Caveolae respond to cell stretch and contribute to stretch-induced signaling
Caveolae respond to cell stretch and contribute to stretch-induced signaling
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DOI：
10.1242/jcs.084376
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发表时间：
2011-11-01
影响因子：
4
通讯作者：
Allen, David G.
中科院分区：
文献类型：
--
作者：
Gervasio, Othon L.;Phillips, William D.;Allen, David G.
小凹是由小凹形成的质膜内陷。小凹膜还富含胆固醇、鞘糖脂和信号酶（例如 Src 激酶）。在这里，我们研究细胞拉伸对小凹动力学和信号传导的影响。用caveolin-3-YFP转染C2成肌细胞导致形成直径50-100 nm的小凹样膜凹坑。鞘糖脂被固定并紧密堆积在质膜富含小窝蛋白的区域内。荧光共振能量转移（FRET）用于评估鞘糖脂堆积程度。成肌细胞在弹性基质上进行短暂（1 分钟）拉伸。拉伸导致鞘糖脂 FRET 减少，这与响应膜张力的小凹坑可逆展开一致。通过免疫荧光评估，表达 Caveolin-3-YFP 的细胞还表现出拉伸诱导的 Src 激酶激活增强。重复拉伸导致富含caveolin-3的膜结构域的运输和重塑，并加速膜鞘糖脂的周转。拉伸诱导的小窝展开、Src 激活以及小窝蛋白和鞘糖脂的重新分布可能反映了细胞对机械应力的适应机制。
Caveolae are invaginations of the plasma membrane that are formed by caveolins. Caveolar membranes are also enriched in cholesterol, glycosphingolipids and signaling enzymes such as Src kinase. Here we investigate the effect of cell stretch upon caveolar dynamics and signaling. Transfection of C2 myoblasts with caveolin-3-YFP led to the formation of caveolae-like membrane pits 50-100 nm in diameter. Glycosphingolipids became immobilized and tightly packed together within caveolin-rich regions of the plasma membrane. Fluorescence resonance energy transfer (FRET) was used to assess the degree of glycosphingolipid packing. Myoblasts were subjected to a brief (1 minute) stretch on an elastic substratum. Stretch caused a reduction in glycosphingolipid FRET, consistent with a reversible unfolding of caveolar pits in response to membrane tension. Cells expressing caveolin-3-YFP also displayed an enhanced stretch-induced activation of Src kinase, as assessed by immunofluorescence. Repeated stretches resulted in the trafficking and remodeling of caveolin-3-rich membrane domains and accelerated turnover of membrane glycosphingolipids. The stretch-induced unfolding of caveolae, activation of Src and redistribution of caveolin and glycosphingolipids might reflect mechanisms of the cellular adaptation to mechanical stresses.