High-speed atomic force microscopy: cooperative adhesion and dynamic equilibrium of junctional microdomain membrane proteins. - Archive ouverte HAL Access content directly
Journal Articles Journal of Molecular Biology Year : 2012

High-speed atomic force microscopy: cooperative adhesion and dynamic equilibrium of junctional microdomain membrane proteins.

(1) , (1) , (2) , (1)
1
2

Abstract

Junctional microdomains, paradigm for membrane protein segregation in functional assemblies, in eye lens fiber cell membranes are constituted of lens-specific aquaporin-0 tetramers (AQP0(4)) and connexin (Cx) hexamers, termed connexons. Both proteins have double function to assure nutrition and mediate adhesion of lens cells. Here we use high-speed atomic force microscopy to examine microdomain protein dynamics at the single-molecule level. We found that the adhesion function of head-to-head associated AQP0(4) and Cx is cooperative. This finding provides first experimental evidence for the mechanistic importance for junctional microdomain formation. From the observation of lateral association-dissociation events of AQP0(4), we determine that the enthalpic energy gain of a single AQP0(4)-AQP0(4) interaction in the membrane plane is -2.7 k(B)T, sufficient to drive formation of microdomains. Connexon association is stronger as dynamics are rarely observed, explaining their rim localization in junctional microdomains.
Embargoed file
Embargoed file
Ne sera jamais visible
Loading...

Dates and versions

inserm-01363148 , version 1 (09-09-2016)

Identifiers

Cite

Adai Colom, Ignacio Casuso, Thomas Boudier, Simon Scheuring. High-speed atomic force microscopy: cooperative adhesion and dynamic equilibrium of junctional microdomain membrane proteins.. Journal of Molecular Biology, 2012, 423 (2), pp.249-56. ⟨10.1016/j.jmb.2012.07.004⟩. ⟨inserm-01363148⟩
45 View
0 Download

Altmetric

Share

Gmail Facebook Twitter LinkedIn More