Download MendeleyThe Molecular Basis for Phosphodependent Substrate Targeting and Regulation of Plks by the Polo-Box Domain
Elia, A., Rellos, P., Haire, L., Chao, J., Ivins, F., Hoepker, K., Mohammad, D., Cantley, L., Smerdon, S.J., Yaffe, M.B.(2003) Cell 115: 83
- PubMed: 14532005
- DOI: https://doi.org/10.1016/s0092-8674(03)00725-6
- Primary Citation of Related Structures:
1UMW - PubMed Abstract:
Polo-like kinases (Plks) perform crucial functions in cell-cycle progression and multiple stages of mitosis. Plks are characterized by a C-terminal noncatalytic region containing two tandem Polo boxes, termed the Polo-box domain (PBD), which has recently been implicated in phosphodependent substrate targeting. We show that the PBDs of human, Xenopus, and yeast Plks all recognize similar phosphoserine/threonine-containing motifs. The 1.9 A X-ray structure of a human Plk1 PBD-phosphopeptide complex shows that the Polo boxes each comprise beta6alpha structures that associate to form a 12-stranded beta sandwich domain. The phosphopeptide binds along a conserved, positively charged cleft located at the edge of the Polo-box interface. Mutations that specifically disrupt phosphodependent interactions abolish cell-cycle-dependent localization and provide compelling phenotypic evidence that PBD-phospholigand binding is necessary for proper mitotic progression. In addition, phosphopeptide binding to the PBD stimulates kinase activity in full-length Plk1, suggesting a conformational switching mechanism for Plk regulation and a dual functionality for the PBD.
Organizational Affiliation:
Center for Cancer Research, Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.
