| 1992 |
SAF-A (hnRNPU) was identified as a novel nuclear DNA-binding protein with high affinity for scaffold/matrix attachment region (SAR/MAR) DNA elements; the purified protein binds at multiple sites to SAR elements, particularly A/T-rich stretches, forms large protein aggregates, and mediates formation of looped DNA structures. |
Protein purification, DNA binding assays, electron microscopy, competition studies with synthetic polynucleotides |
The EMBO journal |
High |
1324173
|
| 1994 |
SAF-A and hnRNP-U are the same protein; it binds chromosomal DNA in vivo (UV cross-linking), binds both double-stranded and single-stranded DNA and RNA in vitro, likely at different binding sites, forming higher-order nucleic acid-protein complexes. |
UV cross-linking in vivo, filter-binding assays, biochemical fractionation |
European journal of biochemistry |
High |
8174554
|
| 1994 |
Two isoforms of hnRNP-U (form 1 and form 2) were purified; they differ in primary structure but both bind single- and double-stranded DNA and RNA and specifically bind/aggregate the human SAR element MII; the isoforms form morphologically distinct nucleic acid-protein complexes (unbranched filaments vs. spheres ~35 nm diameter). |
Chromatographic purification, filter binding, electron microscopy |
Biochemistry |
High |
8068679
|
| 1997 |
SAF-A contains a novel bipartite SAR-specific DNA-binding domain independent of the RGG RNA-binding domain; during apoptosis, caspase-dependent cleavage within this DNA-binding domain abolishes DNA binding and detaches SAF-A from nuclear structural sites, while hnRNP complex association (RNA metabolism function) is preserved. |
Domain mapping, in vitro cleavage assays, nuclear fractionation, immunofluorescence |
The EMBO journal |
High |
9405365
|
| 1997 |
hnRNP-U/SAF-A is directly bound to chromosomal DNA in vivo, demonstrated by formaldehyde cross-linking of living cells followed by CsCl density gradient purification; dimethylsulfate cross-linking and limited protease digestion confirmed direct DNA binding (not via other proteins). |
Chemical cross-linking (formaldehyde, dimethylsulfate), CsCl density gradient centrifugation, western blotting, protease digestion |
Biochemistry |
High |
9204873
|
| 2000 |
Caspase-3 cleaves SAF-A at a noncanonical site (SALD after Asp-100); point mutation D100A abrogates cleavage by recombinant caspase-3 in vitro and during apoptosis in vivo. |
In vitro cleavage with recombinant caspase-3, MALDI-TOF mass spectrometry, Edman sequencing, site-directed mutagenesis |
The Journal of biological chemistry |
High |
10671544
|
| 2002 |
hnRNP-U is the major nuclear binding partner of the SCF(β-TrCP) ubiquitin ligase subunit β-TrCP/E3RS; it acts as a pseudosubstrate that occupies E3RS stoichiometrically, stabilizes the E3 component, and is responsible for its nuclear localization; hnRNP-U binding is abolished by phospho-IκBα peptide competition or a point mutation in the E3RS WD region, and hnRNP-U is stable (not degraded) unlike canonical substrates. |
Affinity purification, mass spectrometry, co-immunoprecipitation, competition assays, point mutagenesis |
Genes & development |
High |
11850407
|
| 2002 |
hnRNP-U/SAF-A binds to an episomally replicating vector (pEPI-1) containing an S/MAR element in vivo, demonstrated by cis-diamminedichloroplatinum II cross-linking followed by nuclear matrix co-purification and immunoprecipitation of the crosslinked DNA-protein complex. |
Cis-DDP cross-linking, nuclear matrix co-purification, southwestern analysis, immunoprecipitation |
EMBO reports |
High |
11897664
|
| 2003 |
SAF-A is enriched on the inactive X chromosome (Xi) through its RGG RNA-binding domain; after near-complete removal of DNA and chromatin proteins, SAF-A remains with the nuclear matrix at the Xi position, suggesting RNA-dependent (possibly XIST RNA) association contributing to Xi nuclear architecture. |
Immunofluorescence, nuclear matrix extraction, domain deletion analysis (RGG box mutants) |
Chromosoma |
High |
14608463
|
| 2006 |
hnRNP-U directly interacts with the Wilms' tumor suppressor WT1; the interaction involves WT1 zinc-fingers and the middle domain of hnRNP-U, does not require other proteins or nucleic acids, and hnRNP-U modulates WT1 transcriptional activation of a bona fide WT1 target gene. |
Co-immunoprecipitation of endogenous proteins, domain mapping pulldowns, transcriptional reporter assay |
Oncogene |
High |
16924231
|
| 2006 |
hnRNP-U enhances expression of specific genes including TNF-α, GADD45A, HEXIM1, HOXA2, IER3, NHLH2, and ZFY by binding to and stabilizing their mRNAs (particularly via 3' UTR binding), increasing mRNA half-life. |
mRNA stability assays, RNA immunoprecipitation, overexpression/knockdown experiments |
FEBS letters |
Medium |
17174306
|
| 2008 |
SAF-A binds the 3'-flanking region of the Bmal1 promoter with circadian timing (in vivo footprinting), correlating with Bmal1 expression; this binding is required for circadian transcriptional regulation of Bmal1. |
In vivo footprinting, chromatin immunoprecipitation, reporter gene assay |
Molecular and cellular biology |
Medium |
18332112
|
| 2009 |
hnRNP-U/SAF-A is phosphorylated at Ser59 specifically by DNA-PK in vitro and in cells in response to DNA double-strand breaks; this was identified using a cell-free system and confirmed in cells with DSB-inducing agents. |
Cell-free kinase assay, mass spectrometry mapping, western blotting with phospho-specific antibody, DNA damage induction |
Biochemical and biophysical research communications |
High |
19351595
|
| 2009 |
SAF-A Ser59 phosphorylation by DNA-PK in response to DSB inducers is exclusively dependent on DNA-PK and inversely correlates with the cell's capacity to repair DSBs by nonhomologous end joining (NHEJ); cells deficient in NHEJ show prolonged phosphorylation. |
Phospho-specific antibody, DNA-PK inhibitor, NHEJ-deficient cell lines, kinase mapping |
Cell cycle |
High |
19844162
|
| 2010 |
B23/NPM1, upon transcription repression-induced nucleolar segregation, translocates to the cytoplasm and forms a sequential complex with hnRNPU and hnRNPA1; this complex is regulated by RNA Polymerase I inhibition (not Pol II) and by hnRNPU-bound mRNAs (3'-UTR of Bcl-xL); disruption of the complex by ectopic Bcl-xL 3'-UTR enhances apoptosis, suggesting the complex promotes cell survival. |
Co-immunoprecipitation, subcellular fractionation, RNA immunoprecipitation, ectopic RNA overexpression, apoptosis assays |
Oncogene |
Medium |
20101230
|
| 2010 |
SAF-A/Saf-A is recruited to the inactive X chromosome (Xi) by Xist RNA at the developmental transition to Xi maintenance, concomitantly with Ash2l and macroH2A; a mutant Xist that does not repress genes still recruits SAF-A, indicating recruitment is separable from gene silencing. |
Immunofluorescence, RNA FISH, genetic analysis with mutant Xist in ES cell differentiation |
Development |
High |
20150277
|
| 2011 |
SAF-A regulates kinetochore-microtubule attachment and spindle organization during mitosis; it localizes to spindles, spindle midzone, and cytoplasmic bridge; co-immunoprecipitates with nucleolin, Aurora-A, and TPX2; SAF-A can bind microtubules directly and contributes to targeting Aurora-A to mitotic spindle MTs; depletion causes mitotic delay, chromosome misalignment, and spindle assembly defects. |
RNAi depletion, immunofluorescence, co-immunoprecipitation, microtubule binding assay, live-cell imaging |
Journal of cell science |
High |
21242313
|
| 2011 |
Endogenous SAF-A interacts with the C-terminal domain (CTD) of RNA Polymerase II independently of CTD phosphorylation and mRNA; SAF-A also exists in complexes with Sox2, Oct4, and STAT3 in ES cells; SAF-A binds the Oct4 proximal promoter and its depletion reduces Oct4 expression. |
Co-immunoprecipitation of endogenous proteins, ChIP, RNA interference, reporter assays |
Cellular reprogramming |
Medium |
21235343
|
| 2011 |
SAF-A interacts with BRG1 (ATPase motor of the SWI/SNF chromatin remodeling complex) in mouse ES cells; interaction is RNA-independent and persists upon differentiation; dual depletion of SAF-A and BRG1 abolishes global RNA Pol II transcription while leaving RNA Pol I transcription unaffected. |
Co-immunoprecipitation, co-localization, proximity ligation assay, RNA interference, transcription assay |
PloS one |
Medium |
22162999
|
| 2012 |
hnRNP U regulates U2 snRNP maturation and Cajal body morphology; genome-wide CLIP-seq shows hnRNP U binds virtually all classes of regulatory noncoding RNAs including all snRNAs required for splicing; hnRNP U loss globally alters alternative splicing through modulation of core splicing machinery. |
RNAi screen, CLIP-seq, RNA-seq, nuclear fractionation, Cajal body imaging |
Molecular cell |
High |
22325991
|
| 2012 |
hnRNPUL proteins 1 and 2 (hnRNPU-like, not hnRNPU itself) bind the DSB sensor complex MRN (MRE11-RAD50-NBS1) and are recruited to DNA damage in an MRN-dependent, interdependent manner to stimulate DNA-end resection and promote BLM helicase recruitment; this is noted as a related but distinct protein family. |
Co-immunoprecipitation, laser micro-irradiation, RNAi depletion, DNA repair assays |
Molecular cell |
Medium |
22365830
|
| 2012 |
hnRNP-U directly interacts with NEIL1 DNA glycosylase via NEIL1's C-terminal domain; hnRNP-U stimulates NEIL1 base excision activity for 5-hydroxyuracil primarily by enhancing product release; the interacting regions in hnRNP-U map to both N and C termini (Kd ~54 nM); depletion of hnRNP-U epistatically sensitizes cells to low-level oxidative damage together with NEIL1 depletion. |
Co-immunoprecipitation, in vitro BER assay, domain mapping pulldown, circular dichroism, PONDR prediction, genetic epistasis (siRNA) |
The Journal of biological chemistry |
High |
22902625
|
| 2014 |
SAF-A exhibits biphasic dynamics at DNA damage sites: rapid recruitment dependent on poly(ADP-ribose) binding, followed by prolonged exclusion dependent on ATM, ATR, and DNA-PK activity; the RNA-binding domain recapitulates this behavior; SAF-A exclusion is coupled to R-loop removal at transcribed damage sites, forming part of an anti-R-loop mechanism. |
Laser micro-irradiation, live-cell imaging, PARP inhibitors, ATM/ATR/DNA-PK inhibitors, R-loop reporter, domain deletion mutants |
Nucleic acids research |
High |
25030905
|
| 2015 |
SAF-A Ser59 is phosphorylated in mitosis by PLK1 (not DNA-PKcs); SAF-A interacts with PLK1 in nocodazole-treated cells; Ser59 is dephosphorylated by PP2A in mitosis; cells expressing S59A SAF-A show misaligned chromosomes, lagging chromosomes, polylobed nuclei, and delayed mitotic exit. |
Phospho-specific antibody, kinase inhibitors, PLK1 knockdown, co-immunoprecipitation, site-directed mutagenesis (S59A), live-cell imaging, PP2A inhibitor |
Molecular and cellular biology |
High |
25986610
|
| 2016 |
SAF-A, phosphorylated at Ser59 by DNA-PK early after ionizing radiation, promotes transient release of chromatin-bound NEIL1, preventing premature BER at DSB sites; dephosphorylated (but not phosphomimetic S59D) SAF-A relieves Ku inhibition of DNA glycosylases in vitro, coordinating temporal repair order. |
In vitro DNA glycosylase assay, Ku inhibition assay, phosphomimetic mutants, cell irradiation, chromatin fractionation |
Oncotarget |
High |
27303920
|
| 2017 |
SAF-A/hnRNPU interacts with chromatin-associated RNAs (caRNAs) via its RGG domain to regulate interphase chromatin structure; SAF-A's AAA+ ATPase domain mediates cycles of protein oligomerization with caRNAs in response to ATP binding and hydrolysis; SAF-A oligomerization decompacts large-scale chromatin structure, while monomerization or loss causes aberrant chromosome folding and genome damage accumulation. |
RGG domain mutants, ATPase mutants, Hi-C, FRAP, ATPase assay, DNA damage assays, oligomerization assays |
Cell |
High |
28622508
|
| 2017 |
HNRNPU depletion in mouse hepatocytes increases lamina-associated domain (LAD) coverage, causes global chromatin condensation, compartment switching on 7.5% of genome, decreased TAD boundary strengths at A/B compartment borders, and reduced chromatin loop intensities; HNRNPU mainly associates with active chromatin and 80% of peaks coincide with CTCF or RAD21 binding. |
In situ Hi-C, DamID, ChIP-seq, RNA-seq, conditional knockout in hepatocytes |
Genome research |
High |
29273625
|
| 2018 |
HPSE eRNA binds hnRNPU to facilitate its interaction with p300 acetyltransferase and their co-enrichment on a super enhancer, driving chromatin looping between super enhancer and HPSE promoter and p300-mediated transactivation of EGR1. |
RNA immunoprecipitation, co-immunoprecipitation, ChIP-seq, chromatin conformation capture, gain/loss-of-function |
Oncogene |
Medium |
29511351
|
| 2020 |
hnRNPU retains miR-30c-5p and other microRNAs in the nucleus, preventing their export into large extracellular vesicles; nuclear binding of miR-30c-5p to hnRNPU stabilizes miRNAs and reduces cytoplasmic availability; binding confirmed by RNA-immunoprecipitation, EMSA, and miR-pulldown; a sequence motif AAMRUGCU was identified as a potential sorting signal. |
RNA immunoprecipitation, EMSA, miRNA pulldown, gain/loss-of-function, Taqman array, nanoparticle tracking analysis |
Journal of extracellular vesicles |
Medium |
32944175
|
| 2020 |
HNF4A-AS1 lncRNA binds hnRNPU and facilitates its interaction with CTCF, resulting in CTCF transactivation and transcriptional alteration of HNF4A and glycolysis genes; a small peptide blocking HNF4A-AS1-hnRNPU interaction suppresses this axis. |
RNA immunoprecipitation, co-immunoprecipitation, luciferase reporter, peptide competition, lentiviral shRNA |
Journal of hematology & oncology |
Medium |
32216806
|
| 2020 |
Cytoplasmic hnRNPU directly binds the 3'-UTR of IL-6 mRNA to regulate mRNA stability; this cytoplasmic interaction was identified by optimized HITS-CLIP and validated, revealing a nucleocytoplasmic shuttling function of hnRNPU in mRNA stability control. |
HITS-CLIP (optimized BrdU-CLIP), subcellular fractionation, RNA immunoprecipitation |
PloS one |
Medium |
32302342
|
| 2020 |
Hepatocyte-specific inactivation of hnRNPU disrupts liver chromatin accessibility, activates molecular signature of NASH, and sensitizes mice to diet-induced NASH; mechanistically, hnRNPU deficiency stimulates expression of a truncated TrkB isoform (TRKB-T1) promoting inflammatory signaling and stress-induced cell death. |
Hepatocyte-specific conditional KO, RNA-seq, ChIP-seq, BDNF treatment rescue, NASH dietary model |
Hepatology |
High |
31469911
|
| 2021 |
hnRNPU interacts with WT1 and SOX9 in Sertoli cells and enhances transcription of Sox8 and Sox9 by directly binding their promoter regions (ChIP-qPCR); conditional KO of hnRNPU in Sertoli cells causes testicular atrophy, depletion of Sertoli and germ cells, and male sterility. |
Conditional KO (Cre/loxP), ChIP-qPCR, co-immunoprecipitation, luciferase assay, RNA-seq |
Theranostics |
High |
34815802
|
| 2021 |
SAF-A mutants (but not RNAi depletion) cause dramatic chromatin condensation through dominant negative effects on C0T-1 RNA (repeat-rich heterogeneous nuclear RNA) association with euchromatin; results support a model where SAF-A, chromatin-associated RNAs, and other RNA-binding proteins form a complex dynamic meshwork integral to large-scale chromatin architecture. |
SAF-A domain mutant expression, RNA FISH (C0T-1 RNA), RNAi, chromatin condensation imaging (DAPI) |
Mammalian genome |
Medium |
34859278
|
| 2022 |
SAF-A promotes origin licensing in G1 phase, maintains replication fork progression, and maintains boundaries between early- and late-replicating domains; SAF-A depletion reduces origin activation frequency, increases γ-H2AX, and causes cells to enter quiescence. |
SAF-A depletion (siRNA), DNA fiber assay, single-cell replication timing analysis, γ-H2AX immunofluorescence, flow cytometry |
Journal of cell science |
High |
34888666
|
| 2022 |
CDC20-mediated ubiquitination of hnRNPU promotes its interaction with the CTCF-cohesin complex, modulating chromatin condensation; CDC20 binds hnRNPU through amino acid residues 461-653; loss of this axis contributes to tumor progression and drug resistance. |
Affinity purification-mass spectrometry, co-immunoprecipitation, domain mapping, ubiquitination assay, DAPI/H2B-mCherry chromatin condensation imaging |
Cancers |
Medium |
35954396
|
| 2022 |
HNRNPU loss of function in the developing cortex leads to rapid cell death of both postmitotic neurons and neural progenitors (higher sensitivity in progenitors); alternative splicing and expression of genes involved in cell survival, motility, and synapse formation are dysregulated; pharmacological and genetic agents can partially reverse cortical structural defects. |
Conditional truncation mouse model, immunofluorescence, RNA-seq, alternative splicing analysis, pharmacological rescue |
Nature communications |
High |
35864088
|
| 2022 |
HNRNPU promotes C-NHEJ-mediated switch region joining through the 53BP1-shieldin DNA repair complex, binds S-region RNA/DNA G-quadruplexes to regulate R-loop and ssDNA accumulation; HNRNPU is an intrinsically disordered protein that interacts with both C-NHEJ and R-loop complexes in an RNA-dependent manner; recruitment of HNRNPU and C-NHEJ factors is sensitive to liquid-liquid phase separation inhibitors suggesting condensate formation. |
Co-immunoprecipitation, S-S joining assay, G-quadruplex binding assay, R-loop detection (DRIP), phase separation inhibitors, HNRNPU KO |
Cell reports |
High |
36943867
|
| 2022 |
HNRNPU promotes triple-negative breast cancer progression via association with DDX5; the HNRNPU-DDX5 complex prevents intron retention of MCM10 pre-mRNA (reducing nonsense-mediated decay and activating Wnt/β-catenin) and promotes LMO4 transcription at transcription start sites (activating PI3K-Akt-mTOR signaling). |
Co-immunoprecipitation, RNA-seq, splicing analysis, ChIP, KD/OE experiments |
Cell death & disease |
Medium |
36347834
|
| 2022 |
Muscle-specific Hnrnpu KO mice develop adult-onset myopathy with selective atrophy of glycolytic muscle, constitutive Akt activation, and altered expression and splicing of metabolic and signal transduction genes; loss of hnRNPU also causes NF-κB activation and Ly6C+ monocyte infiltration preceding muscle atrophy. |
Muscle-specific conditional KO, RNA-seq, splicing analysis, histology, signaling assays, immune cell flow cytometry |
iScience |
High |
32659719 38797891
|
| 2023 |
SAF-A/hnRNPU binds polyphosphoinositides (PPIn) directly via a lysine-rich polybasic motif (aa 9-24) in the N-terminal SAP domain; deletion of this polybasic region abolishes PPIn interaction while retaining protein structure. |
Quantitative interactomics, PPIn-protein binding assay, deletion mutagenesis |
microPublication biology |
Medium |
37038481
|
| 2022 |
lncRHL binds directly to hnRNPU, enhancing its protein stability; hnRNPU then transcriptionally activates Bmal1, leading to inhibition of VLDL secretion in hepatocytes; lncRHL deficiency accelerates hnRNPU protein degradation and suppresses Bmal1 transcription. |
RNA immunoprecipitation, co-immunoprecipitation, protein stability assay, ChIP, gene manipulation in mice and hepatocytes |
Diabetes |
Medium |
35771993
|
| 2025 |
The SAF-A SAP domain (and its serines S14 and S26) is required for XIST RNA localization on the inactive X chromosome, XIST-dependent histone modifications on Xi, normal protein dynamics (FRAP), and cell proliferation; the SAP domain provides a distinct Xi localization signal; SAF-A is a highly dynamic protein interacting with nascent transcripts rather than being part of a static nuclear scaffold. |
Allelic reconstitution, FRAP, immunofluorescence, RNA FISH, phosphomimetic/phospho-null SAP domain mutants, cell proliferation assays |
PLoS genetics |
High |
40493679
|
| 2025 |
The SAF-A ATPase domain and RGG repeats control SAF-A nuclear dynamics; RGG repeats mediate interaction with nascent transcripts; both domains are required for maintaining XIST RNA and facultative heterochromatin marks on Xi, for proper mRNA splicing, and for cell proliferation; ATP binding and hydrolysis have distinct effects on Xi maintenance. |
Allelic reconstitution, FRAP, transcriptome analysis, RNA FISH, chromatin immunoprecipitation, cell proliferation assays, ATP binding/hydrolysis mutants |
bioRxivpreprint |
High |
41473319
|
| 2025 |
α-Satellite RNAs bind SAF-A and are required for recruitment of SAF-A back to chromatin upon mitotic exit; depletion of either α-satellite RNA or SAF-A causes chromosome missegregation; SAF-A is excluded from chromatin genome-wide during mitosis and both α-satellite RNAs and SAF-A are essential for nuclear lamina reassembly. |
RNA depletion (siRNA), immunofluorescence, RNA FISH, chromatin fractionation, RNA immunoprecipitation, chromosome segregation assay |
Nucleic acids research |
High |
40219970
|
| 2025 |
HNRNPU associates with the mammalian SWI/SNF chromatin-remodeling complex (including SMARCA4 and SMARCC2), has a previously unrecognized role in translation, associates with mRNAs encoding neurodevelopmental proteins, and HNRNPU silencing reprograms methylation at active and bivalent promoters of neurodevelopmental transcription factors. |
Protein-protein interaction mapping, RNA target identification (RIP/CLIP), genome-wide DNA methylation profiling (EPIC arrays), protein co-immunoprecipitation in neural stem cells |
Nucleic acids research |
Medium |
41674383
|
| 2025 |
HNRNPU is required for long-range Polycomb recruitment by lncRNAs Airn, Kcnq1ot1, and Xist; HNRNPU exhibited enriched and correlated association with all three lncRNAs, and was required for PRC-directed histone modifications induced by all three, without being necessary for proper localization of Airn or Kcnq1ot1. |
RNA immunoprecipitation from formaldehyde-crosslinked cells (27 antibodies), HNRNPU KO, ChIP for PRC modifications, RNA FISH |
bioRxivpreprint |
Medium |
40791421
|
| 2024 |
hnRNPU is essential for establishing the spermatogonial stem cell (SSC) pool; conditional loss in prospermatogonia arrests differentiation and migration to the basement membrane; hnRNPU binds Vrk1, Slx4, and Dazl transcripts that undergo aberrant alternative splicing upon hnRNPU depletion. |
Conditional KO (Cre/loxP), single-cell RNA-seq, RNA immunoprecipitation, splicing analysis |
Cell reports |
High |
38625792
|