Project description:The project aimed to identify interaction sites of RNF168 with the Nucleosomes. RNF168 interaction with the Nucleosome was probed by BS3 crosslinking to support structure modeling based on NMR and mutagenesis experiments
Project description:Genome-wide distribution of proteins and histone marks in CD43 negative mouse resting B cells ChIP-seq analyses of Aurora B, Ring1B, Bcx7, USP16, H3K27me3, and Ezh2 were carried out on wild-typeCD43 negative resting B cells. ChIP-seq datasets obtained from Aurora B knockout and RingiB knockout cells were used as negative controls to validate the signals for Aurora B and Ring1B from wild-type cells. 8WG16 ChIP-seq datasets were generated from WT (Cre-ERt2 homozygous) and Ring1B KO (Cre-ERt2/Rnf2 flox homozygous). RNAP-S5ph ChIP-seq datasets were generated from WT (Cre-ERt2 homozygous) and Aurkb KO (Cre-ERt2/Aurkb flox homozygous). ChIP-seq analyses of H3S28 phosphorylation (H3S28ph) and H2AK119 monoubiquitination (H2Aub1) in wild-type (Cre-ERt2 homozygous) and Aurora B KO (Cre-ERt2/Aurkb flox homozygous) CD43 negative resting B cells treated with 250nM tamoxifen (4-hydroxytamoxifen) for 48 hours. ChIP-seq analyses of the levels of unphosphorylated RNA Pol II (8WG16) and serine 5-phosphorylated RNA Pol II (RNAP-S5ph) were conducted in Aurkb KO (Cre-ERt2/Aurkb flox homozygous) and Ring1B KO (Cre-ERt2/Rnf2 flox homozygous) CD43 negative resting B cells treated with 250nM tamoxifen (4-hydroxytamoxifen) for 48 hours respectively). All libraries were prepared from sonicated, formaldehyde-crossilinked chromatin. For H2Aub1, ChIP was performed using micrococcal nuclease-digested, unfixed chromatin, instead.
Project description:Epigenetic regulators have emerged as critical factors governing the biology of cancer. Here, in the context of melanoma, we show that RNF2 is prognostic, exhibiting progression-correlated expression in human melanocytic neoplasms. Through a series of gain of function and loss of function studies, we establish that RNF2 is oncogenic and pro-metastatic. Mechanistically, RNF2-mediated invasive behavior is dependent on its ability to mono-ubiquitinate H2AK119 at the promoter of LTBP2, resulting in silencing of this negative regulator of TGFβ signaling. In contrast, RNF2's oncogenic activity did not require its catalytic activity nor derives from its canonical gene repression function, rather RNF2 drives proliferation through direct transcriptional up-regulation of the cell cycle regulator CCND2. In summary, RNF2 regulates distinct biological processes in the genesis and progression of melanoma via distinct molecular mechanisms, underscoring the complex and multi-faceted actions of epigenetic regulators in cancer. RNF2 is overexpressed in immortalized human melanocytes HMEL-BRAFV600E to address impact of RNF2 overexpression in melanoma and identify RNF2 target genes. ChIP was performed to identify RNF2 binding sites using antibody against the V5 tag.
Project description:Nucleotide excision repair (NER) is the major DNA repair pathway that removes UV-induced and bulky DNA lesions. There is currently no structure of NER intermediates, which form around the large multisubunit transcription factor IIH (TFIIH). Here we report the cryo-EM structure of an NER intermediate containing TFIIH and the NER factor XPA. Compared to its transcription conformation, the TFIIH structure is rearranged such that its ATPase subunits XPB and XPD bind double- and single-stranded DNA, consistent with their translocase and helicase activities, respectively. XPA releases the inhibitory kinase module of TFIIH, displaces a ‘plug’ element from the DNA-binding pore in XPD, and together with the NER factor XPG stimulates XPD activity. Our results explain how TFIIH is switched from a transcription to a repair factor, and provide the basis for a mechanistic analysis of the NER pathway.
Project description:Epigenetic regulators have emerged as critical factors governing the biology of cancer. Here, in the context of melanoma, we show that RNF2 is prognostic, exhibiting progression-correlated expression in human melanocytic neoplasms. Through a series of gain of function and loss of function studies, we establish that RNF2 is oncogenic and pro-metastatic. Mechanistically, RNF2-mediated invasive behavior is dependent on its ability to mono-ubiquitinate H2AK119 at the promoter of LTBP2, resulting in silencing of this negative regulator of TGFβ signaling. In contrast, RNF2's oncogenic activity did not require its catalytic activity nor derives from its canonical gene repression function, rather RNF2 drives proliferation through direct transcriptional up-regulation of the cell cycle regulator CCND2. In summary, RNF2 regulates distinct biological processes in the genesis and progression of melanoma via distinct molecular mechanisms, underscoring the complex and multi-faceted actions of epigenetic regulators in cancer. RNF2 is overexpressed in immortalized human melanocytes HMEL-BRAFV600E to address impact of RNF2 overexpression in melanoma. GFP was overexpressed in HMEL-BRAFV600E cells as a control cell line. Expression profiling using microarray was performed and compared between RNF2 overexpressing versus GFP overexpressing HMEL-BRAFV600E cells.
Project description:The PTEN:P-Rex2 complex is a commonly mutated signaling nodes in metastatic cancer. The dual-specificity phosphatase PTEN canonically functions as a tumour suppressor by hydrolysing PI(3,4,5)P3 to PI(4,5)P2 to inhibit PI3K-AKT signaling. P-Rex2 is a RhoGTPase guanine nucleotide exchange factor activated by both Gβγ and PI(3,4,5)P3 downstream of G protein-coupled receptor and receptor tyrosine kinase signaling. Assembly of the PTEN:P-Rex2 complex inhibits the activity of both proteins, and its dysregulation can drive PI3K-AKT signaling and cell proliferation. However, structural insights into both PTEN:P-Rex2 complex assembly and its dysregulation by cancer-associated mutations remain limited. Here, using crosslinking mass spectrometry and functional studies, we provide mechanistic insights into PTEN:P-Rex2 complex assembly and co-inhibition. PTEN is anchored to P-Rex2 by interactions between the PTEN C-terminal tail PDZ-interacting motif and the second PDZ domain of P-Rex2. This interaction bridges PTEN across the P-Rex2 surface, occluding PI(3,4,5)P3 hydrolysis. Conversely, PTEN both allosterically promotes an autoinhibited P-Rex2 conformation and occludes Gβγ binding. These insights allow us to define a new gain-of-function class of cancer mutations within the PTEN:P-Rex2 interface that uncouples PTEN inhibition of Rac1 signaling. In addition, we observe synergy between PTEN deactivating and P-Rex2 truncation mutations that combine to drive Rac1 activation to a greater extent than either single mutation alone.
Project description:The goal was to obtain the differential transcriptome in the deep cones between shallow and deep wounds and between the Yorkshire and Duroc breeds over time. We made shallow and deep wounds on the backs of 3 Yorkshire and 3 Duroc pigs, biopsied the wounds at 1 2 3 12 and 20 weeks, extracted and amplified the RNA from the deep cones, and hybridized the Affymetrix GeneChip®. We compared wound depth by breed over time; the system included 3 factors (depth, breed and time). The system also included repeated measures since the same pigs were used at each time. It also included paired data since the shallow and deep wounds compared were located on the same pig.
Project description:Langerhans cells (LC) in skin help initiate the immune response to locally presented antigens. We performed high-resolution single-cell RNA-sequencing (scRNAseq) analysis for antigen presenting cells including LC in normal mouse skin, and in mouse skin expressing the human papillomavirus (HPV) 16 E7 oncogene. Ear skin was collected from normal and trangenic mice. Dissociated CD45+ cells were processed for scRNA-seq using the 10X Genomics Chromium 3' gene expression kit (v2).
Project description:To determine if there is a physical interaction between the FOXF1 promoter and putative enhancer sequences ~250kb upstream of the promoter chromosome conformation capture-on-chip (4C) analysis was performed. An unanticipated and tremendous amount of the non-coding sequences of the human genome are transcribed. Long non-coding RNAs (lncRNAs) are non-protein coding transcripts longer than 200 nucleotides and their functions remain enigmatic. We demonstrate that deletions of lncRNA genes cause a lethal lung developmental disorder, Alveolar Capillary Dysplasia with Misalignment of Pulmonary Veins (ACD/MPV), with parent of origin effects. We identify non-coding overlapping deletions 250 kb upstream to FOXF1 in nine patients with ACD/MPV that arose de novo specifically on the maternally inherited chromosome and delete a fetal lung-specific EST, part of an lncRNA. These deletions define distant cis-regulatory region that harbors a differentially methylated CpG island, binds GLI2 depending on the methylation status of this CpG island, and physically interacts with and up-regulates the FOXF1 promoter, consistent with the absence of the fetal lung-transcribed lncRNA perturbing FOXF1 regulation. LncRNA-mediated chromatin interactions may be responsible for position effect phenomenon and potentially cause many disorders of human development. 4C analysis using 16q24.1 specific 3x720K arrays demonstrated physical interaction between the FOXF1 promoter and distant putative regulatory sequences, about 250 kb upstream in human pulomonary microvascular endothelial cells; 2 biological replicates performed; this chromatin looping was not detected in lymphoblasts that do not express FOXF1 and hence serve as a negative control.