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

Article Article scientifique Article Passive coupling of membrane tension and cell volume during active response of cells to osmosis eng 2021-11-16 2021-11-16 author Roffay Chloé 0000-0002-7498-8782 881437 author Molinard Guillaume 769261 author Kim Kyoohyun 0000-0003-1808-775X author Urbanska Marta author Andrade Virginia 0000-0001-7027-4099 author Barbarasa Victoria 881157 author Nowak Paulina 0000-0001-5786-2339 903702 author Mercier Vincent 847100 author Garcia-Calvo Jose 0000-0002-1873-0293 author Matile Stefan 0000-0002-8537-8349 129654 author Loewith Robbie Joséph 0000-0002-2482-603X 630703 author Echard Arnaud 0000-0001-7402-1398 author Guck Jochen 0000-0002-1453-6119 author Lenz Martin author Roux Aurélien 0000-0002-6088-0711 716946 e2103228118 10.1073/pnas.2103228118 34785592 0027-8424 http://www.pnas.org/lookup/doi/10.1073/pnas.2103228118 <p>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 from the 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.</p> Cell volume Flipper-TR Mechanobiology Osmotic shocks Plasma membrane tension Dewey 540 Dewey 570 36 Département de chimie organique 141 39 Département de biochimie 144 43 Département de biologie moléculaire 161 false 814 Groupe Loewith 761 Groupe Matile 769 Groupe Roux Proceedings of the National Academy of Sciences of the United States of America 118 47 c6dca7f6-be4f-407d-a088-4817a5c3eb14 Article (Published version) Public Article-scientifique-from-unpaywall.pdf 2956316 application/pdf CC BY-NC-ND-4.0 openAccess Faculté des sciences / Section de chimie et biochimie / Département de chimie organique Faculté des sciences / Section de chimie et biochimie / Département de biochimie Faculté des sciences / Section de biologie / Département de biologie moléculaire

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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			2021	442	301

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