scholarly journals Redox Regulation of Nonmuscle Myosin Heavy Chain during Integrin Engagement

2012 ◽  
Vol 2012 ◽  
pp. 1-9 ◽  
Author(s):  
Tania Fiaschi ◽  
Giacomo Cozzi ◽  
Paola Chiarugi
Keyword(s):  
Myosin Heavy Chain ◽  
Heavy Chain ◽  
Redox Regulation ◽  
Movement Analysis ◽  
Mass Spectrometry Analysis ◽  
Actin Binding ◽  
Nonmuscle Myosin ◽  
Spectrometry Analysis ◽  
Process Mass Spectrometry

On the basis of our findings reporting that cell adhesion induces the generation of reactive oxygen species (ROS) after integrin engagement, we were interested in identifying redox-regulated proteins during this process. Mass spectrometry analysis led us to identify nonmuscle myosin heavy chain (nmMHC) as a target of ROS. Our results show that, while nmMHC is reduced in detached/rounded cells, it turns towards an oxidized state in adherent/spread cells due to the integrin-engaged ROS machinery. The functional role of nmMHC redox regulation is suggested by the redox sensitivity of its association with actin, suggesting a role of nmMHC oxidation in cytoskeleton movement. Analysis of muscle MHC (mMHC) redox state during muscle differentiation, a process linked to a great and stable decrease of ROS content, shows that the protein does not undergo a redox control. Hence, we propose that the redox regulation of MHC in nonprofessional muscle cells is mandatory for actin binding during dynamic cytoskeleton rearrangement, but it is dispensable for static and highly organized cytoskeletal contractile architecture in differentiating myotubes.

scholarly journals Structural Characterization of Act c 10.0101 and Pun g 1.0101—Allergens from the Non-Specific Lipid Transfer Protein Family

Molecules ◽  
2021 ◽  
Vol 26 (2) ◽  
pp. 256
Author(s):  
Andrea O’Malley ◽  
Swanandi Pote ◽  
Ivana Giangrieco ◽  
Lisa Tuppo ◽  
Anna Gawlicka-Chruszcz ◽  
...  
Keyword(s):  
Immunoglobulin E ◽  
Lipid Transfer Protein ◽  
Mass Spectrometry Analysis ◽  
Lipid Transfer ◽  
Helical Structures ◽  
Spectrometry Analysis ◽  
X Ray Crystallography ◽  
Transfer Protein ◽  
Specific Lipid

(1) Background: Non-specific lipid transfer proteins (nsLTPs), which belong to the prolamin superfamily, are potent allergens. While the biological role of LTPs is still not well understood, it is known that these proteins bind lipids. Allergen nsLTPs are characterized by significant stability and resistance to digestion. (2) Methods: nsLTPs from gold kiwifruit (Act c 10.0101) and pomegranate (Pun g 1.0101) were isolated from their natural sources and structurally characterized using X-ray crystallography (3) Results: Both proteins crystallized and their crystal structures were determined. The proteins have a very similar overall fold with characteristic compact, mainly α-helical structures. The C-terminal sequence of Act c 10.0101 was updated based on our structural and mass spectrometry analysis. Information on proteins’ sequences and structures was used to estimate the risk of cross-reactive reactions between Act c 10.0101 or Pun g 1.0101 and other allergens from this family of proteins. (4) Conclusions: Structural studies indicate a conformational flexibility of allergens from the nsLTP family and suggest that immunoglobulin E binding to some surface regions of these allergens may depend on ligand binding. Both Act c 10.0101 and Pun g 1.0101 are likely to be involved in cross-reactive reactions involving other proteins from the nsLTP family.

scholarly journals The Olsenella Uli Induced Pneumonia: A Case Report

2021 ◽  
Author(s):  
Yufen Yan ◽  
Hong Li ◽  
Shuai Li ◽  
Shuhui Liu ◽  
Nan Jia ◽  
...  
Keyword(s):  
Therapeutic Strategy ◽  
Pulmonary Infection ◽  
Mass Spectrometry Analysis ◽  
Causative Role ◽  
Positive Bacterium ◽  
Spectrometry Analysis ◽  
First Case ◽  
Infection Treatment ◽  
Third Generation Cephalosporins

Abstract Olsenella uli is a Gram-positive bacterium common in the oral cavity or gastrointestinal tract. Here we reported a first case of human pneumonia caused by the Olsenella uli. The identification of Olsenella uli was based on micromorphology, sequence analysis and mass spectrometry analysis of the bacteria recovered from sputum. Ceftazidime，one of the third generation cephalosporins was used for the anti-infection treatment of the patient. CT results showed a significant improvement of the pulmonary lesion and pleural effusion and recovery from pulmonary infection after 10 days. The mechanism underlying Olsenella uli induced pneumonia is unclear, our report suggests a causative role of gingival bacteria in pathogenesis of pneumonia, and the intervention by Ceftazidime may offer a therapeutic strategy for Olsenella uli infection.

Quantitative proteomics identifies FOLR1 to drive sorafenib resistance via activating autophagy in hepatocellular carcinoma cells

2021 ◽  
Author(s):  
Hongwei Chu ◽  
Changqing Wu ◽  
Qun Zhao ◽  
Rui Sun ◽  
Kuo Yang ◽  
...  
Keyword(s):  
Hepatocellular Carcinoma ◽  
Folate Receptor ◽  
Mass Spectrometry Analysis ◽  
Label Free ◽  
Spectrometry Analysis ◽  
Underlying Mechanisms ◽  
Related Proteins ◽  
Hcc Cells

Abstract Sorafenib is commonly used to treat advanced human hepatocellular carcinoma (HCC). However, clinical efficacy has been limited by drug resistance. In this study, we used label-free quantitative proteomic analysis to systematically investigate the underlying mechanisms of sorafenib resistance in HCC cells. A total of 1709 proteins were confidently quantified. Among them, 89 were differentially expressed, and highly enriched in the processes of cell-cell adhesion, negative regulation of apoptosis, response to drug and metabolic processes involving in sorafenib resistance. Notably, folate receptor α (FOLR1) was found to be significantly upregulated in resistant HCC cells. In addition, in-vitro studies showed that overexpression of FOLR1 decreased the sensitivity of HCC cells to sorafenib, whereas siRNA-directed knockdown of FOLR1 increased the sensitivity of HCC cells to sorafenib. Immunoprecipitation-mass spectrometry analysis suggested a strong link between FOLR1 and autophagy related proteins. Further biological experiments found that FOLR1-related sorafenib resistance was accompanied by the activation of autophagy, whereas inhibition of autophagy significantly reduced FOLR1-induced cell resistance. These results suggest the driving role of FOLR1 in HCC resistance to sorafenib, which may be exerted through FOLR1-induced autophagy. Therefore, this study may provide new insights into understanding the mechanism of sorafenib resistance.

Pinpointing cysteine oxidation sites by high-resolution proteomics reveals a mechanism of redox-dependent inhibition of human STING

2021 ◽  
Vol 14 (680) ◽  
pp. eaaw4673
Author(s):  
Natalia Zamorano Cuervo ◽  
Audray Fortin ◽  
Elise Caron ◽  
Stéfany Chartier ◽  
Nathalie Grandvaux
Keyword(s):  
Posttranslational Modifications ◽  
Protein Function ◽  
Disulfide Bonds ◽  
Redox Regulation ◽  
Mass Spectrometry Analysis ◽  
Type I ◽  
Cysteine Oxidation ◽  
Spectrometry Analysis ◽  
Host Interactions ◽  
In Cells

Protein function is regulated by posttranslational modifications (PTMs), among which reversible oxidation of cysteine residues has emerged as a key regulatory mechanism of cellular responses. Given the redox regulation of virus-host interactions, the identification of oxidized cysteine sites in cells is essential to understand the underlying mechanisms involved. Here, we present a proteome-wide identification of reversibly oxidized cysteine sites in oxidant-treated cells using a maleimide-based bioswitch method coupled to mass spectrometry analysis. We identified 2720 unique oxidized cysteine sites within 1473 proteins with distinct abundances, locations, and functions. Oxidized cysteine sites were found in numerous signaling pathways, many relevant to virus-host interactions. We focused on the oxidation of STING, the central adaptor of the innate immune type I interferon pathway, which is stimulated in response to the detection of cytosolic DNA by cGAS. We demonstrated the reversible oxidation of Cys148 and Cys206 of STING in cells. Molecular analyses led us to establish a model in which Cys148 oxidation is constitutive, whereas Cys206 oxidation is inducible by oxidative stress or by the natural ligand of STING, 2′3′-cGAMP. Our data suggest that the oxidation of Cys206 prevented hyperactivation of STING by causing a conformational change associated with the formation of inactive polymers containing intermolecular disulfide bonds. This finding should aid the design of therapies targeting STING that are relevant to autoinflammatory disorders, immunotherapies, and vaccines.

Abstract 416: Sarcomere Disassembly After Unloading is Regulated by Ubiquitination and Acetylation of Capz and α-actinin

2020 ◽  
Vol 127 (Suppl_1) ◽  
Author(s):  
Christopher Solís ◽  
R John Solaro ◽  
Chad M Warren ◽  
Brenda Russell
Keyword(s):  
Ventricular Myocytes ◽  
Mass Spectrometry Analysis ◽  
Actin Binding ◽  
Mechanical Forces ◽  
Post Translational Modification ◽  
Spectrometry Analysis ◽  
Time Period ◽  
Omecamtiv Mecarbil ◽  
Myocyte Contractility ◽  
Sarcomere Assembly

Cardiac function mainly depends on the total myocyte mass in the ventricles. Assembly and disassembly of sarcomeres occurs to adjust this mass to altered mechanical demand. In the heart, hypertrophic cardiomyopathy results from myofibrillar assembly controlled by post-translational modification of proteins directed by signaling pathways. More is known about assembly on loading than disassembly on unloading. Here, the hypothesis tested is that unloading of mechanical forces affects acetylation (Ac) and ubiquitination (Ub) of the actin-binding proteins, α-actinin and CapZ. Omecamtiv mecarbil (0.5 μM) and mavacamten (1 μM) were used to increase (load) and decrease (unload) cardiomyocyte tension, respectively, via their action on myosin ATPase. Mavacamten decreased myocyte contractility in rat ventricular myocytes (NRVMs) and caused significant sarcomere disassembly by 6 h and 70% atrophy by 24 h. Assembly was preserved with omecamtiv mecarbil (0.5 μM) over the 24 h time period. Post-translational modification was determined in loaded and unloaded NRVMs at 6 h of drug treatment. Bottom-up mass spectrometry analysis showed single residues in α-actinin and CapZ that were acetylated or ubiquitinated. Acetylation levels appeared to increase in the mavacamten-treated samples while these levels are preserved in untreated and omecamtiv mecarbil-treated samples. Ac and Ub in the Z-discs were quantified on immunofluorescent images. The Z-discs colocalized oligo-Ub (K-48 oligo-Ub linkage) and Ac in untreated samples; this Z-disc localization of Ub and Ac was diminished with unloading. Fluorescence recovery after photobleaching (FRAP) measurements of the dynamics of α-actinin and CapZ after reduced cell tension with mavacamten (1 μM) and omecamtiv mercabil (0.5 μM) are ongoing. Overall, results suggest sarcomere assembly is regulated by mechanical forces through a mechanism involving Ac and Ub of myofibrillar proteins. These findings could have consequences for cardiac heart disease with abnormal sarcomeric proteostasis.

B2 exon splicing of nonmuscle myosin heavy chain IIB is differently regulated in developing and adult rat brain

2000 ◽  
Vol 37 (4) ◽  
pp. 299-306 ◽  
Author(s):  
Taisuke Miyazaki ◽  
Masahiko Watanabe ◽  
Akihiko Yamagishi ◽  
Masayuki Takahashi
Keyword(s):  
Myosin Heavy Chain ◽  
Rat Brain ◽  
Heavy Chain ◽  
Nonmuscle Myosin ◽  
Adult Rat ◽  
Exon Splicing ◽  
Adult Rat Brain
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