N-terminomics Analysis of Mouse cultured cortical neuron during excitotoxicity
Ontology highlight
ABSTRACT:
INSTRUMENT(S): LTQ Orbitrap
ORGANISM(S): Mus Musculus (mouse)
TISSUE(S): Cell Culture
SUBMITTER: 
Syeda Sadia Ameen
LAB HEAD: A/Prof. Dr. Heung-Chin Cheng
PROVIDER: PXD040648 | Pride | 2023-04-07
REPOSITORIES: Pride
Similar Datasets
Project description:Protein N-termini are prone to post translational modification and are major determinants of protein stability in bacteria, eukaryotes, and perhaps also in chloroplasts. Most chloroplast proteins undergo N-terminal maturation, but this is poorly understood due to insufficient experimental information and the N-termini of mature chloroplast proteins cannot be accurately predicted. This motivated an extensive characterization of chloroplast protein N-termini using terminal amine isotopic labeling of substrates (TAILS). Many nuclear-encoded plastid proteins accumulated with two or three different N-termini; we evaluated the significance of these different proteoforms. Ala, Val, Thr (often in N-α acetylated form) and Ser were the most frequently observed N-terminal residues, even after normalization for their frequency in the plastid proteome, while other residues were absent or highly under-represented. Plastid-encoded proteins showed a similar distribution of N-terminal residues, but with a higher frequency of Met. Infrequent residues such as Ile, Arg, Cys, Pro, Asp and Glu were observed for several abundant proteins likely reflecting functional regulation through their N-termini. In contrast, the thylakoid lumenal proteome showed a wide diversity of N-terminal residues, including those typically associated with instability (Asp, Glu, Leu, Phe). We propose that after cleavage of the chloroplast transit peptide by stromal processing peptidase, additional processing by unidentified peptidases occurs to avoid unstable or otherwise unfavorable N-terminal residues. The possibility of a chloroplast N-end rule is discussed. This work provides a baseline for understanding N-terminal processing and maturation of chloroplast proteins.
2015-10-22 | PXD002476 | Pride
Project description:The constant increase in the obese and overweight population creates opportunities for novel therapeutic innovations to allow people to eat without getting fat and getting sick. Here, fed a hyperlipidic diet (HD)C57BL6 thimet oligopeptidase null (THOP1-/-) male mice were shown to gain only 25% (females gained 60%) of the weight gained by control wild type (WT) mice. Distinct from WT mice,THOP1-/- fed HD exhibited normal blood glucose levels and no insulin resistance. THOP1-/-fed HD phenotype benefits also include regular blood cholesterol levels, reduced fat in adipose and liver tissues, increased adipose tissue adrenergic-stimulated lipolysis, and greater resistance and endurance on treadmill running tests at high intensity. THOP1-/-compared to WT have alterations on the expression levels of specific genes and microRNAs related to obesity. Intracellular peptides that had their relative levels altered in THOP1-/-were shown to modulate the expression levels of genes and mature microRNAs associated to obesity, in 3T3L1 adipocyte. The ubiquitous existence of intracellular peptides in different cells of different species suggests a broader biological significance of the present results, connecting proteasomal protein degradation to protein synthesis. These exciting results suggest THOP1 and intracellular peptides as novel therapeutic targets to control obesity and obesity-associated diseases.
2020-02-24 | PXD016265 | Pride
Project description:Translation initiation generally occurs at AUG codons in eukaryotes although it has been shown that non-AUG or non-canonical translation initiation can also occur. However, the evidence for non-canonical translation initiation sites (TISs) is largely indirect and based on ribosome profiling studies. Here, using a strategy specifically designed to enrich N-termini of proteins, we demonstrate that many human proteins are translated at non-canonical TISs. The large majority of TISs that mapped to 5’ untranslated regions were non-canonical and led to N-terminal extension of annotated proteins or translation of upstream small open reading frames (uORF). There has been little controversy on whether the corresponding amino acid to the start codon is incorporated at TIS or methionine is still incorporated. Notably, methionine was incorporated at almost all non-canonical TISs identified in this study. Comparison of the TISs determined through mass spectrometry with ribosome profiling data revealed that about two-thirds of the novel annotations were indeed supported by ribosome profiling data. The sequence orthology analysis and relative translation frequency analysis of non-canonical TISs over canonical ones suggests that those non-canonical TISs are not leaky but they can have certain biological functions. Overall, this study provides evidence of protein translation initiation at non-canonical TISs and indicates that further studies are required for elucidation of functional implications of such non-canonical translation initiation.
2017-11-23 | PXD006633 | Pride
Project description:To profile the human substrate degradome of the SARS-CoV-2 main viral protease and to investigate whether 3CLpro cleavage of cellular substrates dampens host antiviral responses induced by type I interferons, we treated BEAS-2B cells with interferon-alpha (N = 3), interferon-beta (N = 3), or vehicle (N = 3), retrieve and exposed native proteome extracts from human embryonic kidney to 3CLpro cleavage. Then, N Terminal Amine Labeling of Substates (TAILS) was used to identify the substrates. Here, heavy [+34] isotope dimethyl labeling is performed at the whole protein level in the 3CLpro-exposed samples, and the P1' side of substrates substrates was revealed by comparing to the samples exposed to inactive mutant labeled with ligh [+28 Da] dimethyl.
2021-11-03 | PXD026815 | Pride
Project description:To profile the human substrate degradome of the SARS-CoV-2 main viral protease by exposingnative proteome extracts from human embryonic kidney (HEK-293) cells (N = 3) to 3CLpro cleavage. Then, N Terminal Amine Labeling of Substates (TAILS) was used to identify the substrates. Here, heavy [+34] isotope dimethyl labeling is performed at the whole protein level in the 3CLpro-exposed samples, and the P1' side of substrates substrates was revealed by comparing to the samples exposed to inactive mutant labeled with ligh [+28 Da] dimethyl.
2021-11-03 | PXD026797 | Pride
Project description:Mito-TAILS N-terminomics analysis of proteolytic events during EPEC infection of human epithelial cells, on whole-cell level and mitochondria.
2020-05-21 | PXD016994 | Pride
Project description:Infective endocarditis results in the growth of a vegetative mass on native or bio prosthetic valves hindering function and increasing risk of thromboses. This study set out to determine the proteomic composition of these vegetations including the influence of different micro-organisms and the proteases known to be present. Our data has allowed us to describe for first time the influence different infectious organisms have on vegetation growth. Including the contribution the immune response and circulatory proteins/cells make in composing a vegetation. Furthermore, we describe the protease activity and both known and novel cleavage sites in a plethora of targets. This data provides a deep insight into the homogeneity and heterogeneity of vegetation composition.
2020-07-29 | PXD016415 | Pride
Project description:Infective endocarditis results in the growth of a vegetative mass on native or bio prosthetic valves hindering function and increasing risk of thromboses. This study set out to determine the proteomic composition of these vegetations including the influence of different micro-organisms and the proteases known to be present. Our data has allowed us to describe for first time the influence different infectious organisms have on vegetation growth. Including the contribution of the immune response and circulatory proteins/cells make in composing a vegetation. Furthermore, we describe the protease activity and both known and novel cleavage sites in a plethora of targets. This data provides a deep insight into the homogeneity and heterogeneity of vegetation composition.
2020-07-29 | PXD019129 | Pride
Project description:Immune checkpoint blockade (ICB) leads to durable and complete tumour regression in some patients but in others gives temporary, partial or no response. Accordingly, significant efforts are underway to identify tumour-intrinsic mechanisms underlying ICB resistance. Results from a published CRISPR screen in a mouse model suggested that targeting STUB1, an E3 ligase involved in protein homeostasis, may overcome ICB resistance but the molecular basis of this effect remains unclear. Herein, we report an under-appreciated role of STUB1 to dampen the interferon gamma (IFNg) response. Genetic deletion of STUB1 increased IFNGR1 abundance on the cell surface and thus enhanced the downstream IFNg response as showed by multiple approaches including Western blotting, flow cytometry, qPCR, phospho-STAT1 assay, immunopeptidomics, proteomics, and gene expression profiling. Human prostate and breast cancer cells with STUB1 deletion were also susceptible to cytokine-induced growth inhibition. Furthermore, blockade of STUB1 protein function recapitulated the STUB1-null phenotypes. Despite these encouraging in vitro data and positive implications from clinical datasets, we did not observe in vivo benefits of inactivating Stub1 in mouse syngeneic tumour models - with or without combination with anti-PD-1 therapy. However, our findings elucidate STUB1 as a barrier to IFNg sensing, prompting further investigations to assess if broader inactivation of human STUB1 in both tumors and immune cells could overcome ICB resistance.
2022-08-18 | PXD035392 | Pride
Project description:Differential proteolytic processing in control and mitochondrial clpp protease-deficient mice were compared.
2020-06-01 | PXD014159 | Pride