Enhanced cell‐free transcription of the ribosomal protein L<sub>32</sub> gene by the polyoma virus enhancer PEA3 DNA‐binding protein

The mouse‐ribosomal‐protein‐L32‐gene promoter contains a 12‐bp sequence motif within the 5′‐upstream region termed the β element which shows significant similarity with the consensus sequence of the polyoma‐virus‐enhancer PEA3. A cloned PEA3 DNA‐binding protein, expressed in Escherichia coli and purified, activates the expression of the ribosomal‐protein‐L32 gene in a cell‐free system. Moreover, the PEA3 protein participates in the formation of the ribosomal‐protein‐L32‐promoter – preinitiation‐transcription complex. The preinitiation complex formed with PEA3 is resistant to competition by oligonucleotides containing the β element. In addition anti‐PEA3 serum interacts with a factor in mouse L1210 nuclear extract that binds to the β element, causing a supershift in a mobility‐shift assay. Our study demonstrates for the first time that the PEA3 protein can transactivate a cellular gene in a cell‐free transcription system.

Enhanced cell‐free transcription of the ribosomal protein L₃₂ gene by the polyoma virus enhancer PEA3 DNA‐binding protein Journal Articles