Markey Cancer Center and Department of Molecular & Biomedical Pharmacology; University of Kentucky; Lexington, KY USA.
Cell Adh Migr. 2014;8(1):49-54. doi: 10.4161/cam.27480. Epub 2013 Jan 1.
Recent discoveries have unveiled the roles of a complicated network of E3 ubiquitin ligases in regulating cell migration machineries. The E3 ubiquitin ligases Smurf1 and Cul/BACURD ubiquitinate RhoA to regulate stress fiber formation and cell polarity, and ASB2α ubiquitinates filamins to modulate cytoskeletal stiffness, thus regulating cell spreading and cell migration. HACE1, XIAP, and Skp1-Cul1-F-box bind to Rac1 and cause its ubiquitination and degradation, thus suppressing lamellipodium protrusions, while PIAS3, a SUMO ligase, activates Rac1 to promote lamellipodium dynamics. Smurf1 also enhances Rac1 activation but it does not ubiquitinate Rac1. Both Smurf1 and HECTD1 regulate focal adhesion (FA) assembly and (or) disassembly through ubiquitinating the talin head domain and phosphatidylinositol 4 phosphate 5-kinase type I γ (PIPKIγ90), respectively. Thus, E3 ubiquitin ligases regulate stress fiber formation, cell polarity, lamellipodium protrusions, and FA dynamics through ubiquitinating the key proteins that control these processes.
最近的发现揭示了一个复杂的 E3 泛素连接酶网络在调节细胞迁移机制中的作用。E3 泛素连接酶 Smurf1 和 Cul/BACURD 泛素化 RhoA,以调节应力纤维形成和细胞极性,而 ASB2α 泛素化细丝蛋白以调节细胞骨架的刚性,从而调节细胞铺展和细胞迁移。HACE1、XIAP 和 Skp1-Cul1-F-box 与 Rac1 结合并导致其泛素化和降解,从而抑制片状伪足突起,而 SUMO 连接酶 PIAS3 激活 Rac1 以促进片状伪足动力学。Smurf1 也增强 Rac1 的激活,但不泛素化 Rac1。Smurf1 和 HECTD1 分别通过泛素化桩蛋白头部结构域和磷脂酰肌醇 4 磷酸 5-激酶 Iγ(PIPKIγ90)来调节粘着斑(FA)的组装和(或)解体。因此,E3 泛素连接酶通过泛素化控制这些过程的关键蛋白来调节应力纤维形成、细胞极性、片状伪足突起和 FA 动力学。