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Silva RA, Palladino MV, Cavalheiro RP, Machado D, Cruz BLG, Paredes-Gamero EJ, Gomes-Marcondes MCC, Zambuzzi WF, Vasques L, Nader HB, Souza ACS, Justo GZ. Activation of the low molecular weight protein tyrosine phosphatase in keratinocytes exposed to hyperosmotic stress. PLoS One 2015; 10:e0119020. [PMID: 25781955 PMCID: PMC4363792 DOI: 10.1371/journal.pone.0119020] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2014] [Accepted: 01/15/2015] [Indexed: 12/18/2022] Open
Abstract
Herein, we provide new contribution to the mechanisms involved in keratinocytes response to hyperosmotic shock showing, for the first time, the participation of Low Molecular Weight Protein Tyrosine Phosphatase (LMWPTP) activity in this event. We reported that sorbitol-induced osmotic stress mediates alterations in the phosphorylation of pivotal cytoskeletal proteins, particularly Src and cofilin. Furthermore, an increase in the expression of the phosphorylated form of LMWPTP, which was followed by an augment in its catalytic activity, was observed. Of particular importance, these responses occurred in an intracellular milieu characterized by elevated levels of reduced glutathione (GSH) and increased expression of the antioxidant enzymes glutathione peroxidase and glutathione reductase. Altogether, our results suggest that hyperosmostic stress provides a favorable cellular environment to the activation of LMWPTP, which is associated with increased expression of antioxidant enzymes, high levels of GSH and inhibition of Src kinase. Finally, the real contribution of LMWPTP in the hyperosmotic stress response of keratinocytes was demonstrated through analysis of the effects of ACP1 gene knockdown in stressed and non-stressed cells. LMWPTP knockdown attenuates the effects of sorbitol induced-stress in HaCaT cells, mainly in the status of Src kinase, Rac and STAT5 phosphorylation and activity. These results describe for the first time the participation of LMWPTP in the dynamics of cytoskeleton rearrangement during exposure of human keratinocytes to hyperosmotic shock, which may contribute to cell death.
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Affiliation(s)
- Rodrigo A. Silva
- Departamento de Bioquímica, Instituto de Biologia, Universidade Estadual de Campinas, Campinas, São Paulo, Brazil
| | - Marcelly V. Palladino
- Departamento de Bioquímica (Campus São Paulo), Universidade Federal de São Paulo, São Paulo, São Paulo, Brazil
| | - Renan P. Cavalheiro
- Departamento de Bioquímica (Campus São Paulo), Universidade Federal de São Paulo, São Paulo, São Paulo, Brazil
| | - Daisy Machado
- Departamento de Bioquímica, Instituto de Biologia, Universidade Estadual de Campinas, Campinas, São Paulo, Brazil
| | - Bread L. G. Cruz
- Departamento de Bioquímica, Instituto de Biologia, Universidade Estadual de Campinas, Campinas, São Paulo, Brazil
| | - Edgar J. Paredes-Gamero
- Departamento de Bioquímica (Campus São Paulo), Universidade Federal de São Paulo, São Paulo, São Paulo, Brazil
| | - Maria C. C. Gomes-Marcondes
- Departamento de Bioquímica, Instituto de Biologia, Universidade Estadual de Campinas, Campinas, São Paulo, Brazil
| | - Willian F. Zambuzzi
- Departamento de Química e Bioquímica, IBB, Universidade Estadual Paulista, Botucatu, São Paulo, Brazil
| | - Luciana Vasques
- Departamento de Genética e Biologia Evolutiva, Universidade de São Paulo, São Paulo, São Paulo, Brazil
| | - Helena B. Nader
- Departamento de Bioquímica (Campus São Paulo), Universidade Federal de São Paulo, São Paulo, São Paulo, Brazil
| | - Ana Carolina S. Souza
- Centro de Ciências Naturais e Humanas, Universidade Federal do ABC, Santo André, São Paulo, Brazil
| | - Giselle Z. Justo
- Departamento de Bioquímica, Instituto de Biologia, Universidade Estadual de Campinas, Campinas, São Paulo, Brazil
- Departamento de Bioquímica (Campus São Paulo) and Departamento de Ciências Biológicas (Campus Diadema), Universidade Federal de São Paulo, São Paulo, São Paulo, Brazil
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Araki T, Vu LH, Sasaki N, Kawata T, Eichinger L, Williams JG. Two Dictyostelium tyrosine kinase-like kinases function in parallel, stress-induced STAT activation pathways. Mol Biol Cell 2014; 25:3222-33. [PMID: 25143406 PMCID: PMC4196871 DOI: 10.1091/mbc.e14-07-1182] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2014] [Revised: 08/04/2014] [Accepted: 08/07/2014] [Indexed: 01/07/2023] Open
Abstract
When Dictyostelium cells are hyperosmotically stressed, STATc is activated by tyrosine phosphorylation. Unusually, activation is regulated by serine phosphorylation and consequent inhibition of a tyrosine phosphatase: PTP3. The identity of the cognate tyrosine kinase is unknown, and we show that two tyrosine kinase-like (TKL) enzymes, Pyk2 and Pyk3, share this function; thus, for stress-induced STATc activation, single null mutants are only marginally impaired, but the double mutant is nonactivatable. When cells are stressed, Pyk2 and Pyk3 undergo increased autocatalytic tyrosine phosphorylation. The site(s) that are generated bind the SH2 domain of STATc, and then STATc becomes the target of further kinase action. The signaling pathways that activate Pyk2 and Pyk3 are only partially overlapping, and there may be a structural basis for this difference because Pyk3 contains both a TKL domain and a pseudokinase domain. The latter functions, like the JH2 domain of metazoan JAKs, as a negative regulator of the kinase domain. The fact that two differently regulated kinases catalyze the same phosphorylation event may facilitate specific targeting because under stress, Pyk3 and Pyk2 accumulate in different parts of the cell; Pyk3 moves from the cytosol to the cortex, whereas Pyk2 accumulates in cytosolic granules that colocalize with PTP3.
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Affiliation(s)
- Tsuyoshi Araki
- College of Life Sciences, Welcome Trust Biocentre, University of Dundee, Dundee DD1 5EH, United Kingdom
| | - Linh Hai Vu
- Center for Biochemistry, Institute of Biochemistry I, 50931 Cologne, Germany
| | - Norimitsu Sasaki
- Department of Biology, Faculty of Science, Toho University, 2-2-1 Miyama, Funabashi, Chiba 274-8510, Japan
| | - Takefumi Kawata
- Department of Biology, Faculty of Science, Toho University, 2-2-1 Miyama, Funabashi, Chiba 274-8510, Japan
| | - Ludwig Eichinger
- Center for Biochemistry, Institute of Biochemistry I, 50931 Cologne, Germany
| | - Jeffrey G Williams
- College of Life Sciences, Welcome Trust Biocentre, University of Dundee, Dundee DD1 5EH, United Kingdom
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