Enucleation of human erythroblasts involves non-muscle myosin IIB
Enucleation of human erythroblasts involves non-muscle myosin IIB
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DOI：
10.1182/blood-2011-06-361907
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发表时间：
2012-01-26
期刊：
影响因子：
20.3
通讯作者：
Sawada, Kenichi
中科院分区：
文献类型：
--
作者：
Ubukawa, Kumi;Guo, Yong-Mei;Sawada, Kenichi
哺乳动物成红细胞经历去核，这一过程被认为与胞质分裂类似。尽管肌动蛋白、非肌肉肌球蛋白 II 和其他几种蛋白质的组合对于正确的胞质分裂至关重要，但非肌肉肌球蛋白 II 在去核中的作用仍不清楚。在这项研究中，我们研究了各种细胞分裂抑制剂对胞质分裂和去核的影响。为此，我们使用人集落形成单位红细胞（CFU-E）和纯化的CD34（+）细胞产生的成熟成红细胞分别作为胞质分裂和去核测定的靶细胞。在这里，我们发现，肌球蛋白II（一种非肌肉肌球蛋白II ATP酶的抑制剂）对肌球蛋白的抑制作用阻止了细胞分裂和去核，这表明非肌肉肌球蛋白II不仅在胞质分裂中而且在去核中发挥着重要作用。当非肌肉肌球蛋白重链（NMHC）IIA或IIB的功能被肌球蛋白杆片段、肌球蛋白IIA或IIB的外源表达抑制时，每个杆片段阻断CFU-E的增殖，但只有IIB的杆片段抑制成熟红细胞的去核。这些数据表明亚型中的 NMHC IIB 参与人成红细胞的去核。 （血。201 2；119(4):1036-1044）
Mammalian erythroblasts undergo enucleation, a process thought to be similar to cytokinesis. Although an assemblage of actin, non-muscle myosin II, and several other proteins is crucial for proper cytokinesis, the role of non-muscle myosin II in enucleation remains unclear. In this study, we investigated the effect of various celldivision inhibitors on cytokinesis and enucleation. For this purpose, we used human colony-forming unit-erythroid (CFU-E) and mature erythroblasts generated from purified CD34(+) cells as target cells for cytokinesis and enucleation assay, respectively. Here we show that the inhibition of myosin by blebbistatin, an inhibitor of non-muscle myosin II ATPase, blocks both cell division and enucleation, which suggests that non-muscle myosin II plays an essential role not only in cytokinesis but also in enucleation. When the function of non-muscle myosin heavy chain (NMHC) IIA or IIB was inhibited by an exogenous expression of myosin rod fragment, myosin IIA or IIB, each rod fragment blocked the proliferation of CFU-E but only the rod fragment for IIB inhibited the enucleation of mature erythroblasts. These data indicate that NMHC IIB among the isoforms is involved in the enucleation of human erythroblasts. (Blood. 201 2;119(4):1036-1044)