Lipid- and protein-directed photosensitizer proximity labeling captures the cholesterol interactome
Ontology highlight
ABSTRACT:
INSTRUMENT(S):
ORGANISM(S): Homo Sapiens (human) Mus Musculus (mouse)
TISSUE(S): Primary Cell, Cell Culture
SUBMITTER: 
Andrew Becker
LAB HEAD: Keriann Marie
PROVIDER: PXD054875 | Pride | 2024-08-22
REPOSITORIES: Pride
Dataset's files
| Action | DRS | |||
|---|---|---|---|---|
| BSA_C3-biotin-azide.pepXML | Pepxml | |||
| BSA_C3-biotin-azide.raw | Raw | |||
| BSA_C4-biotin-azide.pepXML | Pepxml | |||
| BSA_C4-biotin-azide.raw | Raw | |||
| Chol-JF570-hv-1.raw | Raw |
Items per page: 5 1 - 5 of 244 |
Similar Datasets
Project description:Neocarzilin (NCA) is a natural product exhibiting potent anti-migratory as well as anti-proliferative effects. While the vesicle amide transport protein 1 (VAT-1) was previously shown to inhibit migration upon NCA binding, the molecular mechanisms responsible for impaired proliferation remained elusive. We here introduce a chemical probe closely resembling the structural and stereochemical features of NCA and unravel bone marrow stromal antigen 2 (BST-2) as a second major target in cancer cells. The antiproliferative mechanism of NCA was confirmed in corresponding BST-2 knockout (KO) cells which were less sensitive to compound treatment. Vice versa, overexpression of the target in the KO reduced proliferation comparable to wild type (wt) cells. Whole proteome mass-spectrometric (MS) analysis of NCA treated wt and KO cancer cells unraveled affected pathways linked to EGFR signaling and demonstrated reduced levels of BST-2 upon NCA treatment. In-depth analysis of BST-2 levels in response to proteasome and lysosome inhibitors, confirmed a lysosomal degradation path upon NCA treatment. As BST-2 is mediating the release of EGFR from lipid rafts to turn on proliferation signaling pathways, reduced BST-2 levels led to attenuated phosphorylation of EGFR and downstream targets. Furthermore, fluorescence microscopy confirmed colocalization of BST-2 and lipid rafts in presence of NCA. Overall, NCA represents a versatile anti-cancer natural product with a unique dual mode of action and unconventional inhibition of proliferation via BST-2 degradation.
2024-11-26 | PXD050453 | Pride
Project description:Usnic acid is a natural product with versatile biological activities against various organisms. We here utilize a chemical proteomic strategy to gain insights into its target scope in bacterial and human cells. First, we excluded DNA binding as a major reason for its antibacterial activity and second commenced with target profiling which unravelled several metal cofactor-dependent enzymes in both species. This is in line with the metal complexation activities of usnic acid and suggests a polypharmacological mode of action. Interestingly, our synthetic studies revealed a selectivity switch at usnic acid which maintains antibacterial activity but lacks strong cytotoxic effects.
2024-08-10 | PXD049013 | Pride
Project description:Efficient methods to introduce bioorthogonal groups, such as terminal alkynes, into biomolecules are important tools for chemical biology. State-of-the-art approaches are based on the introduction of a linker between the targeted amino acid and the alkyne, and still present limitations of either reactivity, selectivity or adduct stability. Herein, we present a new ethynylation method of cysteine residues based on the use of ethynylbenziodoxolone (EBX) reagents. In contrast to other approaches, the acetylene group is directly introduced onto the thiol group of cysteine and can be used in one-pot in a copper-catalyzed alkyne-azide cycloaddition (CuAAC) for further functionalization. Labeling proceeded with reaction rates comparable or higher than the most often used iodoacetamide on peptides or maleimide on the antibody trastuzumab. Under optimized conditions, high cysteine selectivity was observed. The reagents were also used in living cells for cysteine proteomic profiling and displayed a much-improved coverage of the cysteinome compared to previously reported iodoacetamide or hypervalent iodine-reagent based probes. Fine-tuning of the EBX reagents allowed optimization of their reactivity and physical properties for the desired application.
2020-04-07 | PXD018165 | Pride
Project description:To assess the impact of the bactericidal compounds CymA and ecumicin on the mycobacterial proteome and to monitor proteome remodeling by the AAA+ ClpC1 protease machinery, we performed a LFQ proteomics analysis treating the cells at bactericidal compound concentration. We identified new players of the mycobacterial ClpC1 stress response (ClpC2 and ClpC3), as novel bacterial antibiotic resistance mechanism.
2023-06-07 | PXD037234 | Pride
Project description:Macrocyclic peptides are attractive for chemoproteomic applications due to their modular synthesis and potential for high target selectivity. We describe a solid phase synthesis method for the efficient generation of libraries of small macrocycles that contain an electrophile and alkyne handle. The modular synthesis produces libraries that can be directly screened using simple SDS-PAGE readouts and then optimal lead molecules applied to proteomic analysis. We generated a library of 480 macrocyclic peptides containing the weakly reactive fluorosulfate (OSF) electrophile. Initial screening of a subset of the library containing each of the various diversity elements identified initial molecules of interest. The corresponding positional and confirmational isomers were then screened to select molecules that showed specific protein labeling patterns that were dependent on the probe structure. The most promising hits were applied to standard chemoproteomic workflows to identify protein targets. Our results demonstrate the feasibility of rapid, on-resin synthesis of diverse macrocyclic electrophiles to generate new classes of covalent ligands.
2023-03-02 | PXD039931 | Pride
Project description:The microbiota generates structurally diverse small molecules that can regulate host physiology and disease. Of these microbiota metabolites, bile acids have emerged as important modulators of host immunity and microbial pathogenesis. While the modes of action for different bile acids on host pathways are becoming more apparent, the mechanisms by which these prominent microbiota metabolites suppress microbial virulence pathways are less clear. To identify the direct protein targets of bile acids in Salmonella, we have generated three photoaffinity bile acid reporters (alk-X-CDCA, alk-X-UDCA, alk-X-LCA) and performed chemical proteomics. Using a combination of photocrosslinking with bile acid chemical reporters and label-free proteomics, we performed a quantitative analysis of bile acid interacting proteins in Salmonella with or without UV-mediated photocrosslinking. These studies revealed bile acid can interact with many Salmonella proteins, such as extracellular or secreted proteins, T3SS components and motility-related proteins, as predicted by Gene Ontology analysis. In addition, cytoplasmic and membrane proteins including metabolic enzymes are also identified. Notably, HilD, an important transcriptional regulator of S. Typhimurium virulence was also identified by the alk-X-CDCA reporter. This study highlights the utility of chemical proteomics to identify the direct protein targets and mechanisms of action for microbiota metabolites in bacterial pathogens.
2022-09-29 | PXD034373 | Pride
Project description:In this experiment, we've examined chromatin conformation of OG2 (B6; CBA-Tg(Pou5f1-EGFP)2Mnn/J; stock number 004654) mouse stem cells cultured as described in (Shi et al., 2008), using different amounts of starting cells. We performed a modified in situ Hi-C protocol for 6 samples digested with MboI restriction enzyme having as starting material 1 million (M), 100 thousand (k), 50k, 25k, 10k or 1k cells. As well as, to 2 samples digested with HindIII restriction enzyme that had as starting material 5M or 100k cells. Traditional in situ Hi-C protocols recommend 5-10 million starting cells. The aim of the experiment was to assess the impact of decreasing the cell number on reproducibility, library complexity, chromatin structure visualization in order to adapt the method to the study of rare cell populations. Furthermore, we have characterised the 3D structure of peripheral blood mononuclear cells (PBMCs) obtained from a blood extraction from a healthy donor and from a lymph node biopsy from a DLBCL patient as a proof of concept for the suitability of Low-C for rare cell population analysis.
2018-11-30 | E-MTAB-5875 | biostudies-arrayexpress
Project description:Affinity based protein profiling (AfBPP) is a widely applied methodology for target identification of bioactive molecules. Photocrosslinkers such as benzophenone, diazirine and aryl azide irreversibly link the molecule of interest to its dedicated target protein upon irradiation with UV light. Despite their prevalent application in chemical biology little is known about photolinker-specific off-targets affecting the reliability of results. Here we investigate background protein labelling in intact human cell lines via gel-free quantitative proteomics. Characteristic off-targets were identified for each photo-reactive group and compiled in a comprehensive inventory (photome). In a proof of principle study, H8, an established inhibitor of protein kinase A (PKA), was equipped with a diazirine moiety and revealed, by alignment with the photo-background, unprecedented insight into its in situ proteome targets. Taken together, our findings provide an experimental guideline to surmount photoprobe ambiguity and focus results on biologically relevant binders.
2016-12-05 | PXD004009 | Pride
Project description:In this experiment, we've examined chromatin conformation differences of E14 mESC against cohesin and Ring1b degrons. We performed a modified in situ Hi-C protocol from (Rao et al., 2014) that can be found in detail at (Díaz et al., 2018). Samples were digested with MboI restriction enzyme. The aim of the experiment was to characterize the role of cohesin and polycomb on the 3D structure of mouse chromatin.
2020-01-23 | E-MTAB-7816 | biostudies-arrayexpress
Project description:Although it is recognised that CD8+ T memory stem cells (Tscm) are heterogeneous in phenotype and function, very few studies have sought to systematically examine these characteristics, particularly in human samples, as the population as a whole is rare and antigen-specific cells even more so. For each T cell subsets investigated, we have performed optimized RNAseq for small number of cells by adapting the Smartseq2 protocol from scRNAseq. The mini-bulk number of cells was chosen to reduce heterogeneity but also maintain an adequate transcriptomics signal. Adapted from Smartseq2 protocol from scRNAseq described by Picelli et al, cell lysis buffer was prepared by adding 1 μl RNase inhibitor (Clontech, Mountain View, USA) to 19 μl Triton X‐100 solution (0.2% v/v). CD8 T cell subpopulations (TN, TSCM, TCM and TEM together with TSCM CXCR3hi/lo and CD122hi/lo) were bulk sorted (50 cells/sample, with replicates) directly into 96-well PCR plates containing 2 μl lysis buffer, 1 μl dNTP mix (10 mM) and 1 μl oligo‐dT primer at 5 μM. Plates were stored at -80 °C until ready to perform the assay. Reverse-transcription and PCR amplifications were performed as described, with the exception of reducing the IS PCR primer to a 50 nM final concentration and increasing the number of cycles to 28. Sequencing libraries were prepared using the Nextera XT Library Preparation Kit (Illumina; San Diego, USA) and sequencing was performed on Illumina NextSeq500 sequencing platforms with 2×150bp paired-end read output, the read depth was approximately 1.3 million reads per sample.
2022-03-10 | E-MTAB-10208 | biostudies-arrayexpress