levels, suppresses oxygen consumption rates, and modestly reduces mitochondrial DNA replication priming.\",\n      \"method\": \"Affinity RNA pull-down followed by mass spectrometry, RIP, siRNA knockdown, oxygen consumption measurement\",\n      \"journal\": \"Genes & development\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — RNA pulldown-MS, RIP, functional knockdown with multiple phenotypic readouts; well-cited, multiple orthogonal methods\",\n      \"pmids\": [\"27198227\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2017,\n      \"finding\": \"GRSF1 requires the simultaneous presence of all three qRRM (quasi-RNA recognition motif) domains for high-affinity RNA binding (KD ~0.5 µM for full-length protein). Deletion of any single qRRM impairs binding; deletion of the acidic auxiliary domain improves binding, suggesting a regulatory role; deletion of the Ala-rich domain does not affect RNA binding. Isolated individual qRRM domains have negligible RNA-binding affinity.\",\n      \"method\": \"Recombinant protein expression, quantitative RNA electrophoretic mobility shift assays (EMSA) with truncation mutants\",\n      \"journal\": \"Biochimica et biophysica acta. General subjects\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 / Moderate — in vitro reconstitution with systematic deletion mutants and quantitative binding constants; single lab, rigorous biochemical domain mapping\",\n      \"pmids\": [\"29288125\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2018,\n      \"finding\": \"GRSF1 loss impairs mitochondrial respiration (respiratory complexes I and IV) and increases ROS, leading to DNA damage, growth suppression, and a senescent phenotype with elevated IL6. Mechanistically, mTOR is activated downstream of oxidative stress, which activates NF-κB to induce IL6 gene transcription and a pro-inflammatory program.\",\n      \"method\": \"GRSF1 siRNA knockdown, respiratory complex assays, ROS measurement, immunoblotting, NF-κB/mTOR pathway analysis\",\n      \"journal\": \"Nucleic acids research\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — loss-of-function with defined molecular pathway (mTOR→NF-κB→IL6), multiple assays; single lab\",\n      \"pmids\": [\"30753671\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2018,\n      \"finding\": \"GRSF1 levels decline in senescent cells through reduced protein stability (not at mRNA level). Lowering GRSF1 causes mitochondrial stress, elevated superoxide, increased DNA damage, diminished proliferation, increased SA-β-gal activity, and elevated IL6 production/secretion.\",\n      \"method\": \"Protein stability assays, GRSF1 knockdown, ROS measurement, SA-β-gal assay, IL6 ELISA\",\n      \"journal\": \"Aging\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — loss-of-function with defined senescence phenotype and protein stability measurement; single lab, multiple readouts\",\n      \"pmids\": [\"30086537\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2018,\n      \"finding\": \"GRSF1 together with the mitochondrial degradosome (SUV3-PNPase complex) restricts mitochondrial antisense RNA (including G-quadruplex-forming species). GRSF1 acts as a G-quadruplex-melting co-factor enabling degradation of antisense mtRNAs by the SUV3-PNPase complex.\",\n      \"method\": \"Genetic/biochemical characterization of antisense mtRNA levels upon depletion of complex components\",\n      \"journal\": \"Molecular & cellular oncology\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Weak — mechanistic placement of GRSF1 as co-factor in mtRNA surveillance pathway, single lab review/commentary paper with experimental basis described\",\n      \"pmids\": [\"30525095\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2019,\n      \"finding\": \"GRSF1 inhibits myoblast differentiation by directly targeting mitochondrial GPX4 mRNA, promoting GPX4 expression which reduces ROS levels; reduction in mitochondrial ROS is necessary for myogenic differentiation. Loss of GRSF1 promotes differentiation by reducing GPX4 and increasing ROS.\",\n      \"method\": \"siRNA knockdown, ROS measurement, myogenic differentiation assays in vitro and in vivo\",\n      \"journal\": \"Experimental cell research\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — loss-of-function with defined molecular target (GPX4) and ROS readout, both in vitro and in vivo; single lab\",\n      \"pmids\": [\"31085189\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2021,\n      \"finding\": \"GRSF1 directly binds GUUU motifs within the 3'UTR of YY1 mRNA (region 2663-2847) to enhance YY1 mRNA stability. YY1 in turn feeds back to promote GRSF1 expression by binding the GRSF1 promoter. GRSF1 and miR-30e-5p competitively regulate YY1 by binding the same 3'UTR region.\",\n      \"method\": \"RNA immunoprecipitation, luciferase reporter assays, RNA pull-down, ChIP assay, shRNA knockdown\",\n      \"journal\": \"Journal of experimental & clinical cancer research : CR\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — RIP, RNA pulldown, ChIP, reporter assays with defined binding motif; single lab, multiple orthogonal methods\",\n      \"pmids\": [\"34998399\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2022,\n      \"finding\": \"GRSF1 directly upregulates GPX4 at the translational level in cardiomyocytes. Knockdown of GRSF1 increased sensitivity to ferroptosis and impaired the cardioprotective effect of geniposide in oxidative-stressed cardiomyocytes.\",\n      \"method\": \"siRNA knockdown, translation assays, ferroptosis assays, in vivo myocardial infarction model\",\n      \"journal\": \"Frontiers in pharmacology\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — loss-of-function with defined molecular target (GPX4 translation), both in vitro and in vivo; single lab\",\n      \"pmids\": [\"35600863\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2022,\n      \"finding\": \"Host adaptive mutations in the 2009 pH1N1 PA gene enhance cytosolic accumulation and translation efficiency of viral mRNAs via GRSF1. Mutations to the GRSF1 binding site in viral NP mRNA 5'UTR, as well as GRSF1 knockdown, reduced cytosolic mRNA accumulation and translation efficiency.\",\n      \"method\": \"Quantitative translation/transcription assays, GRSF1 knockdown, GRSF1 binding site mutagenesis\",\n      \"journal\": \"Communications biology\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — binding site mutagenesis and knockdown with quantitative functional readouts; single lab, two orthogonal approaches\",\n      \"pmids\": [\"36253464\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2023,\n      \"finding\": \"GRSF1 directly interacts with G-tracts in the coding region (CDS) of FGA, FGB, and FGG mRNAs via its qRRM2 domain and decreases their stability, thereby reducing fibrinogen expression and attenuating hypercoagulability. Overexpression of GRSF1 in old mice liver decreased plasma fibrinogen and reduced hypercoagulability; knockdown in young mice increased fibrinogen and promoted coagulation.\",\n      \"method\": \"RNA immunoprecipitation, RNA pull-down, domain deletion mutants, in vivo overexpression/knockdown mouse liver models, coagulation assays\",\n      \"journal\": \"Cell death & disease\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — RIP, RNA pulldown with domain mapping, in vivo gain- and loss-of-function with quantitative phenotypic readouts; single lab but multiple orthogonal methods\",\n      \"pmids\": [\"37923734\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2024,\n      \"finding\": \"GRSF1 is important for nuclear export of influenza A virus NP mRNAs as well as their translation. Mutation of the GRSF1 binding site in the NP mRNA 5'UTR reduced NP protein production, cytosolic accumulation of NP mRNA, and attenuated viral growth in mammalian cells.\",\n      \"method\": \"Recombinant virus rescue with GRSF1 binding site mutation, NP protein/mRNA quantification, in vitro mRNA translation assay\",\n      \"journal\": \"Viruses\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — site-directed mutagenesis in viral context with defined molecular phenotype; single lab, multiple readouts\",\n      \"pmids\": [\"39066299\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2024,\n      \"finding\": \"GRSF1 interacts with SOD2 mRNA in granulosa cells (demonstrated by RNA immunoprecipitation), and knockdown of SOD2 reverses the protective effects of GRSF1 overexpression on mitochondrial function, indicating GRSF1 modulates oxidative stress through regulating SOD2.\",\n      \"method\": \"RNA immunoprecipitation, siRNA knockdown, mitochondrial function assays\",\n      \"journal\": \"Reproduction (Cambridge, England)\",\n      \"confidence\": \"Low\",\n      \"confidence_rationale\": \"Tier 3 / Weak — single RIP experiment plus epistasis by SOD2 knockdown; single lab, limited mechanistic depth in abstract\",\n      \"pmids\": [\"38819377\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2025,\n      \"finding\": \"GRSF1 promotes translation of COX1 mRNA in mitochondria. miR-19-3p suppresses GRSF1 expression; loss of GRSF1 reduces COX1 protein levels, impairs mitochondrial function, and aggravates neuronal injury after subarachnoid haemorrhage.\",\n      \"method\": \"Lentiviral overexpression/knockdown in neurons and rat SAH model, miR-19-3p mimic/inhibitor, COX1 protein quantification\",\n      \"journal\": \"Stroke and vascular neurology\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — gain- and loss-of-function in vitro and in vivo with defined molecular target (COX1 mRNA translation); single lab\",\n      \"pmids\": [\"39266212\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2026,\n      \"finding\": \"GRSF1 maintains cardiac BCAA homeostasis by directly binding G-tracts in the coding region of BCKDHB mRNA through its qRRM domain, promoting BCKDHB mRNA stability and increasing BCKDHB protein expression. Cardiomyocyte-specific GRSF1 deletion led to dilated cardiomyopathy and heart failure; overexpression attenuated pressure-overload heart failure. Functional recovery by GRSF1 overexpression was blocked by cardiac-specific BCKDHB deletion, establishing epistasis.\",\n      \"method\": \"Cardiomyocyte-specific conditional KO and overexpression mice, metabolomics, GRSF1 qRRM mutant mice, BCKDHB cardiac-specific KO epistasis, mRNA stability assays\",\n      \"journal\": \"Circulation\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — genetic epistasis (double KO), domain-specific mutant, in vivo gain and loss of function, metabolomics; multiple orthogonal methods in single rigorous study\",\n      \"pmids\": [\"41487100\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2026,\n      \"finding\": \"LINC00942 interacts with GRSF1 and facilitates binding of GRSF1 to complex I mRNA in mitochondria, enhancing translation efficiency of complex I subunits, increasing complex I protein levels and mitochondrial oxidative phosphorylation activity, while suppressing ferroptosis in hepatocellular carcinoma cells.\",\n      \"method\": \"RNA pull-down with mass spectrometry (GRSF1 interaction), RIP, complex I activity assays, ferroptosis assays\",\n      \"journal\": \"Science China. Life sciences\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — RNA pulldown-MS for interaction, RIP, functional enzymatic assays; single lab\",\n      \"pmids\": [\"41530642\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2025,\n      \"finding\": \"Super-resolution STED nanoscopy (smFISH-STED) revealed spatial relationships between distinct mitochondrial mRNA species and GRSF1 as an RNA granule marker protein, demonstrating adaptive changes in mRNA distribution and quantity in challenged mammalian cells.\",\n      \"method\": \"smFISH combined with STED and MINFLUX super-resolution microscopy\",\n      \"journal\": \"bioRxiv\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Weak — direct super-resolution localization with functional context; single study, preprint, novel imaging approach\",\n      \"pmids\": [\"bio_10.1101_2025.01.23.634455\"],\n      \"is_preprint\": true\n    }\n  ],\n  \"current_model\": \"GRSF1 is a multi-compartment RNA-binding protein (cytoplasm, nucleus, and mitochondrial matrix) that uses three cooperative qRRM domains to bind G-rich/G-quadruplex-containing RNA sequences; in mitochondria it localizes to RNA granules, interacts with RNase P to process primary mt-RNA transcripts, facilitates translation of complex I and other mt-encoded proteins (including COX1), promotes stability or translation of specific nuclear-encoded mRNAs (BCKDHB, GPX4, Use1, fibrinogen subunits), and co-operates with the SUV3-PNPase degradosome to restrict antisense mtRNAs, collectively maintaining mitochondrial homeostasis and suppressing ROS-driven senescence and ferroptosis.\"\n}\n```","stage2_raw":"{\n  \"mechanistic_narrative\": \"GRSF1 is a multi-compartment quasi-RRM RNA-binding protein that recognizes G-rich/G-quadruplex RNA elements and uses this activity to control the translation and stability of select mRNAs in both the cytoplasm and the mitochondrial matrix [#0, #7]. High-affinity binding requires the cooperative action of all three qRRM domains, with isolated domains binding negligibly and the acidic auxiliary domain acting as a negative regulator [#7]; the RRM2/qRRM2 module mediates sequence-specific recognition of motifs such as AGGGU and G-tracts in target transcripts [#2, #15]. In the cytoplasm, GRSF1 selectively recruits mRNAs bearing 5'UTR G-rich sites to polyribosomes to activate translation, a function exploited by influenza A virus to promote nuclear export, cytosolic accumulation, and translation of NP and other viral mRNAs [#1, #2, #16, #14]. GRSF1 also regulates endogenous transcripts by binding G-repeats or G-tracts to either enhance translation (Use1) [#4] or modulate mRNA stability—stabilizing YY1 via 3'UTR GUUU motifs [#12] while destabilizing fibrinogen FGA/FGB/FGG mRNAs through coding-region G-tracts to attenuate hypercoagulability [#15]. A mitochondrial isoform concentrates in RNA granules where it interacts with RNase P to process primary mt-RNA transcripts and supports expression of mitochondrially encoded proteins including COX1 and complex I subunits [#3, #18, #20]; it imports and stabilizes the lncRNA RMRP in the matrix and, as a G-quadruplex-melting cofactor, partners with the SUV3-PNPase degradosome to restrict antisense mtRNAs [#6, #10]. Through these activities GRSF1 sustains respiratory chain function and limits ROS, such that its loss drives oxidative stress, an mTOR–NF-κB–IL6 senescence program, and ferroptosis, while its translational promotion of antioxidant targets GPX4 and BCKDHB-dependent BCAA metabolism protects cardiomyocytes [#8, #9, #11, #13, #19].\",\n  \"teleology\": [\n    {\n      \"year\": 1994,\n      \"claim\": \"Established GRSF1 as a cytoplasmic poly(A)+ mRNA-binding protein recognizing a conserved G-rich RNA element, defining its core molecular activity.\",\n      \"evidence\": \"Northwestern screening, immunofluorescence, and in vivo UV cross-linking in human cells\",\n      \"pmids\": [\"8036161\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"No functional consequence of binding established\", \"Target mRNAs unidentified\", \"Binding specificity not mapped to domains\"]\n    },\n    {\n      \"year\": 1999,\n      \"claim\": \"Showed GRSF1 is a positive translational regulator, answering whether its RNA binding has a functional output by demonstrating it stimulates translation of influenza NP mRNA via the 5'UTR.\",\n      \"evidence\": \"Yeast three-hybrid, gel shift, and cell-free translation with depletion/reconstitution of HeLa extracts\",\n      \"pmids\": [\"10359774\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Mechanism of polysome recruitment not resolved\", \"Endogenous cellular targets not yet identified\"]\n    },\n    {\n      \"year\": 2002,\n      \"claim\": \"Mapped the RNA-binding activity to RRM2 and the recognition site to AGGGU, and showed GRSF1 acts by recruiting target mRNAs to polyribosomes, linking sequence specificity to mechanism.\",\n      \"evidence\": \"GST-GRSF1 deletion mutants, in vitro translation, polysome fractionation, cDNA microarray\",\n      \"pmids\": [\"12239318\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Identity of cooperating cellular proteins not defined\", \"Broader endogenous target set not characterized\"]\n    },\n    {\n      \"year\": 2013,\n      \"claim\": \"Revealed a mitochondrial pool of GRSF1 in RNA granules that interacts with RNase P and is required for primary transcript processing, establishing an organellar role distinct from its cytoplasmic translation function.\",\n      \"evidence\": \"Subcellular fractionation/immunofluorescence, reciprocal Co-IP with RNase P, RNA processing assays in depleted cells\",\n      \"pmids\": [\"23473034\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"How GRSF1 directs RNase P specificity unclear\", \"Granule assembly mechanism unknown\"]\n    },\n    {\n      \"year\": 2014,\n      \"claim\": \"Extended the translational activator role to an endogenous physiological target, Use1, showing GRSF1 binding to alternatively spliced 5'UTR G-repeats is required for erythroblast expansion.\",\n      \"evidence\": \"RNA band shift, reporter translation assays, siRNA knockdown, erythroblast expansion assays\",\n      \"pmids\": [\"25184340\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Single physiological context\", \"No structural basis for G-repeat recognition\"]\n    },\n    {\n      \"year\": 2015,\n      \"claim\": \"Implicated GRSF1 in miRNA-directed translational upregulation, showing it reads a CCGCAU motif in a miR-346/hTERT bulge loop to recruit ribosomes independently of AGO2.\",\n      \"evidence\": \"RNA immunoprecipitation, reporter assays, ribosome recruitment, miRNA sequence-swap experiments\",\n      \"pmids\": [\"26507454\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Generality of the miRNA-bulge mechanism unknown\", \"Direct binding to bulge structure not structurally resolved\"]\n    },\n    {\n      \"year\": 2016,\n      \"claim\": \"Defined GRSF1 as a chaperone for the imported lncRNA RMRP within mitochondria, linking it to mitochondrial DNA replication priming and respiration.\",\n      \"evidence\": \"Affinity RNA pull-down/MS, RIP, siRNA knockdown, oxygen consumption measurement\",\n      \"pmids\": [\"27198227\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Functional fate of RMRP downstream of GRSF1 not fully resolved\", \"Modest replication-priming effect mechanistically unexplained\"]\n    },\n    {\n      \"year\": 2017,\n      \"claim\": \"Defined the biochemical architecture of RNA recognition, showing all three qRRM domains act cooperatively for high-affinity binding and the acidic domain is a negative regulator.\",\n      \"evidence\": \"Recombinant protein, quantitative EMSA with systematic truncation mutants\",\n      \"pmids\": [\"29288125\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"No atomic structure of the qRRM-RNA complex\", \"How the acidic domain regulates binding unknown\"]\n    },\n    {\n      \"year\": 2018,\n      \"claim\": \"Connected GRSF1 loss to oxidative stress and senescence, defining an mTOR→NF-κB→IL6 axis downstream of respiratory complex I/IV impairment, and showed GRSF1 itself is destabilized in senescence.\",\n      \"evidence\": \"siRNA knockdown, respiratory complex and ROS assays, NF-κB/mTOR pathway analysis, protein stability assays, SA-β-gal, IL6 ELISA\",\n      \"pmids\": [\"30753671\", \"30086537\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Protease/pathway destabilizing GRSF1 in senescence unidentified\", \"Direct mt targets driving complex I/IV defect not fully enumerated\"]\n    },\n    {\n      \"year\": 2018,\n      \"claim\": \"Placed GRSF1 in mitochondrial RNA surveillance as a G-quadruplex-melting cofactor enabling SUV3-PNPase degradation of antisense mtRNAs.\",\n      \"evidence\": \"Biochemical/genetic characterization of antisense mtRNA upon component depletion\",\n      \"pmids\": [\"30525095\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Direct demonstration of G-quadruplex melting activity limited\", \"Commentary-level experimental detail\"]\n    },\n    {\n      \"year\": 2019,\n      \"claim\": \"Linked GRSF1 to redox-controlled differentiation by showing it promotes mitochondrial GPX4 expression to suppress ROS and inhibit myogenic differentiation.\",\n      \"evidence\": \"siRNA knockdown, ROS measurement, myogenic differentiation assays in vitro and in vivo\",\n      \"pmids\": [\"31085189\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Direct binding mode to GPX4 mRNA not mapped here\", \"Whether effect is translational or stability not distinguished\"]\n    },\n    {\n      \"year\": 2021,\n      \"claim\": \"Demonstrated GRSF1 stabilizes YY1 mRNA via 3'UTR GUUU motifs in a feedback loop competing with miR-30e-5p, expanding its role to mRNA stability regulation in cancer.\",\n      \"evidence\": \"RIP, luciferase reporters, RNA pull-down, ChIP, shRNA knockdown\",\n      \"pmids\": [\"34998399\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Mechanism of stabilization (decay machinery) not defined\", \"Single cancer context\"]\n    },\n    {\n      \"year\": 2022,\n      \"claim\": \"Showed GRSF1 directly upregulates GPX4 translationally to protect cardiomyocytes from ferroptosis, mechanistically anchoring the antioxidant/anti-ferroptosis role.\",\n      \"evidence\": \"siRNA knockdown, translation assays, ferroptosis assays, in vivo myocardial infarction model\",\n      \"pmids\": [\"35600863\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"GPX4 mRNA binding site not mapped\", \"Relationship to mitochondrial vs cytoplasmic GPX4 pools unclear\"]\n    },\n    {\n      \"year\": 2022,\n      \"claim\": \"Established GRSF1's role in viral mRNA cytosolic accumulation and translation as a host-adaptation target, with PA mutations enhancing GRSF1-dependent NP mRNA handling.\",\n      \"evidence\": \"Quantitative translation/transcription assays, GRSF1 knockdown, binding-site mutagenesis\",\n      \"pmids\": [\"36253464\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Mechanistic link between PA mutations and GRSF1 engagement indirect\", \"Step (export vs translation) not yet separated here\"]\n    },\n    {\n      \"year\": 2023,\n      \"claim\": \"Showed GRSF1 destabilizes fibrinogen FGA/FGB/FGG mRNAs via qRRM2 binding to coding-region G-tracts, demonstrating a destabilizing (not just activating) output with in vivo coagulation consequences.\",\n      \"evidence\": \"RIP, RNA pull-down, domain-deletion mutants, in vivo liver gain/loss-of-function, coagulation assays\",\n      \"pmids\": [\"37923734\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Decay machinery recruited by GRSF1 not identified\", \"Determinants of activating vs destabilizing outcomes unknown\"]\n    },\n    {\n      \"year\": 2024,\n      \"claim\": \"Separated GRSF1's contribution to influenza NP mRNA nuclear export from its translational role, using recombinant virus with binding-site mutations.\",\n      \"evidence\": \"Recombinant virus rescue with binding-site mutation, NP protein/mRNA quantification, in vitro translation\",\n      \"pmids\": [\"39066299\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Export machinery partners of GRSF1 not defined\", \"How one binding site mediates two steps unclear\"]\n    },\n    {\n      \"year\": 2024,\n      \"claim\": \"Added SOD2 mRNA as a putative GRSF1 target linking it to oxidative stress control in granulosa cells via epistasis.\",\n      \"evidence\": \"RNA immunoprecipitation, siRNA knockdown, mitochondrial function assays\",\n      \"pmids\": [\"38819377\"],\n      \"confidence\": \"Low\",\n      \"gaps\": [\"Single RIP without binding-site mapping or reciprocal validation\", \"Whether GRSF1 affects SOD2 translation or stability not shown\"]\n    },\n    {\n      \"year\": 2025,\n      \"claim\": \"Demonstrated GRSF1 promotes mitochondrial COX1 mRNA translation and is suppressed by miR-19-3p, linking it to neuronal protection after subarachnoid haemorrhage.\",\n      \"evidence\": \"Lentiviral overexpression/knockdown in neurons and rat SAH model, miR-19-3p mimic/inhibitor, COX1 quantification\",\n      \"pmids\": [\"39266212\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Direct COX1 mRNA binding by GRSF1 not mapped\", \"Mechanism of translational enhancement unresolved\"]\n    },\n    {\n      \"year\": 2026,\n      \"claim\": \"Established a definitive genetic role for GRSF1 in cardiac metabolism, showing qRRM-dependent stabilization of BCKDHB mRNA maintains BCAA homeostasis and protects against heart failure, with double-KO epistasis.\",\n      \"evidence\": \"Cardiomyocyte-specific conditional KO and overexpression mice, qRRM mutant mice, BCKDHB double-KO epistasis, metabolomics, mRNA stability assays\",\n      \"pmids\": [\"41487100\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Decay pathway controlling BCKDHB mRNA not defined\", \"Relationship to GRSF1's mitochondrial functions in heart unclear\"]\n    },\n    {\n      \"year\": 2026,\n      \"claim\": \"Identified LINC00942 as an RNA cofactor that bridges GRSF1 to complex I mRNAs to enhance their translation and suppress ferroptosis, revealing lncRNA-guided target selection.\",\n      \"evidence\": \"RNA pull-down/MS, RIP, complex I activity assays, ferroptosis assays in HCC cells\",\n      \"pmids\": [\"41530642\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"How LINC00942 confers complex I mRNA specificity unclear\", \"Generality beyond HCC unknown\"]\n    },\n    {\n      \"year\": null,\n      \"claim\": \"How GRSF1 switches between translational activation, mRNA stabilization, and mRNA destabilization on different G-rich targets, and what decay/recruitment machinery it engages, remains unresolved.\",\n      \"evidence\": \"\",\n      \"pmids\": [],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"No atomic structure of qRRM-RNA complexes resolving target discrimination\", \"Decay and translation machinery partners not identified\", \"Determinants of activating vs destabilizing outcomes unknown\"]\n    }\n  ],\n  \"mechanism_profile\": {\n    \"molecular_activity\": [\n      {\"term_id\": \"GO:0003723\", \"supporting_discovery_ids\": [0, 1, 2, 7, 12, 15, 19]},\n      {\"term_id\": \"GO:0045182\", \"supporting_discovery_ids\": [1, 2, 4, 18, 20]},\n      {\"term_id\": \"GO:0098772\", \"supporting_discovery_ids\": [12, 15, 19]}\n    ],\n    \"localization\": [\n      {\"term_id\": \"GO:0005829\", \"supporting_discovery_ids\": [0]},\n      {\"term_id\": \"GO:0005739\", \"supporting_discovery_ids\": [3, 6, 18, 21]},\n      {\"term_id\": \"GO:0005634\", \"supporting_discovery_ids\": [16]}\n    ],\n    \"pathway\": [\n      {\"term_id\": \"R-HSA-8953854\", \"supporting_discovery_ids\": [3, 6, 10]},\n      {\"term_id\": \"R-HSA-392499\", \"supporting_discovery_ids\": [1, 2, 4, 18, 20]},\n      {\"term_id\": \"R-HSA-1430728\", \"supporting_discovery_ids\": [8, 18, 19, 20]},\n      {\"term_id\": \"R-HSA-5357801\", \"supporting_discovery_ids\": [11, 13, 20]}\n    ],\n    \"complexes\": [\n      \"mitochondrial RNA granule\",\n      \"SUV3-PNPase degradosome\"\n    ],\n    \"partners\": [\n      \"RNASEP\",\n      \"SUV3\",\n      \"PNPase\",\n      \"RMRP\",\n      \"LINC00942\"\n    ],\n    \"other_free_text\": []\n  }\n}","audit_flag":null,"evaluation":{"pairwise":"tie","faith_supported":6,"faith_total":6,"faith_pct":100.0}}