title: Interaction of Btk and Akt in B cell signaling.
abstract: Reactive oxygen species (ROS) or reactive oxygen intermediates (ROIs) mediate complex signaling involving multiple pathways. In this report, we demonstrate for the first time that endogenous Bruton's tyrosine kinase (Btk) and Akt can interact with each other in DT40 chicken B cells and human Nalm6 B cells and that this interaction is inducible following H2O2 stimulation. This interaction is supported by visualizing the co-localization of Btk and Akt in the perinuclear region and membrane ruffles in COS-7 cells. We have also shown the involvement of phosphatidylinositol 3-kinase (PI 3-K) and Btk in the phosphorylation of Akt following stimulation by hydrogen peroxide (H2O2). Interestingly, Akt phosphorylation was found in the presence of Btk even in the absence of oxidative stress. In addition, we have investigated the involvement of PI 3-K in the MAPKs and ERK and JNK phosphorylation, in the presence or absence of Btk. Phosphorylation of both ERK and JNK increased when the PI 3-K pathway was inhibited and both pathways were modulated positively by Btk. Taken together, based on the study of endogenous conditions, we show the novel interaction of Btk and Akt in H2O2 signaling in B cells.
authors.affiliation: Karolinska Institutet, Clinical Research Center, Huddinge University Hospital, KFC, Novum Plan 5, SE-141 86 Huddinge, Sweden. jessica.lindvall@crc.ki.se
authors.forename: Jessica
authors.initials: J
authors.lastname: Lindvall
authors.forename: Tahmina C
authors.initials: TC
authors.lastname: Islam
mesh_terms: D000077329:Agammaglobulinaemia Tyrosine Kinase; D000818:Animals; D001402:B-Lymphocytes / Q000378:metabolism*; D019556:COS Cells; D002460:Cell Line; D002645:Chickens; D004305:Dose-Response Relationship, Drug; D004791:Enzyme Inhibitors / Q000494:pharmacology; D006861:Hydrogen Peroxide / Q000494:pharmacology; D015151:Immunoblotting; D008856:Microscopy, Fluorescence; D018384:Oxidative Stress; D010100:Oxygen / Q000378:metabolism; D019869:Phosphatidylinositol 3-Kinases / Q000378:metabolism; D010766:Phosphorylation; D011233:Precipitin Tests; D011485:Protein Binding; D017346:Protein Serine-Threonine Kinases; D011505:Protein-Tyrosine Kinases / Q000378:metabolism*; D011518:Proto-Oncogene Proteins / Q000378:metabolism*; D051057:Proto-Oncogene Proteins c-akt; D015398:Signal Transduction; D013997:Time Factors; D014162:Transfection
chemical_list: D000077329:Agammaglobulinaemia Tyrosine Kinase; D004791:Enzyme Inhibitors; D006861:Hydrogen Peroxide; D010100:Oxygen; D019869:Phosphatidylinositol 3-Kinases; D017346:Protein Serine-Threonine Kinases; D011505:Protein-Tyrosine Kinases; D011518:Proto-Oncogene Proteins; D051057:Proto-Oncogene Proteins c-akt; C000625949:BTK protein, human