MYC dephosphorylation by the PP1/PNUTS phosphatase complex regulates chromatin binding and protein stability
Ontology highlight
ABSTRACT:
INSTRUMENT(S): LTQ Orbitrap Velos
ORGANISM(S): Homo Sapiens (ncbitaxon:9606)
SUBMITTER: 
Brian Raught
PROVIDER: MSV000082424 | MassIVE | Thu May 31 17:20:00 BST 2018
SECONDARY ACCESSION(S): PXD009985
REPOSITORIES: MassIVE
Similar Datasets
Project description: Not available
| S-EPMC6115416 | biostudies-literature
Project description:Proximity-based biotin labeling assay in HEK293 cells using FlagBirA-Myc (WT and mutants) fusion proteins.
2017-11-20 | MSV000081725 | MassIVE
Project description:Constitutively active MYC and reactivated telomerase often co-exist in cancers. While the reactivation of telomerase is thought to be essential for replicative immortality, MYC, in conjunction with co-factors, confers several growth advantages to cancer cells. However, it is unclear which co-factors sustain elevated MYC activity in tumors . Here, we identify TERT, the catalytic subunit of telomerase, as a novel regulator of MYC stability in cancers. Binding of TERT to MYC stabilizes its levels on chromatin, contributing to either activation or repression of its target genes. Mechanistically, TERT regulates MYC ubiquitination and stability, and this effect of TERT is independent of its role on telomeres. Genetic inhibition and knocking out of TERT phenocopied the loss of MYC, resulting in reduced disease burden of early- and late-stage MYC-driven murine lymphomas. Conversly, the ectopic expression of TERT could substitute for reduced MYC in these functions. Finally we show that TERT null mice, unlike Terc null mice, show delayed onset of MYC induced lymphomagenesis. Accordingly, inhibiting TERT function in primary human leukemia cells blocked the expression of MYC targets, while Terc depletion had no effects . Based on our data, we conclude that the re-expression of TERT, a direct MYC target in tumors, provides a feed-forward mechanism to potentiate MYC-dependent oncogenesis. P493 cells were stably infected with the following viruses: pLKO shControl and pLKO shTERT.
2015-04-23 | E-GEOD-60175 | biostudies-arrayexpress
Project description:During infection, virus-specific CD8+ T cells undergo rapid bursts of proliferation and differentiate into effector cells that kill virus infected cells and reduce viral load. This rapid clonal expansion can put T cells at significant risk for replication-induced DNA damage. We found that c-Myc utilizes the E3 ubiquitin ligase, Cul4b, to inextricably link CD8+ T cell expansion to DNA damage response pathways. Following activation, c-Myc increased levels of Cul4b and other members of the CRL4 complex. Despite having abundant c-Myc expression, Cul4b-deficient CD8+ T cells were unable to expand and clear virus. Cul4b-deficient CD8+ T cells accrued DNA damage and succumbed to proliferative catastrophe early after antigen encounter. Mechanistically, Cul4b ablation induced a protracted accumulation of p21 and Cyclin E2 resulting in replication stress. Our data show that, to support cell proliferation, c-Myc must employ Cul4b to maintain genome stability, thereby directly coupling these two interdependent pathways. These data clarify how CD8+ T cells use c-Myc and Cul4b to sustain their potential for extraordinary population expansion, longevity and antiviral responses.
2023-08-29 | PXD041220 | Pride
Project description:DHX15 has been implicated in RNA splicing and ribosome biogenesis, primarily functioning as an RNA helicase. To systematically assess the cellular role of DHX15, we conducted proteomic analysis to investigate the landscape of DHX15 interactome, and identified MYC as a binding partner. DHX15 co-localizes with MYC in cells and directly interacts with MYC in vitro. Importantly, DHX15 contributes to MYC protein stability at the post-translational level and independent of its RNA binding capacity. Mechanistic investigation reveals that DHX15 interferes the interaction between MYC and FBXW7, thereby preventing MYC polyubiquitylation and proteasomal degradation. Consequently, abrogation of DHX15 drastically inhibits MYC-mediated transcriptional output. While DHX15 depletion blocks T-cell development and leukemia cell survival as we recently reported, overexpression of MYC significantly rescues the phenotypic defects. These findings shed new light on the essential role of DHX15 in mammalian cells and suggest that maintaining sufficient MYC expression is a significant contributor to DHX15-mediated cellular functions.
2024-01-26 | PXD046692 | Pride
Project description:Constitutively active MYC and reactivated telomerase often co-exist in cancers. While the reactivation of telomerase is thought to be essential for replicative immortality, MYC, in conjunction with co-factors, confers several growth advantages to cancer cells. However, it is unclear which co-factors sustain elevated MYC activity in tumours . Here, we identify TERT, the catalytic subunit of telomerase, as a novel regulator of MYC stability in cancers. Binding of TERT to MYC stabilizes its levels on chromatin, contributing to either activation or repression of its target genes. Mechanistically, TERT regulates MYC ubiquitination and stability, and this effect of TERT is independent of its role on telomeres. Genetic inhibition and knocking out of TERT phenocopied the loss of MYC, resulting in reduced disease burden of early- and late-stage MYC-driven murine lymphomas. Conversly, the ectopic expression of TERT could substitute for reduced MYC in these functions. Finally we show that TERT null mice, unlike Terc null mice, show delayed onset of MYC induced lymphomagenesis. Accordingly, inhibiting TERT function in primary human leukemia cells blocked the expression of MYC targets, while Terc depletion had no effects . Based on our data, we conclude that the re-expression of TERT, a direct MYC target in tumors, provides a feed-forward mechanism to potentiate MYC-dependent oncogenesis. ChIP was performed using anti-MYC (sc-764) in primary lymphoma cells from Eµ-Myc;Tert -/- mice, Eµ-Myc;Tert +/+ mice, or in P493 cells treated with shTert, P493 shTerc and shControl.
2015-04-23 | E-GEOD-60223 | biostudies-arrayexpress
Project description:Constitutively active MYC and reactivated telomerase often co-exist in cancers. While the reactivation of telomerase is thought to be essential for replicative immortality, MYC, in conjunction with co-factors, confers several growth advantages to cancer cells. However, it is unclear which co-factors sustain elevated MYC activity in tumors . Here, we identify TERT, the catalytic subunit of telomerase, as a novel regulator of MYC stability in cancers. Binding of TERT to MYC stabilizes its levels on chromatin, contributing to either activation or repression of its target genes. Mechanistically, TERT regulates MYC ubiquitination and stability, and this effect of TERT is independent of its role on telomeres. Genetic inhibition and knocking out of TERT phenocopied the loss of MYC, resulting in reduced disease burden of early- and late-stage MYC-driven murine lymphomas. Conversly, the ectopic expression of TERT could substitute for reduced MYC in these functions. Finally we show that TERT null mice, unlike Terc null mice, show delayed onset of MYC induced lymphomagenesis. Accordingly, inhibiting TERT function in primary human leukemia cells blocked the expression of MYC targets, while Terc depletion had no effects . Based on our data, we conclude that the re-expression of TERT, a direct MYC target in tumors, provides a feed-forward mechanism to potentiate MYC-dependent oncogenesis.
2015-04-23 | GSE60175 | GEO
Project description:Tumorigenesis is characterised by changes in transcriptional regulation and the androgen receptor (AR) has been identified as a key driver in prostate cancer. In this study, we show that the hexosamine biosynthetic pathway (HBP) genes are overexpressed in clinical prostate cancer and androgen-regulated in cell-lines. HBP senses metabolic status of the cell and produces an essential substrate for O-GlcNAc transferase (OGT), which regulates target proteins via glycosylation. Using immunohistochemistry, we found that OGT is up-regulated in the protein level in prostate cancer (n=1987) and its expression correlates with high Gleason Score, pT and pN stages and biochemical recurrence (for all, p<0.0001). Both a small molecule inhibitor and siRNAs targeting OGT decreased prostate cancer cell growth. Microarray profiling revealed that the principal effects of the OGT inhibitor in prostate cancer cells are on cell cycle progression and DNA replication. We identified MYC as a candidate upstream regulator of these genes and found that OGT inhibitor caused a dose-dependent loss of c-MYC protein but not mRNA in cell lines. Finally, we observed a statistically significant co-expression between c-MYC and OGT in human prostate cancer samples (n=1306, p=0.0012). Total RNA was extracted and experiment has three biological replicates for each condition, conditions are: 12 hours ST045849, 24 hours ST045849, 12 hours vehicle, 24 hours vehicle, 12 hours siOGT, 24 hours siOGT, 12 hours scrambled, 24 hours scrambled
2013-05-30 | E-GEOD-44624 | biostudies-arrayexpress
Project description:Constitutively active MYC and reactivated telomerase often co-exist in cancers. While the reactivation of telomerase is thought to be essential for replicative immortality, MYC, in conjunction with co-factors, confers several growth advantages to cancer cells. However, it is unclear which co-factors sustain elevated MYC activity in tumours . Here, we identify TERT, the catalytic subunit of telomerase, as a novel regulator of MYC stability in cancers. Binding of TERT to MYC stabilizes its levels on chromatin, contributing to either activation or repression of its target genes. Mechanistically, TERT regulates MYC ubiquitination and stability, and this effect of TERT is independent of its role on telomeres. Genetic inhibition and knocking out of TERT phenocopied the loss of MYC, resulting in reduced disease burden of early- and late-stage MYC-driven murine lymphomas. Conversly, the ectopic expression of TERT could substitute for reduced MYC in these functions. Finally we show that TERT null mice, unlike Terc null mice, show delayed onset of MYC induced lymphomagenesis. Accordingly, inhibiting TERT function in primary human leukemia cells blocked the expression of MYC targets, while Terc depletion had no effects . Based on our data, we conclude that the re-expression of TERT, a direct MYC target in tumors, provides a feed-forward mechanism to potentiate MYC-dependent oncogenesis.
2015-04-23 | GSE60223 | GEO
Project description:Tumorigenesis is characterised by changes in transcriptional regulation and the androgen receptor (AR) has been identified as a key driver in prostate cancer. In this study, we show that the hexosamine biosynthetic pathway (HBP) genes are overexpressed in clinical prostate cancer and androgen-regulated in cell-lines. HBP senses metabolic status of the cell and produces an essential substrate for O-GlcNAc transferase (OGT), which regulates target proteins via glycosylation. Using immunohistochemistry, we found that OGT is up-regulated in the protein level in prostate cancer (n=1987) and its expression correlates with high Gleason Score, pT and pN stages and biochemical recurrence (for all, p<0.0001). Both a small molecule inhibitor and siRNAs targeting OGT decreased prostate cancer cell growth. Microarray profiling revealed that the principal effects of the OGT inhibitor in prostate cancer cells are on cell cycle progression and DNA replication. We identified MYC as a candidate upstream regulator of these genes and found that OGT inhibitor caused a dose-dependent loss of c-MYC protein but not mRNA in cell lines. Finally, we observed a statistically significant co-expression between c-MYC and OGT in human prostate cancer samples (n=1306, p=0.0012).
2013-05-30 | GSE44624 | GEO