美国斯坦福大学医学院的Tobias Meyer、Anjali Bisaria等研究人员合作发现，膜近端F-肌动蛋白限制局部膜突出并指导细胞迁移。该研究于2020年6月12日发表在国际学术期刊《科学》上。

研究人员开发了一种荧光报告基因，用于监测膜突出和细胞迁移过程中近膜F-肌动蛋白（MPA）的密度变化。与总F-肌动蛋白浓度在迁移细胞的前部高不同，MPA密度在前部低而在后部高。从后到前的MPA密度梯度是由较高的丝切蛋白介导的前部F-肌动蛋白变更。

此外，新生的膜凸出从MPA密度降低的区域选择性地向外延伸。因此，局部低MPA密度会引导局部膜突出并在细胞迁移过程中稳定细胞极化。

据介绍，细胞迁移是通过前部F-肌动蛋白的定向聚合作用而由局部膜突出驱动的。但是，质膜旁边的F-肌动蛋白也会束缚该膜，从而抵抗向外的突起。

附：英文原文

Title: Membrane-proximal F-actin restricts local membrane protrusions and directs cell migration

Author: Anjali Bisaria, Arnold Hayer, Damien Garbett, Daniel Cohen, Tobias Meyer

Issue&Volume: 2020/06/12

Abstract: Cell migration is driven by local membrane protrusion through directed polymerization of F-actin at the front. However, F-actin next to the plasma membrane also tethers the membrane and thus resists outgoing protrusions. Here, we developed a fluorescent reporter to monitor changes in the density of membrane-proximal F-actin (MPA) during membrane protrusion and cell migration. Unlike the total F-actin concentration, which was high in the front of migrating cells, MPA density was low in the front and high in the back. Back-to-front MPA density gradients were controlled by higher cofilin-mediated turnover of F-actin in the front. Furthermore, nascent membrane protrusions selectively extended outward from areas where MPA density was reduced. Thus, locally low MPA density directs local membrane protrusions and stabilizes cell polarization during cell migration.

DOI: 10.1126/science.aay7794

Source: https://science.sciencemag.org/content/368/6496/1205