The Involvement of the Tyrosine Kinase c-Src in the Regulation of Reactive Oxygen Species Generation Mediated by NADPH Oxidase-1
- 1 July 2008
- journal article
- Published by American Society for Cell Biology (ASCB) in Molecular Biology of the Cell
- Vol. 19 (7) , 2984-2994
- https://doi.org/10.1091/mbc.e08-02-0138
Abstract
NADPH oxidase (Nox) family enzymes are one of the main sources of cellular reactive oxygen species (ROS), which have been shown to function as second messenger molecules. To date, seven members of this family have been reported, including Nox1-5 and Duox1 and -2. With the exception of Nox2, the regulation of the Nox enzymes is still poorly understood. Nox1 is highly expressed in the colon, and it requires two cytosolic regulators, NoxO1 and NoxA1, as well as the binding of Rac1 GTPase, for its activity. In this study, we investigate the role of the tyrosine kinase c-Src in the regulation of ROS formation by Nox1. We show that c-Src induces Nox1-mediated ROS generation in the HT29 human colon carcinoma cell line through a Rac-dependent mechanism. Treatment of HT29 cells with the Src inhibitor PP2, expression of a kinase-inactive form of c-Src, and c-Src depletion by small interfering RNA (siRNA) reduce both ROS generation and the levels of active Rac1. This is associated with decreased Src-mediated phosphorylation and activation of the Rac1-guanine nucleotide exchange factor Vav2. Consistent with this, Vav2 siRNA that specifically reduces endogenous Vav2 protein is able to dramatically decrease Nox1-dependent ROS generation and abolish c-Src-induced Nox1 activity. Together, these results establish c-Src as an important regulator of Nox1 activity, and they may provide insight into the mechanisms of tumor formation in colon cancers.Keywords
This publication has 52 references indexed in Scilit:
- Nox1 downstream of 12‐lipoxygenase controls cell proliferation but not cell spreading of colon cancer cellsInternational Journal of Cancer, 2007
- Nox1-dependent superoxide production controls colon adenocarcinoma cell migrationBiochimica et Biophysica Acta (BBA) - Molecular Cell Research, 2007
- Evidence for cancer-associated expression of NADPH oxidase 1 (Nox1)-based oxidase system in the human stomachFree Radical Biology & Medicine, 2007
- GEF-H1 Modulates Localized RhoA Activation during Cytokinesis under the Control of Mitotic KinasesDevelopmental Cell, 2007
- The role of Src in solid and hematologic malignanciesCancer, 2006
- Decreased blood pressure in NOX1‐deficient miceFEBS Letters, 2005
- Molecular composition and regulation of the Nox family NAD(P)H oxidasesBiochemical and Biophysical Research Communications, 2005
- Src Family Tyrosine Kinases and Growth Factor SignalingExperimental Cell Research, 2000
- The use of diphenylene iodonium, an inhibitor of NADPH oxidase, to investigate the antimicrobial action of human monocyte derived macrophagesJournal of Immunological Methods, 1990
- Cell transformation by pp60c-src mutated in the carboxy-terminal regulatory domainCell, 1987