Affinage

PSMD9

26S proteasome non-ATPase regulatory subunit 9 · UniProt O00233

Length
223 aa
Mass
24.7 kDa
Annotated
2026-06-10
50 papers in source corpus 23 papers cited in narrative 24 extracted findings
Cross-family judge vs UniProt: Affinage preferred faithfulness: 6/7 claims corpus-supported (86%)

Mechanistic narrative

Synthesis pass · prose summary of the discoveries below

PSMD9 is a proteasome-associated protein that operates at the interface of proteasome assembly and proteostatic signaling, with the yeast ortholog Rpn4 defining a homeostatic feedback circuit and the human protein acting as a PDZ/coiled-coil adaptor that nucleates client-protein interaction networks (PMID:9653651, PMID:11248031, PMID:24720748). Human PSMD9 (p27) was first identified as a subunit of a modulator complex that promotes assembly of the 26S proteasome by stimulating association of the PA700 regulator with the 20S core (PMID:9653651). In yeast, Rpn4 is a short-lived transcriptional activator that binds the PACE element in proteasome gene promoters through direct DNA contacts and is itself degraded by the assembled proteasome, establishing a negative feedback loop that tunes proteasome abundance (PMID:11248031, PMID:11443924, PMID:21954596); this Rpn4-dependent induction sets normal proteasome levels and, when proteasome activity is impaired, drives compensatory upregulation (PMID:15358214, PMID:18832351). Rpn4 turnover proceeds through two independent degradation signals — a ubiquitin-independent route and a ubiquitin-dependent route in which the Ubr2 E3 ligase, Rad6 E2 enzyme, and the MYND-domain cofactor Mub1 ubiquitylate a portable degron centered on Lys-187, enhanced by phosphorylation of Ser-220 in an N-terminal acidic domain (PMID:15090546, PMID:15504724, PMID:16492666, PMID:17532487, PMID:18070918). Rapid Rpn4 degradation is itself essential under genotoxic and proteotoxic stress, where unrestrained target-gene expression is detrimental, and Rpn4 cooperates with the unfolded protein response to clear mislocalized cytosolic proteins (PMID:19933873, PMID:30865586). In human cells, PSMD9 uses its PDZ domain to recognize C-terminal short linear motifs of clients including hnRNPA1, an interaction required for IκBα degradation and NF-κB activation (PMID:24720748, PMID:25009770, PMID:31287951), and uses an N-terminal coiled-coil domain to bind EXKK-motif clients such as hnRNPA2B1, PRDX6, BIP/GRP78, FASN, and DNAJA1, supporting ER-stress/UPR control, lipid droplet and aggresome formation, and mitochondrial regulation (PMID:37665644, PMID:40412052). PSMD9 additionally maintains nucleolar integrity through ribosomal protein interactions (PMID:34077860) and stabilizes EGFR by interacting with the E3 ligase c-Cbl to suppress EGFR ubiquitination and sustain ERK/Akt signaling in hepatocellular carcinoma (PMID:38745188).

Mechanistic history

Synthesis pass · year-by-year structured walk · 16 steps
  1. 1998 Medium

    Established human PSMD9 as a proteasome-associated factor, placing it physically within the 26S proteasome assembly machinery rather than as a free cytosolic protein.

    Evidence cDNA cloning and immunoblot of the p27 modulator subunit co-fractionating with PA700 and 26S proteasome

    PMID:9653651

    Open questions at the time
    • Does not define the molecular activity of p27 within the modulator
    • No structural basis for how it stimulates PA700–20S association
  2. 2001 High

    Defined the yeast ortholog Rpn4 as a short-lived transcriptional activator degraded by the proteasome and binding the proteasomal PACE promoter element, articulating the negative feedback model of proteasome homeostasis.

    Evidence Genetic deletion, protein stability assays, Rpn4–Rpn2 interaction, gel retardation, affinity purification and reporter assays in yeast

    PMID:11248031 PMID:11443924

    Open questions at the time
    • Mapping of the degron only localized to the N-terminal region at this stage
    • Did not identify the E2/E3 machinery
  3. 2004 High

    Resolved the degradation logic of Rpn4 into two independent degrons and identified the Ubr2/Rad6 ubiquitylation machinery, while genetically confirming the feedback circuit controls proteasome levels.

    Evidence In vivo/in vitro degradation and ubiquitylation assays, lysine mutagenesis, genetic deletion and stable-mutant epistasis in yeast

    PMID:15090546 PMID:15358214 PMID:15504724

    Open questions at the time
    • Ubiquitin-independent degron mechanism not defined
    • Additional cofactors of the Ubr2/Rad6 pathway unknown at this point
  4. 2006 High

    Pinpointed Lys-187 plus a proximal acidic domain as a portable degradation signal, defining the molecular determinants of ubiquitin-targeted Rpn4 turnover.

    Evidence Site-directed lysine mutagenesis with in vivo and in vitro ubiquitylation assays

    PMID:16492666

    Open questions at the time
    • Does not address how lysine selection is regulated
    • Structural basis of degron recognition not resolved
  5. 2007 High

    Showed that Ser-220 phosphorylation and the cofactor Mub1 are required for efficient Ubr2-mediated ubiquitylation, completing the reconstituted enzymology of the ubiquitin-dependent pathway.

    Evidence Phosphosite mutagenesis, genome-wide deletion screen, in vitro reconstitution with Ubr2/Rad6/Mub1, binding assays in yeast

    PMID:17532487 PMID:18070918

    Open questions at the time
    • Identity of the Rpn4 kinase not established
    • How phosphorylation and Mub1 cooperate mechanistically unresolved
  6. 2008 High

    Demonstrated physiological consequence: loss of Rpn4-driven proteasome gene expression lowers proteasome activity and causes cell-cycle and stress phenotypes, validating the regulon's importance.

    Evidence PACE-site promoter mutagenesis, proteasome activity assays, cell-cycle and stress sensitivity analysis in yeast

    PMID:18832351

    Open questions at the time
    • Does not isolate which target genes drive each phenotype
  7. 2009 High

    Showed that rapid Rpn4 degradation is itself essential under stress, establishing why the feedback loop must be transient rather than constitutive.

    Evidence Degron-defective stabilized Rpn4 mutant combined with transcription-dead point mutation, viability and epistasis assays in yeast

    PMID:19933873

    Open questions at the time
    • Which overexpressed targets cause toxicity not pinned down
  8. 2010 Medium

    Connected Rpn4 and the proteasome to DNA double-strand break repair, broadening its role beyond proteasome subunit supply to genome maintenance.

    Evidence Yeast genetics, ChIP of Yku70 and Rpn4/proteasome at DSBs, NHEJ assays

    PMID:20376190

    Open questions at the time
    • Direct versus indirect role of proteasome at DSBs unresolved
    • Single-lab observation
  9. 2011 Medium

    Confirmed Rpn4 reaches proteasomal promoters through direct DNA binding rather than protein bridging, settling the recruitment mechanism.

    Evidence Dam methylase footprinting in vivo in yeast

    PMID:21954596

    Open questions at the time
    • Single method, single lab
    • Does not address co-activator requirements
  10. 2014 High

    Defined human PSMD9 as a PDZ-domain adaptor that recognizes C-terminal motifs of clients and links hnRNPA1 to IκBα degradation and NF-κB activation, and showed the yeast degron functions across species.

    Evidence Reciprocal co-IP, PDZ/C-terminal mutagenesis, NF-κB reporter and siRNA in HEK293; peptide screening and recombinant binding; cross-species reporter degron assay

    PMID:24720748 PMID:25009770 PMID:25157437

    Open questions at the time
    • Whether PSMD9 adaptor function is proteasome-coupled in each case unclear
    • In vivo relevance of the broad client list not all established
  11. 2015 Medium

    Mapped a minimal PACE-core hexamer and extended the Rpn4 regulon to proteasome assembly chaperone genes, refining the transcriptional logic of the feedback circuit.

    Evidence Promoter deletion/mutation and reporter assays in yeast

    PMID:25747386

    Open questions at the time
    • Single method type
    • Does not quantify regulon-wide occupancy
  12. 2019 High

    Showed Rpn4 is induced both post-transcriptionally and transcriptionally during ER stress and cooperates with the UPR, and refined the PSMD9 PDZ specificity into a druggable inhibitor of NF-κB signaling.

    Evidence Titratable ER stress system, genetic screen and UPR epistasis in yeast; peptide affinity assays, MD simulations and NF-κB inhibitor validation

    PMID:30865586 PMID:31287951

    Open questions at the time
    • Signaling pathways triggering RPN4 induction only partially defined
    • Human relevance of the yeast ER-stress circuit not tested
  13. 2021 Medium

    Revealed a nucleolar maintenance role for human PSMD9, linking it to ribosomal protein localization and p53 stability.

    Evidence PSMD9 KO in MCF7 cells, NPM1 immunofluorescence, EM, ribosomal protein pulldown, Actinomycin D treatment

    PMID:34077860

    Open questions at the time
    • Mechanism linking PSMD9 to ribosomal protein trafficking unresolved
    • Whether proteasome activity is required is not addressed
  14. 2023 Medium

    Identified an EXKK short linear motif recognized by the PSMD9 coiled-coil domain, defining a second client-recognition surface that controls UPR, lipid droplet, and aggresome biology.

    Evidence AP-MS, in vitro peptide/protein binding, PSMD9 KO and rescue with UPR and lipid droplet assays in HEK293

    PMID:37665644

    Open questions at the time
    • How EXKK binding mechanistically alters client fate unclear
    • Single-lab interaction set
  15. 2024 Medium

    Connected PSMD9 to receptor tyrosine kinase signaling by showing it binds c-Cbl, suppresses EGFR ubiquitination, and sustains ERK/Akt in hepatocellular carcinoma.

    Evidence Co-IP, EGFR ubiquitination assay, confocal trafficking imaging, siRNA knockdown, in vitro and in vivo tumor models

    PMID:38745188

    Open questions at the time
    • Whether the effect requires PSMD9's proteasomal role not separated
    • Direct structural basis of PSMD9–c-Cbl binding undefined
  16. 2025 Medium

    Extended the EXKK interaction network to the mitochondrial chaperone DNAJA1, linking PSMD9 client binding to chaperone stability and mitochondrial membrane potential.

    Evidence In vitro binding with purified proteins, DNAJA1 motif mutagenesis, co-IP from MCF7, mitochondrial membrane potential assay

    PMID:40412052

    Open questions at the time
    • How PSMD9 binding stabilizes DNAJA1 mechanistically unresolved
    • Physiological consequence of altered membrane potential not defined

Open questions

Synthesis pass · forward-looking unresolved questions
  • It remains unresolved how the conserved proteasome-assembly/feedback function of PSMD9/Rpn4 mechanistically integrates with the human PSMD9 adaptor activities (PDZ and EXKK client networks) across NF-κB, EGFR, nucleolar, UPR, and mitochondrial pathways.
  • No structure of human PSMD9 bound to a proteasome subunit
  • Whether human PSMD9 retains a transcriptional/feedback role like yeast Rpn4 is untested
  • Whether the diverse human client interactions are proteasome-dependent is unknown

Mechanism profile

Synthesis pass · controlled-vocabulary classification · explore literature graph →
Molecular activity
GO:0060090 molecular adaptor activity 3 GO:0140110 transcription regulator activity 3 GO:0003677 DNA binding 2 GO:0098772 molecular function regulator activity 2
Localization
GO:0005634 nucleus 3 GO:0005829 cytosol 2 GO:0005730 nucleolus 1
Pathway
R-HSA-392499 Metabolism of proteins 4 R-HSA-74160 Gene expression (Transcription) 3 R-HSA-162582 Signal Transduction 2 R-HSA-8953897 Cellular responses to stimuli 2
Partners
CBLDNAJA1HNRNPA1MUB1PRDX6RAD6RPN2UBR2
Complex memberships
26S proteasome / PA700 modulator complex

Evidence

Reading pass · 24 per-paper findings extracted from the source corpus
Year Finding Method Journal Conf PMIDs
1998 Human PSMD9 (p27) was identified as a subunit of the modulator trimer complex that stimulates association of the PA700 regulator with the 20S proteasome to form the active 26S proteasome. Immunoblot analysis showed p27 is associated with both the modulator complex and the 26S proteasome complex. cDNA cloning, immunoblot analysis with anti-p27 antibody, biochemical fractionation Genomics Medium 9653651
2001 Yeast Rpn4 (ortholog of PSMD9) is an extremely short-lived transcriptional activator (t1/2 ~2 min) that directly interacts with RPN2 (a 26S proteasome subunit) and is degraded by the assembled active proteasome, establishing a negative feedback circuit controlling proteasome homeostasis. Genetic deletion, protein stability assays, direct interaction assay (RPN4-RPN2 co-interaction), cell-cycle analysis Proceedings of the National Academy of Sciences of the United States of America High 11248031
2001 The degradation signal (degron) of yeast Rpn4 was mapped to its N-terminal region, outside the transcription-activation domains. Domain mapping by deletion analysis Proceedings of the National Academy of Sciences of the United States of America Medium 11248031
2001 Yeast Rpn4 binds the PACE element (5'-GGTGGCAAA-3') found in promoters of proteasomal genes and acts as a transcriptional activator; the protein was purified by affinity chromatography and confirmed by microsequencing. Gel retardation assay, affinity chromatography purification, microsequencing, reporter gene assay Molekuliarnaia biologiia High 11443924
2004 Proteasomal degradation of yeast Rpn4 is mediated by two independent degradation signals: one leading to ubiquitylation on internal lysine(s), and one that is ubiquitin-independent. Both degrons must be inactivated to stabilize Rpn4. In vivo and in vitro degradation assays, mutagenesis of lysine residues The Journal of biological chemistry High 15090546
2004 Ubr2 (E3 ubiquitin ligase) and Rad6 (E2 ubiquitin-conjugating enzyme) mediate ubiquitin-dependent degradation of yeast Rpn4. Rpn4 was demonstrated to be a physiological substrate of Ubr2 through in vivo and in vitro assays. Rad6 directly interacts with Ubr2 and is required for this pathway. In vivo and in vitro ubiquitylation assays, genetic deletion analysis, synthetic growth defect assay The Journal of biological chemistry High 15504724
2004 Rpn4-induced proteasome expression is required for normal proteasome levels in yeast; when proteasome activity is impaired, proteasome expression increases in an Rpn4-dependent manner. A stable form of Rpn4 elevates proteasome expression, confirming the feedback model. Genetic epistasis, stable Rpn4 mutant expression, proteasome activity assays Biochemical and biophysical research communications High 15358214
2006 Lysine 187 of yeast Rpn4 is the preferred ubiquitination site chosen from multiple susceptible lysines; lysine 187 together with a proximal acidic domain constitutes a portable degradation signal. In vivo and in vitro ubiquitylation assays, site-directed mutagenesis of lysine residues The Journal of biological chemistry High 16492666
2007 Phosphorylation of Ser-220 (and to a lesser extent Ser-214) in the N-terminal acidic domain (NAD, aa 211-229) of yeast Rpn4 enhances binding to Ubr2 and is required for efficient ubiquitylation and degradation. The phosphorylation-dependent ubiquitylation signal (NAD) is not the major Ubr2-binding site but is essential for degradation. Phosphorylation site mutagenesis, in vivo and in vitro ubiquitylation assays, binding assays Biochimica et biophysica acta High 17532487
2007 Mub1 (a MYND-domain protein) is an essential cofactor for Rpn4 ubiquitylation: it directly interacts with both Ubr2 and Rpn4, and in vitro reconstitution of Rpn4 ubiquitylation requires Mub1 in addition to Ubr2 and Rad6. Mub1 is itself a short-lived substrate of the Ubr2/Rad6 ligase. Genome-wide deletion screen, in vitro reconstitution ubiquitylation assay, co-immunoprecipitation/direct interaction assays Molecular and cellular biology High 18070918
2008 Loss of Rpn4-induced proteasome expression (via disruption of Rpn4-binding site in PRE1 promoter) lowers active proteasome levels, causes G2/M cell-cycle delay, and sensitizes cells to various stresses. Promoter mutagenesis (PACE site disruption), proteasome activity assay, cell-cycle analysis, stress sensitivity assays Genetics High 18832351
2009 Proteasomal degradation of Rpn4 is critical for cell survival under stress: a stabilized Rpn4 mutant retaining transcriptional activity severely reduces viability under genotoxic and proteotoxic stress, an effect abolished by a mutation abrogating transcriptional activity, indicating that overexpression of Rpn4 target genes is detrimental under stress. Stabilized Rpn4 mutant (degron-defective), transcription-activity point mutation, viability assays, genetic epistasis with proteasome mutations Genetics High 19933873
2010 Inhibition of Rpn4 proteasomal degradation impairs nonhomologous end-joining (NHEJ) repair of DNA double-strand breaks; NHEJ gene expression is downregulated, Yku70 recruitment to DSBs is reduced, and Rpn4 and the proteasome are recruited to DSB sites. Yeast genetics, chromatin immunoprecipitation (Yku70 and Rpn4/proteasome recruitment to DSB), NHEJ assay, synthetic growth defect with checkpoint mutants PloS one Medium 20376190
2011 Dam methylase-based mapping showed that yeast Rpn4 is recruited to proteasomal gene promoters only through direct DNA interactions (not via protein intermediaries). Dam methylase footprinting in vivo model system Molekuliarnaia biologiia Medium 21954596
2014 Human PSMD9 interacts with hnRNPA1 via a PDZ domain–C-terminal motif interaction; this interaction is required for IκBα proteasomal degradation and NF-κB activation (both basal and TNF-α-induced). hnRNPA1 interacts directly with IκBα and with the proteasome upon TNF-α treatment, while PSMD9 associates constitutively with the proteasome. Point mutations in the PSMD9 PDZ domain or deletion of the hnRNPA1 C-terminus disrupt the interaction and reduce NF-κB activity. Co-immunoprecipitation, PDZ domain mutagenesis, C-terminal deletion of hnRNPA1, NF-κB reporter assay, siRNA knockdown in HEK293 cells The FEBS journal High 24720748
2014 The central domain of yeast Rpn4 functions as a portable, interspecies proteasomal degradation signal (degron) capable of destabilizing GFP and Alpha-fetoprotein reporter proteins in human HEK293T cells as well as in yeast. Reporter protein fusion assay in yeast and mammalian cells, proteasome inhibitor treatment FEBS letters Medium 25157437
2014 PSMD9 interacts with hnRNPA1, S14 (ribosomal protein), CSH1 (growth hormone), E12 (transcription factor), and IL6 receptor via its PDZ domain recognizing C-terminal short linear motifs of client proteins; interactions confirmed with full-length recombinant proteins and in mammalian cells. C-terminal peptide screening, recombinant protein binding assays, mammalian cell co-immunoprecipitation, structural modeling FEBS open bio Medium 25009770
2015 A minimal hexamer 'PACE-core' sequence within PACE elements is sufficient to respond to Rpn4 transcriptional activation and is found in promoters of proteasome assembly chaperone genes, extending Rpn4's transcriptional regulon beyond subunit-encoding genes. Promoter deletion/mutation analysis, reporter gene assays FEBS letters Medium 25747386
2019 Rpn4 abundance increases during ER stress first post-transcriptionally, then transcriptionally. Induction of RPN4 transcription during ER stress is triggered by cytosolic mislocalization of secretory proteins and is mediated by multiple signaling pathways; Rpn4 cooperates with the UPR to accelerate clearance of misfolded cytosolic proteins. Titratable ER stress system, genetic screen, RPN4 expression analysis, epistasis with UPR mutants, protein clearance assays in yeast eLife High 30865586
2019 The PSMD9 PDZ domain binds C-terminal peptides with a preference for hydrophobic residues at the P0 position and cysteine at P-2; a low-affinity tetrapeptide was converted to a high-affinity binder (~5 μM) that inhibits PSMD9-hnRNPA1 interaction and NF-κB signaling. Peptide binding affinity assays, molecular dynamics simulations, NF-κB activity assay with peptide inhibitor Biochemistry Medium 31287951
2021 PSMD9 is required to maintain nucleolar morphology and integrity; PSMD9-null MCF7 cells show disrupted nucleolar structure (by NPM1 immunofluorescence and electron microscopy), accumulation of WT p53, slow growth, and failure of ribosomal proteins RPS25 and RPL15 to localize to the nucleolus. Multiple ribosomal proteins co-purify/pull-down with PSMD9. PSMD9 knockout in MCF7 cells, NPM1 immunofluorescence, electron microscopy, ribosomal protein co-purification/pulldown, Actinomycin D treatment Biochemical and biophysical research communications Medium 34077860
2023 PSMD9 interacts with proteins carrying an EXKK short linear motif (SLiM) via its coiled-coil N-terminal domain; validated interactions include hnRNPA2B1 (ERKK motif) and PRDX6 (EAKK motif) using purified proteins. PSMD9 KO in HEK293 cells induces ER stress and UPR, reduces aggresome and lipid droplet formation; these defects are rescued by PSMD9 re-expression. PSMD9 also interacts with BIP/GRP78 (EDKK) and FASN (ELKK). Affinity purification mass spectrometry (AP-MS), in vitro peptide and protein binding assays, PSMD9 KO and rescue in HEK293 cells, UPR and lipid droplet assays The FEBS journal Medium 37665644
2024 PSMD9 directly interacts with the E3 ubiquitin ligase c-Cbl, suppresses EGFR ubiquitination, and influences EGFR endosomal trafficking and degradation, thereby activating ERK1/2 and Akt signaling in hepatocellular carcinoma cells. PSMD9 knockdown sensitizes HCC cells to erlotinib. Co-immunoprecipitation, immunofluorescence confocal imaging, EGFR ubiquitination assay, siRNA knockdown, in vitro and in vivo tumor models Journal of experimental & clinical cancer research : CR Medium 38745188
2025 PSMD9 directly interacts with DNAJA1 (a mitochondrial chaperone) via the EXKK motif in DNAJA1; the interaction was confirmed by in vitro binding with purified proteins and co-immunoprecipitation from MCF7 cells. Mutations in DNAJA1 disrupting the EXKK motif abolish binding. Upon proteasome inhibition, PSMD9-DNAJA1 interaction is enhanced and DNAJA1 stability increases. PSMD9 depletion leads to elevated mitochondrial membrane potential. In vitro binding assay with purified proteins, site-directed mutagenesis of DNAJA1, co-immunoprecipitation from MCF7 cells, mitochondrial membrane potential assay Biochemical and biophysical research communications Medium 40412052

Source papers

Stage 0 corpus · 50 papers · ranked by NIH iCite citations
Year Title Journal Citations PMID
2001 RPN4 is a ligand, substrate, and transcriptional regulator of the 26S proteasome: a negative feedback circuit. Proceedings of the National Academy of Sciences of the United States of America 363 11248031
2000 Regulatory networks revealed by transcriptional profiling of damaged Saccharomyces cerevisiae cells: Rpn4 links base excision repair with proteasomes. Molecular and cellular biology 267 11027285
2010 Comparative transcriptome profiling analyses during the lag phase uncover YAP1, PDR1, PDR3, RPN4, and HSF1 as key regulatory genes in genomic adaptation to the lignocellulose derived inhibitor HMF for Saccharomyces cerevisiae. BMC genomics 130 21106074
2004 Rpn4 is a physiological substrate of the Ubr2 ubiquitin ligase. The Journal of biological chemistry 76 15504724
2004 Proteasomal degradation of RPN4 via two distinct mechanisms, ubiquitin-dependent and -independent. The Journal of biological chemistry 75 15090546
2004 Homeostatic regulation of the proteasome via an Rpn4-dependent feedback circuit. Biochemical and biophysical research communications 59 15358214
2007 Biting the hand that feeds: Rpn4-dependent feedback regulation of proteasome function. Biochimica et biophysica acta 57 17604855
2007 Yeast adaptation to mancozeb involves the up-regulation of FLR1 under the coordinate control of Yap1, Rpn4, Pdr3, and Yrr1. Biochemical and biophysical research communications 52 18086556
2008 Disruption of Rpn4-induced proteasome expression in Saccharomyces cerevisiae reduces cell viability under stressed conditions. Genetics 50 18832351
2009 Proteasomal degradation of Rpn4 in Saccharomyces cerevisiae is critical for cell viability under stressed conditions. Genetics 49 19933873
1998 cDNA cloning and characterization of a human proteasomal modulator subunit, p27 (PSMD9). Genomics 41 9653651
2015 Identification of minimum Rpn4-responsive elements in genes related to proteasome functions. FEBS letters 38 25747386
2019 The proteasome biogenesis regulator Rpn4 cooperates with the unfolded protein response to promote ER stress resistance. eLife 37 30865586
2007 Genome-wide analysis identifies MYND-domain protein Mub1 as an essential factor for Rpn4 ubiquitylation. Molecular and cellular biology 35 18070918
2006 Identification of the preferential ubiquitination site and ubiquitin-dependent degradation signal of Rpn4. The Journal of biological chemistry 35 16492666
2014 A novel role for the proteasomal chaperone PSMD9 and hnRNPA1 in enhancing IκBα degradation and NF-κB activation - functional relevance of predicted PDZ domain-motif interaction. The FEBS journal 32 24720748
2010 PSMD9 gene in the NIDDM2 locus is linked to type 2 diabetes in Italians. Journal of cellular physiology 25 19877155
2007 Ubiquitin-mediated degradation of Rpn4 is controlled by a phosphorylation-dependent ubiquitylation signal. Biochimica et biophysica acta 23 17532487
2020 Candida glabrata Transcription Factor Rpn4 Mediates Fluconazole Resistance through Regulation of Ergosterol Biosynthesis and Plasma Membrane Permeability. Antimicrobial agents and chemotherapy 22 32571817
2013 Proteasome inhibition enhances resistance to DNA damage via upregulation of Rpn4-dependent DNA repair genes. FEBS letters 22 23954292
2007 PSMD9 gene variants within NIDDM2 may rarely contribute to type 2 diabetes. Journal of cellular physiology 21 17516568
2014 PSMD9 expression predicts radiotherapy response in breast cancer. Molecular cancer 19 24673853
2024 PSMD9 promotes the malignant progression of hepatocellular carcinoma by interacting with c-Cbl to activate EGFR signaling and recycling. Journal of experimental & clinical cancer research : CR 17 38745188
2023 Comprehensive analysis of PSMD family members and validation of PSMD9 as a potential therapeutic target in human glioblastoma. CNS neuroscience & therapeutics 15 37485655
2014 Discovery of novel interacting partners of PSMD9, a proteasomal chaperone: Role of an Atypical and versatile PDZ-domain motif interaction and identification of putative functional modules. FEBS open bio 14 25009770
2010 PSMD9 is linked to MODY3. Journal of cellular physiology 14 20069546
2020 Rpn4 and proteasome-mediated yeast resistance to ethanol includes regulation of autophagy. Applied microbiology and biotechnology 13 32157425
2011 PSMD9 is linked to type 2 diabetes neuropathy. Journal of diabetes and its complications 13 21813292
2010 Inhibition of proteasomal degradation of rpn4 impairs nonhomologous end-joining repair of DNA double-strand breaks. PloS one 13 20376190
2020 PSMD9 expression correlates with recurrence after radiotherapy in patients with cervical cancer. Oncology letters 12 32565983
2016 Tmc1 Is a Dynamically Regulated Effector of the Rpn4 Proteotoxic Stress Response. The Journal of biological chemistry 12 27226598
2001 [Isolation and identification of PACE-binding protein rpn4--a new transcription activator, participating in regulation of 26S proteosome and other genes]. Molekuliarnaia biologiia 12 11443924
2023 The transcription factor Rpn4 activates its own transcription and induces efflux pump expression to confer fluconazole resistance in Candida auris. mBio 11 38014938
2019 A Novel Determinant of PSMD9 PDZ Binding Guides the Evolution of the First Generation of Super Binding Peptides. Biochemistry 10 31287951
2023 The proteasome regulator Rpn4 controls antifungal drug tolerance by coupling protein homeostasis with metabolic responses to drug stress. PLoS pathogens 9 37075064
2021 PSMD9 ribosomal protein network maintains nucleolar architecture and WT p53 levels. Biochemical and biophysical research communications 9 34077860
2019 Deregulation of the 19S proteasome complex increases yeast resistance to 4-NQO and oxidative stress via upregulation of Rpn4- and proteasome-dependent stress responsive genes. FEMS yeast research 8 30629175
2020 Yeast Rpn4 Links the Proteasome and DNA Repair via RAD52 Regulation. International journal of molecular sciences 6 33143019
2014 The central domain of yeast transcription factor Rpn4 facilitates degradation of reporter protein in human cells. FEBS letters 5 25157437
2023 The interaction network of the proteasome assembly chaperone PSMD9 regulates proteostasis. The FEBS journal 4 37665644
2024 The Role of Z Chromosome Localization Gene psmd9 in Spermatogenesis of Cynoglossus semilaevis. International journal of molecular sciences 3 38928079
2017 Functional analysis of Debaryomyces hansenii Rpn4 on a genetic background of Saccharomyces cerevisiae. FEMS yeast research 3 27856503
2023 Impairment of RPN4, a transcription factor, induces ER stress and lipid abnormality in Saccharomyces cerevisiae. Molecular and cellular biochemistry 2 36703093
2022 PSMD9 is linked to T2D age of onset, years of isolated and combined insulin therapy, irregular menses, and hot flashes. European review for medical and pharmacological sciences 2 36524506
2011 [Escherichia coli Dam methylase as a molecular tool for mapping binding sites of the yeast transcription factor Rpn4]. Molekuliarnaia biologiia 2 21954596
2025 Novel interaction with PSMD9 regulates DNAJA1 turnover and mitochondrial polarity. Biochemical and biophysical research communications 1 40412052
2025 Within and beyond the boundaries of proteasomal assembly: PSMD9 chaperone as a multifunctional protein. Essays in biochemistry 1 41738541
2019 [Candida glabrata Rpn4-like Protein Complements the RPN4 Deletion in Saccharomyces cerevisiae]. Molekuliarnaia biologiia 1 31099777
2020 Proteasome modulator 9 (PSMD9) gene rs14259 polymorphism in Alzheimer's disease. Bratislavske lekarske listy 0 32356429
2014 [RPN4 the yeast transcription factor promotes the complex defence against methyi, methanesulfonate]. Molekuliarnaia biologiia 0 25842837

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