Cholesterol-dependent phase separation in cell-derived giant plasma membrane vesicles

Ilya Levental (1) , Fitzroy J Byfield , Pramit Chowdhury , Feng Gai , Tobias Baumgart , Paul A Janmey

1 Department of Bioengineering [Philadelphia]

Cell-derived giant plasma membrane vesicles (GPMVs) enable investigation of lipid phase separation in a system with appropriate biological complexity under physiological conditions, and were used to investigate the cholesterol dependence of domain formation and stability. Cholesterol level is directly related to the abundance of the liquid ordered phase fraction, which is the majority phase in vesicles from untreated cells. Miscibility transition temperature depends on cholesterol and correlates strongly with the presence of detergent-insoluble membrane in cell lysates. Fluorescence correlation spectroscopy reveals two distinct diffusing populations in phase-separated cell membrane-derived vesicles whose diffusivities correspond well to diffusivities in both model systems and live cells. These results extend previous observations in purified lipid systems to the complex environment of the plasma membrane and provide insight into the effect of cholesterol on lipid phase separation and abundance.

Mots clés: Life Sciences

Domaines: Sciences du Vivant [q-bio]

Ilya Levental, Fitzroy J Byfield, Pramit Chowdhury, Feng Gai, Tobias Baumgart, et al.. Cholesterol-dependent phase separation in cell-derived giant plasma membrane vesicles. Biochemical Journal, 2009, 424 (2), pp.163-167. ⟨10.1042/BJ20091283⟩. ⟨hal-00479246⟩