H2B monoubiquitination: t'ub or not t'ub for inducible enhancers.
Ontology highlight
ABSTRACT:
SUBMITTER: Segala G
PROVIDER: S-EPMC5423472 | biostudies-literature | 2017 Mar
REPOSITORIES: biostudies-literature
Publications
H2B monoubiquitination: t'ub or not t'ub for inducible enhancers.
Segala Gregory G Picard Didier D
Transcription 20170208 2
Recently, we reported the unexpected finding that the monoubiquitination of histone H2B (H2Bub1) regulates inducible enhancers. Here, we propose a conceptual framework to reconcile the apparently discrepant roles of H2Bub1 in transcription initiation and elongation, and we discuss how H2Bub1 could regulate cellular processes linked to non-coding transcription. ...[more]
Similar Datasets
Project description:Chromatin reorganization is governed by multiple post-translational modifications of chromosomal proteins and DNA. These histone modifications are reversible, dynamic events that can regulate DNA-driven cellular processes. However, the molecular mechanisms that coordinate histone modification patterns remain largely unknown. In metazoans, reversible protein modification by O-linked N-acetylglucosamine (GlcNAc) is catalysed by two enzymes, O-GlcNAc transferase (OGT) and O-GlcNAcase (OGA). However, the significance of GlcNAcylation in chromatin reorganization remains elusive. Here we report that histone H2B is GlcNAcylated at residue S112 by OGT in vitro and in living cells. Histone GlcNAcylation fluctuated in response to extracellular glucose through the hexosamine biosynthesis pathway (HBP). H2B S112 GlcNAcylation promotes K120 monoubiquitination, in which the GlcNAc moiety can serve as an anchor for a histone H2B ubiquitin ligase. H2B S112 GlcNAc was localized to euchromatic areas on fly polytene chromosomes. In a genome-wide analysis, H2B S112 GlcNAcylation sites were observed widely distributed over chromosomes including transcribed gene loci, with some sites co-localizing with H2B K120 monoubiquitination. These findings suggest that H2B S112 GlcNAcylation is a histone modification that facilitates H2BK120 monoubiquitination, presumably for transcriptional activation.
| S-EPMC7289526 | biostudies-literature
Project description:Monoubiquitination of histone H2BK120/123 plays multiple roles in regulating transcription, DNA replication and the DNA damage response. The structure of a nucleosome in complex with the dimeric RING E3 ligase, Bre1, reveals that one RING domain binds to the nucleosome acidic patch, where it can position the Rad6 E2, while the other RING domain contacts the DNA. Comparisons with H2A-specific E3 ligases suggests a general mechanism of tuning histone specificity via the non-E2-binding RING domain.
| S-EPMC10081246 | biostudies-literature
Project description:AimTo investigate H2B monoubiquitination (uH2B) and H3K4 di- and tri-methylation (H3K4-2me, H3K4-3me) levels and their clinical significance in gastric cancer (GC).MethodsImmunohistochemistry (IGC) was used to detect the differential levels of uH2B, H3K4-2me and H3K4-3me modifications in GC specimens from chemo/radiotherapy-naïve patients who underwent potentially curative surgical resection (n = 159) and in a random sampling of non-tumor gastric epithelium specimens (normal controls, n = 20). The immunohistochemistry (IHC)-detected modifications were classified as negative, low-level, or high-level using a dual-rated (staining intensity and percentage of positively-stained cells) semi-quantitative method. The relationships between uH2B modification levels and clinicopathological parameters of GC were assessed by a Wilcoxon rank sum test (pairwise comparisons) and the Kruskal-Wallis H test (multiple comparisons). The correlation between uH2B modification and survival was estimated by Kaplan-Meier analysis, and the role of uH2B as an independent prognostic factor for survival was assessed by multivariate Cox regression analysis.ResultsThe presence and level of H3K4-2me and H3K4-3me IHC staining was similar between the normal controls and GC specimens. In contrast, the level of uH2B was significantly lower in the malignant gastric tissues (vs normal control tissues) and decreased along with increases in dedifferentiation (well differentiated > moderately differentiated > poorly differentiated). The level of uH2B correlated with tumor differentiation (P < 0.001), Lauren's diffuse- and intestinal-type classification (P < 0.001), lymph node metastasis (P = 0.049) and tumor-node-metastasis stage (P = 0.005). Patients with uH2B+ staining had higher 5-year survival rates than patients with uH2B-staining (52.692 ± 2.452 vs 23.739 ± 5.207, P < 0.001). The uH2B level was an independent prognostic factor for cancer-specific survival (95%CI: 0.237-0.677, P = 0.001).ConclusionuH2B displays differential IHC staining patterns corresponding to progressive stages of GC. uH2B may contribute to tumorigenesis and could be a potential therapeutic target.
| S-EPMC3848160 | biostudies-literature
Project description: Not available
| S-EPMC3410825 | biostudies-literature
Project description:Cancer cells reprogram their energy metabolic system from the mitochondrial oxidative phosphorylation (OXPHOS) pathway to a glucose-dependent aerobic glycolysis pathway. This metabolic reprogramming phenomenon is known as the Warburg effect, a significant hallmark of cancer. However, the detailed mechanisms underlying this event or triggering this reprogramming remain largely unclear. Here, we found that histone H2B monoubiquitination (H2Bub1) negatively regulates the Warburg effect and tumorigenesis in human lung cancer cells (H1299 and A549 cell lines) likely through controlling the expression of multiple mitochondrial respiratory genes, which are essential for OXPHOS. Moreover, our work also suggested that pyruvate kinase M2 (PKM2), the rate-limiting enzyme of glycolysis, can directly interact with H2B in vivo and in vitro and negatively regulate the level of H2Bub1. The inhibition of cell proliferation and nude mice xenograft of human lung cancer cells induced by PKM2 knockdown can be partially rescued through lowering H2Bub1 levels, which indicates that the oncogenic function of PKM2 is achieved, at least partially, through the control of H2Bub1. Furthermore, PKM2 and H2Bub1 levels are negatively correlated in cancer specimens. Therefore, these findings not only provide a novel mechanism triggering the Warburg effect that is mediated through an epigenetic pathway (H2Bub1) but also reveal a novel metabolic regulator (PKM2) for the epigenetic mark H2Bub1. Thus, the PKM2-H2Bub1 axis may become a promising cancer therapeutic target.
| S-EPMC7206070 | biostudies-literature
Project description:Monoubiquitination of histone H2B on Lys 123 (H2BK123ub) is a transient histone modification considered to be essential for establishing H3K4 and H3K79 trimethylation by Set1/COMPASS and Dot1, respectively. Here, we identified Chd1 as a factor that is required for the maintenance of high levels of H2B monoubiquitination, but not for H3K4 and H3K79 trimethylation. Loss of Chd1 results in a substantial loss of H2BK123ub levels with little to no effect on the genome-wide pattern of H3K4 and H3K79 trimethylation. Our data show that nucleosomal occupancy is reduced in gene bodies in both chd1Δ and, as has been shown, K123A mutant backgrounds. We also demonstrated that Chd1's function in maintaining H2BK123ub levels is conserved from yeast to humans. Our study provides evidence that only small levels of H2BK123ub are necessary for full levels of H3K4 and H3K79 trimethylation in vivo and points to a possible role for Chd1 in positively regulating gene expression through promoting nucleosome reassembly coupled with H2B monoubiquitination.
| S-EPMC3347789 | biostudies-literature
Project description:Monoubiquitination of histone H2B on lysine 120 (H2Bub1) is an epigenetic mark generally associated with transcriptional activation, yet the global functions of H2Bub1 remain poorly understood. Ferroptosis is a form of non-apoptotic cell death characterized by the iron-dependent overproduction of lipid hydroperoxides, which can be inhibited by the antioxidant activity of the solute carrier family member 11 (SLC7A11/xCT), a component of the cystine/glutamate antiporter. Whether nuclear events participate in the regulation of ferroptosis is largely unknown. Here, we show that the levels of H2Bub1 are decreased during erastin-induced ferroptosis and that loss of H2Bub1 increases the cellular sensitivity to ferroptosis. H2Bub1 epigenetically activates the expression of SLC7A11. Additionally, we show that the tumor suppressor p53 negatively regulates H2Bub1 levels independently of p53's transcription factor activity by promoting the nuclear translocation of the deubiquitinase USP7. Moreover, our studies reveal that p53 decreases H2Bub1 occupancy on the SLC7A11 gene regulatory region and represses the expression of SLC7A11 during erastin treatment. These data not only suggest a noncanonical role of p53 in chromatin regulation but also link p53 to ferroptosis via an H2Bub1-mediated epigenetic pathway. Overall, our work uncovers a previously unappreciated epigenetic mechanism for the regulation of ferroptosis.
| S-EPMC6607012 | biostudies-literature
Project description:Histone H2B monoubiquitination is a key histone modification that has significant effects on chromatin higher-order structure and gene transcription. Multiple biological processes have been suggested to be tightly related to the dynamics of H2B monoubiquitination. However, a comprehensive understanding of biological roles of H2B monoubiquitination is still poorly understood. In the present study, we developed an efficient tool to disrupt endogenous H2B monoubiquitination levels by using an H2BK120R mutant construct expressed in human cells. Genome-wide microarray analysis of these cells revealed a potential global view of biological functions of H2B monoubiquitination. Bioinformatics analysis of our data demonstrated that while H2B monoubiquitination expectedly affected a number of previously reported biological pathways, we also uncovered the influence of this histone modification on many novel biological processes. Therefore, our work provided valuable information for understanding the role of H2B monoubiquitination and indicated potential directions for its further studies.
| S-EPMC4503354 | biostudies-literature
Project description:Studies in Saccharomyces cerevisiae and Schizosaccharomyces pombe have enhanced our understanding of the regulation and functions of histone H2B monoubiquitination (H2Bub1), a key epigenetic marker with important roles in transcription and other processes. The detection of H2Bub1 in yeasts using immunoblotting has been greatly facilitated by the commercial availability of antibodies against yeast histone H2B and the cross-reactivity of an antibody raised against monoubiquitinated human H2BK120. These antibodies have obviated the need to express epitope-tagged histone H2B to detect H2Bub1 in yeasts. Here, we provide a step-by-step protocol and best practices for the quantification of H2Bub1 in yeast systems, from cell extract preparation to immunoblotting using the commercially available antibodies. We demonstrate that the commercial antibodies can effectively and accurately detect H2Bub1 in S. cerevisiae and S. pombe. Further, we show that the C-terminal epitope-tagging of histone H2B alters the steady-state levels of H2Bub1 in yeast systems. We report a sectioned blot probing approach combined with the serial dilution of protein lysates and the use of reversibly stained proteins as loading controls that together provide a cost-effective and sensitive method for the quantitative evaluation of H2Bub1 in yeast.
| S-EPMC9609377 | biostudies-literature
Project description:Double-strand breaks repaired by homologous recombination (HR) are first resected to form single-stranded DNA, which binds replication protein A (RPA). RPA attracts mediators that load the Rad51 filament to promote strand invasion, the defining feature of HR. How the resection machinery navigates nucleosome-packaged DNA is poorly understood. Here we report that in Schizosaccharomyces pombe a conserved DDB1-CUL4-associated factor (DCAF), Wdr70, is recruited to DSBs as part of the Cullin4-DDB1 ubiquitin ligase (CRL4(Wdr70)) and stimulates distal H2B lysine 119 mono-ubiquitination (uH2B). Wdr70 deletion, or uH2B loss, results in increased loading of the checkpoint adaptor and resection inhibitor Crb2(53BP1), decreased Exo1 association and delayed resection. Wdr70 is dispensable for resection upon Crb2(53BP1) loss, or when the Set9 methyltransferase that creates docking sites for Crb2 is deleted. Finally, we establish that this histone regulatory cascade similarly controls DSB resection in human cells.
| S-EPMC4844679 | biostudies-literature