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Guo C, Mattingly RR, Stemmer PM, Rosenspire AJ. At low levels, inorganic mercury interference with antigen signaling is associated with modifications to a panel of novel phosphoserine sites in B cell receptor pathway proteins. Toxicol In Vitro 2023; 89:105564. [PMID: 36736710 DOI: 10.1016/j.tiv.2023.105564] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2022] [Revised: 12/23/2022] [Accepted: 01/29/2023] [Indexed: 02/04/2023]
Abstract
Epidemiological studies indicate that human and animal exposure to environmental mercury (Hg) disrupts normal immune system function, but the molecular mechanism responsible for this is still unresolved. We have previously utilized phospho-proteomic mass spectrometry to demonstrate that in the absence of B Cell Receptor (BCR) stimulation, exposure of B cells to Hg induces significant changes to a great many elements of the BCR signaling pathway in a concentration dependent manner. In this report, we have extended those initial findings by utilizing mass spectrometry to evaluate in detail the effect of low-level Hg exposure on BCR induced phospho-proteomic changes. Specifically, murine WEHI-231 B lymphoma cells were exposed to environmentally relevant levels of Hg with or without concomitant BCR stimulation. The cellular phospho-proteomes were then profiled by LC-MS/MS. We found that for low-level exposures, Hg interference with signal transduction across the BCR pathway was predominantly associated with modification of phosphorylation of 12 phosphosites located on seven different proteins. Nine sites were serine, two sites tyrosine and one site threonine. Most of these sites are novel, in the sense that only the two tyrosine and one of the serine sites have previously been reported to be associated with BCR signaling.
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Affiliation(s)
- Chunna Guo
- Department of Biochemistry, Microbiology and Immunology, Wayne State University, Detroit, MI, USA
| | - Raymond R Mattingly
- Department of Pharmacology & Toxicology, Brody School of Medicine, East Carolina University, Greenville, NC 27834, USA
| | - Paul M Stemmer
- Institute of Environmental Health Sciences, Wayne State University, Detroit, MI, USA.
| | - Allen J Rosenspire
- Department of Biochemistry, Microbiology and Immunology, Wayne State University, Detroit, MI, USA.
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Pérez CA, Shah EG, Butler IJ. Mercury-induced autoimmunity: Report of two adolescent siblings with Morvan syndrome "plus" and review of the literature. J Neuroimmunol 2020; 342:577197. [PMID: 32126315 DOI: 10.1016/j.jneuroim.2020.577197] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2019] [Revised: 02/08/2020] [Accepted: 02/21/2020] [Indexed: 02/06/2023]
Abstract
Heavy metal toxicity is a global health concern. Mercury intoxication has been implicated in the etiology and pathogenesis of autoimmune disease, including Morvan syndrome. We describe two siblings with overlapping features of distinct autoimmune syndromes following accidental exposure to elemental mercury. Morvan syndrome was the predominant clinical phenotype. In addition to the characteristic anti-leucine-rich glioma-inactivated protein 1 (LGI1) and anti-contactin-associated protein-like 2 (Caspr2) autoantibodies, glutamic acid decarboxylase 65-kilodalton isoform (GAD65), and N-type and P/Q-type voltage-gated calcium channel (VGCC) antibodies were detected. Treatment with chelation therapy, glucocorticoids, and intravenous immunoglobulin was unsuccessful, but complete resolution of symptoms was achieved following treatment with rituximab. Herein, we perform an extensive review of the literature with a focus on the emerging concepts of mercury-induced autoimmunity and the role of mercury in the etiopathogenesis of autoimmune diseases of the nervous system.
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Affiliation(s)
- Carlos A Pérez
- Division of Multiple Sclerosis and Neuroimmunology, Department of Neurology, University of Texas Health Science Center at Houston, Houston, TX, USA.
| | - Ekta G Shah
- Division of Child and Adolescent Neurology, Department of Pediatrics, University of Texas Health Science Center at Houston, Houston, TX, USA
| | - Ian J Butler
- Division of Child and Adolescent Neurology, Department of Pediatrics, University of Texas Health Science Center at Houston, Houston, TX, USA
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Yang Z, Zhao Y, Li Q, Shao Y, Yu X, Cong W, Jia X, Qu W, Cheng L, Xue P, Zhou Z, He M, Zhang Y. Developmental exposure to mercury chloride impairs social behavior in male offspring dependent on genetic background and maternal autoimmune environment. Toxicol Appl Pharmacol 2019; 370:1-13. [PMID: 30862457 DOI: 10.1016/j.taap.2019.03.006] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2018] [Revised: 02/03/2019] [Accepted: 03/08/2019] [Indexed: 10/27/2022]
Abstract
To date, the connection between inorganic mercury (Hg) and social behavior remains incompletely understood. The aim of this study was to investigate the influence of maternal autoimmunity by inorganic Hg (Hg2+) exposure on social behavior of offspring. Wild-type (WT) and immunoglobulin deficient (Ig-/-) B10.S dams fertilized by male WT B10.S or SJL mice were treated with 50 μM Hg chloride (HgCl2). Non-pregnant female WT B10.S mice were used to investigate factors regulating HgCl2-induced autoimmunity to brain. HgCl2 selectively impaired social behavior in male offspring, but not female offspring from WT B10.S dams × male SJL, in that only male offspring displayed reduced time distribution with the stranger mouse, decreased sniffing to the stranger mouse and increased self-grooming. HgCl2 did not disrupt social behavior of male or female offspring from WT B10.S dams × male WT B10.S or Ig-/- B10.S dams × male SJL. The offspring from WT and Ig-/- B10.S dams × male SJL had equivalent autoimmunity to brain antigens during HgCl2 exposure, indicating that maternal, but not offspring-derived anti-brain antibodies (Ab) impaired social behavior of the offspring. Non-pregnant WT B10.S mice treated with HgCl2 had increased anti-brain Ab dependent on increase in CD4 T cell activation and IFNγ signaling to macrophages. IFNγ interaction with macrophages drove B cells and plasma cells to produce IgG. Therefore, HgCl2 selectively impaired social behavior in males with certain genetic background via maternally derived anti-brain Ab production, thus providing a novel insight into our current understanding of Hg toxicity.
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Affiliation(s)
- Zhengli Yang
- School of Public Health and Key Laboratory of Public Health Safety, MOE, Fudan University, Shanghai 200032, China
| | - Yifan Zhao
- School of Public Health and Key Laboratory of Public Health Safety, MOE, Fudan University, Shanghai 200032, China
| | - Qian Li
- School of Public Health and Key Laboratory of Public Health Safety, MOE, Fudan University, Shanghai 200032, China
| | - Yiming Shao
- School of Public Health and Key Laboratory of Public Health Safety, MOE, Fudan University, Shanghai 200032, China
| | - Xinchun Yu
- School of Public Health and Key Laboratory of Public Health Safety, MOE, Fudan University, Shanghai 200032, China
| | - Wei Cong
- Institutes of Brain Science, State Key Laboratory of Medical Neurobiology, Fudan University, Shanghai 200032, China
| | - Xiaodong Jia
- Shanghai Municipal Center for Disease Control and Prevention, Shanghai 200336, China
| | - Weidong Qu
- School of Public Health and Key Laboratory of Public Health Safety, MOE, Fudan University, Shanghai 200032, China
| | - Longzhen Cheng
- Department of Biology, Southern University of Science and Technology, Shenzhen 518055, China
| | - Peng Xue
- School of Public Health and Key Laboratory of Public Health Safety, MOE, Fudan University, Shanghai 200032, China
| | - Zhijun Zhou
- School of Public Health and Key Laboratory of Public Health Safety, MOE, Fudan University, Shanghai 200032, China
| | - Miao He
- Institutes of Brain Science, State Key Laboratory of Medical Neurobiology, Fudan University, Shanghai 200032, China
| | - Yubin Zhang
- School of Public Health and Key Laboratory of Public Health Safety, MOE, Fudan University, Shanghai 200032, China.
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Carruthers NJ, Rosenspire AJ, Caruso JA, Stemmer PM. Low level Hg 2+ exposure modulates the B-cell cytoskeletal phosphoproteome. J Proteomics 2017; 173:107-114. [PMID: 29199152 DOI: 10.1016/j.jprot.2017.11.026] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2017] [Revised: 10/31/2017] [Accepted: 11/28/2017] [Indexed: 10/18/2022]
Abstract
Exposure of Wehi-231 B-cells to Hg2+ for 5min resulted in concentration dependent changes in protein phosphorylations. Phosphorylation was quantified using mass spectrometry to analyze TiO2 and anti-pTyr antibody selected phosphopeptides from Wehi-231 digests. The most frequent and largest amplitude responses to Hg2+ exposure were increased phosphorylation although a decrease was observed for 1% of phosphoproteins detected in the untreated cells. A subset of proteins responded with an increase in phosphorylation to Hg2+ exposure at low micromolar concentrations. The majority of proteins required Hg2+ over 20μM in order to increase phosphorylation. Ser/Thr phosphorylations are prominent in the cytoskeletal organization and the GTPase signaling systems and these systems are notable as the primary ones responding to the lowest concentrations of Hg2+. Systems that required higher concentrations of Hg2+ to increase phosphorylation included immune receptor signaling. The proteins for which an increase in phosphorylation occurred at Hg2+ above 20μM have a higher proportion of pTyr sites. Anti Ig stimulation of Wehi-231 cells confirmed that cytoskeletal protein phosphorylation and GTPase signaling are modulated in physiologically relevant B-cell receptor activation. Candidate kinases that respond to Hg2+ exposure at the low μM concentrations include MAP Kinase 1, CaM Kinase II delta and PAK2. SIGNIFICANCE Mercury (Hg) is a wide spread environmental toxicant. Epidemiological and laboratory studies suggest that exposure to environmental Hg at current levels, which have been perceived to be non-toxic, may contribute to immune system dysfunction and autoimmune disease in humans and animals respectively. While we have previously shown that exposure of B lymphocytes to low levels of mercury interferes with B-cell receptor signaling mediated by post transcriptional phosphorylation events, overall the mechanism that is responsible for increased autoimmunity in mercury exposed human or animal populations is not well understood. The current study evaluated the dose dependent actions of mercury to change phosphorylation in the Wehi-231 cell line, an immature B-cell model in which actions of mercury on development of cell function can be evaluated. The study identified the cytoskeletal proteins as the most sensitive to modulation by mercury with changes in Ser/Thr phosphorylation being observed at the lowest concentrations of mercury. These findings indicate that the actions of mercury on B-cell immune function and development are at least in part likely mediated through changes in cytoskeletal protein phosphorylation.
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Affiliation(s)
- Nicholas J Carruthers
- Institute of Environmental Health Sciences, Wayne State University, Detroit, MI, USA
| | - Allen J Rosenspire
- Department of Immunology and Microbiology, Wayne State University, Detroit, MI, USA
| | - Joseph A Caruso
- Institute of Environmental Health Sciences, Wayne State University, Detroit, MI, USA
| | - Paul M Stemmer
- Institute of Environmental Health Sciences, Wayne State University, Detroit, MI, USA.
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Carruthers NJ, Stemmer PM, Chen B, Valeriote F, Gao X, Guatam SC, Shaw J. Phosphoproteome and transcription factor activity profiling identify actions of the anti-inflammatory agent UTL-5g in LPS stimulated RAW 264.7 cells including disrupting actin remodeling and STAT-3 activation. Eur J Pharmacol 2017; 811:66-73. [PMID: 28576409 PMCID: PMC5581996 DOI: 10.1016/j.ejphar.2017.05.049] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2016] [Revised: 05/24/2017] [Accepted: 05/29/2017] [Indexed: 11/25/2022]
Abstract
UTL-5g is a novel small-molecule TNF-alpha modulator. It reduces cisplatin-induced side effects by protecting kidney, liver, and platelets, thereby increasing tolerance for cisplatin. UTL-5g also reduces radiation-induced acute liver toxicity. The mechanism of action for UTL-5g is not clear at the present time. A phosphoproteomic analysis to a depth of 4943 phosphopeptides and a luminescence-based transcription factor activity assay were used to provide complementary analyses of signaling events that were disrupted by UTL-5g in RAW 264.7 cells. Transcriptional activity downstream of the interferon gamma, IL-6, type 1 Interferon, TGF-β, PKC/Ca2+ and the glucocorticoid receptor pathways were disrupted by UTL-5g. Phosphoproteomic analysis indicated that hyperphosphorylation of proteins involved in actin remodeling was suppressed by UTL-5g (gene set analysis, FDR < 1%) as was phosphorylation of Stat3, consistent with the IL-6 results in the transcription factor assay. Neither analysis indicated that LPS-induced activation of the NF-kB, cAMP/PKA and JNK signaling pathways were affected by UTL-5g. This global characterization of UTL-5g activity in a macrophage cell line discovered that it disrupts selected aspects of LPS signaling including Stat3 activation and actin remodeling providing new insight on how UTL-5g acts to reduce cisplatin-induced side effects.
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Affiliation(s)
- Nicholas J Carruthers
- Wayne State University, Institute of Environmental Health Sciences, 540 East Canfield Ave., Room 2105, Detroit, MI 48202, United States.
| | - Paul M Stemmer
- Wayne State University, Institute of Environmental Health Sciences, 540 East Canfield Ave., Room 2105, Detroit, MI 48202, United States.
| | - Ben Chen
- 21st Century Therapeutics, Inc., 440 Burroughs, Suite 447, Detroit, MI 48202, United States.
| | - Frederick Valeriote
- Henry Ford Health System, Internal Medicine, 440 Burroughs, Suite 415, Detroit, MI 48202, United States.
| | - Xiaohua Gao
- Henry Ford Health System, Department of Surgery, One Ford Place, Oncology Research Laboratory, 4D, Detroit, MI 48202, United States.
| | - Subhash C Guatam
- Henry Ford Health System, Department of Surgery, One Ford Place, Oncology Research Laboratory, 4D, Detroit, MI 48202, United States.
| | - Jiajiu Shaw
- 21st Century Therapeutics, Inc., 440 Burroughs, Suite 447, Detroit, MI 48202, United States; Henry Ford Health System, Internal Medicine, 440 Burroughs, Suite 415, Detroit, MI 48202, United States.
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Caruso JA, Carruthers N, Shin N, Gill R, Stemmer PM, Rosenspire A. Mercury alters endogenous phosphorylation profiles of SYK in murine B cells. BMC Immunol 2017; 18:37. [PMID: 28716125 PMCID: PMC5514489 DOI: 10.1186/s12865-017-0221-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2017] [Accepted: 07/07/2017] [Indexed: 02/02/2023] Open
Abstract
BACKGROUND Epidemiological evidence and animal models suggest that exposure to low and non-neurotoxic concentrations of mercury may contribute to idiosyncratic autoimmune disease. Since defects in function and signaling in B cells are often associated with autoimmunity, we investigated whether mercury exposure might alter B cell responsiveness to self-antigens by interfering with B cell receptor (BCR) signal transduction. In this study we determined the effects of mercury on the protein tyrosine kinase SYK, a critical protein involved in regulation of the BCR signaling pathway. METHODS Phosphorylation sites of murine SYK were mapped before and after treatment of WEHI cell cultures with mercury, or with anti-IgM antibody (positive control) or pervanadate (a potent phosphatase inhibitor). Phosphopeptides were enriched by either titanium dioxide chromatography or anti-phosphotyrosine immunoaffinity, and analyzed by liquid chromatography-mass spectrometry. Select SYK phosphosite cluster regions were profiled for responsiveness to treatments using multiple reaction monitoring (MRM) methodology. RESULTS A total of 23 phosphosites were identified with high probability in endogenous SYK, including 19 tyrosine and 4 serine residues. For 10 of these sites phosphorylation levels were increased following BCR activation. Using MRM to profile changes in phosphorylation status we found that 4 cluster regions, encompassing 8 phosphosites, were activated by mercury and differentially responsive to all 3 treatments. Phosphorylation of tyrosine-342 and -346 residues were most sensitive to mercury exposure. This cluster is known to propagate normal BCR signal transduction by recruiting adaptor proteins such as PLC-γ and Vav-1 to SYK during formation of the BCR signalosome. CONCLUSIONS Our data shows that mercury alters the phosphorylation status of SYK on tyrosine sites known to have a role in promoting BCR signals. Considering the importance of SYK in the BCR signaling pathway, these data suggest that mercury can alter BCR signaling in B cells, which might affect B cell responsiveness to self-antigen and have implications with respect to autoimmunity and autoimmune disease.
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Affiliation(s)
- Joseph A Caruso
- Institute of Environmental Health Sciences, Center for Urban Responses to Environmental Stressors (CURES), Wayne State University, Detroit, MI, 48201, USA.
| | - Nicholas Carruthers
- Institute of Environmental Health Sciences, Center for Urban Responses to Environmental Stressors (CURES), Wayne State University, Detroit, MI, 48201, USA
| | - Namhee Shin
- Institute of Environmental Health Sciences, Center for Urban Responses to Environmental Stressors (CURES), Wayne State University, Detroit, MI, 48201, USA
| | - Randal Gill
- Department of Immunology and Microbiology, Center for Urban Responses to Environmental Stressors (CURES), Wayne State University, Detroit, MI, 48201, USA
| | - Paul M Stemmer
- Institute of Environmental Health Sciences, Center for Urban Responses to Environmental Stressors (CURES), Wayne State University, Detroit, MI, 48201, USA
| | - Allen Rosenspire
- Department of Immunology and Microbiology, Center for Urban Responses to Environmental Stressors (CURES), Wayne State University, Detroit, MI, 48201, USA
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Psatha K, Kollipara L, Voutyraki C, Divanach P, Sickmann A, Rassidakis GZ, Drakos E, Aivaliotis M. Deciphering lymphoma pathogenesis via state-of-the-art mass spectrometry-based quantitative proteomics. J Chromatogr B Analyt Technol Biomed Life Sci 2016; 1047:2-14. [PMID: 27979587 DOI: 10.1016/j.jchromb.2016.11.005] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2016] [Revised: 10/18/2016] [Accepted: 11/04/2016] [Indexed: 12/13/2022]
Abstract
Mass spectrometry-based quantitative proteomics specifically applied to comprehend the pathogenesis of lymphoma has incremental value in deciphering the heterogeneity in complex deregulated molecular mechanisms/pathways of the lymphoma entities, implementing the current diagnostic and therapeutic strategies. Essential global, targeted and functional differential proteomics analyses although still evolving, have been successfully implemented to shed light on lymphoma pathogenesis to discover and explore the role of potential lymphoma biomarkers and drug targets. This review aims to outline and appraise the present status of MS-based quantitative proteomic approaches in lymphoma research, introducing the current state-of-the-art MS-based proteomic technologies, the opportunities they offer in biological discovery in human lymphomas and the related limitation issues arising from sample preparation to data evaluation. It is a synopsis containing information obtained from recent research articles, reviews and public proteomics repositories (PRIDE). We hope that this review article will aid, assimilate and assess all the information aiming to accelerate the development and validation of diagnostic, prognostic or therapeutic targets for an improved and empowered clinical proteomics application in lymphomas in the nearby future.
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Affiliation(s)
- Konstantina Psatha
- Institute of Molecular Biology and Biotechnology, FORTH, Heraklion, Greece; School of Medicine, National and Kapodistrian University of Athens, Athens, Greece; Department of Pathology, School of Medicine, University of Crete, Heraklion, Greece
| | - Laxmikanth Kollipara
- Leibniz-Institut für Analytische Wissenschaften - ISAS - e.V., Dortmund, Germany
| | | | - Peter Divanach
- Institute of Molecular Biology and Biotechnology, FORTH, Heraklion, Greece
| | - Albert Sickmann
- Leibniz-Institut für Analytische Wissenschaften - ISAS - e.V., Dortmund, Germany; Department of Chemistry, College of Physical Sciences, University of Aberdeen, Aberdeen, Scotland, United Kingdom; Medizinische Fakultät, Medizinische Proteom-Center (MPC), Ruhr-Universität Bochum, Bochum, Germany
| | - George Z Rassidakis
- School of Medicine, National and Kapodistrian University of Athens, Athens, Greece; Department of Pathology and Cytology, Karolinska University Hospital and Karolinska Institute, Radiumhemmet, Stockholm, SE-17176, Sweden
| | - Elias Drakos
- Department of Pathology, School of Medicine, University of Crete, Heraklion, Greece
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Helou YA, Salomon AR. Protein networks and activation of lymphocytes. Curr Opin Immunol 2015; 33:78-85. [PMID: 25687331 DOI: 10.1016/j.coi.2015.01.019] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2014] [Revised: 01/30/2015] [Accepted: 01/30/2015] [Indexed: 12/30/2022]
Abstract
The signal transduction pathways initiated by lymphocyte activation play a critical role in regulating host immunity. High-resolution mass spectrometry has accelerated the investigation of these complex and dynamic pathways by enabling the qualitative and quantitative investigation of thousands of proteins and phosphoproteins simultaneously. In addition, the unbiased and wide-scale identification of protein-protein interaction networks and protein kinase substrates in lymphocyte signaling pathways can be achieved by mass spectrometry-based approaches. Critically, the integration of these discovery-driven strategies with single-cell analysis using mass cytometry can facilitate the understanding of complex signaling phenotypes in distinct immunophenotypes.
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Affiliation(s)
- Ynes A Helou
- Department of Molecular Pharmacology, Physiology, and Biotechnology, Brown University, Providence, RI 02912, USA
| | - Arthur R Salomon
- Department of Molecular Biology, Cell Biology, and Biochemistry, Brown University, Providence, RI 02912, USA.
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Caruso JA, Stemmer PM, Dombkowski A, Caruthers NJ, Gill R, Rosenspire AJ. A systems toxicology approach identifies Lyn as a key signaling phosphoprotein modulated by mercury in a B lymphocyte cell model. Toxicol Appl Pharmacol 2014; 276:47-54. [PMID: 24440445 DOI: 10.1016/j.taap.2014.01.002] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2013] [Revised: 12/24/2013] [Accepted: 01/04/2014] [Indexed: 01/10/2023]
Abstract
Network and protein-protein interaction analyses of proteins undergoing Hg²⁺-induced phosphorylation and dephosphorylation in Hg²⁺-intoxicated mouse WEHI-231 B cells identified Lyn as the most interconnected node. Lyn is a Src family protein tyrosine kinase known to be intimately involved in the B cell receptor (BCR) signaling pathway. Under normal signaling conditions the tyrosine kinase activity of Lyn is controlled by phosphorylation, primarily of two well known canonical regulatory tyrosine sites, Y-397 and Y-508. However, Lyn has several tyrosine residues that have not yet been determined to play a major role under normal signaling conditions, but are potentially important sites for phosphorylation following mercury exposure. In order to determine how Hg²⁺ exposure modulates the phosphorylation of additional residues in Lyn, a targeted MS assay was developed. Initial mass spectrometric surveys of purified Lyn identified 7 phosphorylated tyrosine residues. A quantitative assay was developed from these results using the multiple reaction monitoring (MRM) strategy. WEHI-231 cells were treated with Hg²⁺, pervanadate (a phosphatase inhibitor), or anti-Ig antibody (to stimulate the BCR). Results from these studies showed that the phosphoproteomic profile of Lyn after exposure of the WEHI-231 cells to a low concentration of Hg²⁺ closely resembled that of anti-Ig antibody stimulation, whereas exposure to higher concentrations of Hg²⁺ led to increases in the phosphorylation of Y-193/Y-194, Y-501 and Y-508 residues. These data indicate that mercury can disrupt a key regulatory signal transduction pathway in B cells and point to phospho-Lyn as a potential biomarker for mercury exposure.
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Affiliation(s)
- Joseph A Caruso
- Institute of Environmental Health Sciences, Wayne State University, Detroit, MI, USA
| | - Paul M Stemmer
- Institute of Environmental Health Sciences, Wayne State University, Detroit, MI, USA
| | - Alan Dombkowski
- Department of Pediatrics, Wayne State University, Detroit, MI, USA
| | - Nicholas J Caruthers
- Institute of Environmental Health Sciences, Wayne State University, Detroit, MI, USA
| | - Randall Gill
- Department of Immunology and Microbiology, Wayne State University, Detroit, MI, USA
| | - Allen J Rosenspire
- Department of Immunology and Microbiology, Wayne State University, Detroit, MI, USA.
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