Phosphorylation meets proteolysis

Phosphorylation is a reversible post-translational modification that regulates many proteins and enzymes, including proteases, as shown by two recent publications. Huang and colleagues and Velázquez-Delgado and Hardy (this issue of Structure) describe how phosphorylation activates the protease activity of the deubiquitinating enzyme DUBA and how it inhibits caspase-6, respectively.