PP1 Phosphatase Complexes: Undruggable No Longer.

The identification of inhibitors targeting regulatory subunits of serine/threonine PP1 phosphatases reported by Krzyzosiak et al. is a significant step in expanding the pharmacological regulation of phosphorylation beyond kinases. The selective inhibitor of the R15B phosphatase regulatory subunit, termed Raphin1, protects cells from stress and delays neurodegeneration in a mouse model of Huntington's disease.