Non-muscle myosin 2 filaments are processive in cells.
Non-muscle myosin 2 filaments are processive in cells.
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非肌肉肌球蛋白 2 丝在细胞中持续进行。
DOI：
10.1101/2023.02.24.529920
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发表时间：
2023
期刊：
影响因子：
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通讯作者：
Beach,JordanR
中科院分区：
文献类型：
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作者：
Vitriol,EricA;Quintanilla,MelissaA;Tidei,JosephJ;Troughton,LeeD;Cody,Abigail;Cisterna,BrunoA;Jane,MakenzieL;Oakes,PatrickW;Beach,JordanR
细胞成分的定向运输通常依赖于细胞骨架马达的持续运动。肌球蛋白 2 马达主要参与相反方向的肌动蛋白丝来驱动收缩事件，因此传统上不被视为进行性的。然而，最近使用纯化的非肌肉肌球蛋白 2 (NM2) 进行的体外实验表明，肌球蛋白 2 丝可以持续移动。在这里，我们将持续性建立为 NM2 的细胞特性。中枢神经系统衍生的 CAD 细胞中的进行性运行在终止于前缘的突起中的成束肌动蛋白上最为明显。我们发现体内的加工速度与体外测量结果一致。 NM2 以丝状形式对抗片状伪足逆行流动，尽管在缺乏肌动蛋白动力学的情况下仍可能发生顺行运动。比较 NM2 同工型的持续合成能力，我们发现 NM2A 的移动速度略快于 NM2B。最后，我们证明这不是细胞特异性的特性，因为我们观察到 NM2 在成纤维细胞的板层和亚核应力纤维中的类似进行性运动。总的来说，这些观察结果进一步拓宽了 NM2 的功能以及已经无处不在的马达可以发挥作用的生物过程。
Directed transport of cellular components is often dependent on the processive movements of cytoskeletal motors. Myosin 2 motors predominantly engage actin filaments of opposing orientation to drive contractile events and are therefore not traditionally viewed as processive. However, recent in vitro experiments with purified nonmuscle myosin 2 (NM2) demonstrated myosin 2 filaments could move processively. Here, we establish processivity as a cellular property of NM2. Processive runs in central nervous system-derived CAD cells are most apparent on bundled actin in protrusions that terminate at the leading edge. We find that processive velocities in vivo are consistent with in vitro measurements. NM2 makes these processive runs in its filamentous form against lamellipodia retrograde flow, though anterograde movement can still occur in the absence of actin dynamics. Comparing the processivity of NM2 isoforms, we find that NM2A moves slightly faster than NM2B. Finally, we demonstrate that this is not a cell-specific property, as we observe processive-like movements of NM2 in the lamella and subnuclear stress fibers of fibroblasts. Collectively, these observations further broaden NM2 functionality and the biological processes in which the already ubiquitous motor can contribute.