Survey of the Phosphorylation Status of the Schizosaccharomyces pombe Deubiquitinating Enzyme (DUB) Family

Ubiquitination plays a role in virtually every cellular signaling pathway ranging from cell cycle control to DNA damage response to endocytosis and gene regulation. The bulk of our knowledge of the ubiquitination system is centered on modification of specific substrate proteins and the enzymatic cascade of ubiquitination. Our understanding of the regulation of the reversal of these modifications (deubiquitination) lags significantly behind. We recently reported a multifaceted study of the fission yeast Schizosaccharomyces pombe DUBs including characterization of their binding partners, in vitro enzymatic activity and subcellular localization. (1) Over half of the 20 fission yeast DUBs have a stable protein partner and some of those partners regulate the localization and/or activity of their cognate DUB. As a next step in understanding how DUBs might otherwise be regulated, we investigated the phosphostatus of the entire fission yeast DUB family using LC-MS/MS, and here we discuss the possible implications of phosphoregulation.