Isolation and identification of PACE-binding protein Rpn4, a new transcriptional activator regulating 26S-proteasomal and other genes

A new upstream activating sequence (UAS) 5 ' -GGTGGCAAA-3 ' was detected in the promoters of 27 out of the 33 proteasomal genes and of several genes r elated to the ubiquitin-proteasomal system of Saccharomyces cerevisiae. The sequence was termed proteasome-associated control clement (PACE). Gel reta rdation assay revealed specific binding of PACE with an extracted protein. The protein (63K) was purified by affinity chromatography and was homogeneo us by SDS-PAGE. Microsequencing showed that the protein is Rpn4p. The abili ty of Rpn4p to activate transcription was demonstrated with constructs cont aining fragments of the RPN5 and CDC48 gene promoters and reporter cat. Bin ding to PACE, Rpn4p may act as a common transcription factor on the proteas omal and proteasome-related genes.