Ezrin, a membrane-cytoskeleton linker protein, plays an essential role in cell polarity establishment, cell migration and division. Recent studies show that ezrin phosphorylation regulates breast cancer metastasis by promoting cancer cell survivor and promotes intrahepatic metastasis via cell migration. However, it was less characterized whether there are additional post-translational modifications and/or post-translational cross-talks on ezrin underlying context-dependent breast cancer cell migration and invasion. Here we show that ezrin is acetylated by PCAF in breast cancer cells in response to CCL18 stimulation. Ezrin physically interacts with PCAF and is a cognate substrate of PCAF. The acetylation site of ezrin was mapped by mass spectrometric analyses and dynamic acetylation of ezrin is essential for CCL18-induced breast cancer cell migration and invasion. Mechanistically, the acetylation reduced the lipid-binding activity of ezrin to ensure a robust and dynamic cycling between the plasma membrane and cytosol in response to CCL18 stimulation. Biochemical analyses show that ezrin acetylation prevents the phosphorylation of Thr567. Using atomic force microscopic measurements, our study revealed that acetylation of ezrin induced its unfolding into dominant structure which prevents ezrin phosphorylation at Thr567. Thus, these results present a previously undefined mechanism by which CCL18-elicited cross-talks between the acetylation and phosphorylation on ezrin control breast cancer cell migration and invasion. This suggests that targeting PCAF signaling could be a potential therapeutic strategy for combating hyperactive ezrin-driven cancer progression.

中文翻译：

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ezrin 的乙酰化调节 CCL18 引起的细胞迁移的膜-细胞骨架相互作用。

Ezrin 是一种膜-细胞骨架连接蛋白，在细胞极性建立、细胞迁移和分裂中起着至关重要的作用。最近的研究表明，ezrin 磷酸化通过促进癌细胞存活来调节乳腺癌转移，并通过细胞迁移促进肝内转移。然而，关于 ezrin 是否存在额外的翻译后修饰和/或翻译后串扰，与上下文相关的乳腺癌细胞迁移和侵袭相关的特征较少。在这里，我们展示了响应 CCL18 刺激的乳腺癌细胞中的 ezrin 被 PCAF 乙酰化。Ezrin 与 PCAF 物理相互作用，是 PCAF 的同源底物。ezrin 的乙酰化位点通过质谱分析进行定位，ezrin 的动态乙酰化对于 CCL18 诱导的乳腺癌细胞迁移和侵袭至关重要。从机制上讲，乙酰化降低了埃兹蛋白的脂质结合活性，以确保质膜和细胞质之间响应 CCL18 刺激的稳健和动态循环。生化分析表明，埃兹蛋白乙酰化阻止了 Thr567 的磷酸化。使用原子力显微镜测量，我们的研究表明 ezrin 的乙酰化诱导其展开成主导结构，从而阻止了 Thr567 处的 ezrin 磷酸化。因此，这些结果提出了一种以前未定义的机制，通过该机制，CCL18 引发的 ezrin 乙酰化和磷酸化之间的串扰控制了乳腺癌细胞的迁移和侵袭。