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Blood Coagulation & Fibrinolysis : An... Dec 2019: Protein S Tokushima (p.Lys196Glu) and two protein C gene variants (p.Arg189Trp, p.Lys193del) are hereditary thrombophilia in Japanese and Chinese populations,...
: Protein S Tokushima (p.Lys196Glu) and two protein C gene variants (p.Arg189Trp, p.Lys193del) are hereditary thrombophilia in Japanese and Chinese populations, respectively; however, their diagnosis by plasma analyses is difficult because of the type II deficiency phenotype. Three gene variant genotypes were examined in young Japanese women (n = 231). Plasma total protein S activity and total protein S antigen levels were measured using a total protein S assay system, protein C and protein S activities by clot-based methods, and protein C and free protein S antigen levels by latex agglutination methods. protein S Tokushima (p.Lys196Glu) and protein C p.Lys193del variants were prevalent among participants with allele frequencies of 1.08 and 0.86%, respectively, whereas any carrier of protein C p.Arg189Trp variant was not identified. The plasma phenotype of the type II deficiency of protein S Tokushima heterozygotes was demonstrated by decreased total protein S activity with a normal total protein S antigen level; however, the protein C activities of protein C p.Lys193del heterozygotes were within reference intervals, whereas their protein C antigen levels were elevated. We compared the diagnostic accuracy of the total protein S activity/total protein S antigen ratio for identifying protein S Tokushima heterozygotes with that of the clot-based protein S activity/free protein S antigen ratio and found that sensitivity and specificity of 100% each was only achieved by the former. Protein S Tokushima and protein C p.Lys193del are prevalent among young Japanese women, and a plasma analysis using the total protein S assay system is more accurate than the clot-based protein S activity/free protein S antigen ratio for diagnosing protein S Tokushima carriers.
Topics: Adult; Antigens; Asian People; Female; Gene Frequency; Heterozygote; Humans; Japan; Mutation; Phenotype; Plasma; Protein C; Protein S; Thrombophilia; Young Adult
PubMed: 31490209
DOI: 10.1097/MBC.0000000000000854 -
Journal of Visualized Experiments : JoVE Apr 2020Protein S-acylation, also referred to as S-palmitoylation, is a reversible post-translational modification of cysteine residues with long-chain fatty acids via a labile...
Protein S-acylation, also referred to as S-palmitoylation, is a reversible post-translational modification of cysteine residues with long-chain fatty acids via a labile thioester bond. S-acylation, which is emerging as a widespread regulatory mechanism, can modulate almost all aspects of the biological activity of proteins, from complex formation to protein trafficking and protein stability. The recent progress in understanding of the biological function of protein S-acylation was achieved largely due to the development of novel biochemical tools allowing robust and sensitive detection of protein S-acylation in a variety of biological samples. Here, we describe acyl resin-assisted capture (Acyl-RAC), a recently developed method based on selective capture of endogenously S-acylated proteins by thiol-reactive Sepharose beads. Compared to existing approaches, Acyl-RAC requires fewer steps and can yield more reliable results when coupled with mass spectrometry for identification of novel S-acylation targets. A major limitation in this technique is the lack of ability to discriminate between fatty acid species attached to cysteines via the same thioester bond.
Topics: Acylation; Protein S
PubMed: 32338654
DOI: 10.3791/61016 -
FASEB Journal : Official Publication of... Apr 2020Reactive oxygen species (ROS) increase during adipogenesis and in obesity. Oxidants react with cysteine residues of proteins to form glutathione (GSH) adducts,...
Reactive oxygen species (ROS) increase during adipogenesis and in obesity. Oxidants react with cysteine residues of proteins to form glutathione (GSH) adducts, S-glutathionylation, that are selectively removed by glutaredoxin-1 (Glrx). We have previously reported that Glrx knockout mice had increased protein S-glutathionylation and developed obesity by an unknown mechanism. In this study, we demonstrated that 3T3L1 adipocytes differentiation increased ROS and protein S-glutathionylation. Glrx ablation elevated protein S-glutathionylation and lipid content in 3T3L1 cells. Glrx replenishment decreased the lipid content of Glrx KO 3T3L1 cells. Glrx KO also increased protein expression and protein S-glutathionylation of the adipogenic transcription factor CCAAT enhancer-binding protein (C/EBP) β. Protein S-glutathionylation decreased the interaction of C/EBPβ and protein inhibitor of activated STAT (PIAS) 1, a small ubiquitin-related modifier E3 ligase that facilitates C/EBPβ degradation. Experiments with truncated mutant C/EBPβ demonstrated that PIAS1 interacted with the liver-enriched inhibitory protein (LIP) region of C/EBPβ. Furthermore, mass spectrometry analysis identified protein S-glutathionylation of Cys201 and Cys296 in the LIP region of C/EBPβ. The C201S, C296S double-mutant C/EBPβ prevented protein S-glutathionylation and preserved the interaction with PIAS1. In summary, Glrx ablation stimulated 3T3L1 cell differentiation and adipogenesis via increased protein S-glutathionylation of C/EBPβ, stabilizing and increasing C/EBPβ protein levels.
Topics: 3T3-L1 Cells; Adipocytes; Adipogenesis; Animals; CCAAT-Enhancer-Binding Protein-beta; Gene Expression Regulation; Glutaredoxins; Glutathione; Mice; Mice, Knockout; Protein Processing, Post-Translational; Protein S
PubMed: 32141127
DOI: 10.1096/fj.201902575R -
Antioxidants & Redox Signaling Sep 2017Trypanosomatids have a unique trypanothione-based thiol redox metabolism. The parasite-specific dithiol is synthesized from glutathione and spermidine, with...
AIMS
Trypanosomatids have a unique trypanothione-based thiol redox metabolism. The parasite-specific dithiol is synthesized from glutathione and spermidine, with glutathionylspermidine as intermediate catalyzed by trypanothione synthetase. In this study, we address the oxidative stress response of African trypanosomes with special focus on putative protein S-thiolation.
RESULTS
Challenging bloodstream Trypanosoma brucei with diamide, HO or hypochlorite results in distinct levels of reversible overall protein S-thiolation. Quantitative proteome analyses reveal 84 proteins oxidized in diamide-stressed parasites. Fourteen of them, including several essential thiol redox proteins and chaperones, are also enriched when glutathione/glutaredoxin serves as a reducing system indicating S-thiolation. In parasites exposed to HO, other sets of proteins are modified. Only three proteins are S-thiolated under all stress conditions studied in accordance with a highly specific response. HO causes primarily the formation of free disulfides. In contrast, in diamide-treated cells, glutathione, glutathionylspermidine, and trypanothione are almost completely protein bound. Remarkably, the total level of trypanothione is decreased, whereas those of glutathione and glutathionylspermidine are increased, indicating partial hydrolysis of protein-bound trypanothione. Depletion of trypanothione synthetase exclusively induces protein S-glutathionylation. Total mass analyses of a recombinant peroxidase treated with T(SH) and either diamide or hydrogen peroxide verify protein S-trypanothionylation as stable modification.
INNOVATION
Our data reveal for the first time that trypanosomes employ protein S-thiolation when exposed to exogenous and endogenous oxidative stresses and trypanothione, despite its dithiol character, forms protein-mixed disulfides.
CONCLUSION
The stress-specific responses shown here emphasize protein S-trypanothionylation and S-glutathionylation as reversible protection mechanism in these parasites. Antioxid. Redox Signal. 27, 517-533.
Topics: Diamide; Glutathione; Humans; Hydrogen Peroxide; Hypochlorous Acid; Oxidative Stress; Protein S; Proteome; Protozoan Proteins; Spermidine; Sulfhydryl Compounds; Trypanosoma brucei brucei
PubMed: 28338335
DOI: 10.1089/ars.2016.6947 -
Research and Practice in Thrombosis and... Jan 2018FV-Short is a normal splice variant of Factor V (FV) having a short B domain, which exposes a high affinity-binding site for tissue factor pathway inhibitor α (TFPIα)....
BACKGROUND
FV-Short is a normal splice variant of Factor V (FV) having a short B domain, which exposes a high affinity-binding site for tissue factor pathway inhibitor α (TFPIα). FV-Short and TFPIα circulate in complex in plasma.
OBJECTIVES
The aim was to elucidate whether FV-Short affects TFPIα as inhibitor of coagulation FXa and to test whether the TFPIα-cofactor activity of protein S is influenced by FV-Short.
METHODS
Recombinant FV, wild-type FV-Short and a FV-Short thrombin-cleavage resistant variant were expressed and purified. The influence of FV and FV-Short variants and/or protein S on the FXa inhibitory activity of TFPIα was monitored both in a purified system and in a plasma-based thrombin generation assay.
RESULTS
FV-Short had intrinsically weak TFPIα-cofactor activity but with protein S present, FV-Short yielded efficient inactivation of FXa. Protein S alone did not promote full TFPIα-activity. Intact FV was inefficient at low protein S concentrations and had 10-fold lower activity compared to FV-Short at physiological protein S levels. Activation of FV-Short by thrombin resulted in the loss of the TFPIα-cofactor activity. The synergistic TFPIα-cofactor activity of FV-Short and protein S was also demonstrated in plasma using a thrombin generation assay.
CONCLUSIONS
FV-Short and protein S are highly efficient, synergistic cofactors to TFPIα in the regulation of FXa activity, whereas full length FV has lower activity. Our results suggest the formation of an efficient FXa-inhibitory complex between FV-Short, TFPIα and protein S on the surface of negatively charged phospholipids.
PubMed: 30046712
DOI: 10.1002/rth2.12057 -
Saudi Journal of Biological Sciences Oct 2023The "A" protein plays an essential role in the pathogenicity and virulence of this bacterial species. To gain deeper insights into the protein's characteristics, we...
BACKGROUND
The "A" protein plays an essential role in the pathogenicity and virulence of this bacterial species. To gain deeper insights into the protein's characteristics, we conducted an in-depth analysis of its sequence and structure.
OBJECTIVE
This study aimed to unravel the underlying genetic and structural components that contribute to the protein's functional properties.
RESULTS
Utilizing various bioinformatics tools and techniques, we first examined the protein's primary sequence, identifying key amino acid residues and potential functional domains. Additionally, we employed computational modeling and simulation approaches to determine the tertiary structure of the "A" protein. Through this comprehensive analysis, we discovered novel features and interactions within the protein's structure, shedding light on its potential mechanisms of action. Furthermore, we investigated the protein's evolutionary conservation and compared it with related proteins from other bacterial species.
CONCLUSIONS
Overall, our findings provide valuable insights into the sequence and structure of the Staphylococcus aureus "A" protein, which may have implications for understanding its role in pathogenicity and guiding the development of novel therapeutic strategies.
PubMed: 37766889
DOI: 10.1016/j.sjbs.2023.103812 -
The Journal of Cell Biology Aug 2023As eukaryotic cells progress through cell division, the nuclear envelope (NE) membrane must expand to accommodate the formation of progeny nuclei. In Saccharomyces...
As eukaryotic cells progress through cell division, the nuclear envelope (NE) membrane must expand to accommodate the formation of progeny nuclei. In Saccharomyces cerevisiae, closed mitosis allows visualization of NE biogenesis during mitosis. During this period, the SUMO E3 ligase Siz2 binds the inner nuclear membrane (INM) and initiates a wave of INM protein SUMOylation. Here, we show these events increase INM levels of phosphatidic acid (PA), an intermediate of phospholipid biogenesis, and are necessary for normal mitotic NE membrane expansion. The increase in INM PA is driven by the Siz2-mediated inhibition of the PA phosphatase Pah1. During mitosis, this results from the binding of Siz2 to the INM and dissociation of Spo7 and Nem1, a complex required for the activation of Pah1. As cells enter interphase, the process is then reversed by the deSUMOylase Ulp1. This work further establishes a central role for temporally controlled INM SUMOylation in coordinating processes, including membrane expansion, that regulate NE biogenesis during mitosis.
Topics: Cell Nucleus; Mitosis; Nuclear Envelope; Nuclear Proteins; Saccharomyces cerevisiae; Saccharomyces cerevisiae Proteins; Sumoylation; Organelle Biogenesis
PubMed: 37398994
DOI: 10.1083/jcb.202208137 -
Blood Jul 2018There is a Commentary on this article in this issue.
There is a Commentary on this article in this issue.
Topics: Animals; Down-Regulation; Hep G2 Cells; Humans; Hypoxia; Hypoxia-Inducible Factor 1, alpha Subunit; Liver; Mice; Mice, Knockout; Protein S; Thrombosis
PubMed: 29784640
DOI: 10.1182/blood-2018-04-841585 -
Biochimica Et Biophysica Acta May 2016In order to optimize their multiple cellular functions, peroxisomes must collaborate and communicate with the surrounding organelles. A common way of communication... (Review)
Review
In order to optimize their multiple cellular functions, peroxisomes must collaborate and communicate with the surrounding organelles. A common way of communication between organelles is through physical membrane contact sites where membranes of two organelles are tethered, facilitating exchange of small molecules and intracellular signaling. In addition contact sites are important for controlling processes such as metabolism, organelle trafficking, inheritance and division. How peroxisomes rely on contact sites for their various cellular activities is only recently starting to be appreciated and explored and the extent of peroxisomal communication, their contact sites and their functions are less characterized. In this review we summarize the identified peroxisomal contact sites, their tethering complexes and their potential physiological roles. Additionally, we highlight some of the preliminary evidence that exists in the field for unexplored peroxisomal contact sites.
Topics: Arabidopsis; Biological Transport; Endoplasmic Reticulum; Gene Expression Regulation; Humans; Lipid Droplets; Membrane Proteins; Membrane Transport Proteins; Peroxins; Peroxisomes; Pichia; Protein Isoforms; Saccharomyces cerevisiae; Saccharomyces cerevisiae Proteins; Signal Transduction
PubMed: 26384874
DOI: 10.1016/j.bbamcr.2015.09.016 -
Virology Feb 2018Efferocytosis, the phagocytic clearance of apoptotic cells, can provide host protection against certain types of viruses by mediating phagocytic clearance of infected...
Efferocytosis, the phagocytic clearance of apoptotic cells, can provide host protection against certain types of viruses by mediating phagocytic clearance of infected cells undergoing apoptosis. It is known that HIV-1 induces apoptosis and HIV-1-infected cells are efferocytosed by macrophages, although its molecular mechanisms are unknown. To elucidate the roles that efferocytosis of HIV-1-infected cells play in clearance of infected cells, we sought to identify molecules that mediate these processes. We found that protein S, present in human serum, and its homologue, Gas6, can mediate phagocytosis of HIV-1-infected cells by bridging receptor tyrosine kinase Mer, expressed on macrophages, to phosphatidylserine exposed on infected cells. Efferocytosis of live infected cells was less efficient than dead infected cells; however, a significant fraction of live infected cells were phagocytosed over 12h. Our results suggest that efferocytosis not only removes dead cells, but may also contribute to macrophage removal of live virus producing cells.
Topics: Animals; HIV Infections; HIV-1; Humans; Intercellular Signaling Peptides and Proteins; Macrophages; Phagocytosis; Protein S
PubMed: 29304470
DOI: 10.1016/j.virol.2017.12.025