Passive coupling of membrane tension and cell volume during active response of cells to osmosis

Roffay C, Molinard G, Kim K, Urbanska M, Andrade V, Barbarasa V, Nowak P, Mercier V, Garcia-Calvo J, Matile S, Loewith R, Echard A, Guck J, Lenz M, Roux A (2021)

Publication Type: Journal article

Publication year: 2021

Journal

Proceedings of the National Academy of Sciences of the United States of America National Academy of Sciences

Book Volume: 118

Article Number: e2103228118

Journal Issue: 47

DOI: 10.1073/pnas.2103228118

Abstract

During osmotic changes of their environment, cells actively regulate their volume and plasma membrane tension that can passively change through osmosis. How tension and volume are coupled during osmotic adaptation remains unknown, as their quantitative characterization is lacking. Here, we performed dynamic membrane tension and cell volume measurements during osmotic shocks. During the first few seconds following the shock, cell volume varied to equilibrate osmotic pressures inside and outside the cell, and membrane tension dynamically followed these changes. A theoretical model based on the passive, reversible unfolding of the membrane as it detaches fromthe actin cortex during volume increase quantitatively describes our data. After the initial response, tension and volume recovered from hypoosmotic shocks but not from hyperosmotic shocks. Using a fluorescent membrane tension probe (fluorescent lipid tension reporter [Flipper-TR]), we investigated the coupling between tension and volume during these asymmetric recoveries. Caveolae depletion and pharmacological inhibition of ion transporters and channels, mTORCs, and the cytoskeleton all affected tension and volume responses. Treatments targeting mTORC2 and specific downstream effectors caused identical changes to both tension and volume responses, their coupling remaining the same. This supports that the coupling of tension and volume responses to osmotic shocks is primarily regulated by mTORC2.

Authors with CRIS profile

Jochen Guck

Involved external institutions

University of Geneva / Université de Genève (UNIGE) CH Switzerland (CH) Max-Planck-Institut für die Physik des Lichts (MPL) / Max Planck Institute for the Science of Light DE Germany (DE) University of Paris 4 - Paris-Sorbonne / Université paris IV Paris-Sorbonne FR France (FR) École Polytechnique - Université Paris-Saclay FR France (FR)

How to cite

APA:

Roffay, C., Molinard, G., Kim, K., Urbanska, M., Andrade, V., Barbarasa, V.,... Roux, A. (2021). Passive coupling of membrane tension and cell volume during active response of cells to osmosis. Proceedings of the National Academy of Sciences of the United States of America, 118(47). https://doi.org/10.1073/pnas.2103228118

MLA:

Roffay, Chloe, et al. "Passive coupling of membrane tension and cell volume during active response of cells to osmosis." Proceedings of the National Academy of Sciences of the United States of America 118.47 (2021).

BibTeX: Download