The high throughput characterization of protein N-termini is becoming an emerging challenge in the proteomics and proteogenomics fields. The present study describes the free N-terminome analysis of human mitochondria-enriched samples using trimethoxyphenyl phosphonium (TMPP) labelling approaches. Owing to the extent of protein import and cleavage for mitochondrial proteins, determining the new N-termini generated after translocation/processing events for mitochondrial proteins is crucial to understand the transformation of precursors to mature proteins. The doublet N-terminal oriented proteomics (dN-TOP) strategy based on a double light/heavy TMPP labelling has been optimized in order to improve and automate the workflow for efficient, fast and reliable high throughput N-terminome analysis. A total of 2714 proteins were identified and 897 N-terminal peptides were characterized (424 N-α-acetylated and 473 TMPP-labelled peptides). These results allowed the precise identification of the N-terminus of 693 unique proteins corresponding to 26% of all identified proteins. Overall, 120 already annotated processing cleavage sites were confirmed while 302 new cleavage sites were characterized. The accumulation of experimental evidence of mature N-termini should allow increasing the knowledge of processing mechanisms and consequently also enhance cleavage sites prediction algorithms. Complete datasets have been deposited to the ProteomeXchange Consortium with identifiers PXD001521, PXD001522 and PXD001523 (http://proteomecentral.proteomexchange.org/dataset/PXD001521, http://proteomecentral.proteomexchange.org/dataset/PXD0001522 and http://proteomecentral.proteomexchange.org/dataset/PXD001523, respectively).

Download full-text PDF

Source
http://dx.doi.org/10.1002/pmic.201400617DOI Listing

Publication Analysis

Top Keywords

n-terminome analysis
12
cleavage sites
12
analysis human
8
high throughput
8
tmpp labelling
8
mitochondrial proteins
8
proteins
6
human mitochondrial
4
mitochondrial proteome
4
proteome high
4

Similar Publications

The cardiopulmonary nematode Angiostrongylus vasorum can cause severe disease in dogs, including coagulopathies manifesting with bleeding. We analysed A. vasorum excretory/secretory protein (ESP)-treated dog plasma and serum by N-terminome analysis using Terminal Amine Isotopic Labelling of Substrates (TAILS) to identify cleaved host substrates.

View Article and Find Full Text PDF

Analysis of mitochondrial targeting signal cleavage and protein processing by mass spectrometry.

Methods Enzymol

October 2024

Faculty of Biology, University of Freiburg, Freiburg, Germany; CIBSS-Centre for Integrative Biological Signaling Studies, University of Freiburg, Freiburg, Germany. Electronic address:

The majority of mitochondrial proteins are encoded in the nucleus, synthesized in the cytosol and imported into mitochondria mediated by an N-terminal mitochondrial targeting sequences (MTS). After import, the MTS is cleaved off by the mitochondrial processing peptidase (MPP) and subsets of the imported proteins are further processed by the aminopeptidase intermediate cleaving peptidase 55 (ICP55), the mitochondrial intermediate peptidase (MIP), octapeptidyl aminopeptidase 1 (Oct1) or other proteolytic enzymes. Mutations that impair the mitochondrial processing machinery or mitochondrial protein degradation result in rare but severe human diseases.

View Article and Find Full Text PDF

Analysis of the N-terminome of Physcomitrella reveals N-terminal monomethylation of nuclear-encoded, mitochondria-localized proteins. Post- or co-translational N-terminal modifications of proteins influence their half-life as well as mediating protein sorting to organelles via cleavable N-terminal sequences that are recognized by the respective translocation machinery. Here, we provide an overview on the current modification state of the N-termini of over 4500 proteins from the model moss Physcomitrella (Physcomitrium patens) using a compilation of 24 N-terminomics datasets.

View Article and Find Full Text PDF

Extracellular proteolysis critically regulates cellular and tissue responses and is often dysregulated in human diseases. The crosstalk between proteolytic processing and other major post-translational modifications (PTMs) is emerging as an important regulatory mechanism to modulate protease activity and maintain cellular and tissue homeostasis. Here, we focus on matrix metalloproteinase (MMP)-mediated cleavages and N-acetylgalactosamine (GalNAc)-type of O-glycosylation, two major PTMs of proteins in the extracellular space.

View Article and Find Full Text PDF

Global analysis of N-myristoylation and its heterogeneity by combining N-terminomics and nanographite fluoride-based solid-phase extraction.

Talanta

August 2024

Department of Chemistry and Liver Cancer Institute, Zhongshan Hospital, Fudan University, Shanghai 200433, PR China; Institutes of Biomedical Sciences and NHC Key Laboratory of Glycoconjugates Research, Fudan University, Shanghai 200032, PR China. Electronic address:

N-myristoylation is one of the most widespread and important lipidation in eukaryotes and some prokaryotes, which is formed by covalently attaching various fatty acids (predominantly myristic acid C14:0) to the N-terminal glycine of proteins. Disorder of N-myristoylation is critically implicated in numerous physiological and pathological processes. Here, we presented a method for purification and comprehensive characterization of endogenous, intact N-glycine lipid-acylated peptides, which combined the negative selection method for N-terminome and the nanographite fluoride-based solid-phase extraction method (NeS-nGF SPE).

View Article and Find Full Text PDF

Want AI Summaries of new PubMed Abstracts delivered to your In-box?

Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!