TY - JOUR
T1 - In vitro activation of the IκB kinase complex by human T-cell leukemia virus type-1 tax
AU - Mukherjee, Sohini
AU - Negi, Veera S.
AU - Keitany, Gladys
AU - Tanaka, Yuetsu
AU - Orth, Kim
PY - 2008/5/30
Y1 - 2008/5/30
N2 - Human T-cell leukemia virus type-I expresses Tax, a 40-kDa oncoprotein that activates IκB kinase (IKK), resulting in constitutive activation of NFκB. Herein, we have developed an in vitro signaling assay to analyze IKK complex activation by recombinant Tax. Using this assay in combination with reporter assays, we demonstrate that Tax-mediated activation of IKK is independent of phosphatases. We show that sustained activation of the Tax-mediated activation of the NFκB pathway is dependent on an intact Hsp90-IKK complex. By acetylating and thereby preventing activation of the IKK complex by the Yersinia effector YopJ, we demonstrate that Tax-mediated activation of the IKK complex requires a phosphorylation step. Our characterization of an in vitro signaling assay system for the mechanism of Tax-mediated activation of the IKK complex with a variety of mutants and inhibitors results in a working model for the biochemical mechanism of Tax-induced activation.
AB - Human T-cell leukemia virus type-I expresses Tax, a 40-kDa oncoprotein that activates IκB kinase (IKK), resulting in constitutive activation of NFκB. Herein, we have developed an in vitro signaling assay to analyze IKK complex activation by recombinant Tax. Using this assay in combination with reporter assays, we demonstrate that Tax-mediated activation of IKK is independent of phosphatases. We show that sustained activation of the Tax-mediated activation of the NFκB pathway is dependent on an intact Hsp90-IKK complex. By acetylating and thereby preventing activation of the IKK complex by the Yersinia effector YopJ, we demonstrate that Tax-mediated activation of the IKK complex requires a phosphorylation step. Our characterization of an in vitro signaling assay system for the mechanism of Tax-mediated activation of the IKK complex with a variety of mutants and inhibitors results in a working model for the biochemical mechanism of Tax-induced activation.
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U2 - 10.1074/jbc.M704831200
DO - 10.1074/jbc.M704831200
M3 - Article
C2 - 18223255
AN - SCOPUS:47249123709
SN - 0021-9258
VL - 283
SP - 15127
EP - 15133
JO - Journal of Biological Chemistry
JF - Journal of Biological Chemistry
IS - 22
ER -