Actin-cytoskeleton dynamics in non-monotonic cell spreading
Actin-cytoskeleton dynamics in non-monotonic cell spreading
复制标题
DOI：
10.4161/cam.2.2.6190
复制
发表时间：
2008-04-01
影响因子：
3.2
通讯作者：
Gerisch, Guenther
中科院分区：
文献类型：
--
作者：
Heinrich, Doris;Youssef, Simon;Gerisch, Guenther
运动细胞在基质表面上的伸展伴随着它们的肌动蛋白网络的重组。我们发现，在Dictyostelium的高度能动的细胞传播是非单调的，因此不同的传播细胞通过一系列定期的阶段。定量的增益和损失的接触面积揭示了波动的力量的突出和回缩，占主导地位的相互作用的Dictyosteoblastoma细胞与基板。这些波动的分子基础阐明了双荧光标记的丝状肌动蛋白与蛋白质，突出的肌动蛋白系统中的特定活动。通过从密集肌动蛋白聚集的区域中分选出肌球蛋白-II来建立前-尾极性。肌球蛋白-IB识别突出的前部区域，Arp 2/3复合物定位于从前部突出的板状伪足。冠状蛋白被用作肌动蛋白分解的敏感指示剂，以可视化铺展细胞中聚合和解聚的微妙平衡。与网格蛋白共定位的短寿命肌动蛋白斑块表明，即使在底物附着的细胞表面扩展时，也会发生膜内化。我们的结论是，非单调的细胞传播的特点是由马达蛋白与调节蛋白，无论是促进或终止肌动蛋白聚合的规模上秒形成的时空模式。
The spreading of motile cells on a substrate surface is accompanied by reorganization of their actin network. We show that spreading in the highly motile cells of Dictyostelium is non-monotonic, and thus differs from the passage of spreading cells through a regular series of stages. Quantification of the gain and loss of contact area revealed fluctuating forces of protrusion and retraction that dominate the interaction of Dictyostelium cells with a substrate. The molecular basis of these fluctuations is elucidated by dual-fluorescence labeling of filamentous actin together with proteins that highlight specific activities in the actin system. Front-to-tail polarity is established by the sorting out of myosin-II from regions where dense actin assemblies are accumulating. Myosin-IB identifies protruding front regions, and the Arp2/3 complex localizes to lamellipodia protruded from the fronts. Coronin is used as a sensitive indicator of actin disassembly to visualize the delicate balance of polymerization and depolymerization in spreading cells. Short-lived actin patches that co-localize with clathrin suggest that membrane internalization occurs even when the substrate-attached cell surface expands. We conclude that non-monotonic cell spreading is characterized by spatiotemporal patterns formed by motor proteins together with regulatory proteins that either promote or terminate actin polymerization on the scale of seconds.