Abstract
Reactive oxygen species (ROS) regulate diverse cellular functions by triggering signal transduction events, such as Src and mitogen-activated protein (MAP) kinases. Here, we report the role of caveolin-1 and Src homology 2 domain-containing protein tyrosine phosphatase 2 (SHP-2) in H2O2-induced signaling pathway in brain astrocytes. H2O2-mediated oxidative stress induced phosphorylation of caveolin-1 and association between p-caveolin-1 and SHP-2. SHP-2 specifically bound to wild-type caveolin-1 similarly to c-Src tyrosine kinase (CSK), but not to phosphorylation-deficient mutant of caveolin-1 (Y14A), and interfered with complex formation between caveolin-1 and CSK. In the presence of CSK siRNA, binding between caveolin-1 and SHP-2 was enhanced by H2O2 treatment, which led to reduced Src phosphorylation at tyrosine (Tyr) 530 and enhanced Src phosphorylation at Tyr 419. In contrast, siRNA targeting of SHP-2 facilitated H2O2-mediated interaction between caveolin-1 and CSK and enhanced Src phosphorylation at Tyr 530, leading to subsequent decrease in Src downstream signaling, such as focal adhesion kinase (FAK) and extracellular signal-related kinase (ERK). Our results collectively indicate that SHP-2 alters Src kinase activity by interfering with the complex formation between CSK and phosphotyrosine caveolin-1 in the presence of H2O2, thus functions as a positive regulator in Src signaling under oxidative stress in brain astrocytes.
Publication types
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Research Support, Non-U.S. Gov't
MeSH terms
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Astrocytes / drug effects*
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Astrocytes / metabolism*
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Astrocytoma / genetics
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Astrocytoma / metabolism
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CSK Tyrosine-Protein Kinase
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Caveolin 1 / genetics
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Caveolin 1 / metabolism*
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Cell Line
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Enzyme Activation
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Extracellular Signal-Regulated MAP Kinases / metabolism
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Focal Adhesion Protein-Tyrosine Kinases / metabolism
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Humans
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Hydrogen Peroxide / pharmacology*
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Phosphorylation / drug effects
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Protein Binding
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Protein Tyrosine Phosphatase, Non-Receptor Type 11 / metabolism*
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Proto-Oncogene Proteins pp60(c-src) / metabolism*
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RNA Interference
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RNA, Small Interfering / genetics
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Reactive Oxygen Species / metabolism
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src-Family Kinases / antagonists & inhibitors*
Substances
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Caveolin 1
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RNA, Small Interfering
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Reactive Oxygen Species
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Hydrogen Peroxide
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CSK Tyrosine-Protein Kinase
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Focal Adhesion Protein-Tyrosine Kinases
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Proto-Oncogene Proteins pp60(c-src)
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src-Family Kinases
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CSK protein, human
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Extracellular Signal-Regulated MAP Kinases
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PTPN11 protein, human
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Protein Tyrosine Phosphatase, Non-Receptor Type 11
Grants and funding
This work was supported by the National Research Foundation of Korea (NRF) grant funded by the Korea government (MSIP) [grant 2012R1A5A2A32671866] and by the National Research Foundation of Korea (NRF) grant funded by the Korea government (MEST) 2010-0029352. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.