Both monovalent cations and plectin are potent modulators of mechanical properties of keratin K8/K18 networks.
Both monovalent cations and plectin are potent modulators of mechanical properties of keratin K8/K18 networks.
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DOI：
10.1039/c6sm00977h
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发表时间：
2016-08
期刊：
影响因子：
3.4
通讯作者：
Ines Martin;Marcin Moch;Marcin Moch;T. Neckernuss;Stephan Paschke;Harald Herrmann;Othmar Marti
中科院分区：
文献类型：
--
作者：
Ines Martin;Marcin Moch;Marcin Moch;T. Neckernuss;Stephan Paschke;Harald Herrmann;Othmar Marti
中间丝（IF）网络是细胞刚性的主要贡献者，因此是保持整个细胞层完整性的重要因素。角蛋白K8和K18 IFs是上皮细胞细胞骨架的基本成分。K8/K18网络的力学性能取决于网络中单个细丝的结构排列。本文探讨了这些网络的结构在体外的影响下，一价阳离子钾和细胞连接蛋白的细胞连接蛋白。而增加钾离子的量导致纤维束，网蛋白在纤维交叉点连接纤维，但不会导致束的形成。通过组装K8/K18网络的微观流变学研究了所得网络的力学。结果表明，由钾离子诱导的成束显着硬化网络。此外，我们的测量结果显示，一旦对应于细胞中存在的超过20%的网蛋白的量被添加到角蛋白IF网络中，网蛋白介导的角蛋白网络刚性就会增加。与此同时，我们研究了细胞刚性在洗涤剂提取的外阴上皮癌衍生的A431细胞原位的影响。这些细胞骨架，主要包含IF，肌动蛋白丝和相关蛋白，表现出显着降低刚度，当plectin下调至正常值的10%左右。因此，我们假设，通过形成IF-IF连接和交联的IF肌动蛋白丝，是一个重要的贡献者细胞刚度。
Intermediate filament (IF) networks are a major contributor to cell rigidity and thus serve as vital elements to preserve the integrity of entire cell layers. Keratin K8 and K18 IFs are the basic constituents of the cytoskeleton of epithelial cells. The mechanical properties of K8/K18 networks depend on the structural arrangements of individual filaments within the network. This paper investigates the architecture of these networks in vitro under the influence of the monovalent cation potassium and that of the cytolinker protein plectin. Whereas increasing amounts of potassium ions lead to filament bundling, plectin interlinks filaments at filament intersection points but does not lead to bundle formation. The mechanics of the resulting networks are investigated by microrheology with assembled K8/K18 networks. It is shown that bundling induced by potassium ions significantly stiffens the network. Furthermore, our measurements reveal an increase in plectin-mediated keratin network rigidity as soon as an amount corresponding to more than 20% of the plectin present in cells is added to the keratin IF networks. In parallel, we investigated the influence of plectin on cell rigidity in detergent-extracted epithelial vulva carcinoma derived A431 cells in situ. These cytoskeletons, containing mostly IFs, actin filaments and associated proteins, exhibit a significantly decreased stiffness, when plectin is downregulated to ≈10% of the normal value. Therefore, we assume that plectin, via the formation of IF-IF connections and crosslinking of IFs to actin filaments, is an important contributor to cell stiffness.