Abstract
Genetic variants in PKD2 which encodes for the polycystin-2 ion channel are responsible for many clinical cases of autosomal dominant polycystic kidney disease (ADPKD). Despite our strong understanding of the genetic basis of ADPKD, we do not know how most variants impact channel function. Polycystin-2 is found in organelle membranes, including the primary cilium—an antennae-like structure on the luminal side of the collecting duct. In this study, we focus on the structural and mechanistic regulation of polycystin-2 by its TOP domain—a site with unknown function that is commonly altered by missense variants. We use direct cilia electrophysiology, cryogenic electron microscopy, and superresolution imaging to determine that variants of the TOP domain finger 1 motif destabilizes the channel structure and impairs channel opening without altering cilia localization and channel assembly. Our findings support the channel-opathy classification of PKD2 variants associated with ADPKD, where polycystin-2 channel dysregulation in the primary cilia may contribute to cystogenesis.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 10329-10338 |
| Number of pages | 10 |
| Journal | Proceedings of the National Academy of Sciences of the United States of America |
| Volume | 117 |
| Issue number | 19 |
| DOIs | |
| State | Published - May 12 2020 |
Funding
ACKNOWLEDGMENTS. We thank Alex Yemelyanov, Pankaj Bhalla, and the expertise of Northwestern University Skin Disease Research Center for their assistance generating the stable cell lines. Some cryo-EM work was performed at the National Center for CryoEM Access and Training and the Simons Electron Microscopy Center located at the New York Structural Biology Center, supported by the NIH Common Fund Transformative High Resolution Cryo-Electron Microscopy program (U24 GM129539) and by grants from the Simons Foundation (SF349247) and New York State. We thank Shenping Wu at Yale University for cryo-EM data collection and the Center for High Performance Computing at the University of Utah for computational support. The following grants were awarded to P.G.D. and funded this work: NIH National Institute of Diabetes and Digestive and Kidney Diseases (1R56DK119709-01, R00 DK106655, 1R01DK123463-01, and NU GoKidney George M. O’Brien Kidney Research Core Center P30DK11485); PKD Foundation Research Grant; Mayo Clinic’s PKD Center Pilot and Feasibility Program grant; and Carl W. Gottschalk Research Scholar Grant from the American Nephrology Society. E.C. was supported by NIH grant R01 DK110575, a discovery award (W81XWH-17-1-0158) from the Department of Defense, and a Pew scholar award from The Pew Charitable Trusts. We thank Alex Yemelyanov, Pankaj Bhalla, and the expertise of Northwestern University Skin Disease Research Center for their assistance generating the stable cell lines. Some cryo-EM work was performed at the National Center for CryoEM Access and Training and the Simons Electron Microscopy Center located at the New York Structural Biology Center, supported by the NIH Common Fund Transformative High Resolution Cryo-Electron Microscopy program (U24 GM129539) and by grants from the Simons Foundation (SF349247) and New York State. We thank Shenping Wu at Yale University for cryo-EM data collection and the Center for High Performance Computing at the University of Utah for computational support. The following grants were awarded to P.G.D. and funded this work: NIH National Institute of Diabetes and Digestive and Kidney Diseases (1R56DK119709-01, R00 DK106655, 1R01DK123463-01, and NU GoKidney George M. O?Brien Kidney Research Core Center P30DK11485); PKD Foundation Research Grant; Mayo Clinic?s PKD Center Pilot and Feasibility Program grant; and Carl W. Gottschalk Research Scholar Grant from the American Nephrology Society. E.C. was supported by NIH grant R01 DK110575, a discovery award (W81XWH-17-1-0158) from the Department of Defense, and a Pew scholar award from The Pew Charitable Trusts.
Keywords
- ADPKD
- Ion channels
- Polycystic kidney disease
- Structural biology
- TRP channels
ASJC Scopus subject areas
- General
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Cryo-EM structure of PKD2 C331S disease variant
Vien, T. N. (Contributor), Wang, J. (Contributor), Ng, L. C. T. (Contributor), Cao, E. (Contributor) & DeCaen, P. G. (Contributor), Protein Data Bank (PDB), Apr 22 2020
DOI: 10.2210/pdb6WB8/pdb, https://www.wwpdb.org/pdb?id=pdb_00006wb8
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