Article
- The EMBO Journal (1998) 17, 6723 - 6729
- doi:10.1093/emboj/17.22.6723
Isolation of cDNAs encoding novel transcription coactivators p52 and p75 reveals an alternate regulatory mechanism of transcriptional activation
Hui Ge1, Yuanzheng Si1 and Robert G. Roeder2
- Laboratory of Molecular Embryology, National Institute of Child Health and Human Development, Bethesda, MD 20892 USA
- Laboratory of Biochemistry and Molecular Biology, The Rockefeller University, New York, NY 10021, USA
Correspondence to:
Hui Ge, E-mail: geh@box-g.nih.gov
Received 27 July 1998; Accepted 15 September 1998; Revised 15 September 1998
Abstract
Transcriptional activation in human cell-free systems containing RNA polymerase II and general initiation factors requires the action of one or more additional coactivators. Here, we report the isolation of cDNAs encoding two novel human transcriptional coactivators (p52 and p75) that are derived from alternatively spliced products of a single gene and share a region of 325 residues, but show distinct coactivator properties. p52 and p75 both show strong interactions with the VP16 activation domain and several components of the general transcriptional machinery. p52, like the previously described PC4, is a potent broad-specificity coactivator, whereas p75 is less active for most activation domains. These results suggest that p52 is a general transcriptional coactivator that mediates functional interactions between upstream sequence-specific activators and the general transcription apparatus, possibly through a novel mechanism.
Keywords:
- coactivators,
- p52,
- p75,
- PC4,
- transcriptional activation
