Project description:Embryonic stem cells (ESCs) maintain high genomic plasticity, essential for their capacity to enter diverse differentiation pathways. Post-transcriptional modifications of chromatin histones play a pivotal role in maintaining this plasticity. We now report that one such modification, monoubiquitylation of histone H2B on lysine 120 (H2BK120ub1), catalyzed by the E3 ligase RNF20, increases during ESC differentiation and is required for efficient execution of this process. This increase is particularly important for the transcriptional induction of long genes during ESC differentiation. Furthermore, we identify USP44 as a deubiquitinase whose downregulation by differentiation signals contributes to the increase in H2BK120ub1. Our findings suggest that optimal ESC differentiation requires dynamic changes in H2B ubiquitylation patterns, which must occur in a timely and well-coordinated manner. RNF20 depleted or control NTera2 cells stimulated with RA for 72 hours
Project description:Embryonic stem cells (ESCs) maintain high genomic plasticity, essential for their capacity to enter diverse differentiation pathways. Post-transcriptional modifications of chromatin histones play a pivotal role in maintaining this plasticity. We now report that one such modification, monoubiquitylation of histone H2B on lysine 120 (H2BK120ub1), catalyzed by the E3 ligase RNF20, increases during ESC differentiation and is required for efficient execution of this process. This increase is particularly important for the transcriptional induction of long genes during ESC differentiation. Furthermore, we identify USP44 as a deubiquitinase whose downregulation by differentiation signals contributes to the increase in H2BK120ub1. Our findings suggest that optimal ESC differentiation requires dynamic changes in H2B ubiquitylation patterns, which must occur in a timely and well-coordinated manner.
Project description:Rnf20 catalyzes lysine 120 mono-ubiquitination of histone H2B (H2Bub1) that has been previously involved in normal differentiation of embryonic stem (ES) and adult stem cells. However, the mechanisms underlying by which Rnf20 is recruited to its target chromosomal loci to generate H2Bub1 are still elusive. Here, we reveal that Fbxl19, a CxxC domain-containing protein, physically interacts with Rnf20, guides it preferentially to CpG island-containing target promoters, and thereby promotes mono-ubiqutination of H2B. We first show that up-regulation of Fbxl19 induces the level of global H2Bub1, while down-regulation of Fbxl19 reduces the level of H2Bub1 in mouse ES cells. Our genome-wide target mapping unveils the preferential occupancy of Fbxl19 on CpG island-containing promoters, and we further show that the binding of Fbxl19 is essential for the recruitment of Rnf20 to its target genes and subsequent H2Bub1. Altogether, our results demonstrate that Fbxl19 plays critical roles in the H2Bub1 pathway by recruiting Rnf20 to CGI target genes specifically and selectively.
Project description:Rnf20 catalyzes lysine 120 mono-ubiquitination of histone H2B (H2Bub1) that has been previously invloved in normal differentiation of embryonic stem (ES) and adult stem cells. However,the mechanims underlying by which Rnf20 is recruited to its target chromosomal loci to generate H2Bub1 is still elusive. Here, we reveal that Fbxl19, a CxxC domain-containing protein, physically interacts with Rnf20, guides it preferentially to CpG island-containing target promoters, and thereby promotes mono-ubiqutination of H2B. We first show that up-regulation of Fbxl19 induces the level of global H2Bub1, while down-regulation of Fbxl19 reduces the level of H2Bub1 in mouse ES cells. Our genome-wide target mapping unveils the preferential occupancy of Fbxl19 on CpG island-containing promoters, and we further show that the binding of Fbxl19 is essential for the recruitment of Rnf20 to its target genes and subsequent H2Bub1. Altogether, our results demonstrate that Fbxl19 plays critical roles in the H2Bub1 pathway by recruiting Rnf20 to CGI target genes specifically and selectively.
Project description:Defective DNA repair and metabolic rewiring are highly intertwined in promoting the development and progression of cancer. However, the molecular players at the interface of these processes remain largely unexplored. Here we show that the Rnf20-HIF1α axis links the DNA damage response and metabolic reprogramming in lung cancer. Haploinsufficiency of Rnf20, catalyzing histone H2B monoubiquitylation (H2Bub1), dramatically increases the occurrence of spontaneous lung adenocarcinoma and small cell lung carcinoma (SCLC) in mice. Mechanistically, ablation of a single Rnf20 allele resulted in insufficient Rnf20-H2Bub1-p53-mediated control and induced pronounced defects in DNA repair, increased cell growth, epithelial-to-mesenchymal transition (EMT), and metabolic rewiring via HIF1α-mediated RNA polymerase II promoter-proximal pause release, which was independent of H2Bub1. Importantly, RNF20 levels are decreased in lung adenocarcinoma and SCLC patients, and this decrease negatively correlates with the expression of HIF1α target genes, suggesting HIF1α inhibition as a promising therapeutic approach for lung cancer patients with decreased RNF20 activity.
Project description:Defective DNA repair and metabolic rewiring are highly intertwined in promoting the development and progression of cancer. However, the molecular players at the interface of these processes remain largely unexplored. Here we show that the Rnf20-HIF1α axis links the DNA damage response and metabolic reprogramming in lung cancer. Haploinsufficiency of Rnf20, catalyzing histone H2B monoubiquitylation (H2Bub1), dramatically increases the occurrence of spontaneous lung adenocarcinoma and small cell lung carcinoma (SCLC) in mice. Mechanistically, ablation of a single Rnf20 allele resulted in insufficient Rnf20-H2Bub1-p53-mediated control and induced pronounced defects in DNA repair, increased cell growth, epithelial-to-mesenchymal transition (EMT), and metabolic rewiring via HIF1α-mediated RNA polymerase II promoter-proximal pause release, which was independent of H2Bub1. Importantly, RNF20 levels are decreased in lung adenocarcinoma and SCLC patients, and this decrease negatively correlates with the expression of HIF1α target genes, suggesting HIF1α inhibition as a promising therapeutic approach for lung cancer patients with decreased RNF20 activity.
Project description:Defective DNA repair and metabolic rewiring are highly intertwined in promoting the development and progression of cancer. However, the molecular players at the interface of these processes remain largely unexplored. Here we show that the Rnf20-HIF1α axis links the DNA damage response and metabolic reprogramming in lung cancer. Haploinsufficiency of Rnf20 which catalyzes monoubiquitylation of histone H2B (H2Bub1), dramatically increased the incidence of spontaneous lung adenocarcinoma and small cell lung cancer (SCLC) in mice. Mechanistically, ablation of a single Rnf20 allele resulted in inadequate tumor suppression via the Rnf20-H2Bub1-p53 axis and induced DNA damage, increased cell growth, epithelial-mesenchymal transition (EMT), and metabolic rewiring through HIF1α-mediated RNA polymerase II promoter-proximal pause release, that was independent of H2Bub1. Importantly, RNF20 levels are reduced in lung adenocarcinoma and SCLC patients, and this reduction negatively correlates with the expression of HIF1α target genes, suggesting HIF1α inhibition as a promising therapeutic approach for lung cancer patients with reduced RNF20 activity
Project description:Defective DNA repair and metabolic rewiring are highly intertwined in promoting the development and progression of cancer. However, the molecular players at the interface of these processes remain largely unexplored. Here we show that the Rnf20-HIF1α axis links the DNA damage response and metabolic reprogramming in lung cancer. Haploinsufficiency of Rnf20, catalyzing histone H2B monoubiquitylation (H2Bub1), dramatically increases the occurrence of spontaneous lung adenocarcinoma and small cell lung carcinoma (SCLC) in mice. Mechanistically, ablation of a single Rnf20 allele resulted in insufficient Rnf20-H2Bub1-p53-mediated control and induced pronounced defects in DNA repair, increased cell growth, epithelial-to-mesenchymal transition (EMT), and metabolic rewiring via HIF1α-mediated RNA polymerase II promoter-proximal pause release, which was independent of H2Bub1. Importantly, RNF20 levels are decreased in lung adenocarcinoma and SCLC patients, and this decrease negatively correlates with the expression of HIF1α target genes, suggesting HIF1α inhibition as a promising therapeutic approach for lung cancer patients with decreased RNF20 activity.
Project description:Defective DNA repair and metabolic rewiring are highly intertwined in promoting the development and progression of cancer. However, the molecular players at the interface of these processes remain largely unexplored. Here we show that the Rnf20-HIF1α axis links the DNA damage response and metabolic reprogramming in lung cancer. Haploinsufficiency of Rnf20, catalyzing histone H2B monoubiquitylation (H2Bub1), dramatically increases the occurrence of spontaneous lung adenocarcinoma and small cell lung carcinoma (SCLC) in mice. Mechanistically, ablation of a single Rnf20 allele resulted in insufficient Rnf20-H2Bub1-p53-mediated control and induced pronounced defects in DNA repair, increased cell growth, epithelial-to-mesenchymal transition (EMT), and metabolic rewiring via HIF1α-mediated RNA polymerase II promoter-proximal pause release, which was independent of H2Bub1. Importantly, RNF20 levels are decreased in lung adenocarcinoma and SCLC patients, and this decrease negatively correlates with the expression of HIF1α target genes, suggesting HIF1α inhibition as a promising therapeutic approach for lung cancer patients with decreased RNF20 activity.
Project description:Neuroblastoma is an embryonic cancer that disproportionately contributes to death in young children. Sequencing data have uncovered few recurrently mutated genes in this cancer though epigenetic pathways have been implicated in disease pathogenesis. We performed a computational screen of deubiquitinating enzymes to identify potential new targets and identified the histone H2B deubiquitinating enzyme USP44 as significantly over-expressed in high-risk tumors. High levels of USP44 significantly correlate with metastatic disease, unfavorable histology, advanced patient age, and MYCN-amplification. The subset of patients with tumors expressing high levels of USP44 have a significantly worse survival, including those with tumors lacking MYCN-amplification. Depleting USP44 in neuroblastoma cell lines leads to diminished proliferation, migration, invasion, as well as impaired neuritic development in response to retinoic acid. Integrated analysis of RNA-seq and ChIP-seq demonstrates a distinct set of genes that is regulated by USP44, including those in Hallmark pathways critical to tumorigenesis – findings that were completely reversed by the re-introduction of USP44. We conclude that USP44 is a novel epigenetic regulator that restrains differentiation and promotes aggressive features. Our data further suggests that USP44 may be a novel target in this disease.