Project description:The goal of the experiment was to determine the role of H2A deubiquitinase in the nerve injury response in peripheral nerve. A Schwann cell specific knockout of the H2A deubiquitinase (Bap1) was generated to compare with wild type mice.
Project description:The proteasome-associated deubiquitinase USP14 has attracted significant attention in recent years due to its potential as a drug target. Here, we employ an inducible USP14 knockout system to dissect early phenotypic and gene expression alterations following USP14 loss. Transcriptomic analysis revealed widespread changes in the expression of actin cytoskeleton components associated with shifts in cellular actin distribution and morphology, as well as changes in the deubiquitinase expression profile. We observed an increase in ubiquitin turnover that appeared to be offset by the upregulation of polyubiquitin genes UBB and UBC.
Project description:Ubiquitination-mediated protein degradation of key transcriptional factors is important to the self-renewal of embryonic stem (ES) cells. However, little is known about the deubiquitination in ES self-renewal and differentiation. Here, we report that deubiquitinase USP21 is an important positive regulator to keep ES cells under undifferentiation stasus by deubiquitination and stabilization of Nanog, a key transcriptional factor of ES cells. Loss of USP21 led to ES cells differentiation and defect in reprogramming.
Project description:Degradation of aggregation-prone tau is regulated by the ubiquitin-proteasome system (UPS) and autophagy, which are impaired in Alzheimer’s disease (AD) and related tauopathies causing tau aggregation. Protein ubiquitination with linkage specificity determines the fate of proteins that can be either degradative or stabilization signals. While the linear M1-linked ubiquitination on protein aggregates is a signaling hub that recruits various ubiquitin-binding proteins for coordinated actions of protein aggregates turnover and inflammatory NF-kB activation, the deubiquitinase OTULIN counteracts with the M1-linked ubiquitin signaling. However, the exact role of OTULIN on tau aggregate clearance in AD is unknown. We did bulk RNA sequencing in human inducible pluripotent stem cell (iPSC)-derived neurons (iPSNs) from a healthy control (WTC11) and an individual with late-onset sporadic AD (sAD2.1), which shows downregulation of ubiquitin ligase activating factors (MAGEA2B and MAGEA) and OTULIN long non-coding RNA (lncRNA-OTULIN) compared to healthy control WTC11 iPSNs. In sAD2.1 iPSNs, downregulated lncRNA-OTULIN is inversely correlated with increased levels of OTULIN protein and phosphorylated tau at p-S202/p-T205 (AT8), p-T231 (AT180), and p-S396/p-S404 (PHF-1). Loss of OTULIN deubiquitinase function using pharmacological inhibitor UC495 or CRISPR-Cas9-mediated OTULIN gene knockout causes a significant reduction of total tau and phosphory-lated tau at AT8 epitope in sAD2.1 iPSNs. Together, our results suggest for the first time a non-canonical function for OTULIN in regulating gene expression and RNA metabolism, which may have a significant pathogenic role in AD and related tauopathies.