Paxillin phosphorylation controls invadopodia/podosomes spatiotemporal organization
Paxillin phosphorylation controls invadopodia/podosomes spatiotemporal organization
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DOI：
10.1091/mbc.e06-01-0088
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发表时间：
2008-02-01
影响因子：
3.3
通讯作者：
Block, Marc R.
中科院分区：
文献类型：
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作者：
Badowski, Cedric;Pawlak, Geraldine;Block, Marc R.
在劳斯肉瘤病毒（RSV）转化的幼仓鼠肾（BHK）细胞中，侵入伪足可以自组织成环状和带状，类似于破骨细胞分化过程中的伪足体分布。单个侵袭伪足的组成是时空调节的，并依赖于侵袭伪足定位沿着环部分：肌动蛋白核心组件之前，周围的整合素和整合素连接的蛋白质的招聘，而肌动蛋白核心的损失是一个先决条件侵袭伪足拆卸。我们已经表明，invadopodia环扩张是由桩蛋白磷酸化酪氨酸31和118，这使得invadopodia拆卸控制。在BHK-RSV细胞中，桩蛋白突变体Y31 F-Y118 F的异位表达诱导侵袭伪足拆卸延迟并损害其自组织。在破骨细胞中，通过桩蛋白敲低也揭示了类似的机制。缺乏桩蛋白磷酸化、钙蛋白酶或细胞外信号调节激酶抑制，导致相似的表型，表明这些蛋白属于相同的调节途径。事实上，我们已经证明桩蛋白磷酸化促进Erk激活，进而激活钙蛋白酶。最后，我们观察到侵袭伪足/伪足体环扩张是BHK-RSV细胞和原代破骨细胞有效降解细胞外基质以及通过细胞单层迁移所必需的。
In Rous sarcoma virus (RSV)-transformed baby hamster kidney (BHK) cells, invadopodia can self-organize into rings and belts, similarly to podosome distribution during osteoclast differentiation. The composition of individual invadopodia is spatiotemporally regulated and depends on invadopodia localization along the ring section: the actin core assembly precedes the recruitment of surrounding integrins and integrin-linked proteins, whereas the loss of the actin core was a prerequisite to invadopodia disassembly. We have shown that invadopodia ring expansion is controlled by paxillin phosphorylations on tyrosine 31 and 118, which allows invadopodia disassembly. In BHK-RSV cells, ectopic expression of the paxillin mutant Y31F-Y118F induces a delay in invadopodia disassembly and impairs their self-organization. A similar mechanism is unraveled in osteoclasts by using paxillin knockdown. Lack of paxillin phosphorylation, calpain or extracellular signal-regulated kinase inhibition, resulted in similar phenotype, suggesting that these proteins belong to the same regulatory pathways. Indeed, we have shown that paxillin phosphorylation promotes Erk activation that in turn activates calpain. Finally, we observed that invadopodia/podosomes ring expansion is required for efficient extracellular matrix degradation both in BHK-RSV cells and primary osteoclasts, and for transmigration through a cell monolayer.