Project description:We identified a novel E2 ubiquitin conjugating activity within the C-terminus domain of MUC1. To determine if E2 ubiquitin conjugating activity of MUC1 is responsible for regulating expression of oncogenic genes we isolated RNA from vector control cells, MUC1 wildtype overexpression cells, and cells that express a serine mutant lacking E2 activity. RNA was isolated from each of the 3 cell lines, S2013.Neo, S2013.MUC1-WT, and S2013.MUC1-Ser. Gene expression was analyzed by spotted microarray and the differences in gene expression were calculated between the cell lines
Project description:We identified a novel E2 ubiquitin conjugating activity within the C-terminus domain of MUC1. To determine if E2 ubiquitin conjugating activity of MUC1 is responsible for regulating expression of oncogenic genes we isolated RNA from vector control cells, MUC1 wildtype overexpression cells, and cells that express a serine mutant lacking E2 activity.
Project description:Gene expression profiling of immortalized human mesenchymal stem cells with hTERT/E6/E7 transfected MSCs. hTERT may change gene expression in MSCs. Goal was to determine the gene expressions of immortalized MSCs.
Project description:Rad6 E2 ubiquitin-conjugating enzyme and Bre1 E3 ubiquitin ligase catalyze histone H2B Lysine-123 monoubiquitination (H2Bub1), which stabilizes nucleosomes and regulates the trans-histone H3K4 and K79 methylation during gene transcription and other nuclear processes. The interaction interfaces within the Rad6-Bre1-containing H2B ubiquitin-conjugating complex has remained unknown. By solving the crystal structure of Rad6 along with a non-RING domain N-terminal region of Bre1, we report a beta-turn in Rad6's so-called backside region away from catalytic pocket as a binding site for a homodimer of Bre1 E3 ligase. Using quantitative ChIP-seq or ChIP-Rx, we further demonstrate that Rad6's backside beta-turn residues also govern the chromatin binding dynamics of the Rad6-Bre1 complex.
Project description:Rad6 E2 ubiquitin-conjugating enzyme and Bre1 E3 ubiquitin ligase catalyze histone H2B Lysine-123 monoubiquitination (H2Bub1), which stabilizes nucleosomes and regulates the trans-histone H3K4 and K79 methylation during gene transcription and other nuclear processes. The interaction interfaces within the Rad6-Bre1-containing H2B ubiquitin-conjugating complex have remained unknown. By solving the crystal structure of Rad6 along with a non-RING domain N-terminal region of Bre1, we report a beta-turn in Rad6's so-called backside region away from catalytic pocket as a binding site for a homodimer of Bre1 E3 ligase. Using quantitative ChIP-seq or ChIP-Rx, we further demonstrate that Rad6's backside beta-turn residues also govern the chromatin binding dynamics and transcriptional regulatory functions of the Rad6-Bre1 complex.
Project description:Proteins can be targeted for degradation by using engineered molecular conjugates to enhance their interaction with eukaryotic ubiquitination machinery. For instance, the fusion of an E3 ubiquitin ligase to a suitable target binding domain creates a biological ‘Proteolysis-Targeting Chimera’ (bioPROTAC). Here we report an analogous approach where the target is recruited directly to an E2 ubiquitin-conjugating enzyme via an attached target binding domain. We demonstrate that E2 bioPROTACs can induce the degradation of the human proteins SHP2, KRAS and Human Antigen R (HuR). Taking advantage of both rational and unbiased combinatorial screening, we identified novel SHP2 degraders that possess unusually weak affinity. Finally, we explored the proteomic impact of E2 vs. E3 bioPROTACs to inform on their wider impact on the cellular proteome.
Project description:Transcriptional profiling of human mesenchymal stem cells comparing normoxic MSCs cells with hypoxic MSCs cells. Hypoxia may inhibit senescence of MSCs during expansion. Goal was to determine the effects of hypoxia on global MSCs gene expression.
Project description:The RING E3 ubiquitin ligase UHRF1 controls DNA methylation through its ability to target the maintenance DNA methyltransferase DNMT1 to newly replicated chromatin. DNMT1 recruitment relies on ubiquitylation of histone H3 by UHRF1, however, how UHRF1 deposits ubiquitin onto the histone is unknown. Here, we demonstrate that the ubiquitin-like domain (UBL) of UHRF1 is essential for RING-mediated H3 ubiquitylation. Using chemical crosslinking and mass spectrometry, biochemical assays and recombinant chromatin substrates we show that the UBL participates in structural rearrangements of UHRF1 upon binding to chromatin and the E2 ubiquitin conjugating enzyme UbcH5a/UBE2D1. Similar to ubiquitin, the UBL exerts its effects through a hydrophobic patch that contacts a regulatory surface on the “backside” of the E2 to stabilise the E2-E3-chromatin complex. Our analysis of the enzymatic mechanism of UHRF1 uncovers an unexpected function of the UBL-domain and defines a new role for this domain in DNMT1-dependent inheritance of DNA methylation.