Post-translational Regulation of FNIP1 Creates a Rheostat for the Molecular Chaperone Hsp90
Rebecca A. Sager,
Mark R. Woodford,
Sarah J. Backe,
Alan M. Makedon,
Alexander J. Baker-Williams,
Bryanna T. DiGregorio,
David R. Loiselle,
Timothy A. Haystead,
Natasha E. Zachara,
Chrisostomos Prodromou,
Dimitra Bourboulia,
Laura S. Schmidt,
W. Marston Linehan,
Gennady Bratslavsky,
Mehdi Mollapour
Affiliations
Rebecca A. Sager
Department of Urology, SUNY Upstate Medical University, Syracuse, NY 13210, USA; Department of Biochemistry and Molecular Biology, SUNY Upstate Medical University, Syracuse, NY 13210, USA; Upstate Cancer Center, SUNY Upstate Medical University, Syracuse, NY 13210, USA
Mark R. Woodford
Department of Urology, SUNY Upstate Medical University, Syracuse, NY 13210, USA; Department of Biochemistry and Molecular Biology, SUNY Upstate Medical University, Syracuse, NY 13210, USA; Upstate Cancer Center, SUNY Upstate Medical University, Syracuse, NY 13210, USA
Sarah J. Backe
Department of Urology, SUNY Upstate Medical University, Syracuse, NY 13210, USA; Department of Biochemistry and Molecular Biology, SUNY Upstate Medical University, Syracuse, NY 13210, USA; Upstate Cancer Center, SUNY Upstate Medical University, Syracuse, NY 13210, USA
Alan M. Makedon
Department of Urology, SUNY Upstate Medical University, Syracuse, NY 13210, USA; Upstate Cancer Center, SUNY Upstate Medical University, Syracuse, NY 13210, USA
Alexander J. Baker-Williams
Department of Urology, SUNY Upstate Medical University, Syracuse, NY 13210, USA; Department of Biochemistry and Molecular Biology, SUNY Upstate Medical University, Syracuse, NY 13210, USA; Upstate Cancer Center, SUNY Upstate Medical University, Syracuse, NY 13210, USA
Bryanna T. DiGregorio
Department of Urology, SUNY Upstate Medical University, Syracuse, NY 13210, USA; Upstate Cancer Center, SUNY Upstate Medical University, Syracuse, NY 13210, USA
David R. Loiselle
Department of Pharmacology and Cancer Biology, Duke University Medical Center, Durham, NC 27710, USA
Timothy A. Haystead
Department of Pharmacology and Cancer Biology, Duke University Medical Center, Durham, NC 27710, USA
Natasha E. Zachara
Department of Biological Chemistry, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
Chrisostomos Prodromou
Genome Damage and Stability Centre, University of Sussex, Brighton BN1 9RQ, UK
Dimitra Bourboulia
Department of Urology, SUNY Upstate Medical University, Syracuse, NY 13210, USA; Department of Biochemistry and Molecular Biology, SUNY Upstate Medical University, Syracuse, NY 13210, USA; Upstate Cancer Center, SUNY Upstate Medical University, Syracuse, NY 13210, USA
Laura S. Schmidt
Basic Science Program, Leidos Biomedical Research, Inc., Frederick National Laboratory for Cancer Research, Frederick, MD 21702, USA; Urologic Oncology Branch, Center for Cancer Research, National Cancer Institute, Bethesda, MD 20892, USA
W. Marston Linehan
Urologic Oncology Branch, Center for Cancer Research, National Cancer Institute, Bethesda, MD 20892, USA
Gennady Bratslavsky
Department of Urology, SUNY Upstate Medical University, Syracuse, NY 13210, USA; Department of Biochemistry and Molecular Biology, SUNY Upstate Medical University, Syracuse, NY 13210, USA; Upstate Cancer Center, SUNY Upstate Medical University, Syracuse, NY 13210, USA
Mehdi Mollapour
Department of Urology, SUNY Upstate Medical University, Syracuse, NY 13210, USA; Department of Biochemistry and Molecular Biology, SUNY Upstate Medical University, Syracuse, NY 13210, USA; Upstate Cancer Center, SUNY Upstate Medical University, Syracuse, NY 13210, USA; Corresponding author
Summary: The molecular chaperone Hsp90 stabilizes and activates client proteins. Co-chaperones and post-translational modifications tightly regulate Hsp90 function and consequently lead to activation of clients. However, it is unclear whether this process occurs abruptly or gradually in the cellular context. We show that casein kinase-2 phosphorylation of the co-chaperone folliculin-interacting protein 1 (FNIP1) on priming serine-938 and subsequent relay phosphorylation on serine-939, 941, 946, and 948 promotes its gradual interaction with Hsp90. This leads to incremental inhibition of Hsp90 ATPase activity and gradual activation of both kinase and non-kinase clients. We further demonstrate that serine/threonine protein phosphatase 5 (PP5) dephosphorylates FNIP1, allowing the addition of O-GlcNAc (O-linked N-acetylglucosamine) to the priming serine-938. This process antagonizes phosphorylation of FNIP1, preventing its interaction with Hsp90, and consequently promotes FNIP1 lysine-1119 ubiquitination and proteasomal degradation. These findings provide a mechanism for gradual activation of the client proteins through intricate crosstalk of post-translational modifications of the co-chaperone FNIP1. : Sager et al. show that casein-kinase-2-mediated sequential phosphorylation of the co-chaperone FNIP1 leads to incremental inhibition of Hsp90 ATPase activity and gradual activation of both kinase and non-kinase clients. O-GlcNAcylation antagonizes phosphorylation of FNIP1, preventing its interaction with Hsp90, and consequently promotes FNIP1 ubiquitination and proteasomal degradation. Keywords: heat shock protein 90, Hsp90, co-chaperone, FNIP1, folliculin-interacting protein 1, serine/threonine protein phosphatase 5, PP5, O-GlcNAcylation, Birt-Hogg-Dubé syndrome, BHD
