title: CCAAT/enhancer-binding proteins modulate human T cell leukemia virus type 1 long terminal repeat activation.
abstract: CCAAT/enhancer-binding protein (C/EBP) basic region/leucine zipper (bZIP) transcription factors have been shown to form heterodimers with cAMP-responsive element binding protein 2 (CREB-2), a transcription factor involved in regulating basal and Tax-mediated transactivation of the human T cell leukemia virus type 1 (HTLV-1) long terminal repeat (LTR). In cells of the monocyte-macrophage lineage (proposed to play a role in HTLV-1 pathogenesis as an accessory target cell), several members of the C/EBP family are expressed at high levels and may have functional impact on both basal and Tax-mediated transactivation of the HTLV-1 LTR. Basal activation of the HTLV-1 LTR was enhanced by overexpression of C/EBPbeta, C/EBPdelta, or C/EBPepsilon, whereas transactivation of the LTR by Tax was inhibited by overexpression of C/EBPalpha and C/EBPbeta. Inhibition of Tax-mediated transactivation of the HTLV-1 LTR was co-activator-independent, did not require C/EBP binding to the Tax-responsive elements, and may involve heterodimerization with CREB factors.
authors.affiliation: Department of Microbiology and Immunology, The Pennsylvania State University, College of Medicine, Hershey, 17033, USA.
authors.forename: Christian
authors.initials: C
authors.lastname: Grant
authors.forename: Michael
authors.initials: M
authors.lastname: Nonnemacher
authors.forename: Pooja
authors.initials: P
authors.lastname: Jain
authors.forename: Devanshi
authors.initials: D
authors.lastname: Pandya
authors.forename: Bryan
authors.initials: B
authors.lastname: Irish
authors.forename: Simon C
authors.initials: SC
authors.lastname: Williams
authors.forename: Brian
authors.initials: B
authors.lastname: Wigdahl
mesh_terms: D001483:Base Sequence; D001667:Binding, Competitive; D022762:CCAAT-Enhancer-Binding Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D004279:DNA, Viral / Q000235:genetics / Q000378:metabolism; D019281:Dimerization; D015967:Gene Expression Regulation, Viral; D016356:Gene Products, tax / Q000378:metabolism; D017930:Genes, Reporter; D016355:Genes, pX; D015368:Human T-lymphotropic virus 1 / Q000235:genetics*; D006801:Humans; D019169:Jurkat Cells; D008954:Models, Biological; D020836:Protein Structure, Quaternary; D020079:Terminal Repeat Sequences; D015533:Transcriptional Activation; D014162:Transfection; D020298:U937 Cells; D050880:p300-CBP Transcription Factors / Q000378:metabolism
chemical_list: D022762:CCAAT-Enhancer-Binding Proteins; D004279:DNA, Viral; D016356:Gene Products, tax; D050880:p300-CBP Transcription Factors