| 2018 |
HELLS and CDCA7 form a stoichiometric bipartite nucleosome remodeling complex on chromatin. HELLS alone fails to remodel nucleosomes, but the HELLS-CDCA7 complex possesses nucleosome remodeling activity. CDCA7 is essential for loading HELLS onto chromatin, and ICF patient mutations in CDCA7 fail to recruit the complex to chromatin. Complex formation is sensitive to Aurora B kinase. |
Xenopus egg extract chromatin proteomics, reconstitution of nucleosome remodeling activity in vitro, chromatin fractionation, ICF mutant analysis |
Proceedings of the National Academy of Sciences of the United States of America |
High |
29339483
|
| 2018 |
CDCA7 and HELLS interact with C-NHEJ proteins Ku80 and Ku70 (co-immunoprecipitation). CDCA7- and HELLS-deficient cells show compromised classical non-homologous end joining activity and significant delay in Ku80 accumulation at DNA damage sites, leading to increased apoptosis, abnormal chromosome segregation, aneuploidy, centrosome amplification, and γH2AX accumulation. |
Co-immunoprecipitation, CRISPR/siRNA knockdown in HEK293 cells, live-cell imaging of Ku80 recruitment, γH2AX immunofluorescence, chromosomal break repair assay |
The Journal of clinical investigation |
High |
30307408
|
| 2020 |
HELLS promotes homologous recombination repair of two-ended DSBs by facilitating end-resection; HELLS interacts with CtIP and promotes CtIP accumulation at IR-induced foci. The ATPase domain of HELLS is required for this DSB repair function. HELLS also contributes to DSB repair within heterochromatic regions during G2. |
Co-immunoprecipitation (HELLS-CtIP interaction), siRNA knockdown, immunofluorescence for IR-induced foci, ATPase domain mutant analysis, cell-cycle staged assays |
Nucleic acids research |
High |
31802118
|
| 2020 |
HELLS is recruited to meiotic recombination hot spots by PRDM9 and forms a pioneer complex with PRDM9. HELLS is necessary for histone modifications and DNA accessibility at hot spots. In male mice lacking HELLS, DSBs are retargeted to other open chromatin sites, leading to germ cell death and sterility. |
Mouse knockout, ChIP-seq, ATAC-seq, DSB mapping, immunofluorescence |
Genes & development |
High |
32001511
|
| 2020 |
HELLS is required for PRDM9 binding and DSB activity at PRDM9-specified meiotic hot spots (but not at PRDM9-independent sites). HELLS is identified as a PRDM9 interacting partner by proteomics. HELLS is also essential for 5-hydroxymethylcytosine (5hmC) enrichment at PRDM9 sites, which is triggered upon PRDM9 binding and histone modification independently of DSB activity. |
Proteomic identification of PRDM9 partners, mouse knockout, ChIP-seq, 5hmC mapping, DSB activity assays |
eLife |
High |
33047671
|
| 2025 |
Cryo-EM structure of human HELLS reveals it assembles into a hexameric (trimer-of-dimers) architecture in its apo (autoinhibited) state, stabilized by interactions between the N-terminal coiled-coil (CC) domain and ATPase Lobe-1, with ATPase Lobe-2 remaining flexible and disengaged. The CC domain functions as both an oligomerization scaffold and an autoinhibitory module. Binding of CDCA7 and DNA promotes formation of an active HELLS-CDCA7-DNA ternary complex, with CDCA7 stimulating HELLS ATPase activity by recognizing hemimethylated CpG dinucleotides. |
Cryo-EM structure determination, biochemical ATPase assays, biophysical binding assays |
Nucleic acids research |
High |
41954988
|
| 2023 |
The zf-4CXXC_R1 domain of CDCA7 selectively binds hemimethylated CpG DNA (not unmethylated or fully methylated CpG) and recruits HELLS to hemimethylated DNA via N-terminal alpha-helix interactions. Cryo-EM of the CDCA7-nucleosome complex shows zf-4CXXC_R1 recognizes hemimethylated CpG in the major groove at linker DNA. ICF disease mutations in the zinc finger domain eliminate hemimethylated DNA binding and HELLS recruitment. |
Cryo-EM, in vitro DNA binding assays, mutagenesis of ICF mutations, reconstitution of HELLS-CDCA7 complex |
bioRxivpreprint |
High |
38187757
|
| 2024 |
The central region of CDCA7 is critical for binding to HELLS, activation of HELLS ATPase activity, and nucleosome sliding activity. The N-terminal region of CDCA7 tends to inhibit ATPase activity. The C-terminal 4CXXC-type zinc finger domain of CDCA7 confers preference for hemimethylated CpG DNA in HELLS-CDCA7 ATPase activity. CDCA7 shows binding preference for hemimethylated CpG DNA and recruits HELLS to hemimethylated replication sites at pericentromeric heterochromatin in mouse ES cells; ICF syndrome zinc finger mutations abolish these activities. |
In vitro ATPase assays with CDCA7 domain mutants, nucleosome sliding assay, DNA binding assays, immunofluorescence in mouse ES cells |
Nucleic acids research |
High |
39142653
|
| 2004 |
Disruption of PASG/HELLS (SNF2-like factor) causes global DNA hypomethylation, developmental growth retardation, and premature aging phenotype in mice. PASG mutant fibroblasts show replicative senescence with increased p16(INK4a) expression associated with down-regulation of bmi-1. PASG is essential for maintaining DNA methylation and gene expression patterns required for normal growth and longevity. |
Mouse knockout (PASG/LSH null), bisulfite sequencing for DNA methylation, qRT-PCR, primary fibroblast senescence assays |
Genes & development |
High |
15105378
|
| 2011 |
HELLS interacts with E2F3A in vivo and cooperates with its oncogenic functions. Depletion of HELLS perturbs induction of E2F-target genes and hinders cell-cycle re-entry and growth. ChIP-seq identifies HELLS binding at promoters of active genes including MLL1, co-regulating E2F3-dependent genes. |
Mass spectrometry identification of E2F3B partners, co-immunoprecipitation, ChIP-seq, siRNA knockdown, cell cycle analysis |
The EMBO journal |
High |
22157815
|
| 2020 |
HELLS-CDCA7 complex is required for accumulation of maintenance DNA methylation machinery (DNMT1/UHRF1) on nascent DNA. CDCA7/HELLS-deficient cells show increased transcription and aberrant DNA:RNA hybrid (R-loop) formation at pericentromeric repeats. Ectopic RNASEH1 expression reduced DNA damage accumulation in ICF mutant cells, indicating the CDCA7/HELLS complex suppresses R-loop-associated DNA damage at pericentromeric repeats. |
Nascent DNA proteomics (iPOND-like), R-loop detection, RNASEH1 rescue experiment, bisulfite sequencing |
Scientific reports |
Medium |
33082427
|
| 2015 |
ATPase-deficient HELLS is retained at the nuclear matrix compartment (defined in part by lamin B1) and shows stronger association with heterochromatin. Wild-type HELLS is highly dynamic at heterochromatic sites (FRAP t1/2 = 0.8s, 61% mobile fraction), while ATPase-deficient HELLS shows reduced dynamics (t1/2 = 4.5s, 30% mobile). ATPase activity is not required for recruitment to heterochromatin but is important for release from these sites. H3K9me3 signaling contributes to efficient release of HELLS from pericentromeric chromatin. |
Chromatin fractionation, FRAP (fluorescence recovery after photobleaching), immunofluorescence microscopy, ATPase domain mutagenesis |
Journal of molecular biology |
High |
25823553
|
| 2021 |
TET proteins interact with HELLS/LSH in vivo and in vitro. Knockout of Lsh in mouse embryonic fibroblasts and embryonic stem cells leads to significant reduction in 5-hydroxymethylcytosine (5hmC) genome-wide. Changes in 5hmC distribution in Lsh knockout cells do not completely overlap with differentially methylated regions, suggesting HELLS regulation of 5hmC is not solely a consequence of 5mC decrease. |
Co-immunoprecipitation (TET-HELLS), Lsh knockout mouse cells, whole-genome 5hmC sequencing (oxBS-seq), bisulfite sequencing |
Epigenetics |
Medium |
33960278
|
| 2011 |
HELLS is essential for meiotic progression in male mice. In the absence of HELLS, spermatogonial proliferation is reduced and germ cell differentiation arrests at the midpachytene stage, with increased abnormal chromosome synapsis, indicating an essential role for HELLS during male meiosis. |
Testis tissue allografting from Hells-/- mice to immunodeficient hosts, BrdU incorporation, cytological analysis of meiotic configurations |
Biology of reproduction |
Medium |
21349825
|
| 2020 |
LSH/HELLS is enriched at meiotic kinetochores and its deletion causes centromere instability, abnormal chromosome segregation, ectopic kinetochore formation, and centromere fusions in oocyte meiosis. LSH knockout oocytes show increased histone H3 phosphorylation at threonine 3 (H3T3ph) and accumulation of major satellite transcripts. LSH knockout reduces HDAC2 and DNMT1 at kinetochores. |
Conditional oocyte-specific Lsh knockout, super-resolution microscopy, immunofluorescence, chromosome spreads |
Nature communications |
High |
32900989
|
| 2020 |
HELLS is required for B cell development and immunoglobulin class switch recombination (CSR). Lsh-deficient B cells proliferate normally but show impaired canonical end-joining (C-NHEJ) during CSR, as demonstrated by digestion-circularization PCR and high-throughput sequencing of CSR junctions. The initiation of recombination (germline transcripts, AID-induced DSBs) is unaffected by Lsh loss. |
Conditional Lsh knockout mouse (Mx1-Cre, Vav-Cre), bone marrow transplantation, B cell in vitro stimulation, End-seq, biotin-labeling DSB assay, digestion-circularization PCR, high-throughput CSR junction sequencing |
Proceedings of the National Academy of Sciences of the United States of America |
High |
32727902
|
| 2019 |
HELLS overexpression in hepatocellular carcinoma increases nucleosome occupancy, obstructs enhancer accessibility, and hinders formation of nucleosome-free regions at transcription start sites, leading to epigenetic silencing of multiple tumor suppressor genes including E-cadherin, FBP1, IGFBP3, XAF1 and CREB3L3. HELLS upregulation in HCC is mediated by hyperactivation of transcription factor SP1. |
CRISPR activation, lentiviral shRNA, CRISPR/Cas9 knockout, RNA-seq, micrococcal nuclease sequencing (MNase-seq), ChIP, in vivo xenograft models |
Hepatology (Baltimore, Md.) |
High |
30516846
|
| 2000 |
HELLS/PASG encodes a SNF2 family chromatin remodeling ATPase whose nuclear localization depends on a nuclear localization sequence in the N-terminal region. Expression is associated with cell proliferation. An in-frame 75-nucleotide deletion found in AML/ALL removes a conserved motif critical for transactivation activity of a related yeast SWI/SNF polypeptide. |
cDNA sequence analysis, expression studies, nuclear localization sequence mapping by deletion analysis |
Cancer research |
Medium |
10910076
|
| 2017 |
Lsh/HELLS ablation in neural stem/progenitor cells (NSPCs) reduces growth, increases apoptosis, and impairs self-renewal. Lsh deletion alters epigenetic states (assessed by ChIP) at specific enhancer regions of Cdkn1a (p21) and Bmp4, and alters their expression. |
Lsh-/- conditional neural stem cell model, RNA-seq, ChIP at enhancer regions, proliferation and apoptosis assays |
Scientific reports |
Medium |
28442710
|
| 2019 |
HELLS interacts with the core oncogenic transcription factors E2F3 and MYC in glioblastoma stem cells (GSCs) to regulate gene expression critical to GSC proliferation and maintenance. Targeting HELLS disrupts GSC proliferation, survival, and self-renewal with induction of replication stress and DNA damage. |
Co-immunoprecipitation (HELLS with E2F3 and MYC), siRNA/shRNA knockdown, proliferation/sphere formation assays, in vivo tumor-bearing mouse model |
JCI insight |
Medium |
30779712
|
| 2021 |
HELLS, together with transcription factor YY1, regulates cytokinesis in ALK- ALCL cells by transcriptional activation of cytoskeleton genes including RhoA, RhoU, and Pak2. HELLS binds target promoters and primes YY1 recruitment and transcriptional activation. RhoA and RhoU mediate HELLS effects on cell proliferation and division. |
RNA-seq, ChIP, bioinformatic prediction, siRNA knockdown of HELLS/YY1/RhoA/RhoU/Pak2, cell proliferation/division assays |
Cell death & disease |
Medium |
33504766
|
| 2024 |
HELLS reduces the persistence of co-transcriptional R-loops and promotes RNA Polymerase II (RNAPII) progression along gene bodies in ALCL cells, loading at intronic regions of target gene promoters. HELLS knockdown sensitizes ALCL cells to chemotherapeutic agents. |
Multi-omics (ChIP-seq, DRIP-seq for R-loops, RNA-seq), RNAPII ChIP-seq, HELLS siRNA knockdown, drug sensitivity assays |
Nucleic acids research |
Medium |
38597676
|
| 2017 |
The S. cerevisiae HELLS homolog Irc5 interacts with the cohesin complex subunit Scc1 and contributes to cohesin binding to chromatin. Loss of IRC5 decreases cohesin levels at centromeres and chromosome arms, causing premature sister chromatid separation. Irc5 translocase activity is required for its function in cohesion. Irc5 loss also reduces chromatin-bound Scc2 (cohesin loader) levels and the Scc1-Scc2 physical interaction. |
Co-immunoprecipitation (Irc5-Scc1), ChIP (cohesin at centromeres/arms), chromosome segregation assays, ATPase mutant analysis, rDNA repeat stability |
Nucleic acids research |
Medium |
28383696
|
| 2025 |
HELLS loss impairs single-strand break (SSB) repair and selectively sensitizes cells to DNA alkylating agents and PARP inhibitors. HELLS shows non-epistatic interactions with PARP1 and functionally compensates for PARP1 deficiency in promoting cell survival in response to DNA alkylation damage. HELLS loss is synthetic lethal with homologous recombination deficiency. |
HELLS knockout/knockdown, SSB repair assays, drug sensitivity assays (alkylating agents, PARPi), epistasis analysis with PARP1 |
Nucleic acids research |
Medium |
41297801
|
| 2023 |
HELLS is required for germinal center (GC) B cell maintenance and generation of high-affinity memory B cells. B-cell-specific Hells knockout leads to dramatic DNA hypomethylation and de-repression of retrotransposons in GC B cells, and premature upregulation of memory B cell or plasma cell markers. DNMT1-specific inhibition phenocopies accelerated GC decay, indicating that DNA-methylation maintenance by HELLS is the key mechanism fine-tuning the GC transcriptional program. |
B-cell-specific conditional Hells knockout, DNMT1 inhibitor treatment, bisulfite sequencing, RNA-seq, retrotransposon analysis |
Nature communications |
High |
37709749
|
| 2025 |
HELLS directly regulates MIEF1 (Mitochondrial elongation factor 1) transcription in liver cancer. HELLS knockdown causes mitochondrial hyperfusion, energy deprivation, and cellular senescence. HELLS knockdown globally increases H3K9me3 with upregulation of SUV39H1 and augmented DNA methylation. The HELLS-MIEF1 axis links nuclear chromatin remodeling to mitochondrial dynamics. |
HELLS loss/gain experiments, MIEF1 ChIP, RNA-seq, mitochondrial morphology/function assays, H3K9me3 ChIP, siRNA epistasis |
Cell death & disease |
Medium |
40175344
|
| 2025 |
HELLS knockdown in HELLS-deficient cells leads to loss of tumor capabilities in osteoclast differentiation context. HELLS directly represses Nr2f2 transcription (demonstrated by ChIP-qPCR and FAIRE-qPCR showing HELLS binding and chromatin accessibility changes at Nr2f2 promoter). Nr2f2 suppression by HELLS maintains mitochondrial quality through coordinated regulation of biogenesis and mitophagy during osteoclast differentiation. |
RNA-seq, ChIP-qPCR, FAIRE-qPCR, siRNA knockdown of Hells and Nr2f2, Nr2f2 inhibitor rescue, mitochondrial function assays |
Cell communication and signaling |
Medium |
41947194
|
| 2025 |
HELLS binds and resolves G-quadruplex (G4) DNA structures in vitro and in chromatin. HELLS-G4 interaction modulates gene expression. Identified as a G4-binding protein via photoclick chemistry-based proteomics using G4 DNA probes from human telomeric sequences. |
Photoclick chemistry-LC-MS/MS proteomics, fluorescence anisotropy, FRET-based G4 unwinding assay, immunofluorescence microscopy, ChIP-seq |
Nucleic acids research |
Medium |
41569154
|
| 2025 |
USP1 interacts with and stabilizes HELLS through deubiquitination, preventing ubiquitin-mediated degradation. USP1 also promotes HELLS SUMOylation by stabilizing the E3 SUMO ligase PIAS1 through deubiquitination. The USP1/PIAS1/HELLS axis drives EMT and homologous recombination repair in HCC cells. |
Co-immunoprecipitation (USP1-HELLS), ubiquitination/SUMOylation assays, functional assays in HCC cells, in vivo xenograft, USP1 inhibitor (ML323) treatment |
Oncogenesis |
Medium |
41430042
|
| 2025 |
HELLS knockout in human pluripotent stem cells induces a global loss of DNA methylation that is most prominent over peri/centromeric satellite repeats (as defined by the telomere-to-telomere genome assembly), but HELLS appears dispensable for local enhancer remodeling and differentiation into the three embryonic germ layers. |
HELLS and DNMT3A/B knockout in human pluripotent stem cells, whole-genome bisulfite sequencing, ATAC-seq, differentiation assays |
Genome biology |
High |
40676590
|
| 2025 |
HELLS alone assembles into a hexameric (trimer-of-dimers) autoinhibited state in its apo form (cryo-EM structure), with the N-terminal coiled-coil (CC) domain stabilizing interactions with ATPase Lobe-1 while Lobe-2 is disengaged. CDCA7 binding and DNA (particularly hemimethylated CpG) promote formation of an active ternary complex and stimulate HELLS ATPase activity. |
Cryo-EM, ATPase assays, biophysical binding assays (preprint version) |
bioRxivpreprint |
Medium |
41669160
|
| 2025 |
ZBTB24, CDCA7 and HELLS function as negative regulators of 2C-like reprogramming in mouse ESCs by maintaining DNA methylation of the Dux cluster. Disruption of HELLS results in Dux hypomethylation and derepression, leading to upregulation of 2C-specific genes. Site-specific re-methylation at the Dux promoter reverses this phenotype. CDCA7 is enriched at the Dux cluster and recruits the CDCA7-HELLS complex to constitutive heterochromatin. |
CRISPR knockout of ZBTB24/CDCA7/HELLS in mESCs, bisulfite sequencing, ChIP, dCas9-based targeted methylation rescue, single-cell RNA-seq |
Nucleic acids research |
High |
40226918
|