The cryo-EM structure of the human uromodulin filament core reveals a unique assembly mechanism
- Institute of Molecular Biology and Biophysics, Swiss Federal Institute of Technology, Switzerland
- Swiss Federal Institute of Technology, Switzerland
- University of Zurich, Switzerland
- Newcastle University, United Kingdom
- ETH Zürich, Switzerland
Abstract
The glycoprotein uromodulin (UMOD) is the most abundant protein in human urine and forms filamentous homopolymers that encapsulate and aggregate uropathogens, promoting pathogen clearance by urine excretion. Despite its critical role in the innate immune response against urinary tract infections, the structural basis and mechanism of UMOD polymerization remained unknown. Here, we present the cryo-EM structure of the UMOD filament core at 3.5 Å resolution, comprised of the bipartite zona pellucida (ZP) module in a helical arrangement with a rise of ~65 Å and a twist of ~180°. The immunoglobulin-like ZPN and ZPC subdomains of each monomer are separated by a long linker that interacts with the preceding ZPC and following ZPN subdomains by β-sheet complementation. The unique filament architecture suggests an assembly mechanism in which subunit incorporation could be synchronized with proteolytic cleavage of the C-terminal pro-peptide that anchors assembly-incompetent UMOD precursors to the membrane.
Data availability
Structures and maps presented in this paper have been deposited to the Protein Data Bank (PDB) and Electron Microscopy Data Base (EMDB) with the following accession codes: 3.5 Å cryoSPARC map EMD-11388, the UMOD AU model PDB ID: 6ZS5, elongated model of UMOD filament derived from cryoSPARC map PDB ID: 6ZYA, 4.7 Å cisTEM map EMD-11471.
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Genome Aggregation Database (GnomAD)Genome Aggregation Database (GnomAD) v2.1.1, GRCh37.
Article and author information
Author details
Jessica J Stanisich
Funding
Schweizerischer Nationalfonds zur Förderung der Wissenschaftlichen Forschung (310030B_176403/1)
- Rudi Glockshuber
Schweizerischer Nationalfonds zur Förderung der Wissenschaftlichen Forschung (31003A_156304)
- Rudi Glockshuber
Schweizerischer Nationalfonds zur Förderung der Wissenschaftlichen Forschung (31003A_179255)
- Martin Pilhofer
H2020 European Research Council (679209)
- Martin Pilhofer
NOMIS Stiftung (n/a)
- Martin Pilhofer
Schweizerischer Nationalfonds zur Förderung der Wissenschaftlichen Forschung (310030_189044)
- Olivier Devuyst
Swiss National Centre of Competence in Research Kidney Control of Homeostasis (n/a)
- Olivier Devuyst
Schweizerischer Nationalfonds zur Förderung der Wissenschaftlichen Forschung (P2ZHP3_195181)
- Eric Olinger
The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.
Ethics
Human subjects: The use of human urine samples for UMOD purification was approved by the Ethical Committee of the UCLouvain Medical School in Brussels, Belgium (Project EUNEFRON, 2011/04May/184). All individuals gave written informed consent.The completed "Consent form for publication in eLife" has been filed on the donor's behalf.
Copyright
© 2020, Stanisich et al.
This article is distributed under the terms of the Creative Commons Attribution License permitting unrestricted use and redistribution provided that the original author and source are credited.
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The cryo-EM structure of the human uromodulin filament core reveals a unique assembly mechanism
eLife 9:e60265.
https://doi.org/10.7554/eLife.60265
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