Control of cell migration by the novel protein phosphatase-2A interacting protein inka2
Control of cell migration by the novel protein phosphatase-2A interacting protein inka2
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DOI：
10.1007/s00441-020-03169-x
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发表时间：
2020-06-01
影响因子：
3.6
通讯作者：
Sakakibara, Shin-ichi
中科院分区：
文献类型：
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作者：
Akiyama, Hiroki;Iwasaki, Yumi;Sakakibara, Shin-ichi
细胞迁移在胚胎发育、创伤愈合、免疫应答和肿瘤转移等生理和病理过程中起着重要作用。在胚胎发育过程中，在迁移细胞中观察到Inka 2转录物，表明Inka 2参与细胞迁移。然而，其确切作用仍不清楚。在这里，我们发现inka 2控制粘着斑动力学和细胞迁移，可能是通过调节蛋白磷酸酶-2A（PP 2A）功能。划痕试验显示，inka 2 shRNA转染的NIH 3 T3细胞显示快速伤口闭合，表明inka 2对细胞迁移的抑制作用。使用全内反射荧光显微镜对表达EGFP-桩蛋白的NIH 3 T3细胞进行活细胞成像，结果显示inka 2敲低增加了局灶性粘连的周转率。已知PP 2A由催化亚基（C）、调节亚基（B）和支架亚基（A）组成，可调节粘着斑，我们研究了inka 2-PP 2A相互作用。免疫沉淀揭示了inka 2和PP 2A C亚基之间的关联。Inka 2与C亚基的结合阻止了A和C亚基之间的结合，表明Inka 2可以抑制PP 2A功能。此外，inka 2表达和PP 2A抑制降低了粘着斑激酶-桩蛋白相互作用，导致粘着斑形成减少。我们评估了药理学PP 2A抑制对inka 2敲低诱导的细胞迁移速度增加的影响，发现用PP 2A抑制剂处理否定了inka 2敲低细胞的加速迁移。这些结果表明，inka 2敲低发挥其作用，通过PP 2A依赖性调节局灶性粘连。我们的研究结果有助于更好地理解细胞迁移的分子机制。
Cell migration is essential for many physiological and pathological processes, including embryonic development, wound healing, immune response and cancer metastasis. Inka2 transcripts are observed in migrating cells during embryonic development, suggesting the involvement of inka2 in cell migration. However, its precise role remains unclear. Here, we found that inka2 controlled focal adhesion dynamics and cell migration, likely by regulating protein phosphatase-2A (PP2A) function. A scratch assay revealed that inka2 shRNA-transfected NIH3T3 cells showed rapid wound closure, indicating an inhibitory effect by inka2 on cell migration. Live-cell imaging of NIH3T3 cells expressing EGFP-paxillin using total internal reflection fluorescence microscopy revealed that inka2 knockdown increased the turnover rate of focal adhesions. Given that PP2A, which consists of catalytic (C), regulatory (B) and scaffolding (A) subunits, is known to regulate focal adhesions, we examined the inka2-PP2A interaction. Immunoprecipitation revealed an association between inka2 and the PP2A C subunit. Binding of Inka2 to the C subunit prevented the association between the A and C subunits, suggesting that inka2 can inhibit PP2A function. Furthermore, both inka2 expression and PP2A inhibition decreased focal adhesion kinase-paxillin interaction, resulting in reduced formation of focal adhesions. We assessed the effect of pharmacological PP2A inhibition on the inka2 knockdown-induced increase in cell migration speed and found that treatment with a PP2A inhibitor negated the accelerated migration of inka2 knockdown cells. These results suggest that inka2 knockdown exerts its effects through PP2A-dependent regulation of focal adhesions. Our findings contribute to a better understanding of the molecular mechanisms underlying cell migration.