Fig. 1.

Subcellular phosphatase activities reset intracellular signaling triggered by growth factors, proinflammatory cytokines, and pathogenic stresses. Hierarchical signaling cascades initiated by extracellular stimuli cause downstream protein phosphorylation. Upon phosphorylation, some signaling proteins are shuttled into (orange arrows) or out of (blue arrows) the nucleus. Compartment- and substrate-specific phosphatases dephosphorylate activated proteins thereby returning proteins to their resting compartment.