Cell line-dependent response of the enhancer element of simian virus 40 to transactivator p40tax encoded by human T-cell leukemia virus type I.
The trans-acting transcriptional factor p40tax of human T-cell leukemia virus type I (HTLV-I) can activate expression not only of its own viral genes but also of other viral and cellular genes. We examined the cis-acting sequences in the simian virus 40 (SV40) enhancer required for its activation by HTLV-I p40tax. Experiments with chloramphenicol acetyltransferase constructs bearing the SV40 enhancer elements revealed that p40tax-dependent transactivation of the SV40 enhancer is mediated through the C element that contains the typical sequence for binding of a nuclear factor NF-kappa B. Activation of the C element by p40tax was seen in a limited set of cell lines as was also seen with the whole enhancer of SV40. Binding of NF-kappa B or NF-kappa B-like factor to the SV40 C element increased when p40tax was expressed. The fact that HTLV-I p40tax utilizes a cellular regulatory mechanism to transactivate the SV40 enhancer in a cell-dependent manner may have implications for the pathogenesis of adult T-cell leukemia.
Nakamura
M
M
Department of Microbiology, Tohoku University School of Medicine, Sendai, Japan.
Niki
M
M
Nagata
K
K
Ohtani
K
K
Saito
S
S
Hinuma
Y
Y
Sugamura
K
K
D001483:Base Sequence; D002460:Cell Line; D004742:Enhancer Elements, Genetic; D015368:Human T-lymphotropic virus 1 / Q000235:genetics*; D006801:Humans; D008969:Molecular Sequence Data; D010957:Plasmids; D011401:Promoter Regions, Genetic; D013539:Simian virus 40 / Q000235:genetics*; D013601:T-Lymphocytes; D015534:Trans-Activators / Q000235:genetics* / Q000502:physiology; D015533:Transcriptional Activation
D015534:Trans-Activators