Project description:In eukaryotes, trimethylation of lysine 9 on histone H3 (H3K9) is associated with transcriptional silencing of transposable elements (TEs). In drosophila ovaries, this heterochromatic repressive mark is thought to be deposited by SetDB1 on TE genomic loci after the initial recognition of nascent transcripts by PIWI-interacting RNAs (piRNAs) loaded on the Piwi protein. Here, we show that the nucleosome remodeler Mi-2, in complex with its partner MEP-1, forms a subunit that is transiently associated, in a MEP-1 C-terminus-dependent manner, with known Piwi interactors, including a recently reported SUMO ligase Su(var)2-10. Together with the histone deacetylase Rpd3, this module is involved in the piRNA-dependent TE silencing, correlated with H3K9 deacetylation and trimethylation. Therefore. drosophila piRNA-mediated transcriptional silencing involves three epigenetic effectors, a remodeler, Mi-2, an eraser, Rpd3 and a writer, SetDB1, in addition to the Su(var)2-10 SUMO ligase.
Project description:The N-terminal three zinc finger motifs of PARP1 are evolutionarily conserved in multicellular organism。However, during apoptosis, human PARP1 is mainly cleaved by caspase 3 at D214. As a result, the truncated PARP1 loses two N-terminal zinc finger motifs and only contains the third zinc finger motif, the BRCT domain, the WGR domain and the C-terminal catalytic domain. Interestingly, when we explored the domain architecture of PARP1 in other organisms, we found that similar to human tPARP1, PARP1 orthologs in several lower organisms do not have the N-terminal two zinc fingers or even they lack the third zinc finger motif. It indicates that even without the first two zinc finger motifs, tPARP1 may still catalyze ADP-ribosylation and play an important role in certain biological processes. To reveal the biological function of tPARP1, we performed tandem affinity purification and searched for the possible substrates.
Project description:Mass spectrometry data comparing the plasma membrane proteins of Nek1-WT and Nek1-Kat2J MEFs enriched by Pierce™ Cell Surface Protein Isolation Kit.
Project description:Mycobacterium abscessus is nowadays under the spotlight of the scientific community. This pathogenic mycobacteria is indeed responsible for a wide spectrum of infections involving mostly pulmonary infections in patients with cystic fibrosis. M. abscessus is intrinsically resistant to a broad range of antibiotics, including most antitubercular drugs, and is considered the most pathogenic and chemotherapy-resistant rapidly growing mycobacterium. Consequently, with very limited treatment options, the development of new therapeutic approaches to fight this pathogen are urgently needed. 38 new analogs of Cyclipostins & Cyclophostin (CyC), compounds naturally produced by Streptomyces species, have been synthesized. Their antibacterial activities against clinical isolates belonging to the M. chelonae-abscessus clade, as well as Gram-negative and Gram-positive bacteria have been evaluated by the REMA method. The intracellular activities of the CyC against intramacrophagic M. abscessus have also been investigated and compared to those of imipenem. The CyCs displayed very low toxicity towards host cells and their inhibitory activity was exclusively restricted to mycobacteria. The best candidate, CyC17, showed a high selectivity for mycobacteria with MIC values (<2 up to 40 µg/mL) comparable to those of most classical antibiotics used to treat M. abscessus infections. Of importance, several CyCs were active against extracellular M. abscessus growth (i.e., CyC17 / CyC18β / CyC25 / CyC26) or against intracellular mycobacteria inside macrophages (i.e., CyC7α,β / CyC8α,β) with MIC values similar to or better than those of standard antibiotics. Based on these results, we intended to identify the potential target enzymes of CyC17/CyC26 in M. abscessus by activity-based protein profiling (ABPP) approach coupled with mass spectrometry differential analysis.
Project description:Mycobacterium abscessus is nowadays under the spotlight of the scientific community. This pathogenic mycobacteria is indeed responsible for a wide spectrum of infections involving mostly pulmonary infections in patients with cystic fibrosis. M. abscessus is intrinsically resistant to a broad range of antibiotics, including most antitubercular drugs, and is considered the most pathogenic and chemotherapy-resistant rapidly growing mycobacterium. Consequently, with very limited treatment options, the development of new therapeutic approaches to fight this pathogen are urgently needed. In this context, 19 oxadiazolone (OX) derivatives have been investigated for their antibacterial activity against both the rough (R) and smooth (S) variants of M. abscessus. Several OXs were active against extracellular M. abscessus growth with moderated minimal inhibitory concentrations (MIC), or intracellularly by inhibiting M. abscessus growth inside infected macrophages with MIC values similar to those of imipenem. Such promising results prompted us to identify the potential target enzymes of the sole extra and intracellular inhibitor of M. abscessus growth, i.e., iBpPPOX via activity-based protein profiling combined with mass spectrometry. This approach led to the identification of 21 potential protein candidates being mostly involved in M. abscessus lipid metabolism and/or in cell wall biosynthesis.
Project description:This article describes a mass spectrometry data set generated from osteogenic differentiated bone marrow stromal cells (BMSCs) and adipose tissue derived stromal cells (ASCs) of a 24-year old healthy donor spiked with iRT peptides. Cells have been identified via FACS-Analysis positive for CD90 and CD105 and negative for CD14, CD34, CD45 and CD11b and tri-lineage differentiation. Obtaining a sufficient amount of high-quality tissue is the key limiting factor for establishing a region-specific spectral library. Hence, combining existing spectral libraries for data-independent acquisition analysis (DIA) can overcome this major limitation. Moreover, these data can be used to map region-specific proteins and to model region-specific pathways. Both can improve our understanding of the functioning in greater depth. In addition, these data can also be used to determine the optimal settings for measuring proteins and peptides of interest. To create the specific spectral library, the tissue was first homogenized and then fractionated via different types of SDS gel electrophoresis, resulting in 11 fractions. These fractions were analysed by nanoHPLC-ESI-MS/MS, resulting in 24 data files.
Project description:The abundance of noncanonical open reading frames present in long noncoding RNAs (lncRNAs) indicates the potential for translational capacity, thereby enabling the generation of multiple functional peptides or proteins. Nevertheless, the existence of peptide or protein products derived from lncRNAs and their specific roles in gastric cancer remain largely unexplored. In this study, we identified HOXA10-HOXA9-derived small protein (HDSP) in gastric cancer by conducting a comprehensive analysis and experimental validation with mass spectrometry and western blotting. HDSP is highly expressed and has oncogenic roles in gastric cancer. Mechanistically, HDSP blocked TRIM25-mediated ubiquitination and degradation by interacting with MECOM. This led to the accumulation of MECOM, which further enhanced the transcription of SPINK1, a gene that promotes cancer through the EGFR signaling pathway. In addition, MECOM promoted the transcription of HOXA10-HOXA9, creating a feedback regulatory loop that activated downstream SPINK1-EGFR signaling. Finally, we found that HDSP knockdown inhibited tumor growth in a patient-derived xenograft (PDX) model, and the infusion of an artificially synthesized HDSP peptide as a neoantigen improved the anti-tumor efficacy of immune cells against gastric cancer in vitro and in vivo. Our findings provide a potential therapeutic target or neoantigen candidate for the treatment of gastric cancer.
Project description:The experiment was carried out during two vegetation seasons from 25th of April to 10th of September. Two Polish potato cultivars, the drought-tolerant Gwiazda and drought-sensitive Oberon were used. Selected tubers with transverse diameters of 3 - 4 cm were pre-sprouted for 2 weeks before planting. Plants were grown in a vegetation hall in pots filled with a thin layer of gravel on the bottom and the universal vegetable soil substrate ‘Hollas’ (Agaris Polska Ltd., Poland) produced from peat with the addition of chalk at a pH range of 5.5-6.5. Additionally, in phase 20 of the BBCH-scale of plant development, MIS-3 (Intermag) fertilizer was applied. Water content (WC) in volumetric basis in soil pots was measured according Black (1965). Weather conditions during the years of study were monitored using a Weather Campbell Station (Campbell Scientific Inc.) located in close proximity, and a thermohygrograph placed between pots. Meteorological data of air temperature, the photosynthetically active radiation, and humidity were comparable in the years of study and favorable for potato development. Three weeks after the initiation of the tuberisation phase (56 DAP), plants were divided into 3 groups, each consisting of 6 plants. The first group of plants was subjected to soil drought (remained without irrigation, day/night temperature 22°C/18°C), the second one to high temperature (day/night temperature 38°C/25°C) and the third one was watered according to needs and at optimal temperature (control plants, day/night temperature 22°C/18°C). Stress application lasted 14 days and finished at 70 DAP. During this period, plants were placed in phytotron equipped with six Hortilux Schreder Lamps with Philips light bulbs of 1600 W each. Air humidity was in the range 65-70%. WC under 14 days of soil drought reached 30% (v/v), and remained 80% (v/v) in control and high temperature conditions. During the recovery period, after 14 days of stress treatment, WC reached control levels. Plant root material for proteomic research was collected on the 14th day of stress treatment (70 DAP).
Project description:Metabolic reprogramming is a hallmark of the immune cells in response to inflammatory stimuli. This metabolic process involves a switch from oxidative phosphorylation (OXPHOS)to glycolysis, or alterations in other metabolic pathways. However, most of the experimental findings have been acquired in murine immune cells and little is known about the metabolic reprogramming of human microglia. In this study, we investigated the transcriptomic and metabolic profiles of mouse and iPSC-derived human microglia challenged with the TLR4 agonist LPS. We found that both species displayed a metabolic shift and an overall increased glycolytic gene signature in response to LPS treatment. The metabolic reprogramming was characterized by the upregulation of hexokinases in mouse microglia and phosphofructokinases in human microglia. This study provides the first direct comparison of energy metabolism between mouse and human microglia, highlighting the species-specific pathways involved in immunometabolism and the importance of considering these differences in translational research.
Project description:Targeted therapies against EGFR show clinical benefit, but resistance to these agents invariably develops. Thus, there is a need for dynamic biomarkers - effect sensors - that reflect treatment with EGFR therapeutics during therapy. Making use of SILAC-labeling we aimed to discover plasma membrane proteins that become differentially expressed after treatment with EGFR inhibitor erlotinib in three erlotinib-sensitive breast cancer cell lines.