Project description:The CD117 mast/stem cell growth factor receptor tyrosine kinase (KIT) is critical for haematopoiesis, melanogenesis, and stem cell maintenance. KIT is commonly activated by mutation in cancers including acute myeloid leukaemia, melanoma, and gastrointestinal stromal tumours (GISTs). The kinase and the juxtamembrane domains of KIT are mutation hotspots; with the kinase domain mutation D816V common in leukaemia, and the juxtamembrane domain mutation V560G common in GISTs. Given the importance of mutant KIT signalling in cancer, we have conducted a proteomic and phosphoproteomic analysis of D816V- and V560G-KIT mutations, using an FDCP1 isogenic cell line model.
Project description:IKKα is a critical regulator of the non-canonical NF-KB signalling pathway. In patients with combined immunodeficiency, we identified a homozygous missense mutation in CHUK gene, coding for IKKα protein, leading to G167R amino acid change in the kinase domain of the protein. This mutation impairs the kinase activity of IKKα, which results in a range of aberratins in innate and adaptive immunity.
Project description:We used microarrays to assess gene expression profiling of 6 patients with a mutation (Arg1174Gln) in the tyrosine kinase domain of the insulin receptor gene (INSR) and 10 matched healthy controls
Project description:We used microarrays to assess gene expression profiling of 6 patients with a mutation (Arg1174Gln) in the tyrosine kinase domain of the insulin receptor gene (INSR) and 10 matched healthy controls Total RNA was purified from skeletal muscle and amplified to biotin-labeled aRNA and hybridized to microarray chips.
Project description:Gain-of kinase function variants in LRRK2 (leucine-rich repeat kinase 2) cause Parkinson’s disease (PD), albeit with incomplete and age-dependent penetrance, offering the prospect of disease-modifying treatment strategies via LRRK2 kinase inhibition. LRRK2 phosphorylates a subgroup of RabGTPases including Rab10 and pathogenic mutations enhance LRRK2-mediated phosphorylation of Rab10 at Thr73. In this study we analyse LRRK2 dependent Rab10Thr73 phosphorylation in human peripheral blood neutrophils isolated from 101 individuals using quantitative immunoblotting and mass spectrometry. Our cohort includes 42 LRRK2 mutation carriers (21 with the G2019S mutation that resides in the kinase domain and 21 with the R1441G mutation that lies within the ROC-COR domain), 27 patients with idiopathic PD, and 32 controls. We show that LRRK2 dependent Rab10 Thr73 phosphorylation is significantly elevated in all R1441G LRRKR2 mutation carriers irrespective of disease status. PD manifesting and non-manifesting G2019S mutation carriers as well as idiopathic PD samples did not display elevated Rab10 Thr73 phosphorylation. Furthermore, we analysed brain samples of 10 G2019S and 1 R1441H mutation carriers as well as 10 individuals with idiopathic PD and 10 controls. We find high variability for pRab10Thr73 phosphorylation amongst donors irrespective of genetic and disease state. We conclude that in vivo LRRK2 dependent pRab10Thr73 analysis in human peripheral blood neutrophils is a specific and robust biomarker for LRRK2 kinase activation for individuals with mutations such as R1441G that enhance pRab10Thr73 phosphorylation over 2-fold. We provide the first evidence that the LRRK2 R1441G mutation enhances LRRK2 kinase activity in a primary human cell.
Project description:Genome-wide DNA methylation profiling of 30 low-grade neuroepithelial tumors with FGFR1 alterations including rosette-forming glioneuronal tumor, pilocytic astrocytoma, dysembryoplastic neuroepithelial tumor, and extraventricular neurocytoma. The Illumina Infinium EPIC 850k Human DNA Methylation Beadchip was used to obtain DNA methylation profiles across approximately 850,000 CpG sites of genomic DNA extracted from formalin-fixed, paraffin-embedded tumor tissue of 30 low-grade neuroepithelial tumors with FGFR1 alterations including kinase domain tandem duplication, in-frame fusion with TACC1, and hotspot missense mutation within the intracellular tyrosine kinase domain.
Project description:ATM kinase is a master regulator of the DNA damage response and loss of ATM leads to primary immunodeficiency and greatly increased risk for lymphoid malignancies. The FATC domain is conserved in Phosphatidylinositol-3-kinase-related protein kinases (PIKKs). Truncation mutation in the FATC domain (R3047X) selectively compromised reactive oxygen species-induced ATM activation in cell-free assays. Here we show that in mouse models, knock-in ATM-R3057X (AtmRX, corresponding to R3047X in human ATM) mutation severely compromises ATM protein stability, and causes T cell development and B cell immunoglobulin class switch recombination defects and infertility resembling ATM-null. The residual ATM R3057X protein retains minimal, yet functional measurable, DNA damage-induced checkpoint activation and significantly delays lymphomagenesis in AtmRX/RX mice compared to Atm-/-. Together, these results support a physiological role of the FATC domain in ATM protein stability and show that minimal ATM activity can prevent growth retardation and delay tumorigenesis without restoring lymphocyte development and fertility.
Project description:Numerous leucine-rich repeat kinase 2 mutations identified throughout the protein are associated with Parkinson disease, however the activating G2019S kinase domain mutation is currently regarded as the most common cause of familial and sporadic forms of this disorder. Despite studies demonstrating the prominent role that its kinase activity plays in the pathobiology of leucine-rich repeat kinase 2, few substrates have been identified and only a subset of these have been linked to disease. Therefore, we utilized protein microarrays to screen over 9,000 human proteins in an unbiased radiometric assay for potential targets of the kinase.