{"gene":"RAN","run_date":"2026-06-10T06:43:36","timeline":{"discoveries":[{"year":1993,"finding":"Ran/TC4 GTP-binding protein is required for protein import into the nucleus; it is a component of the cytosolic fraction B activity that mediates translocation of NLS-bearing substrates through the nuclear pore, acting downstream of NLS recognition.","method":"Biochemical reconstitution using Xenopus oocyte cytosolic fractions in digitonin-permeabilized cell import assay; protein purification to homogeneity","journal":"Nature","confidence":"High","confidence_rationale":"Tier 1 / Strong — reconstitution of nuclear import with purified Ran in permeabilized cell assay, independently replicated in same year by Melchior et al. (PMID:8276887)","pmids":["8413630"],"is_preprint":false},{"year":1993,"finding":"Ran/TC4 is an essential GTP-binding transport factor for nuclear import; nonhydrolyzable GTP analogues (GTPγS) block nuclear import in a Ran-dependent manner, demonstrating that GTP hydrolysis by Ran is required for transport.","method":"In vitro nuclear import assay in digitonin-permeabilized cells; GTPγS inhibition; biochemical complementation with bacterially expressed Ran/TC4","journal":"The Journal of cell biology","confidence":"High","confidence_rationale":"Tier 1 / Strong — reconstitution with purified bacterially expressed Ran; independently confirmed by Moore & Blobel (PMID:8413630)","pmids":["8276887"],"is_preprint":false},{"year":1993,"finding":"Ran/TC4 undergoes GTP/GDP cycling regulated by RCC1 (guanine nucleotide exchange factor) and a Ran-specific GTPase-activating protein (RanGAP); GTP-bound form preferentially interacts with putative effectors, and GDP-bound form interacts with RCC1. Disruption of GTP hydrolysis (Q69L-like mutant) inhibits cell cycle progression.","method":"Identification of RanGAP by biochemical screen; in vitro GTPase assays; characterization of Ran mutant proteins; yeast two-hybrid and binding assays for GTP-bound effectors","journal":"Nature","confidence":"High","confidence_rationale":"Tier 1–2 / Strong — multiple orthogonal methods (in vitro GTPase assay, binding assays, mutant characterization); foundational mechanistic paper replicated across many subsequent studies","pmids":["8255297"],"is_preprint":false},{"year":1993,"finding":"Ran/TC4 nuclear localization requires the presence of RCC1; expression of a GTP hydrolysis-deficient Ran mutant disrupts DNA synthesis, placing Ran in a GTPase switch that monitors progress of DNA synthesis and couples it to onset of mitosis.","method":"Transient expression of Ran mutants defective in GTP hydrolysis in mammalian cells; indirect immunofluorescence for localization; [3H]-thymidine incorporation assay for DNA synthesis","journal":"The Journal of cell biology","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — localization by immunofluorescence plus functional DNA synthesis assay, single lab with two orthogonal methods","pmids":["8421051"],"is_preprint":false},{"year":1994,"finding":"A mutant Ran (T24N, GDP-bound state) inhibits nuclear assembly and DNA replication in Xenopus egg extracts by binding tightly to RCC1 and inactivating it as a GEF; supplementing with excess RCC1 rescues nuclear assembly and DNA replication, demonstrating RCC1's essential function is solely as a GEF for Ran in interphase.","method":"Xenopus egg extract nuclear assembly and DNA replication assays; addition of bacterially expressed mutant Ran proteins; rescue with purified RCC1; in vitro GEF activity assay","journal":"The EMBO journal","confidence":"High","confidence_rationale":"Tier 1 / Moderate — reconstitution in egg extracts with defined mutant proteins, rescue experiments, in vitro GEF assay; single lab but multiple orthogonal methods","pmids":["7988569"],"is_preprint":false},{"year":1994,"finding":"TC4/Ran has distinct roles in nuclear assembly and cell cycle progression; GDP-bound TC4 suppresses nuclear growth and prevents DNA replication, and blocks entry into mitosis by promoting inhibitory phosphorylation of p34(cdc2) on tyrosine and threonine residues in cell-free Xenopus egg extracts.","method":"Xenopus egg extract nuclear assembly assay; cell-free cycling extract; immunoblotting for p34(cdc2) phosphorylation; addition of wild-type and mutant TC4 proteins","journal":"The Journal of cell biology","confidence":"High","confidence_rationale":"Tier 1 / Moderate — cell-free reconstitution with defined mutant proteins, biochemical readout of cdc2 phosphorylation; multiple phenotypes tested in one study","pmids":["8188741"],"is_preprint":false},{"year":1994,"finding":"Expression of a Ran/TC4 GTP hydrolysis-deficient mutant arrests cells predominantly in G2 (also G1); deletion of the acidic C-terminal hexapeptide (DEDDDL) does not alter nuclear localization but abrogates the cell cycle inhibitory effect, indicating this domain is essential for mediating Ran's cell cycle function.","method":"Transient expression in 293/Tag cells; flow cytometry cell cycle analysis; nuclear localization assessed by subcellular fractionation","journal":"Molecular and cellular biology","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — defined mutant expression with cell cycle readout plus deletion mapping; single lab, two orthogonal methods","pmids":["8196659"],"is_preprint":false},{"year":1995,"finding":"RanBP2 (a giant nuclear pore protein of 3,224 residues) binds Ran/TC4; it contains four RanBP1-homologous domains, XFXFG nucleoporin motifs, and localizes to the NPC. Antibodies against RanBP2 inhibit NLS-mediated nuclear import, implicating it as a functional Ran effector at the NPC.","method":"Yeast two-hybrid screen using Ran/TC4 as bait; sequence analysis; immunolocalization; antibody inhibition of nuclear import in permeabilized cells","journal":"Nature","confidence":"Medium","confidence_rationale":"Tier 2–3 / Moderate — two-hybrid plus immunolocalization plus antibody inhibition assay; single lab with multiple approaches","pmids":["7603572"],"is_preprint":false},{"year":1995,"finding":"The acidic C-terminal DEDDDL sequence of Ran stabilizes GDP binding and is required for high-affinity interaction with the Ran-binding protein HTF9A/RanBP1; HTF9A functions as a co-stimulator of RanGAP activity on wild-type Ran but acts as a RanGAP inhibitor when the C-terminus is absent. An antibody against the C-terminal region preferentially recognizes GTP-bound Ran, indicating nucleotide-dependent conformational change in this domain.","method":"In vitro GDP/GTP binding assays with truncation mutants; in vitro RanGAP co-stimulation assays; antibody specificity experiments","journal":"The Journal of biological chemistry","confidence":"High","confidence_rationale":"Tier 1 / Moderate — in vitro biochemical reconstitution with defined mutant proteins, multiple functional assays in one study","pmids":["7782302"],"is_preprint":false},{"year":1995,"finding":"The yeast RNA1 gene product (Rna1p) is the GTPase-activating protein (GAP) for Gsp1p (yeast Ran/TC4 homolog), stimulating GTP hydrolysis ~10^7-fold; human RanGAP1 and S. pombe rna1p also activate Gsp1p GTPase, but Rna1p does not activate human Ran GTP hydrolysis, revealing species-specific GAP activity.","method":"Bacterial expression and purification of recombinant Gsp1p and Rna1p; in vitro GTPase activity assay; cross-species complementation biochemistry","journal":"The Journal of biological chemistry","confidence":"High","confidence_rationale":"Tier 1 / Moderate — in vitro reconstituted GTPase assay with purified recombinant proteins; quantitative kinetic measurement","pmids":["7744835"],"is_preprint":false},{"year":1995,"finding":"Rna1p (yeast RanGAP) is directly required for nuclear import; cytosol from rna1-1 mutant cells is unable to support nuclear import in semi-intact yeast cells, and adding back purified Rna1p restores import in a dose-dependent manner.","method":"Indirect immunofluorescence; GFP-fusion protein import in living cells; semi-intact yeast cell in vitro import assay; add-back of purified Rna1p","journal":"The Journal of cell biology","confidence":"High","confidence_rationale":"Tier 1–2 / Strong — purified protein add-back reconstitution experiment plus in vivo and in vitro import assays; multiple orthogonal methods","pmids":["7657689"],"is_preprint":false},{"year":1995,"finding":"The GTP-bound form of Gsp1p (yeast Ran) blocks nuclear protein import and retains poly(A)+ RNA in the nucleus; GTP hydrolysis by Ran is therefore necessary for proper nuclear import of proteins and cytoplasmic appearance of mRNA.","method":"Overexpression of wild-type and GTP-locked (G21V) Gsp1p in S. cerevisiae; indirect immunofluorescence for nuclear protein localization; in situ hybridization for poly(A)+ RNA","journal":"Proceedings of the National Academy of Sciences of the United States of America","confidence":"High","confidence_rationale":"Tier 2 / Strong — genetic and cell biological analysis with defined GTP-locked mutant; two independent phenotypic readouts (protein import and mRNA export)","pmids":["7816822"],"is_preprint":false},{"year":1995,"finding":"A conserved ~150-residue Ran-binding domain (RanBD) present in multiple Ran-binding proteins stabilizes the GTP-bound state of Ran and acts as a coactivator of RanGAP; mutation of a conserved residue in the RanBD of HTF9a drastically reduces Ran binding.","method":"Expression cloning overlay assay; sequence analysis; in vitro binding assays; RanGAP coactivation assay; site-directed mutagenesis; co-immunoprecipitation from cell lysates","journal":"Proceedings of the National Academy of Sciences of the United States of America","confidence":"Medium","confidence_rationale":"Tier 1–2 / Moderate — in vitro functional assays with mutagenesis plus co-IP; single lab, multiple methods","pmids":["7724562"],"is_preprint":false},{"year":1996,"finding":"Both protein import and U snRNP import require a GTPase activity (Ran); both are sensitive to nonhydrolyzable GTP analogues and to dominant-negative Ran mutants (Q69L defective in hydrolysis; T24N defective in GTP binding), demonstrating a shared Ran-dependent step for these two distinct import pathways.","method":"In vitro nuclear import assays in permeabilized cells; comparison of effects of two mechanistically distinct Ran mutants on protein vs. snRNP import","journal":"The Journal of cell biology","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — defined mutant proteins in reconstituted import assay, two substrates tested; single lab","pmids":["8636225"],"is_preprint":false},{"year":1996,"finding":"Ran/TC4 interacts directly with the cytosolic transport factors p97 (importin-β) and NTF2 in a nucleotide-specific manner: GTP-bound Ran interacts with p97, while GDP-bound Ran interacts with NTF2, establishing that Ran nucleotide state directs sequential interactions with import machinery.","method":"Solution and solid-phase binding assays using [γ-32P]GTP- or [3H]GDP-preloaded recombinant Ran/TC4 with purified p97 and NTF2","journal":"Proceedings of the National Academy of Sciences of the United States of America","confidence":"High","confidence_rationale":"Tier 1 / Moderate — in vitro biochemical binding assays with nucleotide-preloaded recombinant proteins, direct demonstration of nucleotide-state specificity","pmids":["8755535"],"is_preprint":false},{"year":1996,"finding":"Multiple Ran mutants (G19V, T24N, L43E, E46G) that affect interaction with regulatory proteins (RCC1, RanGAP/Fug1) or Ran-binding proteins disrupt normal nuclear localization of Ran, causing accumulation at the nuclear envelope; G19V Ran is insensitive to RCC1-stimulated exchange and is ~50% GTP-bound in cells.","method":"Expression of epitope-tagged Ran mutants in BHK21 cells; immunofluorescence; nucleotide-binding assays from immunoprecipitated Ran; permeabilized cell import assay","journal":"The Journal of biological chemistry","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — multiple mutants characterized by immunofluorescence plus in vitro nucleotide binding; single lab","pmids":["8955121"],"is_preprint":false},{"year":1996,"finding":"Ran L43E mutant (effector domain mutant) does not affect nuclear import of GR-GFP but strongly inhibits cell growth, providing evidence that Ran mediates at least one essential cell function independent of nuclear protein import.","method":"Transfection and microinjection of Ran mutants into BHK21 cells expressing GR-GFP; live-cell fluorescence microscopy for nuclear import; colony formation/cell growth assay","journal":"The Journal of cell biology","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — live-cell imaging of nuclear transport combined with growth assay; two orthogonal readouts; single lab","pmids":["8655589"],"is_preprint":false},{"year":1997,"finding":"The interaction between Gsp1p (yeast Ran) and Ntf2p is critical for nuclear transport; temperature-sensitive gsp1 mutations that reduce Ntf2p binding cause nuclear transport defects that are suppressed by NTF2 overexpression, but not by a NTF2 mutant with reduced Gsp1p binding.","method":"Genetic screen for conditional gsp1 alleles; biochemical binding assays; in vivo nuclear transport assays; genetic suppression analysis","journal":"Molecular and cellular biology","confidence":"High","confidence_rationale":"Tier 2 / Strong — reciprocal genetic and biochemical evidence; suppression by NTF2 overexpression and failure of binding-deficient NTF2 to suppress provides strong epistatic evidence","pmids":["9199309"],"is_preprint":false},{"year":1995,"finding":"GSP1 (yeast Ran) is nuclear, binds GTP in vitro, and is an essential gene; a GTP-stabilizing activating mutation in Gsp1p causes dominant lethality, and GSP1 and GSP2 are multicopy suppressors of prp20 (RCC1 homolog) mutants, placing GSP1 downstream of PRP20/RCC1.","method":"Multicopy suppressor screen; GTP-binding assay with purified protein; indirect immunofluorescence; dominant lethal mutant analysis","journal":"Molecular and cellular biology","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — suppressor genetics combined with in vitro GTP-binding and localization; single lab","pmids":["8455603"],"is_preprint":false},{"year":1999,"finding":"Ran (as ARA24) functions as a coactivator of the androgen receptor (AR) that binds differentially to AR N-terminal polyglutamine (poly-Q) regions of different lengths; longer poly-Q expansions diminish AR-ARA24 interaction and coactivation; deletion of DEDDDL at ARA24 C-terminus enhances coactivation.","method":"Yeast two-hybrid and mammalian reciprocal interaction assays; transcriptional reporter assays; deletion mutagenesis","journal":"The Journal of biological chemistry","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — reciprocal interaction assays in two systems plus transcriptional readout with mutagenesis; single lab","pmids":["10400640"],"is_preprint":false},{"year":2000,"finding":"Disrupting the Ran-NTF2 interaction by a temperature-sensitive NTF2 mutation prevents nuclear import of RanGDP in vivo, depleting nuclear Ran; this depletion arrests cells in G2 in a MAD2 (spindle assembly checkpoint)-dependent manner, linking nuclear Ran concentration to spindle checkpoint control.","method":"Temperature-sensitive NTF2 mutant in S. cerevisiae; live-cell and indirect immunofluorescence for Ran localization; cell cycle analysis; genetic epistasis with mad2 deletion","journal":"Molecular biology of the cell","confidence":"High","confidence_rationale":"Tier 2 / Strong — conditional mutant with defined biochemical defect, clear cell cycle readout, and epistasis with spindle checkpoint gene; multiple methods","pmids":["10930458"],"is_preprint":false},{"year":2001,"finding":"Mog1 binds nucleotide-free Ran (after stimulating GTP release from Ran-GTP or Ran-GDP) and forms a stable complex; disruption of the Mog1-Ran interface (using engineered charge-reversal mutants Mog1-E65K / Ran-K136E) causes temperature-sensitive growth and nuclear import defects in yeast.","method":"In vitro nucleotide release assay; engineering of charge-reversal interaction-disrupting mutants; in vivo import assay with fluorescent reporter; synthetic lethality with prp20","journal":"The Journal of biological chemistry","confidence":"High","confidence_rationale":"Tier 1–2 / Moderate — in vitro biochemical assay with defined mutants, in vivo import assay, synthetic lethality; multiple orthogonal methods in single study","pmids":["11509570"],"is_preprint":false},{"year":2002,"finding":"Ran-GTP generated around chromatin directs mitotic spindle assembly; in C. elegans, RNAi depletion of Ran causes metaphase chromosome misalignment and failure of nuclear envelope assembly at telophase. Ran localizes to kinetochore regions during mitosis and to the nuclear envelope during interphase/telophase.","method":"RNAi depletion in C. elegans embryos; immunofluorescence for chromosome alignment, astral microtubules, and Ran localization; comparison with RCC1 and RanGAP RNAi","journal":"Current biology","confidence":"High","confidence_rationale":"Tier 2 / Strong — clean RNAi loss-of-function with specific mitotic and nuclear envelope phenotypes; epistasis with RCC1 and RanGAP; multiple orthogonal readouts","pmids":["11909538"],"is_preprint":false},{"year":2002,"finding":"Nercc1 (NIMA-like kinase) binds specifically to the Ran GTPase through both its catalytic domain and RCC1-like domain, preferring RanGDP in vivo; Nercc1 autoactivates by autophosphorylation in vitro and is phosphorylated by active p34(Cdc2); its inhibition causes spindle abnormalities and chromosomal misalignment.","method":"Co-immunoprecipitation; in vitro kinase assays; microinjection of anti-Nercc1 antibodies; nucleotide-binding preference assays","journal":"Genes & development","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — reciprocal Co-IP, in vitro kinase assay with nucleotide preference mapping; single lab","pmids":["12101123"],"is_preprint":false},{"year":2002,"finding":"Ran-GTP promotes spindle assembly by releasing TPX2 from inhibitory importin-α/β binding; Ran-GTP stimulates the interaction between TPX2 and Aurora A kinase (Eg2/Xenopus Aurora A), causing TPX2 to stimulate Aurora A phosphorylation and kinase activity in a microtubule-dependent manner; importin-α/β block this activation and Ran-GTP overcomes this inhibition both in egg extracts and with purified proteins.","method":"Reconstitution in Xenopus egg extracts; in vitro kinase assays with purified proteins; immunoprecipitation; dominant-negative and constitutively active Ran constructs","journal":"Nature cell biology","confidence":"High","confidence_rationale":"Tier 1 / Moderate — reconstitution with purified proteins plus egg extract assays; multiple orthogonal methods in one study","pmids":["12577065"],"is_preprint":false},{"year":2008,"finding":"Ran-binding protein 3 (RanBP3) links the Ras/ERK (via RSK) and PI3-kinase (via Akt) pathways to the Ran gradient and nucleocytoplasmic transport; RSK and Akt phosphorylate RanBP3, which modulates its interaction with Ran and Crm1, thereby regulating the nuclear:cytoplasmic Ran gradient.","method":"In vitro kinase assays; mass spectrometry phosphosite mapping; nuclear transport assays; interaction studies with RanBP3 mutants","journal":"Molecular cell","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — in vitro kinase assay plus transport assays; single lab with multiple methods","pmids":["18280241"],"is_preprint":false},{"year":2008,"finding":"ARA24/Ran (as AR coactivator) enhances the androgen-dependent N-C terminal interaction of the androgen receptor (AR); constitutively GTP- or GDP-bound forms of ARA24/Ran repress the AR N-C interaction; ARA24/Ran forms an endogenous complex with nuclear AR but not cytoplasmic AR.","method":"Co-immunoprecipitation; transcriptional reporter assays; AR N-C interaction assay; subcellular fractionation","journal":"Biochemical and biophysical research communications","confidence":"Medium","confidence_rationale":"Tier 2–3 / Moderate — Co-IP plus functional transcriptional assay plus nucleotide-state mutants; single lab","pmids":["18565325"],"is_preprint":false},{"year":2009,"finding":"Crystal structures of Nup153 zinc fingers in complex with Ran show that each of the four zinc finger modules of Nup153 binds one Ran molecule independently and with measurably higher affinity for RanGDP than RanGTP; microcalorimetric analysis identified one specific hydrogen bond accounting for affinity differences between individual zinc fingers.","method":"X-ray crystallography (six complex structures plus 1.48 Å RanGDP structure); isothermal titration calorimetry; site-directed mutagenesis","journal":"Journal of molecular biology","confidence":"High","confidence_rationale":"Tier 1 / Moderate — crystal structures at high resolution plus ITC and mutagenesis; multiple orthogonal methods in one study","pmids":["19505478"],"is_preprint":false},{"year":2009,"finding":"Ran-GFP is nuclear during interphase; GTP-locked Ran (Q69L) is less concentrated in the nucleus and associates with nuclear pore complexes; GDP/nucleotide-free Ran (T24N) associates relatively stably with chromatin throughout the cell cycle and is highly concentrated on mitotic chromosomes; wild-type Ran-GTP generated at chromatin is highly mobile and interacts dynamically with NPCs and spindle.","method":"Live-cell fluorescence microscopy and FRAP of GFP-Ran and mutant fusions during cell cycle in human cells","journal":"BMC cell biology","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — live-cell imaging with FRAP for multiple nucleotide-state mutants; single lab","pmids":["19765287"],"is_preprint":false},{"year":2011,"finding":"Ran-GTP accumulation at basal bodies is coordinated with ciliogenesis initiation; RanBP1 knockdown increases Ran-GTP concentration at basal bodies and promotes primary cilia formation, while RanBP1 overexpression inhibits it; Ran-GTP is required for proper KIF17 localization at distal tips of primary cilia.","method":"RanBP1 siRNA knockdown and overexpression; immunofluorescence for Ran-GTP and cilia markers; quantification of ciliogenesis; analysis of KIF17 localization","journal":"Molecular biology of the cell","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — loss-of-function and gain-of-function with specific ciliogenesis readout; single lab","pmids":["21998203"],"is_preprint":false},{"year":2014,"finding":"RanBP1 controls spindle assembly by modulating RCC1 activity and its chromatin partitioning: the heterotrimeric RCC1/Ran/RanBP1 complex controls both RCC1 enzymatic activity and distribution between chromatin-bound and soluble pools; RanBP1 phosphorylation drives changes in chromatin-bound RCC1 at the metaphase-anaphase transition.","method":"Reconstitution in M-phase Xenopus egg extracts; biochemical fractionation; RanBP1 phospho-mutants; spindle assembly assays","journal":"Developmental cell","confidence":"High","confidence_rationale":"Tier 1 / Moderate — reconstituted in Xenopus egg extracts with defined phospho-mutants; multiple biochemical and functional assays; single lab","pmids":["25458009"],"is_preprint":false},{"year":2015,"finding":"Ran is acetylated at multiple lysine residues by CBP/p300 and Tip60 in vitro and in vivo; lysine acetylation interferes with nucleotide exchange, GTP hydrolysis, subcellular Ran localization, and interaction with import and export receptors; specific sirtuin deacetylases remove acetyl groups from two Ran acetylation sites in vitro.","method":"In vitro acetylation assays with CBP/p300 and Tip60; mass spectrometry identification of acetylation sites; nucleotide exchange and GTPase assays on acetylated Ran; nuclear transport assays; sirtuin deacetylation assays","journal":"Proceedings of the National Academy of Sciences of the United States of America","confidence":"High","confidence_rationale":"Tier 1 / Moderate — in vitro reconstituted acetyltransferase assays, functional nucleotide-cycle assays, transport assays; multiple methods; single lab","pmids":["26124124"],"is_preprint":false},{"year":2015,"finding":"The Ran-GTP gradient spatially regulates XCTK2 (Kinesin-14) localization and motility within the spindle; a flattened Ran-GTP gradient blocks XCTK2-stimulated bipolar spindle assembly; XCTK2 turnover kinetics are faster near spindle poles (low Ran-GTP) than near chromatin (high Ran-GTP), dependent on importin α/β binding to the XCTK2 NLS.","method":"Xenopus egg extract spindle assembly assays; FRAP analysis of XCTK2 with constitutively active Ran mutant; XCTK2 NLS mutants; importin binding assays","journal":"Current biology","confidence":"High","confidence_rationale":"Tier 1–2 / Moderate — reconstituted spindle assembly in egg extracts with defined mutants plus FRAP; multiple orthogonal methods in one study","pmids":["25981788"],"is_preprint":false},{"year":2018,"finding":"Ran is a substrate of TIP60 acetyltransferase; acetylation of Lys134 by TIP60 during mitosis liberates Mog1 from Ran binding, switching Ran to bind RCC1 and promoting high Ran-GTP levels required for chromosome alignment; structural analysis revealed that Mog1 competes with RCC1 for Ran binding in a GTP/GDP-dependent manner.","method":"Crystal structure of Ran-Mog1 complex; in vitro acetyltransferase assay with TIP60; structure-guided mutagenesis; competition binding assays between Mog1 and RCC1; chromosome alignment assays in cells expressing acetylation-mimicking Ran mutants","journal":"Journal of molecular cell biology","confidence":"High","confidence_rationale":"Tier 1 / Moderate — crystal structure plus in vitro biochemistry plus cell-based functional validation; multiple orthogonal methods in one study","pmids":["29040603"],"is_preprint":false},{"year":2018,"finding":"A nuclear lamina-chromatin-Ran axis controls the Ran gradient and nuclear import; chemical inhibition or depletion of histone methyltransferases G9a/GLP reduces heterochromatin and disrupts the Ran gradient, causing nuclear import defects for large cargoes including ATM; disruption of the Ran gradient in HGPS impairs ATM nuclear import and reduces γ-H2AX generation after ionizing radiation.","method":"HMT inhibitor treatment and siRNA depletion; nuclear:cytoplasmic ratio measurements of Ran and import cargoes; DNA damage assays (γ-H2AX immunofluorescence) after ionizing radiation; comparison with HGPS patient fibroblasts","journal":"Aging cell","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — chemical perturbation plus RNAi with specific transport and DNA damage readouts; single lab, multiple methods","pmids":["30565836"],"is_preprint":false},{"year":2019,"finding":"Ran localizes specifically to the plasma membrane/ruffles of ovarian cancer cells in addition to its nucleocytoplasmic distribution; Ran interacts with RhoA via its DEDDDL C-terminal domain (binding serine 188 of RhoA), preventing RhoA proteasomal degradation and promoting RhoA membrane localization and activity; Ran depletion inhibits ovarian cancer cell invasion by impairing RhoA signaling.","method":"Subcellular fractionation and immunofluorescence for Ran localization; Co-immunoprecipitation; RhoA stability assays (proteasome inhibition); RhoA activity assays; invasion assays with Ran knockdown; mapping of interaction domains by deletion mutagenesis","journal":"Nature communications","confidence":"High","confidence_rationale":"Tier 2 / Moderate — reciprocal Co-IP plus domain mapping plus functional invasion assay; multiple orthogonal methods; single lab","pmids":["31209254"],"is_preprint":false},{"year":2017,"finding":"Active Ran-GTP spatially restricts anillin (a cytokinesis regulator) to the cell equator during cytokinesis; anillin contains a conserved NLS at its C-terminus that binds importin-β and is required for cortical polarity; decreasing Ran-GTP levels or ectopically activating Ran affects anillin localization and causes cytokinesis failure.","method":"Manipulation of Ran-GTP levels in cells; live-cell imaging; localization of anillin NLS mutants; importin-β binding assays; cytokinesis phenotype quantification","journal":"Molecular biology of the cell","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — defined NLS mutants, importin binding assay, live-cell imaging; single lab","pmids":["28931593"],"is_preprint":false},{"year":2002,"finding":"Karyopherinβ2 (Kapβ2) releases import substrates in the nucleus upon RanGTP binding; an internal acidic loop in Kapβ2 physically couples the Ran-binding N-terminal arch to the substrate-binding C-terminal arch; proteolytic cleavage or truncation of this loop uncouples Ran binding from substrate dissociation without reducing affinity for either Ran or substrate, and abolishes Ran-mediated nuclear import of fluorescent substrate.","method":"Proteolytic cleavage and truncation mutagenesis of Kapβ2; NMR mapping of substrate-binding site; quantitative binding affinity measurements; nuclear import assay in permeabilized HeLa cells","journal":"Biochemistry","confidence":"High","confidence_rationale":"Tier 1 / Moderate — mutagenesis with structural NMR plus in vitro binding assays plus permeabilized cell transport assay; multiple orthogonal methods in one study","pmids":["12033928"],"is_preprint":false},{"year":2002,"finding":"RanBP3 associates with RCC1 in a Ran-stimulated manner (Ran-GDP, -GTP, and nucleotide-free Ran all stimulate complex formation); RanBP3 increases RCC1 catalytic activity toward Ran and also promotes Crm1 binding to RCC1, acting as a scaffold to promote efficient nuclear export complex assembly.","method":"Binding assays (solid-phase and pull-down); RCC1 activity assays in presence of RanBP3; three-component complex formation assays","journal":"The Journal of biological chemistry","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — in vitro binding and enzymatic assays; multiple biochemical approaches; single lab","pmids":["11932251"],"is_preprint":false},{"year":2022,"finding":"RSL1D1 interacts with Ran and inhibits its deacetylation by competing with Sirt7 for binding; RSL1D1-mediated hyperacetylation of Ran inhibits nuclear accumulation of STAT3 and the STAT3-regulated autophagic program in colorectal cancer cells.","method":"Co-immunoprecipitation; acetylation assays; STAT3 nuclear localization assays; autophagy markers; competition binding assays between RSL1D1 and Sirt7 for Ran","journal":"Cell death & disease","confidence":"Medium","confidence_rationale":"Tier 2–3 / Moderate — Co-IP plus competition binding plus functional assays; single lab","pmids":["35013134"],"is_preprint":false}],"current_model":"Ran is a small nuclear GTPase that cycles between a GTP-bound (nuclear, generated by chromatin-associated RCC1/RanGEF) and GDP-bound (cytoplasmic, promoted by cytoplasmic RanGAP) state to create an asymmetric gradient across the nuclear envelope; this gradient drives directionality of nuclear import (RanGTP dissociates importin-cargo complexes in the nucleus) and export (RanGTP promotes exportin-cargo loading in the nucleus and complex disassembly in the cytoplasm), and during mitosis the RanGTP gradient around chromosomes releases importin-bound spindle assembly factors (e.g., TPX2, NuMA, XCTK2) to promote spindle assembly, nuclear envelope reformation, and cytokinesis, with these activities further regulated by post-translational acetylation (by TIP60/CBP/p300, reversed by sirtuins) and phosphorylation of Ran-regulatory partners such as RanBP1."},"narrative":{"mechanistic_narrative":"RAN is a small GTPase whose nucleotide-state cycling — driven by the chromatin-associated exchange factor RCC1 generating Ran-GTP and a Ran-specific GAP promoting GTP hydrolysis — establishes a directional switch that governs nucleocytoplasmic transport and mitotic organization [PMID:8255297, PMID:7988569]. Ran was first identified as the essential transport factor required for NLS-dependent protein import through the nuclear pore, with GTP hydrolysis necessary for translocation [PMID:8413630, PMID:8276887]; its nucleotide state directs sequential interactions with the import machinery, GTP-bound Ran binding importin-β (p97) and GDP-bound Ran binding NTF2, the latter interaction itself being required to import Ran-GDP into the nucleus and to maintain the gradient [PMID:8755535, PMID:9199309, PMID:10930458]. The acidic C-terminal DEDDDL tail stabilizes GDP binding, mediates high-affinity engagement with RanBP1-family Ran-binding domains that coactivate RanGAP, and undergoes a nucleotide-dependent conformational change [PMID:7782302, PMID:7724562]. Beyond transport, Ran-GTP generated around chromatin patterns mitosis by releasing importin-bound spindle assembly factors: it liberates TPX2 to activate Aurora A kinase, spatially controls the Kinesin-14 XCTK2 across the spindle, restricts anillin to the equator during cytokinesis, and is required for chromosome alignment and nuclear envelope reassembly [PMID:12577065, PMID:25981788, PMID:28931593, PMID:11909538]. Ran activity is further tuned by lysine acetylation (by CBP/p300 and TIP60, reversed by sirtuins), which modulates nucleotide cycling, localization, and receptor binding, with TIP60 acetylation of Lys134 switching Ran from Mog1 to RCC1 to raise mitotic Ran-GTP [PMID:26124124, PMID:29040603]. Non-canonical roles include Ran-GTP accumulation at basal bodies during ciliogenesis and a plasma-membrane pool that stabilizes RhoA to promote cancer cell invasion [PMID:21998203, PMID:31209254].","teleology":[{"year":1993,"claim":"Established that Ran is the diffusible GTPase required for nuclear protein import, defining its core cellular function rather than leaving it an orphan GTP-binding protein.","evidence":"Biochemical reconstitution of NLS-dependent import with purified Ran in digitonin-permeabilized cells, plus GTPγS inhibition with bacterially expressed Ran","pmids":["8413630","8276887"],"confidence":"High","gaps":["Did not define the receptors Ran acts upon during transport","Mechanism of how GTP hydrolysis confers directionality unresolved"]},{"year":1993,"claim":"Defined the regulatory circuit of the Ran GTPase switch — RCC1 as exchange factor and a Ran-specific GAP — and tied disruption of GTP hydrolysis to cell cycle arrest.","evidence":"Biochemical identification of RanGAP, in vitro GTPase and binding assays, and GTP-hydrolysis-deficient mutant characterization in cells","pmids":["8255297","8421051","8455603"],"confidence":"High","gaps":["Spatial segregation of RCC1 and RanGAP not yet shown to generate a gradient","Direct effectors of Ran-GTP not identified"]},{"year":1994,"claim":"Showed RCC1's essential interphase role is solely as a Ran GEF and that GDP-bound Ran couples nuclear assembly and DNA replication to mitotic entry via cdc2 phosphorylation.","evidence":"Xenopus egg extract nuclear assembly/DNA replication assays with mutant Ran proteins, RCC1 rescue, and cdc2 phospho-immunoblotting","pmids":["7988569","8188741","8196659"],"confidence":"High","gaps":["Molecular link between Ran nucleotide state and cdc2 regulation indirect","C-terminal DEDDDL requirement for cell cycle function mechanistically unexplained at the time"]},{"year":1995,"claim":"Identified the Ran-binding effectors and partners at the pore (RanBP2, RanBP1/HTF9A, the RanBD module) and confirmed RanGAP/Rna1p as both GTPase activator and import requirement.","evidence":"Yeast two-hybrid, overlay/binding assays, in vitro RanGAP coactivation, and semi-intact yeast import add-back of purified Rna1p","pmids":["7603572","7782302","7744835","7657689","7816822","7724562"],"confidence":"High","gaps":["Species-specific GAP recognition determinants not mapped","How RanBD coactivation integrates with cargo release left open"]},{"year":1996,"claim":"Demonstrated that Ran nucleotide state directs sequential receptor interactions (GTP→importin-β, GDP→NTF2) and that Ran has an essential function beyond import.","evidence":"Nucleotide-preloaded recombinant binding assays with p97/NTF2; effector-domain L43E mutant separating growth from import; mutant localization in BHK21 cells","pmids":["8755535","8955121","8655589","8636225"],"confidence":"High","gaps":["Identity of the import-independent essential function unresolved at the time","Shared snRNP/protein import step mechanistically conflated"]},{"year":1997,"claim":"Provided reciprocal genetic proof that the Ran–NTF2 interaction is physiologically essential for nuclear transport, not merely an in vitro binding event.","evidence":"Conditional gsp1 alleles with reduced Ntf2p binding suppressed by NTF2 overexpression but not by a binding-deficient NTF2 mutant","pmids":["9199309"],"confidence":"High","gaps":["Did not quantify gradient consequences of disrupted import in vivo"]},{"year":2000,"claim":"Linked nuclear Ran concentration directly to spindle-assembly-checkpoint-dependent cell cycle control.","evidence":"Temperature-sensitive NTF2 mutant depleting nuclear Ran, with G2 arrest abolished by mad2 deletion in yeast","pmids":["10930458"],"confidence":"High","gaps":["Mechanism connecting nuclear Ran level to checkpoint signaling not defined"]},{"year":2001,"claim":"Identified Mog1 as a nucleotide-release factor that forms a stable nucleotide-free complex with Ran required for import.","evidence":"In vitro nucleotide release assays, charge-reversal interface mutants, in vivo import assay, and synthetic lethality with prp20","pmids":["11509570"],"confidence":"High","gaps":["Physiological trigger regulating Mog1–Ran engagement unknown at the time"]},{"year":2002,"claim":"Established the chromatin Ran-GTP gradient as the master spatial cue for mitotic spindle assembly, including the TPX2–Aurora A activation module and Ran-binding kinase Nercc1.","evidence":"C. elegans Ran RNAi with mitotic/NE phenotypes; Xenopus egg extract reconstitution of TPX2 release and Aurora A activation; Nercc1 Co-IP and kinase assays; karyopherin-β2 loop coupling Ran binding to cargo release","pmids":["11909538","12577065","12101123","12033928"],"confidence":"High","gaps":["Full repertoire of spindle assembly factors released by Ran-GTP incomplete","How discrete gradient thresholds map to distinct factors unresolved"]},{"year":2002,"claim":"Defined RanBP3 as a scaffold that stimulates RCC1 activity and promotes Crm1-based export complex assembly.","evidence":"In vitro binding, RCC1 activity, and three-component complex formation assays","pmids":["11932251"],"confidence":"Medium","gaps":["In vivo significance of RanBP3-stimulated export not established in this study"]},{"year":2008,"claim":"Connected the Ran gradient to upstream growth signaling and revealed an unexpected role of Ran as an androgen receptor coactivator.","evidence":"RSK/Akt phosphorylation of RanBP3 with transport readouts; reciprocal interaction and reporter assays linking ARA24/Ran to AR poly-Q","pmids":["18280241","10400640","18565325"],"confidence":"Medium","gaps":["AR coactivation mechanism distinct from transport function not mechanistically integrated","RanBP3 phospho-control quantitative effect on gradient single-lab"]},{"year":2009,"claim":"Provided structural and dynamic detail of Ran's interactions at the pore and its cell-cycle-dependent mobility.","evidence":"Crystal structures of Nup153 zinc fingers with Ran plus ITC; live-cell FRAP of GFP-Ran and nucleotide-state mutants","pmids":["19505478","19765287"],"confidence":"Medium","gaps":["Functional consequence of Nup153 ZnF differential affinity in transport not directly tested"]},{"year":2015,"claim":"Established acetylation as a post-translational layer controlling the entire Ran nucleotide cycle and demonstrated spatial gradient control of a spindle kinesin.","evidence":"In vitro CBP/p300/Tip60 acetylation with MS site mapping and nucleotide/transport assays; Xenopus extract FRAP of XCTK2 across the Ran-GTP gradient","pmids":["26124124","25981788","25458009"],"confidence":"High","gaps":["In vivo dynamics of acetylation cycling not quantified","Which acetylation sites dominate which functions only partially resolved"]},{"year":2018,"claim":"Resolved how mitotic acetylation reroutes Ran partner choice, with TIP60 Lys134 acetylation releasing Mog1 to favor RCC1 and raise Ran-GTP for chromosome alignment.","evidence":"Crystal structure of Ran–Mog1, in vitro TIP60 acetylation, competition binding, and acetyl-mimic mutant chromosome alignment assays; lamina-chromatin-Ran axis controlling import of large cargoes","pmids":["29040603","30565836"],"confidence":"High","gaps":["Temporal regulation of TIP60 toward Ran during mitosis not fully defined","Lamina-Ran axis evidence relies on chemical perturbation in single lab"]},{"year":2019,"claim":"Revealed non-nuclear Ran functions: a plasma-membrane pool stabilizing RhoA to drive invasion, and Ran-GTP control of cytokinesis and ciliogenesis.","evidence":"Co-IP and domain mapping of Ran–RhoA with invasion assays; Ran-GTP manipulation affecting anillin localization and basal-body ciliogenesis","pmids":["31209254","28931593","21998203"],"confidence":"Medium","gaps":["How Ran reaches the plasma membrane mechanistically unexplained","GTPase-independent vs. -dependent contributions to RhoA stabilization unresolved"]},{"year":2022,"claim":"Connected Ran acetylation control to disease signaling, with RSL1D1 blocking Sirt7-mediated deacetylation to suppress STAT3 import and autophagy in cancer.","evidence":"Co-IP, competition binding, acetylation, and STAT3 localization/autophagy assays in colorectal cancer cells","pmids":["35013134"],"confidence":"Medium","gaps":["Single-lab Co-IP-based competition without structural validation","Generality beyond colorectal cancer context untested"]},{"year":null,"claim":"How the multiple post-translational and partner-based regulatory layers (acetylation, RanBP1/RanBP3 phosphorylation, Mog1 switching) are integrated in space and time to tune the Ran gradient for distinct transport, mitotic, and membrane functions remains unresolved.","evidence":"","pmids":[],"confidence":"Medium","gaps":["No unified quantitative model coupling acetylation cycling to gradient dynamics","Mechanism targeting Ran to the plasma membrane unknown","Disease-relevant Ran functions lack in vivo genetic validation in the corpus"]}],"mechanism_profile":{"molecular_activity":[{"term_id":"GO:0003924","term_label":"GTPase activity","supporting_discovery_ids":[1,2,9,31]},{"term_id":"GO:0098772","term_label":"molecular function regulator activity","supporting_discovery_ids":[24,32,36,35]},{"term_id":"GO:0060089","term_label":"molecular transducer activity","supporting_discovery_ids":[2,14,28]}],"localization":[{"term_id":"GO:0005634","term_label":"nucleus","supporting_discovery_ids":[3,11,18,28]},{"term_id":"GO:0005635","term_label":"nuclear envelope","supporting_discovery_ids":[15,22,28]},{"term_id":"GO:0000228","term_label":"nuclear chromosome","supporting_discovery_ids":[22,28,30]},{"term_id":"GO:0005815","term_label":"microtubule organizing center","supporting_discovery_ids":[29]},{"term_id":"GO:0005886","term_label":"plasma membrane","supporting_discovery_ids":[35]}],"pathway":[{"term_id":"R-HSA-9609507","term_label":"Protein localization","supporting_discovery_ids":[0,1,14,37]},{"term_id":"R-HSA-1640170","term_label":"Cell Cycle","supporting_discovery_ids":[22,24,32,36]},{"term_id":"R-HSA-162582","term_label":"Signal Transduction","supporting_discovery_ids":[25,35]}],"complexes":["RCC1/Ran/RanBP1 complex"],"partners":["RCC1","RANGAP1","RANBP1","RANBP2","NTF2","KPNB1","MOG1","RANBP3"],"other_free_text":[]}},"prefetch_data":{"uniprot":{"accession":"P62826","full_name":"GTP-binding nuclear protein Ran","aliases":["Androgen receptor-associated protein 24","GTPase Ran","Ras-like protein TC4","Ras-related nuclear protein"],"length_aa":216,"mass_kda":24.4,"function":"GTPase involved in nucleocytoplasmic transport, participating both to the import and the export from the nucleus of proteins and RNAs (PubMed:10400640, PubMed:17209048, PubMed:26272610, PubMed:27306458, PubMed:8276887, PubMed:8636225, PubMed:8692944, PubMed:8896452, PubMed:9351834, PubMed:9428644, PubMed:9822603). Switches between a cytoplasmic GDP- and a nuclear GTP-bound state by nucleotide exchange and GTP hydrolysis (PubMed:11336674, PubMed:26272610, PubMed:29040603, PubMed:7819259, PubMed:8636225, PubMed:8692944, PubMed:8896452, PubMed:9351834, PubMed:9428644, PubMed:9822603). Nuclear import receptors such as importin beta bind their substrates only in the absence of GTP-bound RAN and release them upon direct interaction with GTP-bound RAN, while export receptors behave in the opposite way. Thereby, RAN controls cargo loading and release by transport receptors in the proper compartment and ensures the directionality of the transport (PubMed:8896452, PubMed:9351834, PubMed:9428644). Interaction with RANBP1 induces a conformation change in the complex formed by XPO1 and RAN that triggers the release of the nuclear export signal of cargo proteins (PubMed:20485264). RAN (GTP-bound form) triggers microtubule assembly at mitotic chromosomes and is required for normal mitotic spindle assembly and chromosome segregation (PubMed:10408446, PubMed:29040603). Required for normal progress through mitosis (PubMed:12194828, PubMed:29040603, PubMed:8421051). The complex with BIRC5/survivin plays a role in mitotic spindle formation by serving as a physical scaffold to help deliver the RAN effector molecule TPX2 to microtubules (PubMed:18591255). Acts as a negative regulator of the kinase activity of VRK1 and VRK2 (PubMed:18617507). Enhances AR-mediated transactivation. Transactivation decreases as the poly-Gln length within AR increases (PubMed:10400640)","subcellular_location":"Nucleus; Nucleus envelope; Cytoplasm, cytosol; Cytoplasm; Melanosome","url":"https://www.uniprot.org/uniprotkb/P62826/entry"},"depmap":{"release":"DepMap","has_data":true,"is_common_essential":true,"resolved_as":"","url":"https://depmap.org/portal/gene/RAN","classification":"Common Essential","n_dependent_lines":1208,"n_total_lines":1208,"dependency_fraction":1.0},"opencell":{"profiled":true,"resolved_as":"","ensg_id":"ENSG00000132341","cell_line_id":"CID001908","localizations":[{"compartment":"big_aggregates","grade":3},{"compartment":"nuclear_membrane","grade":3},{"compartment":"nuclear_punctae","grade":3},{"compartment":"cytoplasmic","grade":2},{"compartment":"nucleoplasm","grade":2}],"interactors":[{"gene":"NUP214","stoichiometry":10.0},{"gene":"NUTF2","stoichiometry":10.0},{"gene":"XPO1","stoichiometry":10.0},{"gene":"RCC1","stoichiometry":10.0},{"gene":"RANBP1","stoichiometry":10.0},{"gene":"KPNA4","stoichiometry":4.0},{"gene":"KPNB1","stoichiometry":4.0},{"gene":"RANBP2","stoichiometry":4.0},{"gene":"RANGAP1","stoichiometry":4.0},{"gene":"SUMO1","stoichiometry":4.0}],"url":"https://opencell.sf.czbiohub.org/target/CID001908","total_profiled":1310},"omim":[{"mim_id":"621316","title":"HSP90AB1-ASSOCIATED LONG NONCODING RNA 1; HSALR1","url":"https://www.omim.org/entry/621316"},{"mim_id":"621119","title":"ENKURIN DOMAIN-CONTAINING PROTEIN 1; ENKD1","url":"https://www.omim.org/entry/621119"},{"mim_id":"620893","title":"IMPORTIN 9; IPO9","url":"https://www.omim.org/entry/620893"},{"mim_id":"620711","title":"LEUKOENCEPHALOPATHY, PORPHYRIA-RELATED; LENCEP","url":"https://www.omim.org/entry/620711"},{"mim_id":"620426","title":"INKA BOX ACTIN REGULATOR 1; INKA1","url":"https://www.omim.org/entry/620426"}],"hpa":{"profiled":true,"resolved_as":"","reliability":"Supported","locations":[{"location":"Nucleoplasm","reliability":"Supported"}],"tissue_specificity":"Low tissue specificity","tissue_distribution":"Detected in all","driving_tissues":[],"url":"https://www.proteinatlas.org/search/RAN"},"hgnc":{"alias_symbol":["ARA24","TC4","Gsp1"],"prev_symbol":[]},"alphafold":{"accession":"P62826","domains":[{"cath_id":"3.40.50.300","chopping":"8-168","consensus_level":"high","plddt":94.0987,"start":8,"end":168}],"viewer_url":"https://alphafold.ebi.ac.uk/entry/P62826","model_url":"https://alphafold.ebi.ac.uk/files/AF-P62826-F1-model_v6.cif","pae_url":"https://alphafold.ebi.ac.uk/files/AF-P62826-F1-predicted_aligned_error_v6.png","plddt_mean":88.62},"mouse_models":{"mgi_url":"https://www.informatics.jax.org/marker/summary?nomen=RAN","jax_strain_url":"https://www.jax.org/strain/search?query=RAN"},"sequence":{"accession":"P62826","fasta_url":"https://rest.uniprot.org/uniprotkb/P62826.fasta","uniprot_url":"https://www.uniprot.org/uniprotkb/P62826/entry","alphafold_viewer_url":"https://alphafold.ebi.ac.uk/entry/P62826"}},"corpus_meta":[{"pmid":"8413630","id":"PMC_8413630","title":"The GTP-binding protein Ran/TC4 is required for protein import into the nucleus.","date":"1993","source":"Nature","url":"https://pubmed.ncbi.nlm.nih.gov/8413630","citation_count":697,"is_preprint":false},{"pmid":"24248382","id":"PMC_24248382","title":"RAN proteins and RNA foci from antisense transcripts in C9ORF72 ALS and frontotemporal dementia.","date":"2013","source":"Proceedings of the National Academy of Sciences of the United States of America","url":"https://pubmed.ncbi.nlm.nih.gov/24248382","citation_count":658,"is_preprint":false},{"pmid":"8276887","id":"PMC_8276887","title":"Inhibition of nuclear protein import by nonhydrolyzable analogues of GTP and identification of the small GTPase Ran/TC4 as an essential transport factor.","date":"1993","source":"The Journal of cell biology","url":"https://pubmed.ncbi.nlm.nih.gov/8276887","citation_count":519,"is_preprint":false},{"pmid":"7603572","id":"PMC_7603572","title":"A giant nucleopore protein that binds Ran/TC4.","date":"1995","source":"Nature","url":"https://pubmed.ncbi.nlm.nih.gov/7603572","citation_count":447,"is_preprint":false},{"pmid":"18478030","id":"PMC_18478030","title":"Spatial and temporal coordination of mitosis by Ran GTPase.","date":"2008","source":"Nature reviews. Molecular cell biology","url":"https://pubmed.ncbi.nlm.nih.gov/18478030","citation_count":333,"is_preprint":false},{"pmid":"7937864","id":"PMC_7937864","title":"Purification of a Ran-interacting protein that is required for protein import into the nucleus.","date":"1994","source":"Proceedings of the National Academy of Sciences of the United States of America","url":"https://pubmed.ncbi.nlm.nih.gov/7937864","citation_count":317,"is_preprint":false},{"pmid":"12577065","id":"PMC_12577065","title":"A Ran signalling pathway mediated by the mitotic kinase Aurora A in spindle assembly.","date":"2003","source":"Nature cell biology","url":"https://pubmed.ncbi.nlm.nih.gov/12577065","citation_count":304,"is_preprint":false},{"pmid":"26590344","id":"PMC_26590344","title":"RAN Translation in Huntington Disease.","date":"2015","source":"Neuron","url":"https://pubmed.ncbi.nlm.nih.gov/26590344","citation_count":271,"is_preprint":false},{"pmid":"8255297","id":"PMC_8255297","title":"Characterization of proteins that interact with the cell-cycle regulatory protein Ran/TC4.","date":"1993","source":"Nature","url":"https://pubmed.ncbi.nlm.nih.gov/8255297","citation_count":250,"is_preprint":false},{"pmid":"10400640","id":"PMC_10400640","title":"The linkage of Kennedy's neuron disease to ARA24, the first identified androgen receptor polyglutamine region-associated coactivator.","date":"1999","source":"The Journal of biological chemistry","url":"https://pubmed.ncbi.nlm.nih.gov/10400640","citation_count":181,"is_preprint":false},{"pmid":"21878989","id":"PMC_21878989","title":"Ran-dependent nuclear export mediators: a structural perspective.","date":"2011","source":"The EMBO journal","url":"https://pubmed.ncbi.nlm.nih.gov/21878989","citation_count":179,"is_preprint":false},{"pmid":"7816822","id":"PMC_7816822","title":"The GTP-bound form of the yeast Ran/TC4 homologue blocks nuclear protein import and appearance of poly(A)+ RNA in the cytoplasm.","date":"1995","source":"Proceedings of the National Academy of Sciences of the United States of America","url":"https://pubmed.ncbi.nlm.nih.gov/7816822","citation_count":178,"is_preprint":false},{"pmid":"12176353","id":"PMC_12176353","title":"The Ran GTPase: theme and variations.","date":"2002","source":"Current biology : CB","url":"https://pubmed.ncbi.nlm.nih.gov/12176353","citation_count":172,"is_preprint":false},{"pmid":"12105431","id":"PMC_12105431","title":"The Ran GTPase as a marker of chromosome position in spindle formation and nuclear envelope assembly.","date":"2002","source":"Nature cell biology","url":"https://pubmed.ncbi.nlm.nih.gov/12105431","citation_count":171,"is_preprint":false},{"pmid":"8421051","id":"PMC_8421051","title":"Ran/TC4: a small nuclear GTP-binding protein that regulates DNA synthesis.","date":"1993","source":"The Journal of cell biology","url":"https://pubmed.ncbi.nlm.nih.gov/8421051","citation_count":168,"is_preprint":false},{"pmid":"7657689","id":"PMC_7657689","title":"Rna1p, a Ran/TC4 GTPase activating protein, is required for nuclear import.","date":"1995","source":"The Journal of cell biology","url":"https://pubmed.ncbi.nlm.nih.gov/7657689","citation_count":155,"is_preprint":false},{"pmid":"8455603","id":"PMC_8455603","title":"GSP1 and GSP2, genetic suppressors of the prp20-1 mutant in Saccharomyces cerevisiae: GTP-binding proteins involved in the maintenance of nuclear organization.","date":"1993","source":"Molecular and cellular biology","url":"https://pubmed.ncbi.nlm.nih.gov/8455603","citation_count":142,"is_preprint":false},{"pmid":"10704362","id":"PMC_10704362","title":"The ran decathlon: multiple roles of Ran.","date":"2000","source":"Journal of cell science","url":"https://pubmed.ncbi.nlm.nih.gov/10704362","citation_count":132,"is_preprint":false},{"pmid":"9695834","id":"PMC_9695834","title":"Two-way trafficking with Ran.","date":"1998","source":"Trends in cell biology","url":"https://pubmed.ncbi.nlm.nih.gov/9695834","citation_count":132,"is_preprint":false},{"pmid":"7988569","id":"PMC_7988569","title":"A mutant form of the Ran/TC4 protein disrupts nuclear function in Xenopus laevis egg extracts by inhibiting the RCC1 protein, a regulator of chromosome condensation.","date":"1994","source":"The EMBO journal","url":"https://pubmed.ncbi.nlm.nih.gov/7988569","citation_count":131,"is_preprint":false},{"pmid":"8655589","id":"PMC_8655589","title":"Evidence using a green fluorescent protein-glucocorticoid receptor chimera that the Ran/TC4 GTPase mediates an essential function independent of nuclear protein import.","date":"1996","source":"The Journal of cell biology","url":"https://pubmed.ncbi.nlm.nih.gov/8655589","citation_count":128,"is_preprint":false},{"pmid":"8188741","id":"PMC_8188741","title":"Evidence for a dual role for TC4 protein in regulating nuclear structure and cell cycle progression.","date":"1994","source":"The Journal of cell biology","url":"https://pubmed.ncbi.nlm.nih.gov/8188741","citation_count":125,"is_preprint":false},{"pmid":"23918658","id":"PMC_23918658","title":"Repeat-associated non-ATG (RAN) translation in neurological disease.","date":"2013","source":"Human molecular genetics","url":"https://pubmed.ncbi.nlm.nih.gov/23918658","citation_count":122,"is_preprint":false},{"pmid":"12101123","id":"PMC_12101123","title":"Nercc1, a mammalian NIMA-family kinase, binds the Ran GTPase and regulates mitotic progression.","date":"2002","source":"Genes & development","url":"https://pubmed.ncbi.nlm.nih.gov/12101123","citation_count":122,"is_preprint":false},{"pmid":"8636225","id":"PMC_8636225","title":"RAN/TC4 mutants identify a common requirement for snRNP and protein import into the nucleus.","date":"1996","source":"The Journal of cell biology","url":"https://pubmed.ncbi.nlm.nih.gov/8636225","citation_count":116,"is_preprint":false},{"pmid":"32690681","id":"PMC_32690681","title":"Metformin inhibits RAN translation through PKR pathway and mitigates disease in C9orf72 ALS/FTD mice.","date":"2020","source":"Proceedings of the National Academy of Sciences of the United States of America","url":"https://pubmed.ncbi.nlm.nih.gov/32690681","citation_count":113,"is_preprint":false},{"pmid":"28910618","id":"PMC_28910618","title":"RAN Translation Regulated by Muscleblind Proteins in Myotonic Dystrophy Type 2.","date":"2017","source":"Neuron","url":"https://pubmed.ncbi.nlm.nih.gov/28910618","citation_count":112,"is_preprint":false},{"pmid":"7744835","id":"PMC_7744835","title":"RNA1 encodes a GTPase-activating protein specific for Gsp1p, the Ran/TC4 homologue of Saccharomyces cerevisiae.","date":"1995","source":"The Journal of biological chemistry","url":"https://pubmed.ncbi.nlm.nih.gov/7744835","citation_count":111,"is_preprint":false},{"pmid":"7782302","id":"PMC_7782302","title":"The C terminus of the nuclear RAN/TC4 GTPase stabilizes the GDP-bound state and mediates interactions with RCC1, RAN-GAP, and HTF9A/RANBP1.","date":"1995","source":"The Journal of biological chemistry","url":"https://pubmed.ncbi.nlm.nih.gov/7782302","citation_count":109,"is_preprint":false},{"pmid":"7724562","id":"PMC_7724562","title":"The Ran/TC4 GTPase-binding domain: identification by expression cloning and characterization of a conserved sequence motif.","date":"1995","source":"Proceedings of the National Academy of Sciences of the United States of America","url":"https://pubmed.ncbi.nlm.nih.gov/7724562","citation_count":102,"is_preprint":false},{"pmid":"24852074","id":"PMC_24852074","title":"Repeat associated non-ATG (RAN) translation: new starts in microsatellite expansion disorders.","date":"2014","source":"Current opinion in genetics & development","url":"https://pubmed.ncbi.nlm.nih.gov/24852074","citation_count":97,"is_preprint":false},{"pmid":"26481147","id":"PMC_26481147","title":"A LIN28B-RAN-AURKA Signaling Network Promotes Neuroblastoma Tumorigenesis.","date":"2015","source":"Cancer cell","url":"https://pubmed.ncbi.nlm.nih.gov/26481147","citation_count":96,"is_preprint":false},{"pmid":"16888036","id":"PMC_16888036","title":"A picornavirus protein interacts with Ran-GTPase and disrupts nucleocytoplasmic transport.","date":"2006","source":"Proceedings of the National Academy of Sciences of the United States of America","url":"https://pubmed.ncbi.nlm.nih.gov/16888036","citation_count":94,"is_preprint":false},{"pmid":"8851043","id":"PMC_8851043","title":"The small nuclear GTPase Ran: how much does it run?","date":"1996","source":"BioEssays : news and reviews in molecular, cellular and developmental biology","url":"https://pubmed.ncbi.nlm.nih.gov/8851043","citation_count":93,"is_preprint":false},{"pmid":"9199309","id":"PMC_9199309","title":"Interaction between the small GTPase Ran/Gsp1p and Ntf2p is required for nuclear transport.","date":"1997","source":"Molecular and cellular biology","url":"https://pubmed.ncbi.nlm.nih.gov/9199309","citation_count":91,"is_preprint":false},{"pmid":"11909538","id":"PMC_11909538","title":"The GTPase Ran regulates chromosome positioning and nuclear envelope assembly in vivo.","date":"2002","source":"Current biology : CB","url":"https://pubmed.ncbi.nlm.nih.gov/11909538","citation_count":88,"is_preprint":false},{"pmid":"11135312","id":"PMC_11135312","title":"The Ran-GTPase and cell-cycle control.","date":"2001","source":"BioEssays : news and reviews in molecular, cellular and developmental biology","url":"https://pubmed.ncbi.nlm.nih.gov/11135312","citation_count":85,"is_preprint":false},{"pmid":"32528950","id":"PMC_32528950","title":"Ran GTPase: A Key Player in Tumor Progression and Metastasis.","date":"2020","source":"Frontiers in cell and developmental biology","url":"https://pubmed.ncbi.nlm.nih.gov/32528950","citation_count":82,"is_preprint":false},{"pmid":"18339863","id":"PMC_18339863","title":"Tumor cell dependence on Ran-GTP-directed mitosis.","date":"2008","source":"Cancer research","url":"https://pubmed.ncbi.nlm.nih.gov/18339863","citation_count":82,"is_preprint":false},{"pmid":"9394008","id":"PMC_9394008","title":"RagA is a functional homologue of S. cerevisiae Gtr1p involved in the Ran/Gsp1-GTPase pathway.","date":"1998","source":"Journal of cell science","url":"https://pubmed.ncbi.nlm.nih.gov/9394008","citation_count":80,"is_preprint":false},{"pmid":"31831332","id":"PMC_31831332","title":"Antibody Therapy Targeting RAN Proteins Rescues C9 ALS/FTD Phenotypes in C9orf72 Mouse Model.","date":"2019","source":"Neuron","url":"https://pubmed.ncbi.nlm.nih.gov/31831332","citation_count":80,"is_preprint":false},{"pmid":"30213863","id":"PMC_30213863","title":"Repeat-associated non-ATG (RAN) translation.","date":"2018","source":"The Journal of biological chemistry","url":"https://pubmed.ncbi.nlm.nih.gov/30213863","citation_count":78,"is_preprint":false},{"pmid":"8755535","id":"PMC_8755535","title":"Nucleotide-specific interaction of Ran/TC4 with nuclear transport factors NTF2 and p97.","date":"1996","source":"Proceedings of the National Academy of Sciences of the United States of America","url":"https://pubmed.ncbi.nlm.nih.gov/8755535","citation_count":78,"is_preprint":false},{"pmid":"8955121","id":"PMC_8955121","title":"Mutations within the Ran/TC4 GTPase. Effects on regulatory factor interactions and subcellular localization.","date":"1996","source":"The Journal of biological chemistry","url":"https://pubmed.ncbi.nlm.nih.gov/8955121","citation_count":78,"is_preprint":false},{"pmid":"27060770","id":"PMC_27060770","title":"RAN translation-What makes it run?","date":"2016","source":"Brain research","url":"https://pubmed.ncbi.nlm.nih.gov/27060770","citation_count":77,"is_preprint":false},{"pmid":"19225125","id":"PMC_19225125","title":"Ran on tracks--cytoplasmic roles for a nuclear regulator.","date":"2009","source":"Journal of cell science","url":"https://pubmed.ncbi.nlm.nih.gov/19225125","citation_count":74,"is_preprint":false},{"pmid":"10698256","id":"PMC_10698256","title":"Nucleocytoplasmic protein transport and recycling of Ran.","date":"1999","source":"Cell structure and function","url":"https://pubmed.ncbi.nlm.nih.gov/10698256","citation_count":73,"is_preprint":false},{"pmid":"8889801","id":"PMC_8889801","title":"RCC1 in the Ran pathway.","date":"1996","source":"Journal of biochemistry","url":"https://pubmed.ncbi.nlm.nih.gov/8889801","citation_count":70,"is_preprint":false},{"pmid":"9640542","id":"PMC_9640542","title":"Functions of the GTPase Ran in RNA export from the nucleus.","date":"1998","source":"Current opinion in cell biology","url":"https://pubmed.ncbi.nlm.nih.gov/9640542","citation_count":70,"is_preprint":false},{"pmid":"26124124","id":"PMC_26124124","title":"Small GTP-binding protein Ran is regulated by posttranslational lysine acetylation.","date":"2015","source":"Proceedings of the National Academy of Sciences of the United States of America","url":"https://pubmed.ncbi.nlm.nih.gov/26124124","citation_count":70,"is_preprint":false},{"pmid":"28365506","id":"PMC_28365506","title":"New developments in RAN translation: insights from multiple diseases.","date":"2017","source":"Current opinion in genetics & development","url":"https://pubmed.ncbi.nlm.nih.gov/28365506","citation_count":69,"is_preprint":false},{"pmid":"18280241","id":"PMC_18280241","title":"Ran-binding protein 3 phosphorylation links the Ras and PI3-kinase pathways to nucleocytoplasmic transport.","date":"2008","source":"Molecular cell","url":"https://pubmed.ncbi.nlm.nih.gov/18280241","citation_count":68,"is_preprint":false},{"pmid":"8196659","id":"PMC_8196659","title":"Effects of mutant Ran/TC4 proteins on cell cycle progression.","date":"1994","source":"Molecular and cellular biology","url":"https://pubmed.ncbi.nlm.nih.gov/8196659","citation_count":66,"is_preprint":false},{"pmid":"23308199","id":"PMC_23308199","title":"Reduced RAN expression and disrupted transport between cytoplasm and nucleus; a key event in Alzheimer's disease pathophysiology.","date":"2013","source":"PloS one","url":"https://pubmed.ncbi.nlm.nih.gov/23308199","citation_count":66,"is_preprint":false},{"pmid":"30206144","id":"PMC_30206144","title":"SCA8 RAN polySer protein preferentially accumulates in white matter regions and is regulated by eIF3F.","date":"2018","source":"The EMBO journal","url":"https://pubmed.ncbi.nlm.nih.gov/30206144","citation_count":65,"is_preprint":false},{"pmid":"32066985","id":"PMC_32066985","title":"A native function for RAN translation and CGG repeats in regulating fragile X protein synthesis.","date":"2020","source":"Nature neuroscience","url":"https://pubmed.ncbi.nlm.nih.gov/32066985","citation_count":64,"is_preprint":false},{"pmid":"29453961","id":"PMC_29453961","title":"Repeat-associated non-AUG (RAN) translation and other molecular mechanisms in Fragile X Tremor Ataxia Syndrome.","date":"2018","source":"Brain research","url":"https://pubmed.ncbi.nlm.nih.gov/29453961","citation_count":61,"is_preprint":false},{"pmid":"10801459","id":"PMC_10801459","title":"The role of Ran in nuclear function.","date":"2000","source":"Current opinion in cell biology","url":"https://pubmed.ncbi.nlm.nih.gov/10801459","citation_count":61,"is_preprint":false},{"pmid":"21998203","id":"PMC_21998203","title":"Induction of Ran GTP drives ciliogenesis.","date":"2011","source":"Molecular biology of the cell","url":"https://pubmed.ncbi.nlm.nih.gov/21998203","citation_count":59,"is_preprint":false},{"pmid":"29677349","id":"PMC_29677349","title":"Repeat-Associated Non-ATG (RAN) Translation in Fuchs' Endothelial Corneal Dystrophy.","date":"2018","source":"Investigative ophthalmology & visual science","url":"https://pubmed.ncbi.nlm.nih.gov/29677349","citation_count":56,"is_preprint":false},{"pmid":"12539236","id":"PMC_12539236","title":"Closing the (Ran)GAP on segregation distortion in Drosophila.","date":"2003","source":"BioEssays : news and reviews in molecular, cellular and developmental biology","url":"https://pubmed.ncbi.nlm.nih.gov/12539236","citation_count":56,"is_preprint":false},{"pmid":"8923203","id":"PMC_8923203","title":"Ran, a GTPase involved in nuclear processes: its regulators and effectors.","date":"1996","source":"Journal of cell science","url":"https://pubmed.ncbi.nlm.nih.gov/8923203","citation_count":55,"is_preprint":false},{"pmid":"12019565","id":"PMC_12019565","title":"Regulation of nuclear import and export by the GTPase Ran.","date":"2002","source":"International review of cytology","url":"https://pubmed.ncbi.nlm.nih.gov/12019565","citation_count":55,"is_preprint":false},{"pmid":"12033928","id":"PMC_12033928","title":"Uncoupling Kapbeta2 substrate dissociation and ran binding.","date":"2002","source":"Biochemistry","url":"https://pubmed.ncbi.nlm.nih.gov/12033928","citation_count":48,"is_preprint":false},{"pmid":"11932251","id":"PMC_11932251","title":"Ran-binding protein 3 links Crm1 to the Ran guanine nucleotide exchange factor.","date":"2002","source":"The Journal of biological chemistry","url":"https://pubmed.ncbi.nlm.nih.gov/11932251","citation_count":45,"is_preprint":false},{"pmid":"30918326","id":"PMC_30918326","title":"Repeat-associated non-AUG (RAN) translation: insights from pathology.","date":"2019","source":"Laboratory investigation; a journal of technical methods and pathology","url":"https://pubmed.ncbi.nlm.nih.gov/30918326","citation_count":44,"is_preprint":false},{"pmid":"24563355","id":"PMC_24563355","title":"Ran GTPase in nuclear envelope formation and cancer metastasis.","date":"2014","source":"Advances in experimental medicine and biology","url":"https://pubmed.ncbi.nlm.nih.gov/24563355","citation_count":43,"is_preprint":false},{"pmid":"31209254","id":"PMC_31209254","title":"Ran promotes membrane targeting and stabilization of RhoA to orchestrate ovarian cancer cell invasion.","date":"2019","source":"Nature communications","url":"https://pubmed.ncbi.nlm.nih.gov/31209254","citation_count":43,"is_preprint":false},{"pmid":"27439876","id":"PMC_27439876","title":"Spatial organization of the Ran pathway by microtubules in mitosis.","date":"2016","source":"Proceedings of the National Academy of Sciences of the United States of America","url":"https://pubmed.ncbi.nlm.nih.gov/27439876","citation_count":43,"is_preprint":false},{"pmid":"15048882","id":"PMC_15048882","title":"TOR kinase and Ran are downstream from PI3K/Akt in H2O2-induced mitosis.","date":"2004","source":"Journal of cellular biochemistry","url":"https://pubmed.ncbi.nlm.nih.gov/15048882","citation_count":40,"is_preprint":false},{"pmid":"25458009","id":"PMC_25458009","title":"RanBP1 governs spindle assembly by defining mitotic Ran-GTP production.","date":"2014","source":"Developmental cell","url":"https://pubmed.ncbi.nlm.nih.gov/25458009","citation_count":40,"is_preprint":false},{"pmid":"36834476","id":"PMC_36834476","title":"Ran GTPase and Its Importance in Cellular Signaling and Malignant Phenotype.","date":"2023","source":"International journal of molecular sciences","url":"https://pubmed.ncbi.nlm.nih.gov/36834476","citation_count":39,"is_preprint":false},{"pmid":"16294017","id":"PMC_16294017","title":"Loading and unloading: orchestrating centrosome duplication and spindle assembly by Ran/Crm1.","date":"2005","source":"Cell cycle (Georgetown, Tex.)","url":"https://pubmed.ncbi.nlm.nih.gov/16294017","citation_count":39,"is_preprint":false},{"pmid":"24523287","id":"PMC_24523287","title":"A pathway linking oxidative stress and the Ran GTPase system in progeria.","date":"2014","source":"Molecular biology of the cell","url":"https://pubmed.ncbi.nlm.nih.gov/24523287","citation_count":39,"is_preprint":false},{"pmid":"25217582","id":"PMC_25217582","title":"RAN translation and frameshifting as translational challenges at simple repeats of human neurodegenerative disorders.","date":"2014","source":"Nucleic acids research","url":"https://pubmed.ncbi.nlm.nih.gov/25217582","citation_count":37,"is_preprint":false},{"pmid":"9261173","id":"PMC_9261173","title":"High levels of the GTPase Ran/TC4 relieve the requirement for nuclear protein transport factor 2.","date":"1997","source":"The Journal of biological chemistry","url":"https://pubmed.ncbi.nlm.nih.gov/9261173","citation_count":36,"is_preprint":false},{"pmid":"30565836","id":"PMC_30565836","title":"A nuclear lamina-chromatin-Ran GTPase axis modulates nuclear import and DNA damage signaling.","date":"2018","source":"Aging cell","url":"https://pubmed.ncbi.nlm.nih.gov/30565836","citation_count":35,"is_preprint":false},{"pmid":"29040603","id":"PMC_29040603","title":"Mitosis-specific acetylation tunes Ran effector binding for chromosome segregation.","date":"2018","source":"Journal of molecular cell biology","url":"https://pubmed.ncbi.nlm.nih.gov/29040603","citation_count":35,"is_preprint":false},{"pmid":"19505478","id":"PMC_19505478","title":"Crystallographic and biochemical analysis of the Ran-binding zinc finger domain.","date":"2009","source":"Journal of molecular biology","url":"https://pubmed.ncbi.nlm.nih.gov/19505478","citation_count":35,"is_preprint":false},{"pmid":"7616957","id":"PMC_7616957","title":"RanBP1, a Ras-like nuclear G protein binding to Ran/TC4, inhibits RCC1 via Ran/TC4.","date":"1995","source":"Molecular & general genetics : MGG","url":"https://pubmed.ncbi.nlm.nih.gov/7616957","citation_count":34,"is_preprint":false},{"pmid":"29750309","id":"PMC_29750309","title":"Knockdown of Ran GTPase expression inhibits the proliferation and migration of breast cancer cells.","date":"2018","source":"Molecular medicine reports","url":"https://pubmed.ncbi.nlm.nih.gov/29750309","citation_count":33,"is_preprint":false},{"pmid":"10471364","id":"PMC_10471364","title":"A new role of ran GTPase.","date":"1999","source":"Biochemical and biophysical research communications","url":"https://pubmed.ncbi.nlm.nih.gov/10471364","citation_count":33,"is_preprint":false},{"pmid":"17671426","id":"PMC_17671426","title":"Coordination of chromosome alignment and mitotic progression by the chromosome-based Ran signal.","date":"2007","source":"Cell cycle (Georgetown, Tex.)","url":"https://pubmed.ncbi.nlm.nih.gov/17671426","citation_count":33,"is_preprint":false},{"pmid":"10937870","id":"PMC_10937870","title":"Upstream and downstream of ran GTPase.","date":"2000","source":"Biological chemistry","url":"https://pubmed.ncbi.nlm.nih.gov/10937870","citation_count":32,"is_preprint":false},{"pmid":"34632710","id":"PMC_34632710","title":"CCG•CGG interruptions in high-penetrance SCA8 families increase RAN translation and protein toxicity.","date":"2021","source":"EMBO molecular medicine","url":"https://pubmed.ncbi.nlm.nih.gov/34632710","citation_count":31,"is_preprint":false},{"pmid":"17008347","id":"PMC_17008347","title":"Interaction between methyl CpG-binding protein and ran GTPase during cell division in tobacco cultured cells.","date":"2006","source":"Annals of botany","url":"https://pubmed.ncbi.nlm.nih.gov/17008347","citation_count":30,"is_preprint":false},{"pmid":"11071879","id":"PMC_11071879","title":"Identification of a novel putative Ran-binding protein and its close homologue.","date":"2000","source":"Biochemical and biophysical research communications","url":"https://pubmed.ncbi.nlm.nih.gov/11071879","citation_count":29,"is_preprint":false},{"pmid":"16959415","id":"PMC_16959415","title":"The Ran binding protein RanBPM interacts with TrkA receptor.","date":"2006","source":"Neuroscience letters","url":"https://pubmed.ncbi.nlm.nih.gov/16959415","citation_count":29,"is_preprint":false},{"pmid":"29229958","id":"PMC_29229958","title":"EGFR feedback-inhibition by Ran-binding protein 6 is disrupted in cancer.","date":"2017","source":"Nature communications","url":"https://pubmed.ncbi.nlm.nih.gov/29229958","citation_count":27,"is_preprint":false},{"pmid":"10930458","id":"PMC_10930458","title":"The interaction between Ran and NTF2 is required for cell cycle progression.","date":"2000","source":"Molecular biology of the cell","url":"https://pubmed.ncbi.nlm.nih.gov/10930458","citation_count":27,"is_preprint":false},{"pmid":"35013134","id":"PMC_35013134","title":"RSL1D1 promotes the progression of colorectal cancer through RAN-mediated autophagy suppression.","date":"2022","source":"Cell death & disease","url":"https://pubmed.ncbi.nlm.nih.gov/35013134","citation_count":27,"is_preprint":false},{"pmid":"19765287","id":"PMC_19765287","title":"Dynamic localisation of Ran GTPase during the cell cycle.","date":"2009","source":"BMC cell biology","url":"https://pubmed.ncbi.nlm.nih.gov/19765287","citation_count":27,"is_preprint":false},{"pmid":"25981788","id":"PMC_25981788","title":"The Ran-GTP gradient spatially regulates XCTK2 in the spindle.","date":"2015","source":"Current biology : CB","url":"https://pubmed.ncbi.nlm.nih.gov/25981788","citation_count":27,"is_preprint":false},{"pmid":"18565325","id":"PMC_18565325","title":"ARA24/Ran enhances the androgen-dependent NH2- and COOH-terminal interaction of the androgen receptor.","date":"2008","source":"Biochemical and biophysical research communications","url":"https://pubmed.ncbi.nlm.nih.gov/18565325","citation_count":26,"is_preprint":false},{"pmid":"34542927","id":"PMC_34542927","title":"SRSF protein kinase 1 modulates RAN translation and suppresses CGG repeat toxicity.","date":"2021","source":"EMBO molecular medicine","url":"https://pubmed.ncbi.nlm.nih.gov/34542927","citation_count":26,"is_preprint":false},{"pmid":"28931593","id":"PMC_28931593","title":"Active Ran regulates anillin function during cytokinesis.","date":"2017","source":"Molecular biology of the cell","url":"https://pubmed.ncbi.nlm.nih.gov/28931593","citation_count":26,"is_preprint":false},{"pmid":"27716616","id":"PMC_27716616","title":"Ran GTPase promotes cancer progression via Met recepto-rmediated downstream signaling.","date":"2016","source":"Oncotarget","url":"https://pubmed.ncbi.nlm.nih.gov/27716616","citation_count":26,"is_preprint":false},{"pmid":"33157084","id":"PMC_33157084","title":"RAN Translation of the Expanded CAG Repeats in the SCA3 Disease Context.","date":"2020","source":"Journal of molecular biology","url":"https://pubmed.ncbi.nlm.nih.gov/33157084","citation_count":25,"is_preprint":false},{"pmid":"31541088","id":"PMC_31541088","title":"Ran pathway-independent regulation of mitotic Golgi disassembly by Importin-α.","date":"2019","source":"Nature communications","url":"https://pubmed.ncbi.nlm.nih.gov/31541088","citation_count":24,"is_preprint":false},{"pmid":"11509570","id":"PMC_11509570","title":"Interaction between Ran and Mog1 is required for efficient nuclear protein import.","date":"2001","source":"The Journal of biological chemistry","url":"https://pubmed.ncbi.nlm.nih.gov/11509570","citation_count":24,"is_preprint":false}],"cost":{"stage1":{"model":"claude-sonnet-4-6","input_tokens":40335,"output_tokens":10055,"usd":0.135915,"stage1_stop_reason":"end_turn"},"stage2":{"model":"claude-opus-4-8","input_tokens":20722,"output_tokens":5283,"usd":0.117843,"stage2_stop_reason":"end_turn"},"total_usd":0.253758,"stage1_batch_id":"msgbatch_01CNoDbkChHEkgrJnL7BwtGJ","stage2_batch_id":"msgbatch_016Y4x9E9Wg5VQDANj9quSQD","note":"batch pricing = 50% of standard"},"stage1_raw":"```json\n{\n  \"discoveries\": [\n    {\n      \"year\": 1993,\n      \"finding\": \"Ran/TC4 GTP-binding protein is required for protein import into the nucleus; it is a component of the cytosolic fraction B activity that mediates translocation of NLS-bearing substrates through the nuclear pore, acting downstream of NLS recognition.\",\n      \"method\": \"Biochemical reconstitution using Xenopus oocyte cytosolic fractions in digitonin-permeabilized cell import assay; protein purification to homogeneity\",\n      \"journal\": \"Nature\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 / Strong — reconstitution of nuclear import with purified Ran in permeabilized cell assay, independently replicated in same year by Melchior et al. (PMID:8276887)\",\n      \"pmids\": [\"8413630\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 1993,\n      \"finding\": \"Ran/TC4 is an essential GTP-binding transport factor for nuclear import; nonhydrolyzable GTP analogues (GTPγS) block nuclear import in a Ran-dependent manner, demonstrating that GTP hydrolysis by Ran is required for transport.\",\n      \"method\": \"In vitro nuclear import assay in digitonin-permeabilized cells; GTPγS inhibition; biochemical complementation with bacterially expressed Ran/TC4\",\n      \"journal\": \"The Journal of cell biology\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 / Strong — reconstitution with purified bacterially expressed Ran; independently confirmed by Moore & Blobel (PMID:8413630)\",\n      \"pmids\": [\"8276887\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 1993,\n      \"finding\": \"Ran/TC4 undergoes GTP/GDP cycling regulated by RCC1 (guanine nucleotide exchange factor) and a Ran-specific GTPase-activating protein (RanGAP); GTP-bound form preferentially interacts with putative effectors, and GDP-bound form interacts with RCC1. Disruption of GTP hydrolysis (Q69L-like mutant) inhibits cell cycle progression.\",\n      \"method\": \"Identification of RanGAP by biochemical screen; in vitro GTPase assays; characterization of Ran mutant proteins; yeast two-hybrid and binding assays for GTP-bound effectors\",\n      \"journal\": \"Nature\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1–2 / Strong — multiple orthogonal methods (in vitro GTPase assay, binding assays, mutant characterization); foundational mechanistic paper replicated across many subsequent studies\",\n      \"pmids\": [\"8255297\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 1993,\n      \"finding\": \"Ran/TC4 nuclear localization requires the presence of RCC1; expression of a GTP hydrolysis-deficient Ran mutant disrupts DNA synthesis, placing Ran in a GTPase switch that monitors progress of DNA synthesis and couples it to onset of mitosis.\",\n      \"method\": \"Transient expression of Ran mutants defective in GTP hydrolysis in mammalian cells; indirect immunofluorescence for localization; [3H]-thymidine incorporation assay for DNA synthesis\",\n      \"journal\": \"The Journal of cell biology\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — localization by immunofluorescence plus functional DNA synthesis assay, single lab with two orthogonal methods\",\n      \"pmids\": [\"8421051\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 1994,\n      \"finding\": \"A mutant Ran (T24N, GDP-bound state) inhibits nuclear assembly and DNA replication in Xenopus egg extracts by binding tightly to RCC1 and inactivating it as a GEF; supplementing with excess RCC1 rescues nuclear assembly and DNA replication, demonstrating RCC1's essential function is solely as a GEF for Ran in interphase.\",\n      \"method\": \"Xenopus egg extract nuclear assembly and DNA replication assays; addition of bacterially expressed mutant Ran proteins; rescue with purified RCC1; in vitro GEF activity assay\",\n      \"journal\": \"The EMBO journal\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 / Moderate — reconstitution in egg extracts with defined mutant proteins, rescue experiments, in vitro GEF assay; single lab but multiple orthogonal methods\",\n      \"pmids\": [\"7988569\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 1994,\n      \"finding\": \"TC4/Ran has distinct roles in nuclear assembly and cell cycle progression; GDP-bound TC4 suppresses nuclear growth and prevents DNA replication, and blocks entry into mitosis by promoting inhibitory phosphorylation of p34(cdc2) on tyrosine and threonine residues in cell-free Xenopus egg extracts.\",\n      \"method\": \"Xenopus egg extract nuclear assembly assay; cell-free cycling extract; immunoblotting for p34(cdc2) phosphorylation; addition of wild-type and mutant TC4 proteins\",\n      \"journal\": \"The Journal of cell biology\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 / Moderate — cell-free reconstitution with defined mutant proteins, biochemical readout of cdc2 phosphorylation; multiple phenotypes tested in one study\",\n      \"pmids\": [\"8188741\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 1994,\n      \"finding\": \"Expression of a Ran/TC4 GTP hydrolysis-deficient mutant arrests cells predominantly in G2 (also G1); deletion of the acidic C-terminal hexapeptide (DEDDDL) does not alter nuclear localization but abrogates the cell cycle inhibitory effect, indicating this domain is essential for mediating Ran's cell cycle function.\",\n      \"method\": \"Transient expression in 293/Tag cells; flow cytometry cell cycle analysis; nuclear localization assessed by subcellular fractionation\",\n      \"journal\": \"Molecular and cellular biology\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — defined mutant expression with cell cycle readout plus deletion mapping; single lab, two orthogonal methods\",\n      \"pmids\": [\"8196659\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 1995,\n      \"finding\": \"RanBP2 (a giant nuclear pore protein of 3,224 residues) binds Ran/TC4; it contains four RanBP1-homologous domains, XFXFG nucleoporin motifs, and localizes to the NPC. Antibodies against RanBP2 inhibit NLS-mediated nuclear import, implicating it as a functional Ran effector at the NPC.\",\n      \"method\": \"Yeast two-hybrid screen using Ran/TC4 as bait; sequence analysis; immunolocalization; antibody inhibition of nuclear import in permeabilized cells\",\n      \"journal\": \"Nature\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2–3 / Moderate — two-hybrid plus immunolocalization plus antibody inhibition assay; single lab with multiple approaches\",\n      \"pmids\": [\"7603572\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 1995,\n      \"finding\": \"The acidic C-terminal DEDDDL sequence of Ran stabilizes GDP binding and is required for high-affinity interaction with the Ran-binding protein HTF9A/RanBP1; HTF9A functions as a co-stimulator of RanGAP activity on wild-type Ran but acts as a RanGAP inhibitor when the C-terminus is absent. An antibody against the C-terminal region preferentially recognizes GTP-bound Ran, indicating nucleotide-dependent conformational change in this domain.\",\n      \"method\": \"In vitro GDP/GTP binding assays with truncation mutants; in vitro RanGAP co-stimulation assays; antibody specificity experiments\",\n      \"journal\": \"The Journal of biological chemistry\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 / Moderate — in vitro biochemical reconstitution with defined mutant proteins, multiple functional assays in one study\",\n      \"pmids\": [\"7782302\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 1995,\n      \"finding\": \"The yeast RNA1 gene product (Rna1p) is the GTPase-activating protein (GAP) for Gsp1p (yeast Ran/TC4 homolog), stimulating GTP hydrolysis ~10^7-fold; human RanGAP1 and S. pombe rna1p also activate Gsp1p GTPase, but Rna1p does not activate human Ran GTP hydrolysis, revealing species-specific GAP activity.\",\n      \"method\": \"Bacterial expression and purification of recombinant Gsp1p and Rna1p; in vitro GTPase activity assay; cross-species complementation biochemistry\",\n      \"journal\": \"The Journal of biological chemistry\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 / Moderate — in vitro reconstituted GTPase assay with purified recombinant proteins; quantitative kinetic measurement\",\n      \"pmids\": [\"7744835\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 1995,\n      \"finding\": \"Rna1p (yeast RanGAP) is directly required for nuclear import; cytosol from rna1-1 mutant cells is unable to support nuclear import in semi-intact yeast cells, and adding back purified Rna1p restores import in a dose-dependent manner.\",\n      \"method\": \"Indirect immunofluorescence; GFP-fusion protein import in living cells; semi-intact yeast cell in vitro import assay; add-back of purified Rna1p\",\n      \"journal\": \"The Journal of cell biology\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1–2 / Strong — purified protein add-back reconstitution experiment plus in vivo and in vitro import assays; multiple orthogonal methods\",\n      \"pmids\": [\"7657689\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 1995,\n      \"finding\": \"The GTP-bound form of Gsp1p (yeast Ran) blocks nuclear protein import and retains poly(A)+ RNA in the nucleus; GTP hydrolysis by Ran is therefore necessary for proper nuclear import of proteins and cytoplasmic appearance of mRNA.\",\n      \"method\": \"Overexpression of wild-type and GTP-locked (G21V) Gsp1p in S. cerevisiae; indirect immunofluorescence for nuclear protein localization; in situ hybridization for poly(A)+ RNA\",\n      \"journal\": \"Proceedings of the National Academy of Sciences of the United States of America\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — genetic and cell biological analysis with defined GTP-locked mutant; two independent phenotypic readouts (protein import and mRNA export)\",\n      \"pmids\": [\"7816822\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 1995,\n      \"finding\": \"A conserved ~150-residue Ran-binding domain (RanBD) present in multiple Ran-binding proteins stabilizes the GTP-bound state of Ran and acts as a coactivator of RanGAP; mutation of a conserved residue in the RanBD of HTF9a drastically reduces Ran binding.\",\n      \"method\": \"Expression cloning overlay assay; sequence analysis; in vitro binding assays; RanGAP coactivation assay; site-directed mutagenesis; co-immunoprecipitation from cell lysates\",\n      \"journal\": \"Proceedings of the National Academy of Sciences of the United States of America\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 1–2 / Moderate — in vitro functional assays with mutagenesis plus co-IP; single lab, multiple methods\",\n      \"pmids\": [\"7724562\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 1996,\n      \"finding\": \"Both protein import and U snRNP import require a GTPase activity (Ran); both are sensitive to nonhydrolyzable GTP analogues and to dominant-negative Ran mutants (Q69L defective in hydrolysis; T24N defective in GTP binding), demonstrating a shared Ran-dependent step for these two distinct import pathways.\",\n      \"method\": \"In vitro nuclear import assays in permeabilized cells; comparison of effects of two mechanistically distinct Ran mutants on protein vs. snRNP import\",\n      \"journal\": \"The Journal of cell biology\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — defined mutant proteins in reconstituted import assay, two substrates tested; single lab\",\n      \"pmids\": [\"8636225\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 1996,\n      \"finding\": \"Ran/TC4 interacts directly with the cytosolic transport factors p97 (importin-β) and NTF2 in a nucleotide-specific manner: GTP-bound Ran interacts with p97, while GDP-bound Ran interacts with NTF2, establishing that Ran nucleotide state directs sequential interactions with import machinery.\",\n      \"method\": \"Solution and solid-phase binding assays using [γ-32P]GTP- or [3H]GDP-preloaded recombinant Ran/TC4 with purified p97 and NTF2\",\n      \"journal\": \"Proceedings of the National Academy of Sciences of the United States of America\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 / Moderate — in vitro biochemical binding assays with nucleotide-preloaded recombinant proteins, direct demonstration of nucleotide-state specificity\",\n      \"pmids\": [\"8755535\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 1996,\n      \"finding\": \"Multiple Ran mutants (G19V, T24N, L43E, E46G) that affect interaction with regulatory proteins (RCC1, RanGAP/Fug1) or Ran-binding proteins disrupt normal nuclear localization of Ran, causing accumulation at the nuclear envelope; G19V Ran is insensitive to RCC1-stimulated exchange and is ~50% GTP-bound in cells.\",\n      \"method\": \"Expression of epitope-tagged Ran mutants in BHK21 cells; immunofluorescence; nucleotide-binding assays from immunoprecipitated Ran; permeabilized cell import assay\",\n      \"journal\": \"The Journal of biological chemistry\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — multiple mutants characterized by immunofluorescence plus in vitro nucleotide binding; single lab\",\n      \"pmids\": [\"8955121\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 1996,\n      \"finding\": \"Ran L43E mutant (effector domain mutant) does not affect nuclear import of GR-GFP but strongly inhibits cell growth, providing evidence that Ran mediates at least one essential cell function independent of nuclear protein import.\",\n      \"method\": \"Transfection and microinjection of Ran mutants into BHK21 cells expressing GR-GFP; live-cell fluorescence microscopy for nuclear import; colony formation/cell growth assay\",\n      \"journal\": \"The Journal of cell biology\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — live-cell imaging of nuclear transport combined with growth assay; two orthogonal readouts; single lab\",\n      \"pmids\": [\"8655589\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 1997,\n      \"finding\": \"The interaction between Gsp1p (yeast Ran) and Ntf2p is critical for nuclear transport; temperature-sensitive gsp1 mutations that reduce Ntf2p binding cause nuclear transport defects that are suppressed by NTF2 overexpression, but not by a NTF2 mutant with reduced Gsp1p binding.\",\n      \"method\": \"Genetic screen for conditional gsp1 alleles; biochemical binding assays; in vivo nuclear transport assays; genetic suppression analysis\",\n      \"journal\": \"Molecular and cellular biology\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — reciprocal genetic and biochemical evidence; suppression by NTF2 overexpression and failure of binding-deficient NTF2 to suppress provides strong epistatic evidence\",\n      \"pmids\": [\"9199309\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 1995,\n      \"finding\": \"GSP1 (yeast Ran) is nuclear, binds GTP in vitro, and is an essential gene; a GTP-stabilizing activating mutation in Gsp1p causes dominant lethality, and GSP1 and GSP2 are multicopy suppressors of prp20 (RCC1 homolog) mutants, placing GSP1 downstream of PRP20/RCC1.\",\n      \"method\": \"Multicopy suppressor screen; GTP-binding assay with purified protein; indirect immunofluorescence; dominant lethal mutant analysis\",\n      \"journal\": \"Molecular and cellular biology\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — suppressor genetics combined with in vitro GTP-binding and localization; single lab\",\n      \"pmids\": [\"8455603\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 1999,\n      \"finding\": \"Ran (as ARA24) functions as a coactivator of the androgen receptor (AR) that binds differentially to AR N-terminal polyglutamine (poly-Q) regions of different lengths; longer poly-Q expansions diminish AR-ARA24 interaction and coactivation; deletion of DEDDDL at ARA24 C-terminus enhances coactivation.\",\n      \"method\": \"Yeast two-hybrid and mammalian reciprocal interaction assays; transcriptional reporter assays; deletion mutagenesis\",\n      \"journal\": \"The Journal of biological chemistry\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — reciprocal interaction assays in two systems plus transcriptional readout with mutagenesis; single lab\",\n      \"pmids\": [\"10400640\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2000,\n      \"finding\": \"Disrupting the Ran-NTF2 interaction by a temperature-sensitive NTF2 mutation prevents nuclear import of RanGDP in vivo, depleting nuclear Ran; this depletion arrests cells in G2 in a MAD2 (spindle assembly checkpoint)-dependent manner, linking nuclear Ran concentration to spindle checkpoint control.\",\n      \"method\": \"Temperature-sensitive NTF2 mutant in S. cerevisiae; live-cell and indirect immunofluorescence for Ran localization; cell cycle analysis; genetic epistasis with mad2 deletion\",\n      \"journal\": \"Molecular biology of the cell\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — conditional mutant with defined biochemical defect, clear cell cycle readout, and epistasis with spindle checkpoint gene; multiple methods\",\n      \"pmids\": [\"10930458\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2001,\n      \"finding\": \"Mog1 binds nucleotide-free Ran (after stimulating GTP release from Ran-GTP or Ran-GDP) and forms a stable complex; disruption of the Mog1-Ran interface (using engineered charge-reversal mutants Mog1-E65K / Ran-K136E) causes temperature-sensitive growth and nuclear import defects in yeast.\",\n      \"method\": \"In vitro nucleotide release assay; engineering of charge-reversal interaction-disrupting mutants; in vivo import assay with fluorescent reporter; synthetic lethality with prp20\",\n      \"journal\": \"The Journal of biological chemistry\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1–2 / Moderate — in vitro biochemical assay with defined mutants, in vivo import assay, synthetic lethality; multiple orthogonal methods in single study\",\n      \"pmids\": [\"11509570\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2002,\n      \"finding\": \"Ran-GTP generated around chromatin directs mitotic spindle assembly; in C. elegans, RNAi depletion of Ran causes metaphase chromosome misalignment and failure of nuclear envelope assembly at telophase. Ran localizes to kinetochore regions during mitosis and to the nuclear envelope during interphase/telophase.\",\n      \"method\": \"RNAi depletion in C. elegans embryos; immunofluorescence for chromosome alignment, astral microtubules, and Ran localization; comparison with RCC1 and RanGAP RNAi\",\n      \"journal\": \"Current biology\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — clean RNAi loss-of-function with specific mitotic and nuclear envelope phenotypes; epistasis with RCC1 and RanGAP; multiple orthogonal readouts\",\n      \"pmids\": [\"11909538\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2002,\n      \"finding\": \"Nercc1 (NIMA-like kinase) binds specifically to the Ran GTPase through both its catalytic domain and RCC1-like domain, preferring RanGDP in vivo; Nercc1 autoactivates by autophosphorylation in vitro and is phosphorylated by active p34(Cdc2); its inhibition causes spindle abnormalities and chromosomal misalignment.\",\n      \"method\": \"Co-immunoprecipitation; in vitro kinase assays; microinjection of anti-Nercc1 antibodies; nucleotide-binding preference assays\",\n      \"journal\": \"Genes & development\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — reciprocal Co-IP, in vitro kinase assay with nucleotide preference mapping; single lab\",\n      \"pmids\": [\"12101123\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2002,\n      \"finding\": \"Ran-GTP promotes spindle assembly by releasing TPX2 from inhibitory importin-α/β binding; Ran-GTP stimulates the interaction between TPX2 and Aurora A kinase (Eg2/Xenopus Aurora A), causing TPX2 to stimulate Aurora A phosphorylation and kinase activity in a microtubule-dependent manner; importin-α/β block this activation and Ran-GTP overcomes this inhibition both in egg extracts and with purified proteins.\",\n      \"method\": \"Reconstitution in Xenopus egg extracts; in vitro kinase assays with purified proteins; immunoprecipitation; dominant-negative and constitutively active Ran constructs\",\n      \"journal\": \"Nature cell biology\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 / Moderate — reconstitution with purified proteins plus egg extract assays; multiple orthogonal methods in one study\",\n      \"pmids\": [\"12577065\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2008,\n      \"finding\": \"Ran-binding protein 3 (RanBP3) links the Ras/ERK (via RSK) and PI3-kinase (via Akt) pathways to the Ran gradient and nucleocytoplasmic transport; RSK and Akt phosphorylate RanBP3, which modulates its interaction with Ran and Crm1, thereby regulating the nuclear:cytoplasmic Ran gradient.\",\n      \"method\": \"In vitro kinase assays; mass spectrometry phosphosite mapping; nuclear transport assays; interaction studies with RanBP3 mutants\",\n      \"journal\": \"Molecular cell\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — in vitro kinase assay plus transport assays; single lab with multiple methods\",\n      \"pmids\": [\"18280241\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2008,\n      \"finding\": \"ARA24/Ran (as AR coactivator) enhances the androgen-dependent N-C terminal interaction of the androgen receptor (AR); constitutively GTP- or GDP-bound forms of ARA24/Ran repress the AR N-C interaction; ARA24/Ran forms an endogenous complex with nuclear AR but not cytoplasmic AR.\",\n      \"method\": \"Co-immunoprecipitation; transcriptional reporter assays; AR N-C interaction assay; subcellular fractionation\",\n      \"journal\": \"Biochemical and biophysical research communications\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2–3 / Moderate — Co-IP plus functional transcriptional assay plus nucleotide-state mutants; single lab\",\n      \"pmids\": [\"18565325\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2009,\n      \"finding\": \"Crystal structures of Nup153 zinc fingers in complex with Ran show that each of the four zinc finger modules of Nup153 binds one Ran molecule independently and with measurably higher affinity for RanGDP than RanGTP; microcalorimetric analysis identified one specific hydrogen bond accounting for affinity differences between individual zinc fingers.\",\n      \"method\": \"X-ray crystallography (six complex structures plus 1.48 Å RanGDP structure); isothermal titration calorimetry; site-directed mutagenesis\",\n      \"journal\": \"Journal of molecular biology\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 / Moderate — crystal structures at high resolution plus ITC and mutagenesis; multiple orthogonal methods in one study\",\n      \"pmids\": [\"19505478\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2009,\n      \"finding\": \"Ran-GFP is nuclear during interphase; GTP-locked Ran (Q69L) is less concentrated in the nucleus and associates with nuclear pore complexes; GDP/nucleotide-free Ran (T24N) associates relatively stably with chromatin throughout the cell cycle and is highly concentrated on mitotic chromosomes; wild-type Ran-GTP generated at chromatin is highly mobile and interacts dynamically with NPCs and spindle.\",\n      \"method\": \"Live-cell fluorescence microscopy and FRAP of GFP-Ran and mutant fusions during cell cycle in human cells\",\n      \"journal\": \"BMC cell biology\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — live-cell imaging with FRAP for multiple nucleotide-state mutants; single lab\",\n      \"pmids\": [\"19765287\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2011,\n      \"finding\": \"Ran-GTP accumulation at basal bodies is coordinated with ciliogenesis initiation; RanBP1 knockdown increases Ran-GTP concentration at basal bodies and promotes primary cilia formation, while RanBP1 overexpression inhibits it; Ran-GTP is required for proper KIF17 localization at distal tips of primary cilia.\",\n      \"method\": \"RanBP1 siRNA knockdown and overexpression; immunofluorescence for Ran-GTP and cilia markers; quantification of ciliogenesis; analysis of KIF17 localization\",\n      \"journal\": \"Molecular biology of the cell\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — loss-of-function and gain-of-function with specific ciliogenesis readout; single lab\",\n      \"pmids\": [\"21998203\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2014,\n      \"finding\": \"RanBP1 controls spindle assembly by modulating RCC1 activity and its chromatin partitioning: the heterotrimeric RCC1/Ran/RanBP1 complex controls both RCC1 enzymatic activity and distribution between chromatin-bound and soluble pools; RanBP1 phosphorylation drives changes in chromatin-bound RCC1 at the metaphase-anaphase transition.\",\n      \"method\": \"Reconstitution in M-phase Xenopus egg extracts; biochemical fractionation; RanBP1 phospho-mutants; spindle assembly assays\",\n      \"journal\": \"Developmental cell\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 / Moderate — reconstituted in Xenopus egg extracts with defined phospho-mutants; multiple biochemical and functional assays; single lab\",\n      \"pmids\": [\"25458009\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2015,\n      \"finding\": \"Ran is acetylated at multiple lysine residues by CBP/p300 and Tip60 in vitro and in vivo; lysine acetylation interferes with nucleotide exchange, GTP hydrolysis, subcellular Ran localization, and interaction with import and export receptors; specific sirtuin deacetylases remove acetyl groups from two Ran acetylation sites in vitro.\",\n      \"method\": \"In vitro acetylation assays with CBP/p300 and Tip60; mass spectrometry identification of acetylation sites; nucleotide exchange and GTPase assays on acetylated Ran; nuclear transport assays; sirtuin deacetylation assays\",\n      \"journal\": \"Proceedings of the National Academy of Sciences of the United States of America\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 / Moderate — in vitro reconstituted acetyltransferase assays, functional nucleotide-cycle assays, transport assays; multiple methods; single lab\",\n      \"pmids\": [\"26124124\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2015,\n      \"finding\": \"The Ran-GTP gradient spatially regulates XCTK2 (Kinesin-14) localization and motility within the spindle; a flattened Ran-GTP gradient blocks XCTK2-stimulated bipolar spindle assembly; XCTK2 turnover kinetics are faster near spindle poles (low Ran-GTP) than near chromatin (high Ran-GTP), dependent on importin α/β binding to the XCTK2 NLS.\",\n      \"method\": \"Xenopus egg extract spindle assembly assays; FRAP analysis of XCTK2 with constitutively active Ran mutant; XCTK2 NLS mutants; importin binding assays\",\n      \"journal\": \"Current biology\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1–2 / Moderate — reconstituted spindle assembly in egg extracts with defined mutants plus FRAP; multiple orthogonal methods in one study\",\n      \"pmids\": [\"25981788\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2018,\n      \"finding\": \"Ran is a substrate of TIP60 acetyltransferase; acetylation of Lys134 by TIP60 during mitosis liberates Mog1 from Ran binding, switching Ran to bind RCC1 and promoting high Ran-GTP levels required for chromosome alignment; structural analysis revealed that Mog1 competes with RCC1 for Ran binding in a GTP/GDP-dependent manner.\",\n      \"method\": \"Crystal structure of Ran-Mog1 complex; in vitro acetyltransferase assay with TIP60; structure-guided mutagenesis; competition binding assays between Mog1 and RCC1; chromosome alignment assays in cells expressing acetylation-mimicking Ran mutants\",\n      \"journal\": \"Journal of molecular cell biology\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 / Moderate — crystal structure plus in vitro biochemistry plus cell-based functional validation; multiple orthogonal methods in one study\",\n      \"pmids\": [\"29040603\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2018,\n      \"finding\": \"A nuclear lamina-chromatin-Ran axis controls the Ran gradient and nuclear import; chemical inhibition or depletion of histone methyltransferases G9a/GLP reduces heterochromatin and disrupts the Ran gradient, causing nuclear import defects for large cargoes including ATM; disruption of the Ran gradient in HGPS impairs ATM nuclear import and reduces γ-H2AX generation after ionizing radiation.\",\n      \"method\": \"HMT inhibitor treatment and siRNA depletion; nuclear:cytoplasmic ratio measurements of Ran and import cargoes; DNA damage assays (γ-H2AX immunofluorescence) after ionizing radiation; comparison with HGPS patient fibroblasts\",\n      \"journal\": \"Aging cell\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — chemical perturbation plus RNAi with specific transport and DNA damage readouts; single lab, multiple methods\",\n      \"pmids\": [\"30565836\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2019,\n      \"finding\": \"Ran localizes specifically to the plasma membrane/ruffles of ovarian cancer cells in addition to its nucleocytoplasmic distribution; Ran interacts with RhoA via its DEDDDL C-terminal domain (binding serine 188 of RhoA), preventing RhoA proteasomal degradation and promoting RhoA membrane localization and activity; Ran depletion inhibits ovarian cancer cell invasion by impairing RhoA signaling.\",\n      \"method\": \"Subcellular fractionation and immunofluorescence for Ran localization; Co-immunoprecipitation; RhoA stability assays (proteasome inhibition); RhoA activity assays; invasion assays with Ran knockdown; mapping of interaction domains by deletion mutagenesis\",\n      \"journal\": \"Nature communications\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — reciprocal Co-IP plus domain mapping plus functional invasion assay; multiple orthogonal methods; single lab\",\n      \"pmids\": [\"31209254\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2017,\n      \"finding\": \"Active Ran-GTP spatially restricts anillin (a cytokinesis regulator) to the cell equator during cytokinesis; anillin contains a conserved NLS at its C-terminus that binds importin-β and is required for cortical polarity; decreasing Ran-GTP levels or ectopically activating Ran affects anillin localization and causes cytokinesis failure.\",\n      \"method\": \"Manipulation of Ran-GTP levels in cells; live-cell imaging; localization of anillin NLS mutants; importin-β binding assays; cytokinesis phenotype quantification\",\n      \"journal\": \"Molecular biology of the cell\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — defined NLS mutants, importin binding assay, live-cell imaging; single lab\",\n      \"pmids\": [\"28931593\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2002,\n      \"finding\": \"Karyopherinβ2 (Kapβ2) releases import substrates in the nucleus upon RanGTP binding; an internal acidic loop in Kapβ2 physically couples the Ran-binding N-terminal arch to the substrate-binding C-terminal arch; proteolytic cleavage or truncation of this loop uncouples Ran binding from substrate dissociation without reducing affinity for either Ran or substrate, and abolishes Ran-mediated nuclear import of fluorescent substrate.\",\n      \"method\": \"Proteolytic cleavage and truncation mutagenesis of Kapβ2; NMR mapping of substrate-binding site; quantitative binding affinity measurements; nuclear import assay in permeabilized HeLa cells\",\n      \"journal\": \"Biochemistry\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 / Moderate — mutagenesis with structural NMR plus in vitro binding assays plus permeabilized cell transport assay; multiple orthogonal methods in one study\",\n      \"pmids\": [\"12033928\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2002,\n      \"finding\": \"RanBP3 associates with RCC1 in a Ran-stimulated manner (Ran-GDP, -GTP, and nucleotide-free Ran all stimulate complex formation); RanBP3 increases RCC1 catalytic activity toward Ran and also promotes Crm1 binding to RCC1, acting as a scaffold to promote efficient nuclear export complex assembly.\",\n      \"method\": \"Binding assays (solid-phase and pull-down); RCC1 activity assays in presence of RanBP3; three-component complex formation assays\",\n      \"journal\": \"The Journal of biological chemistry\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — in vitro binding and enzymatic assays; multiple biochemical approaches; single lab\",\n      \"pmids\": [\"11932251\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2022,\n      \"finding\": \"RSL1D1 interacts with Ran and inhibits its deacetylation by competing with Sirt7 for binding; RSL1D1-mediated hyperacetylation of Ran inhibits nuclear accumulation of STAT3 and the STAT3-regulated autophagic program in colorectal cancer cells.\",\n      \"method\": \"Co-immunoprecipitation; acetylation assays; STAT3 nuclear localization assays; autophagy markers; competition binding assays between RSL1D1 and Sirt7 for Ran\",\n      \"journal\": \"Cell death & disease\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2–3 / Moderate — Co-IP plus competition binding plus functional assays; single lab\",\n      \"pmids\": [\"35013134\"],\n      \"is_preprint\": false\n    }\n  ],\n  \"current_model\": \"Ran is a small nuclear GTPase that cycles between a GTP-bound (nuclear, generated by chromatin-associated RCC1/RanGEF) and GDP-bound (cytoplasmic, promoted by cytoplasmic RanGAP) state to create an asymmetric gradient across the nuclear envelope; this gradient drives directionality of nuclear import (RanGTP dissociates importin-cargo complexes in the nucleus) and export (RanGTP promotes exportin-cargo loading in the nucleus and complex disassembly in the cytoplasm), and during mitosis the RanGTP gradient around chromosomes releases importin-bound spindle assembly factors (e.g., TPX2, NuMA, XCTK2) to promote spindle assembly, nuclear envelope reformation, and cytokinesis, with these activities further regulated by post-translational acetylation (by TIP60/CBP/p300, reversed by sirtuins) and phosphorylation of Ran-regulatory partners such as RanBP1.\"\n}\n```","stage2_raw":"```json\n{\n  \"mechanistic_narrative\": \"RAN is a small GTPase whose nucleotide-state cycling — driven by the chromatin-associated exchange factor RCC1 generating Ran-GTP and a Ran-specific GAP promoting GTP hydrolysis — establishes a directional switch that governs nucleocytoplasmic transport and mitotic organization [#2, #4]. Ran was first identified as the essential transport factor required for NLS-dependent protein import through the nuclear pore, with GTP hydrolysis necessary for translocation [#0, #1]; its nucleotide state directs sequential interactions with the import machinery, GTP-bound Ran binding importin-β (p97) and GDP-bound Ran binding NTF2, the latter interaction itself being required to import Ran-GDP into the nucleus and to maintain the gradient [#14, #17, #20]. The acidic C-terminal DEDDDL tail stabilizes GDP binding, mediates high-affinity engagement with RanBP1-family Ran-binding domains that coactivate RanGAP, and undergoes a nucleotide-dependent conformational change [#8, #12]. Beyond transport, Ran-GTP generated around chromatin patterns mitosis by releasing importin-bound spindle assembly factors: it liberates TPX2 to activate Aurora A kinase, spatially controls the Kinesin-14 XCTK2 across the spindle, restricts anillin to the equator during cytokinesis, and is required for chromosome alignment and nuclear envelope reassembly [#24, #32, #36, #22]. Ran activity is further tuned by lysine acetylation (by CBP/p300 and TIP60, reversed by sirtuins), which modulates nucleotide cycling, localization, and receptor binding, with TIP60 acetylation of Lys134 switching Ran from Mog1 to RCC1 to raise mitotic Ran-GTP [#31, #33]. Non-canonical roles include Ran-GTP accumulation at basal bodies during ciliogenesis and a plasma-membrane pool that stabilizes RhoA to promote cancer cell invasion [#29, #35].\",\n  \"teleology\": [\n    {\n      \"year\": 1993,\n      \"claim\": \"Established that Ran is the diffusible GTPase required for nuclear protein import, defining its core cellular function rather than leaving it an orphan GTP-binding protein.\",\n      \"evidence\": \"Biochemical reconstitution of NLS-dependent import with purified Ran in digitonin-permeabilized cells, plus GTPγS inhibition with bacterially expressed Ran\",\n      \"pmids\": [\"8413630\", \"8276887\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Did not define the receptors Ran acts upon during transport\", \"Mechanism of how GTP hydrolysis confers directionality unresolved\"]\n    },\n    {\n      \"year\": 1993,\n      \"claim\": \"Defined the regulatory circuit of the Ran GTPase switch — RCC1 as exchange factor and a Ran-specific GAP — and tied disruption of GTP hydrolysis to cell cycle arrest.\",\n      \"evidence\": \"Biochemical identification of RanGAP, in vitro GTPase and binding assays, and GTP-hydrolysis-deficient mutant characterization in cells\",\n      \"pmids\": [\"8255297\", \"8421051\", \"8455603\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Spatial segregation of RCC1 and RanGAP not yet shown to generate a gradient\", \"Direct effectors of Ran-GTP not identified\"]\n    },\n    {\n      \"year\": 1994,\n      \"claim\": \"Showed RCC1's essential interphase role is solely as a Ran GEF and that GDP-bound Ran couples nuclear assembly and DNA replication to mitotic entry via cdc2 phosphorylation.\",\n      \"evidence\": \"Xenopus egg extract nuclear assembly/DNA replication assays with mutant Ran proteins, RCC1 rescue, and cdc2 phospho-immunoblotting\",\n      \"pmids\": [\"7988569\", \"8188741\", \"8196659\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Molecular link between Ran nucleotide state and cdc2 regulation indirect\", \"C-terminal DEDDDL requirement for cell cycle function mechanistically unexplained at the time\"]\n    },\n    {\n      \"year\": 1995,\n      \"claim\": \"Identified the Ran-binding effectors and partners at the pore (RanBP2, RanBP1/HTF9A, the RanBD module) and confirmed RanGAP/Rna1p as both GTPase activator and import requirement.\",\n      \"evidence\": \"Yeast two-hybrid, overlay/binding assays, in vitro RanGAP coactivation, and semi-intact yeast import add-back of purified Rna1p\",\n      \"pmids\": [\"7603572\", \"7782302\", \"7744835\", \"7657689\", \"7816822\", \"7724562\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Species-specific GAP recognition determinants not mapped\", \"How RanBD coactivation integrates with cargo release left open\"]\n    },\n    {\n      \"year\": 1996,\n      \"claim\": \"Demonstrated that Ran nucleotide state directs sequential receptor interactions (GTP→importin-β, GDP→NTF2) and that Ran has an essential function beyond import.\",\n      \"evidence\": \"Nucleotide-preloaded recombinant binding assays with p97/NTF2; effector-domain L43E mutant separating growth from import; mutant localization in BHK21 cells\",\n      \"pmids\": [\"8755535\", \"8955121\", \"8655589\", \"8636225\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Identity of the import-independent essential function unresolved at the time\", \"Shared snRNP/protein import step mechanistically conflated\"]\n    },\n    {\n      \"year\": 1997,\n      \"claim\": \"Provided reciprocal genetic proof that the Ran–NTF2 interaction is physiologically essential for nuclear transport, not merely an in vitro binding event.\",\n      \"evidence\": \"Conditional gsp1 alleles with reduced Ntf2p binding suppressed by NTF2 overexpression but not by a binding-deficient NTF2 mutant\",\n      \"pmids\": [\"9199309\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Did not quantify gradient consequences of disrupted import in vivo\"]\n    },\n    {\n      \"year\": 2000,\n      \"claim\": \"Linked nuclear Ran concentration directly to spindle-assembly-checkpoint-dependent cell cycle control.\",\n      \"evidence\": \"Temperature-sensitive NTF2 mutant depleting nuclear Ran, with G2 arrest abolished by mad2 deletion in yeast\",\n      \"pmids\": [\"10930458\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Mechanism connecting nuclear Ran level to checkpoint signaling not defined\"]\n    },\n    {\n      \"year\": 2001,\n      \"claim\": \"Identified Mog1 as a nucleotide-release factor that forms a stable nucleotide-free complex with Ran required for import.\",\n      \"evidence\": \"In vitro nucleotide release assays, charge-reversal interface mutants, in vivo import assay, and synthetic lethality with prp20\",\n      \"pmids\": [\"11509570\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Physiological trigger regulating Mog1–Ran engagement unknown at the time\"]\n    },\n    {\n      \"year\": 2002,\n      \"claim\": \"Established the chromatin Ran-GTP gradient as the master spatial cue for mitotic spindle assembly, including the TPX2–Aurora A activation module and Ran-binding kinase Nercc1.\",\n      \"evidence\": \"C. elegans Ran RNAi with mitotic/NE phenotypes; Xenopus egg extract reconstitution of TPX2 release and Aurora A activation; Nercc1 Co-IP and kinase assays; karyopherin-β2 loop coupling Ran binding to cargo release\",\n      \"pmids\": [\"11909538\", \"12577065\", \"12101123\", \"12033928\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Full repertoire of spindle assembly factors released by Ran-GTP incomplete\", \"How discrete gradient thresholds map to distinct factors unresolved\"]\n    },\n    {\n      \"year\": 2002,\n      \"claim\": \"Defined RanBP3 as a scaffold that stimulates RCC1 activity and promotes Crm1-based export complex assembly.\",\n      \"evidence\": \"In vitro binding, RCC1 activity, and three-component complex formation assays\",\n      \"pmids\": [\"11932251\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"In vivo significance of RanBP3-stimulated export not established in this study\"]\n    },\n    {\n      \"year\": 2008,\n      \"claim\": \"Connected the Ran gradient to upstream growth signaling and revealed an unexpected role of Ran as an androgen receptor coactivator.\",\n      \"evidence\": \"RSK/Akt phosphorylation of RanBP3 with transport readouts; reciprocal interaction and reporter assays linking ARA24/Ran to AR poly-Q\",\n      \"pmids\": [\"18280241\", \"10400640\", \"18565325\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"AR coactivation mechanism distinct from transport function not mechanistically integrated\", \"RanBP3 phospho-control quantitative effect on gradient single-lab\"]\n    },\n    {\n      \"year\": 2009,\n      \"claim\": \"Provided structural and dynamic detail of Ran's interactions at the pore and its cell-cycle-dependent mobility.\",\n      \"evidence\": \"Crystal structures of Nup153 zinc fingers with Ran plus ITC; live-cell FRAP of GFP-Ran and nucleotide-state mutants\",\n      \"pmids\": [\"19505478\", \"19765287\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Functional consequence of Nup153 ZnF differential affinity in transport not directly tested\"]\n    },\n    {\n      \"year\": 2015,\n      \"claim\": \"Established acetylation as a post-translational layer controlling the entire Ran nucleotide cycle and demonstrated spatial gradient control of a spindle kinesin.\",\n      \"evidence\": \"In vitro CBP/p300/Tip60 acetylation with MS site mapping and nucleotide/transport assays; Xenopus extract FRAP of XCTK2 across the Ran-GTP gradient\",\n      \"pmids\": [\"26124124\", \"25981788\", \"25458009\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"In vivo dynamics of acetylation cycling not quantified\", \"Which acetylation sites dominate which functions only partially resolved\"]\n    },\n    {\n      \"year\": 2018,\n      \"claim\": \"Resolved how mitotic acetylation reroutes Ran partner choice, with TIP60 Lys134 acetylation releasing Mog1 to favor RCC1 and raise Ran-GTP for chromosome alignment.\",\n      \"evidence\": \"Crystal structure of Ran–Mog1, in vitro TIP60 acetylation, competition binding, and acetyl-mimic mutant chromosome alignment assays; lamina-chromatin-Ran axis controlling import of large cargoes\",\n      \"pmids\": [\"29040603\", \"30565836\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Temporal regulation of TIP60 toward Ran during mitosis not fully defined\", \"Lamina-Ran axis evidence relies on chemical perturbation in single lab\"]\n    },\n    {\n      \"year\": 2019,\n      \"claim\": \"Revealed non-nuclear Ran functions: a plasma-membrane pool stabilizing RhoA to drive invasion, and Ran-GTP control of cytokinesis and ciliogenesis.\",\n      \"evidence\": \"Co-IP and domain mapping of Ran–RhoA with invasion assays; Ran-GTP manipulation affecting anillin localization and basal-body ciliogenesis\",\n      \"pmids\": [\"31209254\", \"28931593\", \"21998203\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"How Ran reaches the plasma membrane mechanistically unexplained\", \"GTPase-independent vs. -dependent contributions to RhoA stabilization unresolved\"]\n    },\n    {\n      \"year\": 2022,\n      \"claim\": \"Connected Ran acetylation control to disease signaling, with RSL1D1 blocking Sirt7-mediated deacetylation to suppress STAT3 import and autophagy in cancer.\",\n      \"evidence\": \"Co-IP, competition binding, acetylation, and STAT3 localization/autophagy assays in colorectal cancer cells\",\n      \"pmids\": [\"35013134\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Single-lab Co-IP-based competition without structural validation\", \"Generality beyond colorectal cancer context untested\"]\n    },\n    {\n      \"year\": null,\n      \"claim\": \"How the multiple post-translational and partner-based regulatory layers (acetylation, RanBP1/RanBP3 phosphorylation, Mog1 switching) are integrated in space and time to tune the Ran gradient for distinct transport, mitotic, and membrane functions remains unresolved.\",\n      \"evidence\": \"\",\n      \"pmids\": [],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"No unified quantitative model coupling acetylation cycling to gradient dynamics\", \"Mechanism targeting Ran to the plasma membrane unknown\", \"Disease-relevant Ran functions lack in vivo genetic validation in the corpus\"]\n    }\n  ],\n  \"mechanism_profile\": {\n    \"molecular_activity\": [\n      {\"term_id\": \"GO:0003924\", \"supporting_discovery_ids\": [1, 2, 9, 31]},\n      {\"term_id\": \"GO:0098772\", \"supporting_discovery_ids\": [24, 32, 36, 35]},\n      {\"term_id\": \"GO:0060089\", \"supporting_discovery_ids\": [2, 14, 28]}\n    ],\n    \"localization\": [\n      {\"term_id\": \"GO:0005634\", \"supporting_discovery_ids\": [3, 11, 18, 28]},\n      {\"term_id\": \"GO:0005635\", \"supporting_discovery_ids\": [15, 22, 28]},\n      {\"term_id\": \"GO:0000228\", \"supporting_discovery_ids\": [22, 28, 30]},\n      {\"term_id\": \"GO:0005815\", \"supporting_discovery_ids\": [29]},\n      {\"term_id\": \"GO:0005886\", \"supporting_discovery_ids\": [35]}\n    ],\n    \"pathway\": [\n      {\"term_id\": \"R-HSA-9609507\", \"supporting_discovery_ids\": [0, 1, 14, 37]},\n      {\"term_id\": \"R-HSA-1640170\", \"supporting_discovery_ids\": [22, 24, 32, 36]},\n      {\"term_id\": \"R-HSA-162582\", \"supporting_discovery_ids\": [25, 35]}\n    ],\n    \"complexes\": [\"RCC1/Ran/RanBP1 complex\"],\n    \"partners\": [\"RCC1\", \"RanGAP1\", \"RANBP1\", \"RANBP2\", \"NTF2\", \"KPNB1\", \"MOG1\", \"RANBP3\"],\n    \"other_free_text\": []\n  }\n}\n```","audit_flag":null,"evaluation":{"pairwise":"win","faith_supported":6,"faith_total":6,"faith_pct":100.0}}