Stimulation of IKK-gamma oligomerization by the human T-cell leukemia virus oncoprotein Tax.
Human T-cell leukemia virus type 1 oncoprotein Tax activates NF-kappaB through direct binding to IKK-gamma, the regulatory component of the IkappaB kinase complex. Mechanisms by which IKK-gamma adapts the Tax signal to the IkappaB kinase are poorly understood. Here we demonstrate that IKK-gamma forms homodimer and homotrimer both in vitro and in yeast or mammalian cells through a C-terminal domain comprising amino acids 251-419. In contrast, Tax protein targets a central region of IKK-gamma, which consists of amino acids 201-250. Interestingly, Tax stimulates the oligomerization of IKK-gamma, likely through direct binding. Taken together, our findings suggest a new model of Tax activation of NF-kappaB, in which Tax interacts with IKK-gamma to stimulate its oligomerization.
Huang
Guo Jin
GJ
National Key Laboratory for Molecular Virology, Institute of Virology, 100 Yingxin Street, 100052, Beijing, PR China.
Zhang
Zhi Qing
ZQ
Jin
Dong Yan
DY
D001704:Biopolymers / Q000737:chemistry / Q000378:metabolism*; D016356:Gene Products, tax / Q000502:physiology*; D006367:HeLa Cells; D006801:Humans; D051550:I-kappa B Kinase; D017346:Protein Serine-Threonine Kinases / Q000737:chemistry / Q000378:metabolism*; D020798:Two-Hybrid System Techniques
D001704:Biopolymers; D016356:Gene Products, tax; D017346:Protein Serine-Threonine Kinases; C496559:CHUK protein, human; D051550:I-kappa B Kinase; C496560:IKBKB protein, human; C496565:IKBKE protein, human