Cofactor Requirements for Transcriptional Activation by Sp1 (original) (raw)

1. A.M. NÄÄR,
2. S. RYU, and
3. R. TJIAN
4. Howard Hughes Medical Institute, University of California, Berkeley, California 94720

Excerpt

The promoter selectivity factor Sp1 is required for efficient transcriptional activation of many cellular and viral genes. Our laboratory has employed in vitro biochemical strategies to investigate the mechanisms of Sp1regulation of gene expression. Our recent reconstitutionexperiments revealed a requirement for multiple cofactoractivities that interface with the basal transcription machinery to support activation by Sp1. Previous studiesdemonstrated that the activation domains of Sp1 andother transcriptional regulators can bind directly to TBPassociated factors (TAFIIs). These factors appear to serveas coactivators mediating recruitment of the transcriptional machinery to the promoter by activators. Furtherrefinement of the in vitro transcription system resulted inthe identification of additional cofactors required for Sp1activation, including a novel factor, CRSP, whose function remains to be established...