Affinage

DHX33

ATP-dependent RNA helicase DHX33 · UniProt Q9H6R0

Length
707 aa
Mass
78.9 kDa
Annotated
2026-06-09
27 papers in source corpus 18 papers cited in narrative 18 extracted findings
Cross-family judge vs UniProt: Affinage preferred faithfulness: 6/6 claims corpus-supported (100%)

Mechanistic narrative

Synthesis pass · prose summary of the discoveries below

DHX33 is a DEAH-box helicase with intrinsic ATP-dependent RNA and DNA duplex-unwinding activity that operates as a multifunctional driver of ribosome biogenesis, transcription, and innate immune sensing, with its ATPase-coupled helicase activity essential across these roles (PMID:29870660, PMID:21930779). In the nucleolus it is a cell cycle-regulated activator of RNA Pol I transcription, associating with rDNA loci and the transcription factor UBF to drive 47S rRNA synthesis; its loss triggers a nucleolar p53 stress response and arrests proliferation (PMID:21930779), a requirement made physiologically concrete in activated B cells where Dhx33 is indispensable for activation-induced rDNA transcription, germinal center reactions, and antibody production (PMID:36631557). Beyond rRNA, DHX33 binds gene promoters at CG-rich regions and recruits a GADD45a/AP-2β complex together with TET1 to drive local DNA demethylation and transcriptional activation of cell cycle, glycolytic (Warburg), HMGB, and other target genes, thereby controlling RNA Pol II loading (PMID:27601587, PMID:32312884, PMID:32617965). DHX33 also promotes cap- and structure-dependent mRNA translation initiation, associating with ribosomal proteins, translation factors, and mRNAs, with a cytoplasmic short isoform partnering DDX3, eIF3, hnRNPs, and PABP (PMID:26100019, PMID:30684270). In the cytoplasm DHX33 functions as a dsRNA sensor that binds dsRNA through its HELICc domain and either nucleates the NLRP3 inflammasome through direct NLRP3 interaction in macrophages or engages IPS-1/MAVS to drive type I IFN in dendritic cells (PMID:23871209, PMID:24037184). DHX33 sits at an oncogenic nexus: it is a c-Myc transcriptional target and a translationally controlled effector of oncogenic Ras via the PI3K/mTOR/MAPK axis (PMID:28498893, PMID:23401854), and its abundance is set post-translationally by GSK-3β phosphorylation at T482 promoting K48-ubiquitination/degradation and by USP36-mediated deubiquitination promoting stability (PMID:36403931, PMID:29273634).

Mechanistic history

Synthesis pass · year-by-year structured walk · 12 steps
  1. 2011 High

    Established DHX33's first defined cellular role by showing it is a nucleolar, cell cycle-regulated activator of Pol I-driven rRNA synthesis rather than an uncharacterized helicase.

    Evidence RNAi, ChIP at rDNA, Co-IP with UBF, dominant-negative NTPase mutant, and rRNA synthesis/proliferation assays in primary fibroblasts

    PMID:21930779

    Open questions at the time
    • Did not resolve how DHX33 is recruited to rDNA versus other genomic loci
    • Catalytic activity was inferred from mutants, not measured directly
  2. 2013 High

    Revealed an unexpected cytoplasmic innate-immune function, defining DHX33 as a dsRNA sensor that bifurcates into inflammasome and IFN signaling depending on cell type.

    Evidence shRNA knockdown, reciprocal Co-IP and domain mapping (HELICc for dsRNA/partner binding) with NLRP3 in macrophages and IPS-1/MAVS in dendritic cells; caspase-1, cytokine, and type I IFN readouts

    PMID:23871209 PMID:24037184

    Open questions at the time
    • How a single helicase chooses between NLRP3 and MAVS pathways is unresolved
    • Relationship between nuclear and cytoplasmic pools not addressed
  3. 2013 High

    Connected DHX33 to oncogenic signaling by showing its expression is gated at translation downstream of Ras through PI3K/mTOR/MAPK, making it a required effector of Ras transformation.

    Evidence Polysome fractionation, pharmacological epistasis (PI3K/mTOR/MAPK inhibitors), shRNA, and in vitro/in vivo transformation assays

    PMID:23401854

    Open questions at the time
    • The specific cis-elements directing translational control of DHX33 mRNA were not mapped
  4. 2015 High

    Expanded DHX33's function from rRNA synthesis to global mRNA translation initiation, showing it resolves structured mRNAs to permit polysome assembly.

    Evidence RNA-IP, MS interactome, polysome profiling and sucrose gradients with helicase-dead rescue

    PMID:26100019

    Open questions at the time
    • Which step of initiation DHX33 acts at mechanistically was not defined beyond 80S accumulation
  5. 2016 High

    Demonstrated DHX33 acts as a direct transcriptional regulator of cell cycle genes via promoter binding and Pol II loading, linking it to proliferation and DNA replication in vivo.

    Evidence ChIP for promoter association and Pol II loading, shRNA phenotyping, and CRISPR knockout in zebrafish

    PMID:27601587

    Open questions at the time
    • How DHX33 is targeted to specific gene promoters was not yet known
  6. 2017 High

    Placed DHX33 in the c-Myc oncogenic circuit and identified pro-invasive transcriptional targets, while a separate study defined USP36 as the deubiquitinase stabilizing DHX33.

    Evidence ChIP for c-Myc→DHX33 and DHX33→MMP9/MMP14/PLAU promoters with tumor assays; Usp36-knockout mouse, ubiquitination/rRNA/protein-synthesis readouts with DHX33-KD phenocopy

    PMID:28498893 PMID:29273634

    Open questions at the time
    • The E3 ligase opposing USP36 was not identified in this work
    • Direct DHX33–USP36 binding interface not mapped
  7. 2018 High

    Provided direct biochemical proof that DHX33 is a bona fide ATP-dependent RNA/DNA helicase and characterized isoform generation by leaky scanning.

    Evidence In vitro ATPase and unwinding assays with purified recombinant protein and ATP-binding/RKK-motif mutants; AUG-codon mutagenesis defining two equally translated isoforms

    PMID:29864424 PMID:29870660

    Open questions at the time
    • No structural model of the helicase or duplex-engagement mechanism
    • Physiological substrate specificity in cells not resolved by in vitro assays
  8. 2019 Medium

    Defined a cytoplasmic short isoform (DHX33-2) with a distinct translation-promoting interactome, distinguishing it from the predominantly nuclear full-length protein.

    Evidence Protein-IP, RIP with RNA-seq, subcellular fractionation and translation assays identifying DDX3/eIF3/hnRNP/PABP partners

    PMID:30684270

    Open questions at the time
    • Functional non-redundancy between isoforms not established by genetic separation
    • Single lab, no reciprocal validation of all partners
  9. 2020 High

    Uncovered the mechanism by which DHX33 activates target genes—recruiting a GADD45a/AP-2β/TET1 demethylation machinery to CG-rich promoters—and applied it to glycolytic gene control underlying the Warburg effect.

    Evidence ChIP, Co-IP of DHX33–GADD45a–AP-2β/TET1, 5-hmC and histone acetylation measurements, RNA-seq and glycolysis assays with knockdown

    PMID:32312884 PMID:32617965

    Open questions at the time
    • The proposed R-loop guidance signal for promoter targeting was not directly demonstrated
    • Whether helicase activity is required for demethylation recruitment not isolated
  10. 2023 High

    Demonstrated a genetic in vivo requirement for Dhx33 in B-cell rRNA upregulation and immunity, and extended the demethylation-driven transcriptional program to HMGB and mevalonate-pathway genes downstream of Ras and mutant p53.

    Evidence B-cell conditional knockout mouse with rRNA/p53/differentiation readouts; ChIP/methylation assays and p53-mutant/KrasG12D mouse epistasis

    PMID:36631557 PMID:37543097 PMID:38143011

    Open questions at the time
    • Mechanism coupling oncogenic genotype to DHX33 target selection not defined
    • HMGB/mevalonate links are Medium-confidence single-lab studies
  11. 2022 Medium

    Established post-translational control of DHX33 abundance through GSK-3β phosphorylation at T482 driving K48-ubiquitination, explaining elevated DHX33 stability in cancers with GSK-3β inactivation.

    Evidence In vitro kinase assay, T482/K94 mutagenesis, ubiquitination and protein-stability assays in cancer cells and fibroblasts

    PMID:36403931

    Open questions at the time
    • The responsible E3 ligase was not identified
    • Single lab; in vivo relevance of the T482 phospho-degron not tested
  12. 2024 Low

    Linked DHX33 to lipid metabolism and ferroptosis sensitivity and provided a candidate small-molecule helicase inhibitor.

    Evidence KY386 inhibitor treatment, FADS1/FADS2/SCD1 expression and ferroptosis/viability assays in vitro and in vivo

    PMID:38973855

    Open questions at the time
    • Indirect mechanistic link; inhibitor specificity for DHX33 not rigorously established
    • Single lab, no genetic confirmation of the ferroptosis axis

Open questions

Synthesis pass · forward-looking unresolved questions
  • How DHX33 partitions between its nuclear (rDNA/promoter), translational, and cytoplasmic immune-sensing functions, and what determines its promoter and substrate selectivity, remains unresolved.
  • No structure of DHX33 or its complexes
  • Signals controlling subcellular partitioning of isoforms unknown
  • Rules for promoter/mRNA target selection undefined

Mechanism profile

Synthesis pass · controlled-vocabulary classification · explore literature graph →
Molecular activity
GO:0003723 RNA binding 4 GO:0140110 transcription regulator activity 4 GO:0003677 DNA binding 3 GO:0140098 catalytic activity, acting on RNA 2 GO:0140299 molecular sensor activity 2 GO:0140657 ATP-dependent activity 2 GO:0016787 hydrolase activity 1 GO:0045182 translation regulator activity 1 GO:0140097 catalytic activity, acting on DNA 1
Localization
GO:0005634 nucleus 3 GO:0005829 cytosol 3 GO:0005730 nucleolus 2
Pathway
R-HSA-74160 Gene expression (Transcription) 4 R-HSA-1430728 Metabolism 3 R-HSA-1643685 Disease 3 R-HSA-168256 Immune System 3 R-HSA-4839726 Chromatin organization 2 R-HSA-8953854 Metabolism of RNA 2 R-HSA-1640170 Cell Cycle 1 R-HSA-392499 Metabolism of proteins 1
Partners
DDX3XGADD45AMAVSNLRP3TET1TFAP2BUBFUSP36
Complex memberships
NLRP3 inflammasome

Evidence

Reading pass · 18 per-paper findings extracted from the source corpus
Year Finding Method Journal Conf PMIDs
2011 DHX33 is a cell cycle-regulated nucleolar protein that associates with ribosomal DNA (rDNA) loci and interacts with the RNA Pol I transcription factor UBF. DHX33 knockdown decreased the association of Pol I with rDNA and caused a dramatic decrease in 47S rRNA synthesis. A DNA binding-defective mutant could not enhance rRNA synthesis, and an NTPase-defective mutant (K94R) acted as a dominant negative, inhibiting endogenous rRNA synthesis. DHX33 deficiency in primary human fibroblasts triggered a nucleolar p53 stress response and attenuated proliferation. Lentiviral RNAi screen, ChIP assay (rDNA association), Co-IP (UBF interaction), dominant-negative mutagenesis, rRNA synthesis assay, cell proliferation assay Molecular and cellular biology High 21930779
2013 DHX33 is a cytosolic RNA sensor that activates the NLRP3 inflammasome. DHX33 binds dsRNA via its helicase C domain, interacts with NLRP3, and forms the inflammasome complex following RNA stimulation. shRNA knockdown of DHX33 blocked caspase-1 activation and IL-18/IL-1β secretion in human macrophages stimulated with poly I:C, reoviral RNA, or bacterial RNA. shRNA knockdown, Co-IP (DHX33-NLRP3 interaction), domain mapping (helicase C domain for dsRNA binding), caspase-1 activation assay, cytokine secretion assay Immunity High 23871209
2013 DHX33 acts as a novel dsRNA sensor in myeloid dendritic cells (mDCs). The HELICc domain of DHX33 binds poly I:C. DHX33 interacts with IPS-1/MAVS via its HELICc region and the C-terminal domain of IPS-1, independently of RIG-I/MDA5. DHX33 knockdown blocked poly I:C- and reovirus-induced type I IFN production and activation of MAP kinases, NF-κB, and IRF3 in mDCs. shRNA knockdown, domain mapping (HELICc binding to poly I:C and IPS-1 C-terminus), Co-IP (DHX33–IPS-1 interaction), type I IFN production assay, MAP kinase/NF-κB/IRF3 activation assays Cellular & molecular immunology High 24037184
2013 DHX33 expression is exclusively controlled at the level of translation. ARF dramatically reduced polysome-associated DHX33 mRNAs, while RasV12 shifted DHX33 mRNAs to actively translating polysomes. RasV12-driven DHX33 translation was sensitive to PI3K, mTOR, and MAPK inhibitors. DHX33 knockdown abolished RasV12-induced rRNA transcription and protein translation and prevented in vitro and in vivo transforming properties of oncogenic Ras. Polysome fractionation, rRNA synthesis assay, pharmacological inhibition (PI3K, mTOR, MAPK), shRNA knockdown, in vitro/in vivo transformation assays Molecular and cellular biology High 23401854
2015 DHX33 promotes mRNA translation initiation. DHX33 associates with ribosomal proteins, translation factors, and mRNAs in intact complexes. DHX33 reduction markedly reduced polyribosome formation and caused global inhibition of mRNA translation, rescued by wild-type but not helicase-defective DHX33. DHX33 loss caused accumulation of mRNA in 80S ribosome complexes, consistent with a stalling at initiation. DHX33 more preferentially promoted structured mRNA translation. RNA immunoprecipitation, mass spectrometry (interactome), polysome profiling, sucrose gradient sedimentation, helicase-dead mutant rescue experiment Molecular and cellular biology High 26100019
2016 DHX33 transcriptionally controls cell cycle genes (cyclins, E2F1, CDC, MCM genes) by physically associating with their promoters and controlling loading of active RNA polymerase II. DHX33 deficiency abrogated cell cycle progression and DNA replication and led to apoptosis. CRISPR-mediated knockout of DHX33 in zebrafish downregulated cyclin A2, cyclin B2, cyclin D1, cyclin E2, cdc6, cdc20, E2F1, and MCM complexes. ChIP assay (promoter association, RNA Pol II loading), shRNA knockdown (cell cycle, DNA replication, apoptosis readouts), CRISPR/Cas9 knockout in zebrafish Molecular and cellular biology High 27601587
2017 c-Myc binds to the DHX33 upstream promoter region and stimulates its transcription, placing DHX33 as a critical downstream target of c-Myc. DHX33 promotes MMP9, MMP14, and PLAU transcription by directly binding to their promoters. Knockdown of DHX33 in c-Myc overexpressing cells significantly reduced cell proliferation, migration, anchorage-independent growth, and inhibited Myc-induced acute myeloid leukemia development. ChIP assay (c-Myc binding to DHX33 promoter; DHX33 binding to MMP9/MMP14/PLAU promoters), shRNA knockdown, in vitro/in vivo tumor assays Carcinogenesis Medium 28498893
2017 USP36 deubiquitinase reduces ubiquitination levels of DHX33 and increases its stability. Loss of USP36 destabilizes DHX33, leading to defects in ribosomal RNA synthesis and protein translation. USP36 knockout in mice causes preimplantation lethality (morula-to-blastocyst block), and shRNA reduction of DHX33 phenocopies USP36 loss in inducing apoptosis and cell cycle arrest. Usp36-knockout mouse model, O-propargyl-puromycin incorporation (protein synthesis), Northern blot (rRNA), ubiquitination assay, shRNA knockdown The Journal of biological chemistry High 29273634
2018 Purified recombinant DHX33 protein possesses both RNA and DNA duplex unwinding (helicase) activity with an ATPase activity dependent on nucleic acid duplexes. ATPase activity is coupled to unwinding activity. Mutation of the key ATP-binding residue abolished DNA/RNA unwinding. Deletion of the RKK motif (involved in rDNA binding) reduced but did not abolish DNA unwinding. In vitro biochemical assay with purified recombinant protein: ATPase assay, helicase/unwinding assay, site-directed mutagenesis (ATP-binding site, RKK motif deletion) Biochemistry High 29870660
2018 DHX33 produces two protein isoforms from two in-frame start codons via leaky scanning during mRNA translation. Both isoforms are translated at equal efficiency. The shorter isoform has similar cellular localization and functions to the full-length protein. Site-directed mutagenesis of AUG codons, expression in cell lines and mouse models, subcellular fractionation/localization assay Biochemical and biophysical research communications Medium 29864424
2019 A 54-kDa short DHX33 variant (DHX33-2, comprising the C-terminal helicase domain) preferentially localizes to the cytoplasm (unlike full-length DHX33-1 which is predominantly nuclear). DHX33-2 interacts with DDX3, eIF3, hnRNPs, and poly(A) binding protein, and binds a subset of mRNAs important in cell proliferation, stimulating their translation. Protein immunoprecipitation, RNA immunoprecipitation, RNA-seq, subcellular fractionation, translation assays Journal of cellular physiology Medium 30684270
2020 DHX33 associates with gene promoters at CG-rich regions and recruits GADD45a (growth arrest and DNA damage protein 45a) together with AP-2β. DHX33 is required for GADD45a-mediated recruitment of TET methylcytosine dioxygenase (Tet1) to gene promoters, causing local DNA demethylation (reduced 5-hydroxymethylcytosine levels) and thereby activating transcription of a subset of genes. R-loop formation at GC-skew regions may serve as a guidance signal. ChIP assay (DHX33 promoter binding), Co-IP (DHX33–GADD45a–AP-2β interaction), 5-hmC measurement (DNA demethylation), shRNA knockdown, RNA Pol II loading assay Molecular and cellular biology High 32312884
2020 DHX33 plays a critical role in the Warburg effect by transcriptionally controlling glycolytic genes (LDHA, PDK1, PKM2, ENO1, ENO2, HK1/2). DHX33 forms a complex with GADD45a and recruits it along with TET1 to glycolytic gene promoters, causing active DNA demethylation and enhanced histone H4 acetylation to promote their transcription. RNA-seq (transcriptome analysis), glycolysis activity assay, ChIP assay (promoter binding), Co-IP (DHX33–GADD45a–TET1 complex), DNA methylation/histone acetylation assays Journal of cellular physiology High 32617965
2022 GSK-3β directly phosphorylates DHX33 at T482, triggering K48-linked ubiquitination-mediated proteasomal degradation of DHX33. K94 on the N-terminal region was identified as a major ubiquitination site. Cancer cells with frequent GSK-3β deactivation have elevated DHX33 stability as a result. In vitro kinase assay (GSK-3β phosphorylation of DHX33), site-directed mutagenesis (T482, K94), ubiquitination assay, protein stability assay in cancer cell lines and normal fibroblasts Cellular signalling Medium 36403931
2023 Dhx33 plays an indispensable role in activation-induced upregulation of rDNA transcription in B cells. B-cell-specific deletion of Dhx33 impaired B-cell development, germinal center reactions, plasma cell differentiation, and antibody production. In the absence of Dhx33, activated B cells failed to upregulate 47S rRNA production and ribosome biogenesis, resulting in nucleolar stress, p53 accumulation, and cell death. CRISPR/Cas9-mediated functional analysis, conditional (B-cell-specific) knockout mouse model, rRNA synthesis assay, p53 immunoblot, flow cytometry (B-cell development/differentiation) Cellular & molecular immunology High 36631557
2023 DHX33 binds to the promoters of HMGB family genes and regulates their transcription through promoter DNA demethylation in cancer cells. In RAS-driven lung tumorigenesis, DHX33 knockout debilitated RAS-induced nuclear HMGB overexpression. ChIP assay (DHX33 binding to HMGB promoters), DNA methylation assay, shRNA/KO in cancer cells and in vivo lung tumor model Cellular signalling Medium 37543097
2023 DHX33 mediates p53-null/mutant-driven upregulation of mevalonate pathway gene transcription. In p53 mutant/KrasG12D mice, DHX33 loss significantly debilitated upregulation of mevalonate pathway genes. DHX33 knockdown in human cancer cells inhibited mevalonate pathway gene transcription, placing DHX33 downstream of mutant p53 and Ras in this metabolic pathway. shRNA knockdown in cancer cells, genetic mouse model (p53 mutant + KrasG12D with DHX33 loss), RNA expression analysis Biochimica et biophysica acta. General subjects Medium 38143011
2024 DHX33 promotes expression of lipid metabolism genes FADS1, FADS2, and SCD1, thereby sensitizing cancer cells to ferroptosis-mediated cell death. A DHX33 helicase inhibitor (KY386) kills cancer cells via the ferroptosis pathway. Small molecule inhibitor (KY386) treatment, gene expression analysis (FADS1/FADS2/SCD1), ferroptosis pathway assays, cell viability assays in vitro and in vivo ACS omega Low 38973855

Source papers

Stage 0 corpus · 27 papers · ranked by NIH iCite citations
Year Title Journal Citations PMID
2013 The DHX33 RNA helicase senses cytosolic RNA and activates the NLRP3 inflammasome. Immunity 174 23871209
2011 Identification of DHX33 as a mediator of rRNA synthesis and cell growth. Molecular and cellular biology 55 21930779
2013 The interaction between the helicase DHX33 and IPS-1 as a novel pathway to sense double-stranded RNA and RNA viruses in myeloid dendritic cells. Cellular & molecular immunology 49 24037184
2017 Loss of the deubiquitinase USP36 destabilizes the RNA helicase DHX33 and causes preimplantation lethality in mice. The Journal of biological chemistry 38 29273634
2016 miR-634 exhibits anti-tumor activities toward hepatocellular carcinoma via Rab1A and DHX33. Molecular oncology 35 27693040
2015 The DHX33 RNA Helicase Promotes mRNA Translation Initiation. Molecular and cellular biology 30 26100019
2017 Role of DHX33 in c-Myc-induced cancers. Carcinogenesis 29 28498893
2018 The RNA helicase DHX33 is required for cancer cell proliferation in human glioblastoma and confers resistance to PI3K/mTOR inhibition. Cellular signalling 24 30552990
2016 DHX33 Transcriptionally Controls Genes Involved in the Cell Cycle. Molecular and cellular biology 24 27601587
2013 P19ARF and RasV¹² offer opposing regulation of DHX33 translation to dictate tumor cell fate. Molecular and cellular biology 24 23401854
2020 DHX33 promotes colon cancer development downstream of Wnt signaling. Gene 18 32004669
2021 Long non-coding RNA HOTAIR promotes hepatocellular carcinoma progression by regulating miR-526b-3p/DHX33 axis. Genes & genomics 17 33843021
2020 Circular RNA DHX33 promotes malignant behavior in ccRCC by targeting miR-489-3p/MEK1 axis. Aging 17 32717723
2020 Function of DHX33 in promoting Warburg effect via regulation of glycolytic genes. Journal of cellular physiology 16 32617965
2020 Targeting RNA helicase DHX33 blocks Ras-driven lung tumorigenesis in vivo. Cancer science 13 32767810
2023 Dhx33 promotes B-cell growth and proliferation by controlling activation-induced rRNA upregulation. Cellular & molecular immunology 12 36631557
2020 DHX33 Recruits Gadd45a To Cause DNA Demethylation and Regulates a Subset of Gene Transcription. Molecular and cellular biology 10 32312884
2018 Recombinant DHX33 Protein Possesses Dual DNA/RNA Helicase Activity. Biochemistry 8 29870660
2013 RNA helicase DHX33 puts a new twist on NLRP3 inflammasome activation. Immunity 7 23890068
2022 GSK-3β phosphorylation of DHX33 leads to its ubiquitination mediated protein degradation. Cellular signalling 4 36403931
2023 Development of small molecule inhibitors targeting RNA helicase DHX33 as anti-cancer agents. Bioorganic & medicinal chemistry letters 3 37838340
2023 DHX33 mediates p53 to regulate mevalonate pathway gene transcription in human cancers. Biochimica et biophysica acta. General subjects 2 38143011
2018 Alternative translation initiation from two in-frame start codons in DHX33 gene. Biochemical and biophysical research communications 2 29864424
2023 RNA helicase DHX33 regulates HMGB family genes in human cancer cells. Cellular signalling 1 37543097
2019 A 54-kDa short variant of DHX33 functions in regulating mRNA translation. Journal of cellular physiology 1 30684270
2026 DHX33 inhibitors induced transcriptional changes for a subset of genes in cancer cells. Scientific reports 0 42243442
2024 An RNA Helicase DHX33 Inhibitor Shows Broad Anticancer Activity via Inducing Ferroptosis in Cancer Cells. ACS omega 0 38973855

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