Ubiquitylation of phosphatidylinositol 4-phosphate 5-kinase type I γ by HECTD1 regulates focal adhesion dynamics and cell migration
Ubiquitylation of phosphatidylinositol 4-phosphate 5-kinase type I γ by HECTD1 regulates focal adhesion dynamics and cell migration
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DOI：
10.1242/jcs.117044
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发表时间：
2013-06-15
影响因子：
4
通讯作者：
Huang, Cai
中科院分区：
文献类型：
--
作者：
Li, Xiang;Zhou, Qi;Huang, Cai
磷脂酰肌醇4-磷酸5-激酶I型γ（PIPKI γ 90）结合塔林并定位于粘着斑（FA）。由PIPKI γ 90产生的磷脂酰肌醇（4，5）-二磷酸（PIP 2）对于FA形成和细胞迁移是必需的。另一方面，PIPKI γ 90和β-整联蛋白尾竞争talin上的重叠结合位点。增强的PIPKI γ 90-talin相互作用抑制talin与β-整联蛋白的结合。尚不清楚在细胞迁移期间原位产生PIP 2后，PIPKI γ 90如何从PIPKI γ 90-talin复合物中除去。在这里，我们表明，PIPKI γ 90是HECTD 1，E3泛素连接酶调节细胞迁移的底物。HECTD 1在赖氨酸97处泛素化PIPKI γ 90并导致PIPKI γ 90降解。突变体PIPKI γ 90（K97 R）的表达增强了PIP 2和PIP 3的产生，抑制了FA组装和分解，并抑制了癌细胞的迁移、侵袭和转移。有趣的是，色氨酸647处的突变消除了PIPKI γ 90（K97 R）对FA动力学的抑制，并部分挽救了癌细胞的迁移和侵袭。因此，通过HECTD 1的循环PIPKI γ 90泛素化和随后的降解在原位PIP 2产生后从talin中去除PIPKI γ 90，为FA动力学和细胞迁移提供了必要的调节机制。
Phosphatidylinositol 4-phosphate 5-kinase type I gamma (PIPKI gamma 90) binds talin and localizes at focal adhesions (FAs). Phosphatidylinositol (4,5)-bisphosphate (PIP2) generated by PIPKI gamma 90 is essential for FA formation and cell migration. On the other hand, PIPKI gamma 90 and the beta-integrin tail compete for overlapping binding sites on talin. Enhanced PIPKI gamma 90-talin interaction suppresses talin binding to the beta-integrin. It is unknown how PIPKI gamma 90 is removed from the PIPKI gamma 90-talin complex after on-site PIP2 production during cell migration. Here we show that PIPKI gamma 90 is a substrate for HECTD1, an E3 ubiquitin ligase regulating cell migration. HECTD1 ubiquitinated PIPKI gamma 90 at lysine 97 and resulted in PIPKI gamma 90 degradation. Expression of the mutant PIPKI gamma 90(K97R) enhanced PIP2 and PIP3 production, inhibited FA assembly and disassembly and inhibited cancer cell migration, invasion and metastasis. Interestingly, mutation at tryptophan 647 abolished the inhibition of PIPKI gamma 90(K97R) on FA dynamics and partially rescued cancer cell migration and invasion. Thus, cycling PIPKI gamma 90 ubiquitylation by HECTD1 and consequent degradation remove PIPKI gamma 90 from talin after on-site PIP2 production, providing an essential regulatory mechanism for FA dynamics and cell migration.