First Author | Mermod N | Year | 1988 |
Journal | Nature | Volume | 332 |
Issue | 6164 | Pages | 557-61 |
PubMed ID | 2833704 | Mgi Jnum | J:30071 |
Mgi Id | MGI:77589 | Doi | 10.1038/332557a0 |
Citation | Mermod N, et al. (1988) Enhancer binding factors AP-4 and AP-1 act in concert to activate SV40 late transcription in vitro. Nature 332(6164):557-61 |
abstractText | The simian virus 40 (SV40) transcriptional enhancer is composed of multiple cis-acting DNA sequence motifs, each individually having a two- to fourfold effect on the efficiency of transcription. When various distinct cis-elements act in combination, however, a dramatic enhancement of transcription initiation often results. SV40-enhancer A-domain sequences were previously shown to be important for early and late transcription in vivo. Here we report the isolation of the enhancer binding factor AP-4, which recognizes a motif in this domain. Purified AP-4 activates SV40 late transcription in vitro, and this stimulation is augmented by the addition of transcription factor AP-1 which binds to adjacent sequences in the A-domain, suggesting coordinate action of the two factors for transcriptional enhancement. AP-1 also represses late transcription from a major in vitro start site which is poorly used in vivo, indicating that AP-1 can act as both a positive and negative regulator of SV40 late transcription. Thus by manipulating the levels of different trans-acting factors in vitro, we can recreate the pattern of SV40 late initiation observed during the viral lytic cycle in vivo. |