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Mapping Molecular Diffusion in the Plasma Membrane by Multiple-Target Tracing (MTT)
Published on: May 27, 2012
Non-uniform membrane diffusion enables steady-state cell polarization via vesicular trafficking
Brian D Slaughter1, Jay R Unruh1, Arupratan Das1
1Stowers Institute for Medical Research, 1000 East 50 Street, Kansas City, MO 64110.
Nature Communications
|January 24, 2013
Summary
Cell polarity is maintained by Cdc42 protein concentration and diffusion within membrane microdomains. These microdomains, enriched with phosphatidylserine, are crucial for sustained cell polarization via vesicular trafficking.
Area of Science:
- Cell Biology
- Biophysics
Background:
- Actin-based vesicular trafficking of Cdc42 influences cell polarization.
- The role of this mechanism in stable cell polarity maintenance has been debated.
Purpose of the Study:
- To investigate the spatial organization of Cdc42 trafficking and its impact on cell polarity.
- To determine the role of membrane microdomains and phosphatidylserine in Cdc42-mediated cell polarization.
Main Methods:
- Spatial segregation analysis of endocytosis and exocytosis.
- Measurement of Cdc42 concentration and diffusion in membrane microdomains.
- Numerical simulations of Cdc42 membrane diffusion.
- Investigation of phosphatidylserine enrichment and its interaction with Cdc42.
Main Results:
- Endocytosis and exocytosis are spatially segregated at the polar plasma membrane.
- Cdc42 exhibits higher concentration and slower diffusion in specific microdomains, correlating with exocytosis sites.
- Non-uniform Cdc42 diffusion in microdomains enables sustained cell polarity.
- Phosphatidylserine is enriched in Cdc42 microdomains and its interaction with Cdc42 is critical for polarization strength.
Conclusions:
- Membrane microdomains play a critical role in vesicular trafficking-mediated cell polarity.
- Spatially regulated Cdc42 diffusion within microdomains is essential for stable cell polarization.
- The interaction between phosphatidylserine and Cdc42 within microdomains is a key determinant of polarization strength.
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