An Unexpected Role for Ubiquitylation of a Transcriptional Activator

The yeast transcriptional activator Gal4 has served as a paradigm for understanding how eukaryotic cells mount rapid transcriptional responses to environmental changes. In this issue of Cell, Muratani et al. (2005) provide evidence that Gal4 ubiquitylation and destruction are required for activation by Gal4. Surprisingly, this modification is required at a postinitiation step in transcription for the production of mRNAs that are correctly processed and fully functional for translation