Mechanisms of PDZ domain scaffold assembly illuminated by use of supported cell membrane sheets
- University of Copenhagen, Denmark
- Free University Brussels (VUB), Belgium
Abstract
PDZ domain scaffold proteins are molecular modules orchestrating cellular signaling in space and time. Here, we investigate assembly of PDZ scaffolds using supported cell membrane sheets, a unique experimental setup enabling direct access to the intracellular face of the cell membrane. Our data demonstrate how multivalent protein-protein and protein-lipid interactions provide critical avidity for the strong binding between the PDZ domain scaffold proteins, PICK1 and PSD-95, and their cognate transmembrane binding partners. The kinetics of the binding were remarkably slow and binding strength two-three orders of magnitude higher than the intrinsic affinity for the isolated PDZ interaction. Interestingly, discrete changes in the intrinsic PICK1 PDZ affinity did not affect overall binding strength but instead revealed dual scaffold modes for PICK1. Our data supported by simulations suggest that intrinsic PDZ domain affinities are finely tuned and encode specific cellular responses, enabling multiplexed cellular functions of PDZ scaffolds.
Data availability
All data generated or analysed during this study are included in the manuscript and supporting files.
Article and author information
Author details
Kenneth Lindegaard Madsen
Funding
National Institutes of Health
- Ulrik Gether
Lundbeckfonden
- Ulrik Gether
Novo Nordisk
- Ulrik Gether
Det Frie Forskningsråd
- Ulrik Gether
The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.
Copyright
© 2019, Erlendsson 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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Mechanisms of PDZ domain scaffold assembly illuminated by use of supported cell membrane sheets
eLife 8:e39180.
https://doi.org/10.7554/eLife.39180
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