McCusker Catherine, Cousin Hélène, Neuner Russell, Alfandari Dominique
Department of Veterinary and Animal Sciences, University of Massachusetts, Amherst, MA 01003, USA.
Mol Biol Cell. 2009 Jan;20(1):78-89. doi: 10.1091/mbc.e08-05-0535. Epub 2008 Oct 22.
Cell adhesion molecules such as cadherins alternate their expression throughout cranial neural crest (CNC) development, yet our understanding of the role of these molecules during CNC migration remains incomplete. The "mesenchymal" cadherin-11 is expressed in the CNC during migration yet prevents migration when overexpressed in the embryo, suggesting that a defined level of cadherin-11-mediated cell adhesion is required for migration. Here we show that members of the meltrin subfamily of ADAM metalloproteases cleave the extracellular domain of cadherin-11 during CNC migration. We show that a fragment corresponding to the putative shed form of cadherin-11 retains biological activity by promoting CNC migration in vivo, in a non-cell-autonomous manner. Additionally, cleavage of cadherin-11 does not affect binding to beta-catenin and downstream signaling events. We propose that ADAM cleavage of cadherin-11 promotes migration by modifying its ability to support cell-cell adhesion while maintaining the membrane-bound pool of beta-catenin associated with the cadherin-11 cytoplasmic domain.
细胞黏附分子,如钙黏蛋白,在颅神经嵴(CNC)发育过程中其表达会发生变化,然而我们对这些分子在CNC迁移过程中的作用的理解仍不完整。“间充质”钙黏蛋白-11在迁移过程中在CNC中表达,但在胚胎中过表达时会阻止迁移,这表明迁移需要特定水平的钙黏蛋白-11介导的细胞黏附。在这里,我们表明ADAM金属蛋白酶的meltrin亚家族成员在CNC迁移过程中切割钙黏蛋白-11的细胞外结构域。我们表明,对应于钙黏蛋白-11假定脱落形式的片段通过以非细胞自主方式促进体内CNC迁移而保留生物活性。此外,钙黏蛋白-11的切割不影响与β-连环蛋白的结合及下游信号事件。我们提出,ADAM对钙黏蛋白-11的切割通过改变其支持细胞间黏附的能力来促进迁移,同时维持与钙黏蛋白-11细胞质结构域相关的膜结合β-连环蛋白池。