title: Identification of CD44 as a downstream target of noncanonical NF-κB pathway activated by human T-cell leukemia virus type 1-encoded Tax protein.
abstract: Our previous study showed Human T-cell leukemia virus type 1 Tax induces osteopontin (OPN) expression by transactivating its promoter. As an extension, we investigated here the possible influence of Tax on CD44, an important receptor for OPN. Co-expression of Tax, but not its NF-κB-defective mutant, significantly increased the reporter gene expression directed by CD44 promoter. Tax-mediated CD44 activation was largely diminished by disrupting an element similar to the noncanonical κβ site found in other IKKα target genes, and further, co-transfection of RelB siRNA abolished CD44 induction by Tax, suggesting an involvement of noncanonical NF-κB pathway in Tax-mediated transactivation. Consistently, chromatin immunoprecipitation revealed a specific interaction of CD44 promoter with RelB-containing complex. Together, these results indicate that D44 gene is one of the downstream target genes of aberrantly activated noncanonical NF-κB signaling by Tax, providing an additional line of evidence explaining how Tax-induced NF-κB signaling is integrated into a fate-determining cellular program.
authors.affiliation: Research and Development Center, FUSO Pharmaceutical Industries, LTD., 2-3-30 Morinomiya, Joto-ku, Osaka 536-8523, Japan.
authors.forename: Jing
authors.initials: J
authors.lastname: Zhang
authors.forename: Osamu
authors.initials: O
authors.lastname: Yamada
authors.forename: Shinya
authors.initials: S
authors.lastname: Kida
authors.forename: Yoshihisa
authors.initials: Y
authors.lastname: Matsushita
authors.forename: Shoji
authors.initials: S
authors.lastname: Yamaoka
authors.forename: Haorile
authors.initials: H
authors.lastname: Chagan-Yasutan
authors.forename: Toshio
authors.initials: T
authors.lastname: Hattori
mesh_terms: D018076:DNA, Complementary / Q000737:chemistry; D005786:Gene Expression Regulation / Q000502:physiology; D016356:Gene Products, tax / Q000235:genetics / Q000378:metabolism*; D020868:Gene Silencing; D006367:HeLa Cells; D015368:Human T-lymphotropic virus 1 / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D018960:Hyaluronan Receptors / Q000235:genetics / Q000378:metabolism*; D019169:Jurkat Cells; D016328:NF-kappa B / Q000235:genetics / Q000378:metabolism*; D053495:Osteopontin / Q000235:genetics / Q000378:metabolism; D011401:Promoter Regions, Genetic; D034741:RNA, Small Interfering / Q000235:genetics / Q000378:metabolism; D051841:Transcription Factor RelB / Q000235:genetics; D015533:Transcriptional Activation
chemical_list: D018076:DNA, Complementary; D016356:Gene Products, tax; D018960:Hyaluronan Receptors; D016328:NF-kappa B; D034741:RNA, Small Interfering; C514970:tax protein, Human T-lymphotrophic virus 1; D053495:Osteopontin; D051841:Transcription Factor RelB