Nucleic Acids Research, 1987, Vol. 15, No. 20 8177-8193
© 1987
Articles |
Contribution of different GC-motifs to the control of simian virus 40 late promoter activity
Laboratoire d'Oncologie Moléculaire, Institut de Recherches Scientifiques sur le Cancer B P No.8, 94802 Villejuif Cedex, France
*To whom correspondence should be addressed
Received August 14, 1987. Revised September 25, 1987. Accepted September 25, 1987.
During the course of lytic infection the 21-bp repeat region regulates differentially the late gene expression; a mutant deleted for this region expresses late genes either to a higher level in the absence of T antigen or to a lower level in the late phase of infection as compared to wild type (23). By analysing a series of clustered point mutations generated within the GC-motifs we show that i) mutations within motifs I and II stimulate late transcription two to three-fold, suggesting that competition for transcription machinery between early-early and late promoters is mediated by these two motifs, ii) after viral replication, simultaneous mutations within motifs IV, V and VI decrease to 23 % the efficiency of late transcription, indicating that these motifs are elements of the late promoter. Moreover comparison of results presented in this paper with results published by Barrera-Saldana et al. strongly suggest that late-early and late promoters are regulated in a similar manner.