LAUSR

In eukaryotes, small ubiquitin-like modifier (SUMO) is a protein family with four different isoforms (S1 to S4) that has enzymes dedicated to conjugating SUMO to target proteins. SUMOylation impacts enzyme location and function and has been implicated in cell division, nuclear transport, and transcriptional regulation. In a new report, investigators describe a method to isolate S2 and S3 conjugated peptides, which does not rely on engineered cell lines or animals carrying a tagged variant of SUMO to facilitate enrichment. The authors identified more than 14,000 sites in human cell culture and nearly 2000 across eight different mouse tissues. In cell culture, a much larger fraction of SUMO2/3 pools were conjugated to targets and is consistent with other reports of high SUMOylation levels in rapidly dividing tissues. Brain had the fewest sites of any mouse tissue and is surprising given that SUMO has been implicated in some neuropathologies. This dataset will serve as a reference of SUMOylation in normal/healthy tissues. CN