Growth cones contain myosin II bipolar filament arrays
Growth cones contain myosin II bipolar filament arrays
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DOI：
10.1002/cm.10038
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发表时间：
2002-06-01
影响因子：
--
通讯作者：
Bridgman, PC
中科院分区：
文献类型：
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作者：
Bridgman, PC
非肌肉肌球蛋白II是神经生长锥中最丰富的肌球蛋白形式之一。在生长锥中发现至少两种具有重叠但不同分布的肌球蛋白II亚型（A和B）。看来，肌球蛋白IIA和IIB可能是必要的正常神经生长和运动，但负责其活动的分子相互作用仍不清楚。例如，这是未知的，如果这些肌球蛋白II亚型产生双极的“微丝”在生长锥类似于其他非肌肉细胞中观察到的。为了确定是否存在微丝在生长锥，我们修改了用于检测微丝在其他细胞类型的电子显微镜制备程序。我们发现的结构，出现非常相似的双极微丝在noneuronal细胞。它们还用肌球蛋白IIA或IIB的抗体标记。因此，生长锥中肌球蛋白II的活性可能与其他非肌肉细胞中的活性相似。双极丝与相反方向的肌动蛋白丝相互作用会产生局部收缩或对肌动蛋白网络施加张力。该活性将负责生长锥中的肌球蛋白II依赖性运动。(C)2002 Wiley-Liss，Inc.
Nonmuscle myosin II is among the most abundant forms of myosin in nerve growth cones. At least two isoforms of myosin II (A and B) that have overlapping but distinct distributions are found in growth cones. It appears that both myosin IIA and IIB may be necessary for normal nerve outgrowth and motility, but the molecular interactions responsible for their activity remain unclear. For instance, it is unknown if these myosin II isoforms produce bipolar "minifilaments" in growth cones similar to those observed in other nonmuscle cells. To determine if minifilaments are present in growth cones, we modified the electron microscopy preparative procedures used to detect minifilaments in other cell types. We found structures that appeared very similar to bipolar minifilaments found in noneuronal cells. They also labeled with antibodies to either myosin IIA or IIB. Thus, the activity of myosin II in growth cones is likely to be similar to that in other nonmuscle cells. Bipolar filaments interacting with oppositely oriented actin filaments will produce localized contractions or exert tension on actin networks. This activity will be responsible for the myosin II dependent motility in growth cones. (C) 2002 Wiley-Liss, Inc.