Simian virus 40 (SV40) T-antigen transcriptional activation mediated through the Oct/SPH region of the SV40 late promoter

Abstract

Simian virus 40 (SV40) large T antigen is a promiscuous transcriptional activator of many viral and cellular promoters. The SV40 late promoter, a primary target for T-antigen transcriptional activation, contains a previously described T-antigen-activatable binding site (SV40 nucleotides 186 to 225). The T-antigenactivatable binding site element contains overlapping octamer (Oct)and SPH (TEF-1)-binding sites (Oct/SPH site). Using this Oct/SPH site as an upstream element in a simple promoter, we show that the SPH sites are necessary for transcriptional activation by T antigen. In addition, we show that when Oct 1 is overproduced, it can eliminate T-antigen-mediated transcriptional activation, as well as basal activity, from the simple Oct/SPH promoter as well as the intact SV40 late promoter. This suggests that one function of T antigen in transcriptional activation of the late promoter is to alter factor binding at the Oct/SPH region to favor binding of factors to the SPH sites.

Transcriptional activation by the human cytomegalovirus immediate-early proteins: requirements for simple promoter structures and interactions with multiple components of the transcription complex

“…The ability of IEP86 to activate many simple promoters and its ability to interact with TBP (14, 20, 26) are similar to our previous observations of transcriptional activation by simian virus 40 (SV40) large T antigen (16,18,19,40). Specifically, T antigen activates many simple promoters and it interacts with TBP.…”

“…Our data show that the promoter structure required for TE protein activation is very simple and can be quite variable, consisting of a TATA element and one of several upstream binding sites for transcription factors. Both of these elements, the TATA box and the USE, are essential for activation, which suggested the possibility of multiple interactions with components of the transcription complex, a situation we have previously studied in relationship to SV40 T antigen (16,18,19).…”

Characterization of the transcription activation function and the DNA binding domain of transcriptional enhancer factor-1.

“…TEF-1 was first identified as a HeLa cell protein that binds cooperatively to tandem repeats of the GT-IIC or Sph enhansons from the simian virus 40 (SV40) enhancer (Davidson et al, 1986(Davidson et al, , 1988Wildeman et al, 1986;Xiao et al, 1987). These TEF-1 binding sites, which have highly degenerate nucleotide sequences, activate transcription from the SV40 early promoter (Davidson et al, 1986;Herr and Clarke, 1986;Zenke et al, 1986;Nomiyama et al, 1987;Ondek et al, 1987Ondek et al, , 1988Schirm et al, 1987;Fromental et al, 1988) and mediate large T antigen activation of the SV40 late promoter (May et al, 1987;Casaz et al, 1991;Gruda and Alwine, 1991;Kelly and Wildeman, 1991). The latter effect possibly involves direct interaction between TEF-l and large T antigen (Gruda et al, 1993).…”

Hypomyelinating peripheral neuropathies and schwannomas in transgenic mice expressing SV40 T-antigen

“…The followina cDNAs were utilized as nrobes: P5. a 1.7 kb fragment of human neuro?ibromin (Wallace et al,19'90) a 0.7 kb BamHl fragment of rat nerve growth factor receptor (Radeke et al, 1987), a 330 bp PstI/PvuII fragment of large T-antigen (Gruda and Alwine, 1993) a full-length cDNA of rat P, (Lemke and Axel, 1985) a 330 bp PvuII fragment of histone H3 (pFF 435C) (Plumb et al, 1983), and a full-length cDNA of rat GAPDH (Fort et al, 1985).…”