Effects of mutation of the SUMO protease Ulp1 on chromatin-associated sumoylation genome-wide in budding yeast

Eukaryotic cells can modulate cellular levels of SUMO conjugation by regulating the enzymes involved in these processes. In budding yeast, for example, heat shock induces a global increase in SUMO conjugation, at least in part by triggering the degradation of the major SUMO protease, Ulp1.

ChIP-seq analyses by our group and others have identified hundreds of sites across the yeast genome that contain sumoylated proteins, including the promoter regions of 265 protein-coding genes, consistent with a role for sumoylation in regulating transcription widely. Paradoxically, despite the overall increase in SUMO conjugation upon heat shock, chromatin-associated sumoylation decreases at most of these loci when temperatures rise.