ABSTRACT: ovary extracts from transgenic flies expressing either GFP alone or a GFP-Pur-alpha fusion protein were prepared and anti-GFP immpunoprecipitates were made. RNA was isolated from the input and bound fractions and analyzed using Affymetrix drosophila 2.0 arrays
Project description:Dual-specificity phosphatase 8 is a MAPK phosphatase that dephosphorylates and inactivates the kinase JNK. DUSP8 is highly expressed in T cells; however, the in vivo role of DUSP8 in T cells remains unclear. Using T-cell-specific DUSP8 conditional knockout (T-DUSP8 cKO) mice, mass spectrometry analysis, chromatin-immunoprecipitation sequencing, and immune analysis, we found that DUSP8 interacted with Pur-α, stimulated interleukin-9 (IL-9) gene expression, and promoted Th9 differentiation. Mechanistically, DUSP8 dephosphorylated the transcriptional repressor Pur-α upon TGF-β signaling, leading to the nuclear export of Pur-α and subsequent IL-9 transcriptional activation. Furthermore, IL-9 mRNA levels were induced in Pur-α-deficient T cells. In addition, T-DUSP8 cKO mice displayed reduction of IL-9 and Th9-mediated immune responses in the allergic asthma model. Reduction of IL-9 mRNA levels in T cells and allergic responses of T-DUSP8 cKO mice was reversed by Pur-α knockout. Remarkably, DUSP8 protein levels and the DUSP8–Pur-α interaction were indeed increased in the cytoplasm of T cells from human asthma patients and atopic dermatitis patients. Collectively, DUSP8 induces TGF-β-stimulated IL-9 transcription and Th9-induced allergic responses by inhibiting the nuclear translocation of the transcriptional repressor Pur-α. DUSP8 may be a T-cell biomarker and therapeutic target for asthma and atopic dermatitis.
Project description:The PUF family of RNA binding proteins has a conserved role in maintaining stem cell self-renewal. FBF is a C. elegans PUF that is required to maintain germline stem cells (GSCs). To understand how FBF controls GSCs, we sought to identify is target mRNAs. Briefly, we immunoprecipitated FBF-mRNA complexes from worm extracts and then used microarrays to identify the FBF-associated mRNAs. To focus on germline targets of FBF, we used a FBF-GFP transgene under the control of a germline promoter and we used an anti-GFP antibody to purify FBF-GFP from worm extracts. In parallel, we also processed a strain expressing TUBULIN-GFP in the germline to control for mRNAs that non-specifically co-purify with GFP. We found that FBF associates with >1,000 unique mRNAs and likely controls a broad network of key cellular and developmental regulators. Experiment Overall Design: Worm extracts were prepared from synchronized adult C. elegans (24 h after L4 stage) expressing either a rescuing FBF-1-GFP or TUB-GFP transgene under the control of a germline promoter (pie-1). An immoblized anti-GFP antibody was then used to purify the GFP fusion proteins from extracts. RNA was then extracted from the pellets and analyzed on Affymetrix microarrays. Four biological replicates were performed, each consisting of a FBF-GFP and a TUB-GFP sample processed in parallel.
Project description:Dual-specificity phosphatase 8 is a MAPK phosphatase that dephosphorylates and inactivates the kinase JNK. DUSP8 is highly expressed in T cells; however, the in vivo role of DUSP8 in T cells remains unclear. Using T-cell-specific DUSP8 conditional knockout (T-DUSP8 cKO) mice, mass spectrometry analysis, chromatin-immunoprecipitation sequencing, and immune analysis, we found that DUSP8 interacted with Pur-α, stimulated interleukin-9 (IL-9) gene expression, and promoted Th9 differentiation. Mechanistically, DUSP8 dephosphorylated the transcriptional repressor Pur-α upon TGF-β signaling, leading to the nuclear export of Pur-α and subsequent IL-9 transcriptional activation. Furthermore, IL-9 mRNA levels were induced in Pur-α-deficient T cells. In addition, T-DUSP8 cKO mice displayed reduction of IL-9 and Th9-mediated immune responses in the allergic asthma model. Reduction of IL-9 mRNA levels in T cells and allergic responses of T-DUSP8 cKO mice was reversed by Pur-α knockout. Remarkably, DUSP8 protein levels and the DUSP8–Pur-α interaction were indeed increased in the cytoplasm of T cells from human asthma patients and atopic dermatitis patients. Collectively, DUSP8 induces TGF-β-stimulated IL-9 transcription and Th9-induced allergic responses by inhibiting the nuclear translocation of the transcriptional repressor Pur-α. DUSP8 may be a T-cell biomarker and therapeutic target for asthma and atopic dermatitis.
Project description:Dual-specificity phosphatase 8 is a MAPK phosphatase that dephosphorylates and inactivates the kinase JNK. DUSP8 is highly expressed in T cells; however, the in vivo role of DUSP8 in T cells remains unclear. Using T-cell-specific DUSP8 conditional knockout (T-DUSP8 cKO) mice, mass spectrometry analysis, chromatin-immunoprecipitation sequencing, and immune analysis, we found that DUSP8 interacted with Pur-α, stimulated interleukin-9 (IL-9) gene expression, and promoted Th9 differentiation. Mechanistically, DUSP8 dephosphorylated the transcriptional repressor Pur-α upon TGF-β signaling, leading to the nuclear export of Pur-α and subsequent IL-9 transcriptional activation. Furthermore, IL-9 mRNA levels were induced in Pur-α-deficient T cells. In addition, T-DUSP8 cKO mice displayed reduction of IL-9 and Th9-mediated immune responses in the allergic asthma model. Reduction of IL-9 mRNA levels in T cells and allergic responses of T-DUSP8 cKO mice was reversed by Pur-α knockout. Remarkably, DUSP8 protein levels and the DUSP8–Pur-α interaction were indeed increased in the cytoplasm of T cells from human asthma patients and atopic dermatitis patients. Collectively, DUSP8 induces TGF-β-stimulated IL-9 transcription and Th9-induced allergic responses by inhibiting the nuclear translocation of the transcriptional repressor Pur-α. DUSP8 may be a T-cell biomarker and therapeutic target for asthma and atopic dermatitis.
Project description:The PUF family of RNA binding proteins has a conserved role in maintaining stem cell self-renewal. FBF is a C. elegans PUF that is required to maintain germline stem cells (GSCs). To understand how FBF controls GSCs, we sought to identify is target mRNAs. Briefly, we immunoprecipitated FBF-mRNA complexes from worm extracts and then used microarrays to identify the FBF-associated mRNAs. To focus on germline targets of FBF, we used a FBF-GFP transgene under the control of a germline promoter and we used an anti-GFP antibody to purify FBF-GFP from worm extracts. In parallel, we also processed a strain expressing TUBULIN-GFP in the germline to control for mRNAs that non-specifically co-purify with GFP. We found that FBF associates with >1,000 unique mRNAs and likely controls a broad network of key cellular and developmental regulators.
Project description:Identification of RNAs that bind to EB1-GFP using RNA-immunoprecipitation followed by sequencing. Ovaries from flies expressing EB1-GFP (and GFP alone as a control) were used to immunoprecipitate crosslinked RNA-EB1GFP complexes using GFP Trap beads. The experiment was performed with three biological replicates for each.
Project description:Wild-type Drosophila melanogaster expressing nuclear GFP-KASH fusion protein in photoreceptors for cell type-specific gene expression profiling (Rh1-Gal4>UAS-GFPKASH ; Genotype = w1118;; P{w+mC=[UAS-GFP-Msp300KASH}attP2, P{ry+t7.2=rh1-GAL4}3, ry506) were raised in 12:12h light:dark cycle at 25°C. Flies were aged for 10 or 40 days post-eclosion, and eyes were harvested from male flies for global quantitative proteomic analysis. Significantly changed proteins were identified that may contribute to age-associated retinal degeneration and loss of visual function in the aging Drosophila eye.
Project description:The synaptic protein α-synuclein is linked through genetics and neuropathology to the pathogenesis of Parkinson’s disease and related disorders. However, the mechanisms by which α-synuclein influences disease onset and progression are incompletely understood. To identify novel pathways and potential therapeutic targets we performed proteomic analysis in a highly penetrant new Drosophila model of α-synucleinopathy. We identified 476 significantly upregulated and 563 significantly downregulated proteins in heads from α-synucleinopathy model flies compared to controls. We then used multiple complementary analyses to identify and prioritize genes and pathways within the large set of differentially expressed proteins for functional studies. We performed Gene Ontology enrichment analysis, integrated our proteomic changes with human Parkinson’s disease genetic studies, and compared the α-synucleinopathy proteome with that of tauopathy model flies, which are relevant to Alzheimer’s disease and related disorders. These approaches identified GTP cyclohydrolase (GCH1) and folate metabolism as candidate mediators of α-synuclein neurotoxicity. In functional validation studies we found that knockdown of Drosophila Gch1 enhanced locomotor deficits in α-synuclein transgenic flies, while folate supplementation protected from α-synuclein toxicity. Our integrative analysis suggested that mitochondrial dysfunction was a common downstream mediator of neurodegeneration. Accordingly, Gch1 knockdown enhanced metabolic dysfunction in α-synuclein transgenic fly brains while folate supplementation partially normalized whole brain bioenergetics. Here we outline and implement an integrative approach to identify and validate potential therapeutic pathways using comparative proteomics and genetics and capitalizing on the facile genetic and pharmacological tools available in Drosophila.
Project description:Purpose: The goals of this study are to compare RNAs bound by translating ribosomes in the presence or absence of Segmented Filamentous Bacteria (SFB) colonization of the small intestine Methods: EDTA fractions containing small intestine epithelial cells from SFB negative and SFB positive mice were harvested. TRAP assay enriching for ribosome bound fraction were enriched using anti-GFP antibodies against GFP-ribosomeL10 fusion protein. mRNA profiles were generated by deep sequencing, using Illumina HighSeq. The sequence reads that passed quality filters were analyzed at the transcript isoform level with two methods: Burrows–Wheeler Aligner (BWA) and TopHat followed by CuffDiff. qRT–PCR validation was performed using SYBR Green assays. Results: SFB colonization upregulate a subset of mRNAs being translated by ribosomes. Conclusions: SFB changes small intestine epithelial cell translation profile.
Project description:Glycolytic (G) bodies were purified from hypoxic yeast using differential centrifugation and immunoprecipitation by Pfk2-GFP-Flag in order to determine the RNAs that localize to G bodies by determining the enrichment of RNAs copurified with G bodies over both the flow through and total RNA fractions. We find significant overlap between enriched RNAs and RNAs bound by glycolysis enzymes in normoxic conditions. Our study determined that RNA is an integral component of G bodies and is required for G body formation. Specific mRNAs are only slightly enriched in G bodies.