Scribble (Scrib) and Lgl1 are conserved polarity proteins that play important roles in different forms of cell polarity. The roles of Scrib and Lgl1 in apical-basal cell polarity has been studied extensively, but little is known about their roles in the cell polarity of migrating cells. Furthermore, the effect of Scrib and Lgl1 interaction on cell polarity is largely unknown. In this study, we show that Scrib, through its LRR domain, forms a complex in vivo with Lgl1. Scrib also forms a complex with myosin II, and Scrib, Lgl1, and myosin II co-localize at the leading edge of migrating cells. The cellular localization and the cytoskeletal association of Scrib and Lgl1 are interdependent, as depletion of either protein affects its counterpart. In addition, depletion of either Scrib or Lgl1 disrupts the cellular localization of myosin II. We show that depletion of either Scrib or Lgl1 affects cell adhesion through the inhibition of focal adhesion disassembly. Finally, we show that Scrib and Lgl1 are required for proper cell polarity of migrating cells. These results provide new insights into the mechanism regulating the cell polarity of migrating cells by Scrib, Lgl1, and myosin II.

Scribble（Scrib）和Lgl1是保守的极性蛋白，在不同形式的细胞极性中起重要作用。Scrib和Lgl1在顶基细胞极性中的作用已被广泛研究，但对其在迁移细胞的细胞极性中的作用知之甚少。此外，Scrib和Lgl1相互作用对细胞极性的影响很大程度上未知。在这项研究中，我们显示Scrib通过其LRR域在体内形成复杂的与Lgl1。Scrib还与肌球蛋白II形成复合物，Scrib，Lgl1和肌球蛋白II共定位在迁移细胞的前沿。Scrib和Lgl1的细胞定位和细胞骨架结合是相互依赖的，因为任何一种蛋白质的消耗都会影响其对应物。此外，Scrib或Lgl1的消耗会破坏肌球蛋白II的细胞定位。我们显示，Scrib或Lgl1的耗竭通过抑制粘着粘连分解而影响细胞粘连。最后，我们显示Scrib和Lgl1是迁移细胞的正确细胞极性所必需的。这些结果为Scrib，Lgl1和肌球蛋白II调控迁移细胞的细胞极性机制提供了新见解。