Subcellular distribution of non-muscle myosin IIb is controlled by FILIP through Hsc70.
Subcellular distribution of non-muscle myosin IIb is controlled by FILIP through Hsc70.
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DOI：
10.1371/journal.pone.0172257
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发表时间：
2017
期刊：
影响因子：
3.7
通讯作者：
Sato M
中科院分区：
文献类型：
--
作者：
Yagi H;Takabayashi T;Xie MJ;Kuroda K;Sato M
神经元棘是一个小的、富含肌动蛋白的树突或躯体突起，作为兴奋性突触的突触后区室。棘的形态反映了突触的活动，并受到内部肌动蛋白细胞骨架动力学的调节，肌动蛋白细胞骨架由肌动蛋白结合蛋白如非肌肉肌球蛋白控制。以前，我们证明了肌球蛋白IIb的亚细胞定位和功能是由其结合伙伴，细丝蛋白-A相互作用蛋白（FILIP）。然而，肌球蛋白IIb的亚细胞分布是如何被FILIP控制的尚不清楚。本研究的目的是确定潜在的结合伙伴的FILIP，有助于其调节非肌肉肌球蛋白IIb。下拉分析检测到一个70 kDa的蛋白质，通过质谱鉴定为伴侣蛋白Hsc 70。Hsc 70与FILIP的结合受Hsc 70的腺苷三磷酸酶（ATP酶）活性控制。此外，FILIP通过结合非肌肉肌球蛋白IIb不需要的结构域结合Hsc 70。Hsc 70的ATP酶活性的抑制削弱了FILIP对非肌肉肌球蛋白IIb亚细胞分布的影响。此外，在原代培养的神经元中，Hsc 70的抑制剂阻碍了FILIP诱导的脊髓形态学变化。总的来说，这些结果表明，Hsc 70与FILIP相互作用，介导其对非肌肉肌球蛋白IIb的影响，并调节脊柱形态。
The neuronal spine is a small, actin-rich dendritic or somatic protrusion that serves as the postsynaptic compartment of the excitatory synapse. The morphology of the spine reflects the activity of the synapse and is regulated by the dynamics of the actin cytoskeleton inside, which is controlled by actin binding proteins such as non-muscle myosin. Previously, we demonstrated that the subcellular localization and function of myosin IIb are regulated by its binding partner, filamin-A interacting protein (FILIP). However, how the subcellular distribution of myosin IIb is controlled by FILIP is not yet known. The objective of this study was to identify potential binding partners of FILIP that contribute to its regulation of non-muscle myosin IIb. Pull-down assays detected a 70-kDa protein that was identified by mass spectrometry to be the chaperone protein Hsc70. The binding of Hsc70 to FILIP was controlled by the adenosine triphosphatase (ATPase) activity of Hsc70. Further, FILIP bound to Hsc70 via a domain that was not required for binding non-muscle myosin IIb. Inhibition of ATPase activity of Hsc70 impaired the effect of FILIP on the subcellular distribution of non-muscle myosin IIb. Further, in primary cultured neurons, an inhibitor of Hsc70 impeded the morphological change in spines induced by FILIP. Collectively, these results demonstrate that Hsc70 interacts with FILIP to mediate its effects on non-muscle myosin IIb and to regulate spine morphology.