title: Protein kinase D2 mediates activation of nuclear factor kappaB by Bcr-Abl in Bcr-Abl+ human myeloid leukemia cells.
abstract: The Bcr-Abl tyrosine kinase activates various signaling pathways including nuclear factor kappaB that mediate proliferation, transformation, and apoptosis resistance in Bcr-Abl(+) myeloid leukemia cells. Here we report that protein kinase (PK) D2, a serine threonine kinase of the PKD family, is a novel substrate of Bcr-Abl. PKD2 was found to be the major isoform of the PKD family expressed in chronic myeloid leukemia cells and is tyrosine phosphorylated by Bcr-Abl in its pleckstrin homology domain. A mutant that mimicks tyrosine phosphorylation of PKD2 in the pleckstrin homology domain activates nuclear factor kappaB independently of its catalytic activity. Furthermore, our data show that Bcr-Abl-induced activation of the nuclear factor kappaB cascade in LAMA84 cells is largely mediated by tyrosine-phosphorylated PKD2. These data present a novel mechanism of Bcr-Abl-induced nuclear factor kappaB activation in myeloid leukemia. Targeting PKD2 tyrosine phosphorylation, not its kinase activity, could be a novel therapeutic approach for the treatment of Bcr-Abl(+) myeloid leukemia.
authors.affiliation: Departments of Internal Medicine I and Internal Medicine III, University of Ulm, Germany, and Afdeling Biochemie, Katholieke Universiteit Leuven, Leuven, Belgium.
authors.forename: Tamara
authors.initials: T
authors.lastname: Mihailovic
authors.forename: Martin
authors.initials: M
authors.lastname: Marx
authors.forename: Alexandra
authors.initials: A
authors.lastname: Auer
authors.forename: Johan
authors.initials: J
authors.lastname: Van Lint
authors.forename: Mathias
authors.initials: M
authors.lastname: Schmid
authors.forename: Christoph
authors.initials: C
authors.lastname: Weber
authors.forename: Thomas
authors.initials: T
authors.lastname: Seufferlein
mesh_terms: D045744:Cell Line, Tumor; D016044:Fusion Proteins, bcr-abl / Q000378:metabolism*; D006801:Humans; D007527:Isoenzymes; D007951:Leukemia, Myeloid / Q000201:enzymology / Q000235:genetics / Q000378:metabolism*; D016297:Mutagenesis, Site-Directed; D016328:NF-kappa B / Q000378:metabolism*; D018384:Oxidative Stress; D010766:Phosphorylation; D000091283:Protein Kinase D2; D011494:Protein Kinases / Q000235:genetics / Q000378:metabolism*; D017434:Protein Structure, Tertiary; D014162:Transfection
chemical_list: D007527:Isoenzymes; D016328:NF-kappa B; D000091283:Protein Kinase D2; D011494:Protein Kinases; D016044:Fusion Proteins, bcr-abl