title: Stimulation of IKK-gamma oligomerization by the human T-cell leukemia virus oncoprotein Tax.
abstract: 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.
authors.affiliation: National Key Laboratory for Molecular Virology, Institute of Virology, 100 Yingxin Street, 100052, Beijing, PR China.
authors.forename: Guo Jin
authors.initials: GJ
authors.lastname: Huang
authors.forename: Zhi Qing
authors.initials: ZQ
authors.lastname: Zhang
authors.forename: Dong Yan
authors.initials: DY
authors.lastname: Jin
mesh_terms: 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
chemical_list: 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