title: Transcriptional activator Tax of HTLV-1 binds to the NF-kappa B precursor p105.
abstract: Human T-cell leukemia virus type 1 (HTLV-1) induces adult T-cell leukemia and also a neurological disease, tropical spastic paraparesis. Tax protein (p40tax) of HTLV-1 activates in trans its own transcriptional enhancer in the long terminal repeat and also those in some cellular genes such as interleukin 2 receptor alpha, granulocyte-macrophage colony-stimulating factor, Fos, Jun and MHC class I. Thus, Tax has been proposed to play a critical role in the pathogenesis induced by HTLV-1 infection. Here, we report formation of a complex of Tax protein with the precursor protein p105 of the NF-kappa B p50 subunit. p105 was co-immunoprecipitated with Tax protein from cells infected with HTLV-1 from cells transfected with the Tax expression plasmid, but not from cells transfected with inactive mutants of Tax. Furthermore, a GST-p105 fusion protein produced in Escherichia coli bound to Tax protein. These results strongly suggest that the trans-activator Tax protein forms a complex with precursor NF-kappa B p105 and plays a role in trans-activation of transcriptional initiation.
authors.affiliation: Department of Cellular and Molecular Biology, University of Tokyo, Japan.
authors.forename: H
authors.initials: H
authors.lastname: Hirai
authors.forename: J
authors.initials: J
authors.lastname: Fujisawa
authors.forename: T
authors.initials: T
authors.lastname: Suzuki
authors.forename: K
authors.initials: K
authors.lastname: Ueda
authors.forename: M
authors.initials: M
authors.lastname: Muramatsu
authors.forename: A
authors.initials: A
authors.lastname: Tsuboi
authors.forename: N
authors.initials: N
authors.lastname: Arai
authors.forename: M
authors.initials: M
authors.lastname: Yoshida
mesh_terms: D016356:Gene Products, tax / Q000378:metabolism*; D015368:Human T-lymphotropic virus 1 / Q000472:pathogenicity*; D006801:Humans; D016328:NF-kappa B / Q000378:metabolism*; D011498:Protein Precursors / Q000378:metabolism*; D015533:Transcriptional Activation
chemical_list: D016356:Gene Products, tax; D016328:NF-kappa B; D011498:Protein Precursors