Watanabe Naoki, Higashida Chiharu
Department of Pharmacology, Kyoto University, Faculty of Medicine, Kyoto 606-8501, Japan.
Exp Cell Res. 2004 Nov 15;301(1):16-22. doi: 10.1016/j.yexcr.2004.08.020.
Taking the advantage of single-molecule imaging, our recent study has revealed surprisingly long processive movement of a Formin protein, mDia1, surfing along with the growing end of actin filaments in living cells. This finding provides direct evidence for the ability of Formins to function as processive cappers that has been postulated from several lines of evidence in biochemical studies. With nucleating filaments from the profilin-actin pool, Formins may effectively generate long actin filaments, and contribute to the generation of the specific actin-based structures, that is, the contractile ring in cytokinesis, actin stress fibers in animal cells, and yeast actin cables. Furthermore, Formins have the potential to function as actin polymerization-driven molecular motors. Although much remains to be tested about the role of this novel molecular mobilization mechanism, cells might utilize actin polymerization energy for cell shape change and/or trafficking via Formin motors.
利用单分子成像技术，我们最近的研究揭示了一种formin蛋白mDia1在活细胞中沿着肌动蛋白丝的生长末端进行惊人的长程持续性运动。这一发现为formin蛋白作为持续性封端蛋白的能力提供了直接证据，这一能力已从生化研究的多条证据中得到推测。通过从肌动蛋白-脯氨酸池中成核细丝，formin蛋白可能有效地产生长肌动蛋白丝，并有助于产生特定的基于肌动蛋白的结构，即胞质分裂中的收缩环、动物细胞中的肌动蛋白应力纤维和酵母肌动蛋白电缆。此外，formin蛋白有潜力作为肌动蛋白聚合驱动的分子马达发挥作用。尽管关于这种新型分子动员机制的作用仍有许多有待测试，但细胞可能通过formin蛋白马达利用肌动蛋白聚合能量来改变细胞形状和/或进行运输。
