Regulation of gene expression by HTLV-I Tax protein.
The human T-cell leukemia virus type I or HTLV-I is the causative agent of adult T-cell leukemia. A protein encoded by HTLV-I, Tax, activates viral gene expression and is essential for transforming T-lymphocytes. Tax activates HTLV-I gene expression via interactions with the ATF/CREB proteins and the coactivators CBP/p300 which assemble as a multiprotein complex on regulatory elements known as 21-bp repeats in the HTLV-I LTR. Tax can also activate expression from cellular genes including the interleukin-2 (IL-2) and the IL-2 receptor genes via increases in nuclear levels of NF-kappaB. Tax modulation of gene expression via the ATF/CREB and NF-kappaB pathways is linked to its transforming properties. This review discusses the mechanisms by which Tax regulates viral and cellular gene expression.
Departments of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, Texas, 75235-8594, USA.
F
F
Bex
R B
RB
Gaynor
D017362:Cyclic AMP Response Element-Binding Protein / Q000378:metabolism; D004742:Enhancer Elements, Genetic / Q000235:genetics; D015967:Gene Expression Regulation, Viral / Q000235:genetics*; D016356:Gene Products, tax / Q000502:physiology*; D015497:HIV-1 / Q000235:genetics*; D051548:Histone Acetyltransferases; D006801:Humans; D016328:NF-kappa B / Q000502:physiology; D056921:Nuclear Receptor Coactivator 3; D011401:Promoter Regions, Genetic / Q000235:genetics; D015534:Trans-Activators / Q000378:metabolism; D015533:Transcriptional Activation / Q000235:genetics; D014764:Viral Proteins / Q000235:genetics*
D017362:Cyclic AMP Response Element-Binding Protein; D016356:Gene Products, tax; D016328:NF-kappa B; D015534:Trans-Activators; D014764:Viral Proteins; D051548:Histone Acetyltransferases; C538866:NCOA3 protein, human; D056921:Nuclear Receptor Coactivator 3