The NESH/Abi-3-based WAVE2 complex is functionally distinct from the Abi-1-based WAVE2 complex.
The NESH/Abi-3-based WAVE2 complex is functionally distinct from the Abi-1-based WAVE2 complex.
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DOI：
10.1186/s12964-015-0119-5
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发表时间：
2015-10-01
期刊：
影响因子：
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通讯作者：
Tani K
中科院分区：
文献类型：
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作者：
Sekino S;Kashiwagi Y;Kanazawa H;Takada K;Baba T;Sato S;Inoue H;Kojima M;Tani K
Abl interactor（Abi）家族蛋白通过参与WAVE复合物在肌动蛋白细胞骨架组织中发挥重要作用。哺乳动物具有三种Abi蛋白：Abi-1、Abi-2和NESH/Abi-3。Abi-1和Abi-2最初被鉴定为Abl酪氨酸激酶结合蛋白。已经公开了Abi-1作为c-Abl和WAVE 2之间的桥梁，并且c-Abl介导的WAVE 2磷酸化促进肌动蛋白重塑。我们之前表明NESH/Abi-3存在于WAVE 2复合物中，但既不与c-Abl结合，也不促进c-Abl介导的WAVE 2磷酸化。在这项研究中，我们对NESH/Abi-3进行了更详细的表征，并将其性质与Abi-1和Abi-2进行了比较。NESH/Abi-3在NIH 3 T3细胞中异位表达，其中Abi-1而非NESH/Abi-3表达。NESH/Abi-3的表达引起内源性Abi-1的降解，这导致基于NESH/Abi-3的WAVE 2复合物的形成。当将这些细胞接种在纤连蛋白包被的培养皿上时，WAVE 2向质膜的易位显著减少，并且外周板状结构的形成受到干扰，这表明基于NESH/Abi-3的WAVE 2复合物不能帮助产生板状突起。接着，在v-src转化的NIH 3 T3细胞中表达Abi-1、Abi-2或NESH/Abi-3。只有在NESH/Abi-3表达的细胞中，Abl激酶抑制剂、甲磺酸伊马替尼或siRNA介导的c-Abl敲低处理才能促进侵袭伪足的形成，侵袭伪足是具有细胞外基质降解活性的腹侧膜突起。结构研究表明，富含脯氨酸的区域和Src同源性3（SH 3）结构域之间的阿比特龙-1的接头区域是至关重要的，它与c-Abl和c-Abl介导的磷酸化WAVE 2的相互作用。基于NESH/Abi-3的WAVE 2复合物与基于Abi-1的WAVE 2复合物在功能上不同，并且NESH/Abi-3可能在某些条件下参与腹侧突起的形成。本文的在线版本（doi：10.1186/s12964-015-0119-5）包含补充材料，可供授权用户使用。
Abl interactor (Abi) family proteins play significant roles in actin cytoskeleton organization through participation in the WAVE complex. Mammals possess three Abi proteins: Abi-1, Abi-2, and NESH/Abi-3. Abi-1 and Abi-2 were originally identified as Abl tyrosine kinase-binding proteins. It has been disclosed that Abi-1 acts as a bridge between c-Abl and WAVE2, and c-Abl-mediated WAVE2 phosphorylation promotes actin remodeling. We showed previously that NESH/Abi-3 is present in the WAVE2 complex, but neither binds to c-Abl nor promotes c-Abl-mediated phosphorylation of WAVE2. In this study, we characterized NESH/Abi-3 in more detail, and compared its properties with those of Abi-1 and Abi-2. NESH/Abi-3 was ectopically expressed in NIH3T3 cells, in which Abi-1, but not NESH/Abi-3, is expressed. The expression of NESH/Abi-3 caused degradation of endogenous Abi-1, which led to the formation of a NESH/Abi-3-based WAVE2 complex. When these cells were plated on fibronectin-coated dishes, the translocation of WAVE2 to the plasma membrane was significantly reduced and the formation of peripheral lamellipodial structures was disturbed, suggesting that the NESH/Abi-3-based WAVE2 complex was unable to help produce lamellipodial protrusions. Next, Abi-1, Abi-2, or NESH/Abi-3 was expressed in v-src-transformed NIH3T3 cells. Only in NESH/Abi-3-expressed cells did treatment with an Abl kinase inhibitor, imatinib mesylate, or siRNA-mediated knockdown of c-Abl promote the formation of invadopodia, which are ventral membrane protrusions with extracellular matrix degradation activity. Structural studies showed that a linker region between the proline-rich regions and the Src homology 3 (SH3) domain of Abi-1 is crucial for its interaction with c-Abl and c-Abl-mediated phosphorylation of WAVE2. The NESH/Abi-3-based WAVE2 complex is functionally distinct from the Abi-1-based one, and NESH/Abi-3 may be involved in the formation of ventral protrusions under certain conditions. The online version of this article (doi:10.1186/s12964-015-0119-5) contains supplementary material, which is available to authorized users.