mechanosensitive channel / DDM / delipidation / MEMBRANE PROTEIN
機能・相同性
機能・相同性情報
intracellular water homeostasis / mechanosensitive monoatomic ion channel activity / protein homooligomerization / monoatomic ion transmembrane transport / identical protein binding / membrane / plasma membrane 類似検索 - 分子機能
Conserved TM helix / Mechanosensitive ion channel, conserved TM helix / Mechanosensitive ion channel MscS, archaea/bacteria type / : / : / Mechanosensitive ion channel MscS, C-terminal / Mechanosensitive ion channel, transmembrane helices 2/3 / Mechanosensitive ion channel MscS, conserved site / Uncharacterized protein family UPF0003 signature. / Mechanosensitive ion channel MscS, C-terminal ...Conserved TM helix / Mechanosensitive ion channel, conserved TM helix / Mechanosensitive ion channel MscS, archaea/bacteria type / : / : / Mechanosensitive ion channel MscS, C-terminal / Mechanosensitive ion channel, transmembrane helices 2/3 / Mechanosensitive ion channel MscS, conserved site / Uncharacterized protein family UPF0003 signature. / Mechanosensitive ion channel MscS, C-terminal / Mechanosensitive ion channel MscS, transmembrane-2 / Mechanosensitive ion channel MscS / Mechanosensitive ion channel, beta-domain / Mechanosensitive ion channel MscS, beta-domain superfamily / LSM domain superfamily 類似検索 - ドメイン・相同性
ジャーナル: Proc Natl Acad Sci U S A / 年: 2021 タイトル: Mechanosensitive channel gating by delipidation. 著者: Vanessa Judith Flegler / Akiko Rasmussen / Karina Borbil / Lea Boten / Hsuan-Ai Chen / Hanna Deinlein / Julia Halang / Kristin Hellmanzik / Jessica Löffler / Vanessa Schmidt / Cihan Makbul / ...著者: Vanessa Judith Flegler / Akiko Rasmussen / Karina Borbil / Lea Boten / Hsuan-Ai Chen / Hanna Deinlein / Julia Halang / Kristin Hellmanzik / Jessica Löffler / Vanessa Schmidt / Cihan Makbul / Christian Kraft / Rainer Hedrich / Tim Rasmussen / Bettina Böttcher / 要旨: The mechanosensitive channel of small conductance (MscS) protects bacteria against hypoosmotic shock. It can sense the tension in the surrounding membrane and releases solutes if the pressure in the ...The mechanosensitive channel of small conductance (MscS) protects bacteria against hypoosmotic shock. It can sense the tension in the surrounding membrane and releases solutes if the pressure in the cell is getting too high. The membrane contacts MscS at sensor paddles, but lipids also leave the membrane and move along grooves between the paddles to reside as far as 15 Å away from the membrane in hydrophobic pockets. One sensing model suggests that a higher tension pulls lipids from the grooves back to the membrane, which triggers gating. However, it is still unclear to what degree this model accounts for sensing and what contribution the direct interaction of the membrane with the channel has. Here, we show that MscS opens when it is sufficiently delipidated by incubation with the detergent dodecyl-β-maltoside or the branched detergent lauryl maltose neopentyl glycol. After addition of detergent-solubilized lipids, it closes again. These results support the model that lipid extrusion causes gating: Lipids are slowly removed from the grooves and pockets by the incubation with detergent, which triggers opening. Addition of lipids in micelles allows lipids to migrate back into the pockets, which closes the channel even in the absence of a membrane. Based on the distribution of the aliphatic chains in the open and closed conformation, we propose that during gating, lipids leave the complex on the cytosolic leaflet at the height of highest lateral tension, while on the periplasmic side, lipids flow into gaps, which open between transmembrane helices.