Download MendeleyStructural and functional basis of protein phosphatase 5 substrate specificity.
Oberoi, J., Dunn, D.M., Woodford, M.R., Mariotti, L., Schulman, J., Bourboulia, D., Mollapour, M., Vaughan, C.K.(2016) Proc Natl Acad Sci U S A 113: 9009-9014
- PubMed: 27466404 Search on PubMedSearch on PubMed Central
- DOI: https://doi.org/10.1073/pnas.1603059113
- Primary Citation Related Structures:
5HPE - PubMed Abstract:
The serine/threonine phosphatase protein phosphatase 5 (PP5) regulates hormone- and stress-induced cellular signaling by association with the molecular chaperone heat shock protein 90 (Hsp90). PP5-mediated dephosphorylation of the cochaperone Cdc37 is essential for activation of Hsp90-dependent kinases. However, the details of this mechanism remain unknown. We determined the crystal structure of a Cdc37 phosphomimetic peptide bound to the catalytic domain of PP5. The structure reveals PP5 utilization of conserved elements of phosphoprotein phosphatase (PPP) structure to bind substrate and provides a template for many PPP-substrate interactions. Our data show that, despite a highly conserved structure, elements of substrate specificity are determined within the phosphatase catalytic domain itself. Structure-based mutations in vivo reveal that PP5-mediated dephosphorylation is required for kinase and steroid hormone receptor release from the chaperone complex. Finally, our data show that hyper- or hypoactivity of PP5 mutants increases Hsp90 binding to its inhibitor, suggesting a mechanism to enhance the efficacy of Hsp90 inhibitors by regulation of PP5 activity in tumors.
- Institute of Structural and Molecular Biology, Biological Sciences, University College London and Birkbeck College, London WC1E 7HX, United Kingdom;
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