Project description:Global phosphoproteomic screen to identify the first cellular substrates of CDKL5. CDKL5 knock-out U2OS cells and CDKL5 wt U2OS cells were generated for the TMT-based phosphoproteomic. Thi leads to the identification and further validation of several phosphopetides of MAP1S, CEP131 and CDKL5 itself. The phosphoproteomic analysis allowed the identification of the first cellular substrates for CDKL5 kinase.
Project description:Huntington’s disease (HD) symptoms are driven to a large extent by dysfunction of the basal ganglia circuitry. HD patients exhibit reduced striatal phoshodiesterase 10 (PDE10) levels. Using HD mouse models that exhibit reduced PDE10, we demonstrate the benefit of pharmacologic PDE10 inhibition to acutely correct basal ganglia circuitry deficits. PDE10 inhibition restored corticostriatal input and boosted cortically driven indirect pathway activity. Cyclic nucleotide signaling is impaired in HD models and PDE10 loss may represent a homeostatic adaptation to maintain signaling. Elevation of both cAMP and cGMP by PDE10 inhibition were required for rescue. Phosphoproteomic profiling of striatum in response to PDE10 inhibition highlighted plausible neural substrates responsible for the improvement. Early chronic PDE10 inhibition in Q175 mice showed improvements beyond those seen with acute administration after symptom onset, including partial reversal of striatal deregulated transcripts and the prevention of the emergence of HD neurophysiological deficits.
Project description:It is unclear to what extent Tau molecular pathology in murine models reflect human Tauopathies. Nevertheless, mouse models that overexpress human mutant Tau (P301S and P301L) are widely used in studies of Tauopathies and Alzheimer’s Disease (AD). In this study, we perform an in-depth temporally and spatially resolved mass spectrometry-based proteomic analysis of P301S (hTau.P301S) and P301L (rTg(tauP301L)4510) mice as well as human patients with AD or frontotemporal dementia due to the P301L mutation, to identify differences and similarities between human AD, animal models and human P301L patients. Both mouse models and human P301L patients show progressive Tau accumulation driven by Tau phosphorylation during disease progression as also observed in early human AD. However, Tau ubiquitination and acetylation, important in human AD, are less or not represented in the mouse models or in P301L patients. Our analyses provide guidance regarding designing mechanistic studies and testing of Tau directed therapeutics.
Project description:TO identified its potential phosphorylated substrates by investigating differential phosphorylated sites in the testes of wild-type (w1118) and dTSSK-/- male flies using quantitative phosphoproteomic analysis
Project description:Aberrant signaling pathway activity is a hallmark of tumorigenesis and progression, which has guided targeted inhibitor design for over 30 years. Yet, adaptive resistance mechanisms, induced by rapid, context-specific signaling network rewiring, continue to challenge therapeutic efficacy. By leveraging progress in proteomic technologies and network-based methodologies over the past decade we developed VESPA—an algorithm designed to elucidate mechanisms of cell response and adaptation to drug perturbations—and used it to analyze 7-point phosphoproteomic time series from colorectal cancer cells treated with clinically-relevant inhibitors and control media. Interrogation of tumor-specific enzyme/substrate interactions accurately inferred kinase and phosphatase activity, based on their inferred substrate phosphorylation state, effectively accounting for signal cross-talk and sparse phosphoproteome coverage. The analysis elucidated time-dependent signaling pathway response to each drug perturbation and, more importantly, cell adaptive response and rewiring that was experimentally confirmed by CRISPRko assays, suggesting broad applicability to cancer and other diseases.