Reference - Detail
|Author||Kaito Y, Kataoka R, Takechi K, Mihara T, Tamura M.|
|Title||Nox1 activation by βPix and the role of Ser-340 phosphorylation.|
Rac is an activating factor for Nox1, an O2(-)-generating NADPH oxidase, expressed in the colon and other tissues. Rac requires a GDP-GTP exchange factor for activation. Nox1 activation by βPix has been demonstrated in cell lines. We examined the effects of βPix and its phosphomimetic mutant on endogenous Nox1 in Caco-2 cells transfected with Noxo1 and Noxa1. βPix expression enhanced O2(-) production in resting cells and cells stimulated with EGF or phorbol ester. βPix(S340E) further enhanced O2(-) production, while βPix(S340A) eliminated the βPix effect. βPix(S340E), but not βPix(S340A), had higher affinity and GEF activity for Rac than wild-type βPix. These results suggest that βPix phosphorylation at Ser-340 upregulates Nox1 through Rac activation, confirming Rac as a trigger for acute Nox1-dependent ROS production.
|MeSH||Adaptor Proteins, Vesicular Transport / metabolism Amino Acid Sequence Amino Acid Substitution Caco-2 Cells Enzyme Activation Epidermal Growth Factor / physiology Guanosine Triphosphate / chemistry Humans Hydrolysis Mutagenesis, Site-Directed NADPH Oxidase 1 NADPH Oxidases / metabolism* Phosphorylation Protein Binding Protein Processing, Post-Translational* Rho Guanine Nucleotide Exchange Factors / chemistry Rho Guanine Nucleotide Exchange Factors / genetics Rho Guanine Nucleotide Exchange Factors / metabolism* Serine / metabolism Superoxides / metabolism rac GTP-Binding Proteins / chemistry|
|Human and Animal Cells||CACO-2(RCB0988)|