Sturge Justin, Wienke Dirk, Isacke Clare M
Breakthrough Breast Cancer Research Centre, The Institute of Cancer Research, London SW3 6JB, England, UK.
J Cell Biol. 2006 Oct 23;175(2):337-47. doi: 10.1083/jcb.200602125. Epub 2006 Oct 16.
The regulated assembly and disassembly of focal adhesions and adherens junctions contributes to cell motility and tumor invasion. Pivotal in this process is phosphorylation of myosin light chain-2 (MLC2) by Rho kinase (ROCK) downstream of Rho activation, which generates the contractile force necessary to drive disassembly of epithelial cell-cell junctions and cell-matrix adhesions at the rear of migrating cells. How Rho-ROCK-MLC2 activation occurs at these distinct cellular locations is not known, but the emerging concept that endocytic dynamics can coordinate key intracellular signaling events provides vital clues. We report that endosomes containing the promigratory receptor Endo180 (CD280) can generate Rho-ROCK-MLC2-based contractile signals. Moreover, we provide evidence for a cellular mechanism in which Endo180-containing endosomes are spatially localized to facilitate their contractile signals directly at sites of adhesion turnover. We propose migration driven by Endo180 as a model for the spatial regulation of contractility and adhesion dynamics by endosomes.
粘着斑和黏着连接的有序组装与拆卸有助于细胞运动和肿瘤侵袭。在这个过程中起关键作用的是Rho激酶(ROCK)在Rho激活下游对肌球蛋白轻链2(MLC2)的磷酸化,这产生了驱动迁移细胞后部上皮细胞间连接和细胞-基质黏附拆卸所需的收缩力。Rho-ROCK-MLC2激活如何在这些不同的细胞位置发生尚不清楚,但内吞动力学可以协调关键细胞内信号事件这一新兴概念提供了重要线索。我们报告称,含有促迁移受体Endo180(CD280)的内体可以产生基于Rho-ROCK-MLC2的收缩信号。此外,我们提供了一种细胞机制的证据,即含有Endo180的内体在空间上定位,以直接在黏附周转部位促进其收缩信号。我们提出由Endo180驱动的迁移作为内体对收缩性和黏附动力学进行空间调节的模型。