Although contractile processes, from tissue invagination to cell intercalation, utilize diverse ratcheting mechanisms, little is known about how ratcheting becomes engaged at specific cell surfaces. In this issue of Developmental Cell, Maio et al. demonstrate that PI(3,4,5)P3 is a paramount regulator of the Sbf/RabGEF-Rab35 ratchet mechanism.

中文翻译：

---

插入或内陷：PI(3,4,5)P3 控制细胞成形中的膜收缩开关

尽管从组织内陷到细胞嵌入的收缩过程利用了不同的棘轮机制，但关于棘轮如何在特定细胞表面参与的知之甚少。在本期Developmental Cell 中，Maio 等人。证明 PI(3,4,5)P3 是 Sbf/RabGEF-Rab35 棘轮机制的重要调节器。