Mechanisms of mammalian polo-like kinase 1 (Plk1) localization: Self-versus non-self-priming

Mammalian polo-like kinase 1 (Plk1) has been studied intensively as a key element in regulating diverse mitotic events during M-phase progression. Plk1 is spatially regulated through the targeting activity of the conserved polo-box domain (PBD) present in the C-terminal non-catalytic region. Over the years, studies have demonstrated that the PBD forms a phospho-epitope binding module and the PBD-dependent interaction is critical for proper subcellular localization of Plk1. The current prevailing model is that the PBD binds to a phospho-epitope generated by Cdc2 or other Pro-directed kinases. Here we discuss a recent finding that Plk1 also self-promotes its localization by generating its own PBD-docking site.