Open AccessNegative-acting factor and superantigen are separable activities of the mouse mammary tumor virus long terminal repeat.
Author(s) -
Stefan Wintersperger,
Brian Salmons,
Thomas Miethke,
Volker Erfle,
Hermann Wagner,
Walter H. Günzburg
Publication year - 1995
Publication title -
proceedings of the national academy of sciences of the united states of america
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.011
H-Index - 771
eISSN - 1091-6490
pISSN - 0027-8424
DOI - 10.1073/pnas.92.7.2745
Subject(s) - long terminal repeat , promoter , superantigen , mouse mammary tumor virus , biology , microbiology and biotechnology , open reading frame , gene , heterologous , transcription (linguistics) , recombinant dna , genetics , gene expression , staphylococcus aureus , peptide sequence , linguistics , philosophy , bacteria
The open reading frame contained within the long terminal repeat (LTR) of mouse mammary tumor virus encodes Naf, a negative regulator of transcription, as well as a superantigen activity, Sag, which causes the deletion of specific classes of T cells. In the present study, the effect of Naf expression on different promoters and the coding requirements for Naf and Sag have been investigated. Sag activity was found to require only sequences in the LTR, whereas sequences located within the gag gene were additionally required for functional Naf activity. Surprisingly, both the classic promoter and a recently described promoter located in the LTR can give rise to both functional Naf and Sag. Further analysis of Naf revealed that the downregulatory effect was mediated by sequences located in the LTR and that heterologous promoters were also affected by Naf.