In this work, electrophoretically mediated microanalysis (EMMA) was applied to the in-capillary tryptic digestion of proteins for proteomic purposes. Compared with classical in-solution tryptic digestion or the trypsin reactor commonly used for this purpose, the EMMA-based method is rapid, can be automated and requires only a small amount of trypsin preparation. Moreover, the protein digestion and the analysis of the resulting peptides are integrated into one procedure. A combination of the EMMA methodology with a partial filling technique was used in this study, since the pH optimum of the trypsin reaction differs strongly from the best pH for the CZE separation of peptides. In this set-up, a part of the capillary is filled with the best buffer for the tryptic digestion (50 mM Tris-HCl buffer, pH 8.5) whereas the rest of the capillary is filled with the BGE optimal for peptide separation (0.1 M phosphate buffer, pH 2.5). As the proteins differ in their isoelectric points, a sandwich type of injection was used. The analysed protein is thus injected between two trypsin zones, which ensures their mixing and digestion. The analysis of one protein comprising both the digestion and the peptide separation is then completed in 1 h using a commercial instrument for CE with no modifications.

• MeSH
• cytochromy c chemie   MeSH
• elektroforéza kapilární metody   MeSH
• inzulin chemie   MeSH
• kaseiny chemie   MeSH
• peptidové fragmenty chemie   MeSH
• proteiny chemie   MeSH
• proteomika metody   MeSH
• trypsin chemie   MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• práce podpořená grantem MeSH

After shining as the ultimate separation - sequencing technique used for the successful completion of the Human Genome Project, in the early 2000s CE experienced lowered popularity among separation scientists. The renewed interest in recent years relates to the separation needs, especially in proteomics, metabolomics, and glycomics, where CE complements liquid chromatography techniques. This interest is further boosted by the regulators requiring additional separation techniques for characterization of newly developed pharmaceuticals. This paper gives a short overview of recent developments in the on-line interfacing of CE separation techniques with electrospray ionization/mass spectrometric analysis. Both the instrumentation and selected CE/ESI/MS applications including analyses of peptides, proteins, and glycans are discussed with the stress on research published in the past 3 years. Techniques related to the proteomic and glycomic analyses such as sample preconcentration, on-line protein digestion, and analyte derivatization prior CE/ESI/MS analysis are also included.

• MeSH
• elektroforéza kapilární metody   MeSH
• hmotnostní spektrometrie s elektrosprejovou ionizací metody   MeSH
• lidé MeSH
• peptidy analýza   chemie   MeSH
• polysacharidy analýza   chemie   MeSH
• proteiny analýza   chemie   MeSH
• proteomika metody   MeSH
• systémová integrace MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• přehledy MeSH

The overexpression of Mdm2 has been linked to the loss of p53 tumour suppressor activity in several human cancers. Here, we present results suggesting that ubiquitin-specific peptidase 48 (USP48), a deubiquitinase that has been linked in previous reports to the NF-κB signaling pathway, is a novel Mdm2 binding partner that promotes Mdm2 stability and enhances Mdm2-mediated p53 ubiquitination and degradation. In contrast to other deubiquitinating enzymes (DUBs) that have been previously implicated in the regulation of Mdm2 protein stability, USP48 did not induce Mdm2 stabilization by significantly reducing Mdm2 ubiquitination levels. Moreover, two previously characterized USP48 mutants lacking deubiquitinase activity were also capable of efficiently stabilizing Mdm2, indicating that USP48 utilizes a non-canonical, deubiquitination-independent mechanism to promote Mdm2 oncoprotein stability. This study represents, to the best of our knowledge, the first report suggesting DUB-mediated target protein stabilization that is independent of its deubiquitinase activity. In addition, our results suggest that USP48 might represent a new mechanism of crosstalk between the NF-κB and p53 stress response pathways.

• MeSH
• buněčné linie MeSH
• lidé MeSH
• nádorový supresorový protein p53 metabolismus   MeSH
• posttranslační úpravy proteinů MeSH
• proteolýza MeSH
• protoonkogenní proteiny c-mdm2 metabolismus   MeSH
• regulace genové exprese * MeSH
• specifické proteázy ubikvitinu metabolismus   MeSH
• ubikvitinace MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Wnt and BMP signaling pathways are two key molecular machineries regulating development and homeostasis. The efficient coordination of Wnt and BMP is essential in many developmental processes such as establishment of antero-posterior and dorso-ventral body axis, regulation of convergent extension, or development of various organ systems. SMAD ubiquitination regulatory factor (Smurf) family of E3 ubiquitin ligases are important and evolutionary conserved regulators of TGF-β/BMP signaling pathways. Smurf2 has been previously shown to regulate Wnt/planar cell polarity (PCP) signaling pathway by ubiquitinating Prickle1, one of the key components of PCP. We explored the role of Smurf2 in Wnt pathways in further detail and identified that Smurf2 is also a ubiquitin ligase of Dishevelled (DVL), the key cytoplasmic signal transducer in the Wnt pathway. Interestingly, the Smurf2 and DVL relationship expands beyond substrate-E3 ligase. We can show that DVL activates Smurf2, which allows Smurf2 to ubiquitinate its substrates from Wnt/PCP (Prickle1) as well as TGF-β/BMP (Smad2) pathways more efficiently. Using SMAD7 as an example of Smurf2 activator we show that DVL and SMAD7 both activates Smurf2 activity. In HEK293 cells the deficiency of DVL phenocopies absence of Smurf2 and leads to the increased phosphorylation of R-Smads. Smurf2-DVL connection provides a novel and intriguing point of crosstalk for Wnt and BMP pathways.

• MeSH
• biologické modely MeSH
• HEK293 buňky MeSH
• kostní morfogenetické proteiny metabolismus   MeSH
• lidé MeSH
• nádorové supresorové proteiny metabolismus   MeSH
• protein dishevelled metabolismus   MeSH
• proteiny s doménou LIM metabolismus   MeSH
• proteolýza MeSH
• signální dráha Wnt * MeSH
• signální transdukce MeSH
• transformující růstový faktor beta metabolismus   MeSH
• ubikvitinace MeSH
• ubikvitinligasy metabolismus   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

The main objective of this study was to develop an effective in-gel trypsin digestion protocol using aqueous-acetonitrile solvent system to facilitate MS analysis and maximize the number of identified proteins from biological samples. The procedure, where 80% acetonitrile was present in the trypsin reaction mixture, increased the number of matched peptides, and allowed the identification of more proteins with higher coverage than the common digestion protocol. Vimentin, annexins, tubulin, actin, peptidyl-prolyl cis-trans isomerase or alpha-enolase are examples of important proteins that change during the progress cancer. These were isolated from human breast cancer cells and were used for this study.

• MeSH
• acetonitrily chemie   MeSH
• lidé MeSH
• nádorové buněčné linie MeSH
• nádorové proteiny analýza   izolace a purifikace   metabolismus   MeSH
• nádory metabolismus   patologie   MeSH
• peptidy analýza   MeSH
• proteomika metody   MeSH
• spektrometrie hmotnostní - ionizace laserem za účasti matrice MeSH
• trypsin metabolismus   MeSH
• vysokoúčinná kapalinová chromatografie MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Profiling of biological relationships between different molecular layers dissects regulatory mechanisms that ultimately determine cellular function. To thoroughly assess the role of protein post-translational turnover, we devised a strategy combining pulse stable isotope-labeled amino acids in cells (pSILAC), data-independent acquisition mass spectrometry (DIA-MS), and a novel data analysis framework that resolves protein degradation rate on the level of mRNA alternative splicing isoforms and isoform groups. We demonstrated our approach by the genome-wide correlation analysis between mRNA amounts and protein degradation across different strains of HeLa cells that harbor a high grade of gene dosage variation. The dataset revealed that specific biological processes, cellular organelles, spatial compartments of organelles, and individual protein isoforms of the same genes could have distinctive degradation rate. The protein degradation diversity thus dissects the corresponding buffering or concerting protein turnover control across cancer cell lines. The data further indicate that specific mRNA splicing events such as intron retention significantly impact the protein abundance levels. Our findings support the tight association between transcriptome variability and proteostasis and provide a methodological foundation for studying functional protein degradation.

• MeSH
• alternativní sestřih MeSH
• HeLa buňky MeSH
• hmotnostní spektrometrie MeSH
• izoformy RNA genetika   metabolismus   MeSH
• izotopové značení metody   MeSH
• lidé MeSH
• messenger RNA genetika   metabolismus   MeSH
• protein - isoformy analýza   metabolismus   MeSH
• proteiny analýza   metabolismus   MeSH
• proteolýza MeSH
• proteomika metody   MeSH
• průběh práce MeSH
• regulace genové exprese u nádorů MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

The RNA editing enzyme adenosine deaminase acting on RNA 1 (ADAR1) is essential for correct functioning of innate immune responses. The ADAR1p110 isoform is mainly nuclear and ADAR1p150, which is interferon (IFN) inducible, is predominately cytoplasmic. Using three different methods - co-immunoprecipitation (co-IP) of endogenous ADAR1, Strep-tag co-IP and BioID with individual ADAR1 isoforms - a comprehensive interactome was generated during both homeostasis and the IFN response. Both known and novel interactors as well as editing regulators were identified. Nuclear proteins were detected as stable interactors with both ADAR1 isoforms. In contrast, BioID identified distinct protein networks for each ADAR1 isoform, with nuclear components observed with ADAR1p110 and components of cytoplasmic cellular condensates with ADAR1p150. RNase A digestion distinguished between distal and proximal interactors, as did a double-stranded RNA (dsRNA)-binding mutant of ADAR1 which demonstrated the importance of dsRNA binding for ADAR1 interactions. IFN treatment did not affect the core ADAR1 interactomes but resulted in novel interactions, the majority of which are proximal interactions retained after RNase A treatment. Short treatment with high molecular weight poly(I:C) during the IFN response resulted in dsRNA-binding-dependent changes in the proximal protein network of ADAR1p110 and association of the ADAR1p150 proximal protein network with some components of antiviral stress granules.

• MeSH
• adenosindeaminasa * metabolismus   genetika   MeSH
• buněčné jádro * metabolismus   MeSH
• cytoplazma * metabolismus   MeSH
• dvouvláknová RNA metabolismus   genetika   MeSH
• editace RNA MeSH
• HEK293 buňky MeSH
• HeLa buňky MeSH
• interferony metabolismus   genetika   MeSH
• lidé MeSH
• mapy interakcí proteinů MeSH
• poly I-C farmakologie   MeSH
• protein - isoformy * metabolismus   genetika   MeSH
• proteiny vázající RNA * metabolismus   genetika   MeSH
• vazba proteinů MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH

To date, the effects of specific modification types and sites on protein lifetime have not been systematically illustrated. Here, we describe a proteomic method, DeltaSILAC, to quantitatively assess the impact of site-specific phosphorylation on the turnover of thousands of proteins in live cells. Based on the accurate and reproducible mass spectrometry-based method, a pulse labeling approach using stable isotope-labeled amino acids in cells (pSILAC), phosphoproteomics, and a unique peptide-level matching strategy, our DeltaSILAC profiling revealed a global, unexpected delaying effect of many phosphosites on protein turnover. We further found that phosphorylated sites accelerating protein turnover are functionally selected for cell fitness, enriched in Cyclin-dependent kinase substrates, and evolutionarily conserved, whereas the glutamic acids surrounding phosphosites significantly delay protein turnover. Our method represents a generalizable approach and provides a rich resource for prioritizing the effects of phosphorylation sites on protein lifetime in the context of cell signaling and disease biology.

• MeSH
• buněčný cyklus fyziologie   MeSH
• cyklin-dependentní kinasy genetika   metabolismus   MeSH
• fosfoproteiny chemie   metabolismus   MeSH
• fosforylace MeSH
• glutamáty metabolismus   MeSH
• hmotnostní spektrometrie metody   MeSH
• izotopové značení metody   MeSH
• lidé MeSH
• nádorové buněčné linie MeSH
• peptidy metabolismus   MeSH
• peroxiredoxin VI chemie   metabolismus   MeSH
• proteolýza * MeSH
• proteom genetika   metabolismus   MeSH
• proteomika metody   MeSH
• sekvence aminokyselin MeSH
• sestřihové faktory chemie   metabolismus   MeSH
• signální transdukce genetika   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Research Support, N.I.H., Extramural MeSH

Open tubular capillary enzyme reactors were studied for rapid protein digestion and possible on-line integration into a CE/ESI/MS system. The need to minimize the time of the analyte molecules to diffuse towards the surface immobilized enzyme and to maximize the surface-to-volume (S/V) ratio of the open tubular reactors dictated the use of very narrow bore capillaries. Extremely small protein amounts (atto-femtomoles loaded) could be digested with enzymes immobilized directly on the inside wall of a 10 microm I.D. capillary. Covalently immobilized L-1-tosylamido-2-phenylethyl chloromethyl ketone (TPCK)-trypsin and pepsin A were tested for the surface immobilization. The enzymatic activity was characterized in the flow-through mode with on-line coupling to electrospray ionization-time of flight-mass spectrometer (ESI/TOF-MS) under a range of protein concentrations, buffer pH's, temperatures and reaction times. The optimized reactors were tested as the nanospray needles for fast identification of proteins using CE-ESI/TOF-MS.

• MeSH
• biokompatibilní potahované materiály MeSH
• elektroforéza kapilární metody   MeSH
• elektroforéza mikročipová MeSH
• elektrolyty MeSH
• enzymy imobilizované chemická syntéza   klasifikace   MeSH
• financování organizované MeSH
• hmotnostní spektrometrie s elektrosprejovou ionizací metody   MeSH
• mikrochemie MeSH
• on-line systémy MeSH
• pepsin A metabolismus   MeSH
• proteiny analýza   chemie   MeSH
• sekvenční analýza proteinů metody   MeSH
• senzitivita a specificita MeSH
• studie proveditelnosti MeSH
• trypsin metabolismus   MeSH

In mammals, leptin and tumor-necrosis factor (TNF) are prominent interacting adipokines mediating appetite control and insulin sensitivity. While TNF pleiotropically functions in immune defense and cell survival, leptin is largely confined to signaling energy stores in adipocytes. Knowledge about the function of avian leptin and TNF is limited and they are absent or lowly expressed in adipose, respectively. Employing radiation-hybrid mapping and FISH-TSA, we mapped TNF and its syntenic genes to chicken chromosome 16 within the major histocompatibility complex (MHC) region. This mapping position suggests that avian TNF has a role in regulating immune response. To test its possible interaction with leptin within the immune system and beyond, we compared the transcription patterns of TNF, leptin and their cognate receptors obtained by meta-analysis of GenBank RNA-seq data. While expression of leptin and its receptor (LEPR) were detected in the brain and digestive tract, TNF and its receptor mRNAs were primarily found in viral-infected and LPS-treated leukocytes. We confirmed leptin expression in the duodenum by immunohistochemistry staining. Altogether, we suggest that whereas leptin and TNF interact as adipokines in mammals, in birds, they have distinct roles. Thus, the interaction between leptin and TNF may be unique to mammals.

• MeSH
• buněčné linie MeSH
• duodenum metabolismus   MeSH
• kur domácí genetika   metabolismus   MeSH
• leptin genetika   metabolismus   MeSH
• leptinové receptory metabolismus   MeSH
• mapování chromozomů * MeSH
• mapování pomocí radiačních hybridů MeSH
• messenger RNA genetika   metabolismus   MeSH
• metafáze genetika   MeSH
• receptory TNF genetika   metabolismus   MeSH
• regulace genové exprese * MeSH
• savci genetika   MeSH
• signální transdukce * MeSH
• syntenie genetika   MeSH
• TNF-alfa genetika   metabolismus   MeSH
• trávení * MeSH
• zvířata MeSH
• Check Tag
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH