Homo sapiens
Ontology highlight
ABSTRACT:
PROVIDER: PRJNA134117 | ENA |
REPOSITORIES: ENA
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Project description:The Hace1 E3 ligase is a tumor suppressor in stressed cells. Through unknown mechanisms, Hace1 indirectly targets the cyclin D1 proto-oncogene for proteasomal degradation during nutrient depletion. We now show that Hace1 targets HIF1alpha for VHL-dependent degradation during hypoxia. To better understand these diverse actions we performed mass spectrometry to identify Hace1-interacting proteins. We show that Hace1 interacts with cullin-associated NEDD8-dissociated protein 1 (CAND1) under nutrient depletion and hypoxia. CAND1 binds cullins and prevents their entry into cullin ring E3 ligase (CRL) complexes, thus blocking CRL activity. Hace1 binding releases CUL1/2 from CAND1, facilitating assembly of CRL complexes to degrade cyclin D1 and HIF1alpha, respectively. These findings suggest a broad role for Hace1 in regulating tumor suppressive CRL E3 ligases. In this study, we used gene expression profiling to characterize how Hace1 overexpression affect the transcriptional response to hypoxic stress Using Affymetrix exon-level microarrays, we compared the expression profile of HEK293 cells overexpressing either Hace1 or MSCV vector alone, under hypoxia or normoxia
2011-07-01 | E-GEOD-25452 | biostudies-arrayexpress
Project description:The Hace1 E3 ligase is a tumor suppressor in stressed cells. Through unknown mechanisms, Hace1 indirectly targets the cyclin D1 proto-oncogene for proteasomal degradation during nutrient depletion. We now show that Hace1 targets HIF1alpha for VHL-dependent degradation during hypoxia. To better understand these diverse actions we performed mass spectrometry to identify Hace1-interacting proteins. We show that Hace1 interacts with cullin-associated NEDD8-dissociated protein 1 (CAND1) under nutrient depletion and hypoxia. CAND1 binds cullins and prevents their entry into cullin ring E3 ligase (CRL) complexes, thus blocking CRL activity. Hace1 binding releases CUL1/2 from CAND1, facilitating assembly of CRL complexes to degrade cyclin D1 and HIF1alpha, respectively. These findings suggest a broad role for Hace1 in regulating tumor suppressive CRL E3 ligases. In this study, we used gene expression profiling to characterize how Hace1 overexpression affect the transcriptional response to hypoxic stress
2011-07-01 | GSE25452 | GEO
Project description:Heterobifunctional proteolysis-targeting chimeric compounds leverage the activity of E3 ligases to induce degradation of target oncoproteins and exhibit potent preclinical antitumor activity. To dissect the mechanisms regulating tumor cell sensitivity to different classes of pharmacological "degraders" of oncoproteins, we performed genome-scale CRISPR/Cas9-based gene-editing studies. We observed that myeloma cell resistance to "degraders" of different targets (BET bromodomain proteins, CDK9) and operating through CRBN (degronimids) or VHL is primarily mediated by prevention of, rather than adaptation to, breakdown of the target oncoprotein; involves loss-of-function for the cognate E3 ligase or interactors/regulators of the respective cullin-RING ligase (CRL) complex. The substantial gene-level differences for CRBN- vs. VHL-based degraders explains mechanistically the lack of cross-resistance for degraders targeting the same protein via different E3 ligase/CRLs.
2021-02-12 | GSE162205 | GEO
Project description:E3 ubiquitin ligases of the Cullin RING Ligase (CRL) family assemble into multiprotein complexes to diversify substrate adaptors and ensure selectivity in substrate engagement for degradation. Here we show a novel mechanism whereby mutations in substrate adaptors can drive neo-substrate degradation in cancer. KBTBD4 is a CRL3 substrate adaptor harbouring recurrent indel mutations in a subset of non-WNT/non-SHH medulloblastomas. We show that these mutations, arising in the substrate recognition domain of KBTBD4, promote the recruitment and ubiquitylation of the REST Corepressor (CoREST), which forms a complex to modulate chromatin accessibility and transcriptional programmes. We observe that this neomorphic activity of KBTBD4 mutants induces changes in epigenetic markers and significant alterations in transcription, diverting normal cellular programmes towards increased stemness. These results highlight mutation-driven neomorphic E3 ligase activity as a previously unrecognised mechanism in tumorigenesis, with implications for medulloblastoma pathogenesis and treatment.
2022-03-30 | GSE197240 | GEO
Project description:PROteolysis Targeting Chimeras (PROTACs) are bifunctional molecules that degrade target proteins through recruiting E3 ligases. However, their application is limited in part because few E3 ligases can be recruited by known E3 ligase ligands. In this study, we identified piperlongumine (PL), a natural product, as a covalent E3 ligase recruiter, which induces CDK9 degradation when it is conjugated with SNS032, a CDK9 inhibitor. The lead conjugate 955 can potently degrade CDK9 in a ubiquitin-proteasome-dependent manner and is much more potent than SNS-032 against various tumor cells in vitro. Mechanistically, we identified KEAP1 as the E3 ligase recruited by 955 to degrade CDK9 through a TurboID-based proteomics study, which was further confirmed by KEAP1 knockout and the nanoBRET ternary complex formation assay. In addition, PL-Ceritinib conjugate can degrade EML4-ALK fusion oncoprotein, suggesting that PL may have a broader application as a covalent E3 ligase ligand in targeted protein degradation.
2022-06-26 | GSE206612 | GEO
Project description:Activation of tumor suppressors for the treatment of human cancer has been a long sought, yet elusive strategy. PTEN is a critical tumor suppressive phosphatase that is active in its dimer configuration at plasma membrane. Poly-ubiquitination by the ubiquitin E3 ligase WWP1 (WW domain containing ubiquitin E3 ligase 1) suppressed the dimerization, membrane recruitment, and function of PTEN. Either genetic ablation or pharmacological inhibition of WWP1 triggered PTEN reactivation, and unleashed tumor suppressive activity. WWP1 appears to be a direct MYC (MYC proto-oncogene) target gene and was critical for MYC-driven tumorigenesis. We identified indole-3-carbinol, a compound found in cruciferous vegetables, as a natural and potent WWP1 inhibitor. Thus, our findings unravel a potential therapeutic strategy for cancer prevention and treatment through PTEN reactivation.
2019-05-17 | GSE126789 | GEO
Project description:Mutation of the gene PARK2 is the most common cause of early-onset Parkinson's Disease (PD)1,2. PARK2 encodes a gene product with E3 ubiquitin ligase activity3. In a search for multisite tumor suppressors, we identified PARK2 as a frequently targeted gene on chromosome 6q25.2-q27 in cancer. Here, we describe inactivating somatic mutations and frequent intragenic deletions of PARK2 in human malignancies. The PARK2 mutations in cancer occur in the same domains, and sometimes, at the same residues as the germline mutations causing familial PD. Cancer-specific mutations abrogate the growth suppressive effects of PARK2. PARK2 mutations in cancer decrease the gene product's E3 ligase activity, compromising its ability to ubiquitinate cyclin E and resulting in mitotic instability. These data strongly point to PARK2 as a tumor suppressor on 6q25.2-q27. PARK2, a gene that causes neuronal dysfunction when mutated in the germline, may instead contribute to oncogenesis when altered in non-neuronal somatic cells. Human colorectal samples were profiled on Agilent 244K aCGH arrays per manufacturer's instructions. Pooled reference normal DNA was used as the reference.
2010-06-22 | E-GEOD-18638 | biostudies-arrayexpress
Project description:The TRIM37 gene is mutatedin Mulbery nanism, a rare autosomal recessive disorder, and is in the 17q23 chromosomal region that is amplified in up to ~40% of breast cancers. Trim37 contains a RING finger domain, a hallmark of E3 ubiquitin ligases, but the protein substrate(s) of Trim37 is unknown. Mono-ubiquitination of histone H2A is a chromatin modification associated with transcriptional repression and here we report that Trim37 is an H2A ubiquitin ligase. Genome-wide Chip-CHIP experiments indicate that in human breast cancer cells containing amplified 17q23, Trim37 is bound to the promoters of many tumor suppressor genes. RNA interference (RNAi)-mediated knockdown of Trim37 results in loss of ubiquitinated H2A, dissociation of PRC1 and PRC2, and transcriptional reactivation of silenced genes. Knockdown of Trim37 in human breast cancer cells containing amplified 17q23 substantially decreases tumor growth in mouse xenografts. Collectively, our results reveal Trim37 as a new H2A ubiquitin ligase that is overexpressed in a subset of breast cancers and redirects PRC2 to silence tumor suppressors and other genes resulting in oncogenesis. Identification of TRIM37 Binding targets in MCF7 cells from the two replicate experiments
2014-10-06 | E-GEOD-48196 | biostudies-arrayexpress
Project description:E3 ubiquitin ligases of the Cullin RING Ligase (CRL) family assemble into multiprotein complexes to diversify substrate adaptors and ensure selectivity in substrate engagement for degradation. Here we show a novel mechanism whereby mutations in substrate adaptors can drive neo-substrate degradation in cancer. KBTBD4 is a CRL3 substrate adaptor harbouring recurrent indel mutations in a subset of non-WNT/non-SHH medulloblastomas. We show that these mutations, arising in the substrate recognition domain of KBTBD4, promote the recruitment and ubiquitylation of the REST Corepressor (CoREST), which forms a complex to modulate chromatin accessibility and transcriptional programmes. We observe that this neomorphic activity of KBTBD4 mutants induces changes in epigenetic markers and significant alterations in transcription, diverting normal cellular programmes towards increased stemness. These results highlight mutation-driven neomorphic E3 ligase activity as a previously unrecognised mechanism in tumorigenesis, with implications for medulloblastoma pathogenesis and treatment.
2022-10-14 | PXD031683 | Pride
Project description:Ubiquitin ligation is typically executed by hallmark E3 catalytic domains. Two such domains, "cullin-RING" and "RBR", are individually found in several hundred E3 ligases in humans, and collaborate with E2 enzymes to catalyze ubiquitylation. However, the vertebrate-specific CUL9 complex with RBX1 (also called ROC1), of interest due to its tumor suppressive interaction with TP53, uniquely encompasses both cullin-RING and RBR domains. Here, cryo-EM, biochemistry, and cellular assays elucidate a 1.8 MDa hexameric CUL9-RBX1 assembly. Within one dimeric subcomplex, an E2-bound RBR domain is activated by neddylation of its own cullin domain and positioning from the adjacent CUL9-RBX1 in trans. Our data show CUL9 as unique amongst RBX1-bound cullins in dependence on the metazoan-specific UBE2F neddylation enzyme, while the RBR domain protects it from deneddylation. Substrate ubiquitylation relies on both CUL9's neddylated cullin and RBR domains achieving self-assembled and chimeric cullin-RING/RBR E3 ligase activity.
2024-04-09 | PXD047229 | Pride