Hefei National Laboratory for Physical Sciences at Microscale and School of Life Sciences, University of Science and Technology of China, Hefei, Anhui 230027, China.
J Biol Chem. 2010 Jun 18;285(25):19060-7. doi: 10.1074/jbc.M110.100396. Epub 2010 Apr 19.
Nucleophosmin/B23, an abundant nucleolar protein, plays multiple roles in cell growth and proliferation, and yet, little has been studied about its function in regulating dynamics of microtubules. Here, we report that B23 directly interacts with Eg5, a member of the kinesin family, in the cytosol. The DNA/RNA binding domain of B23 and the motor domain of Eg5 were found to be involved in their interaction. Both in vivo and in vitro evidences showed that B23 acts as an upstream regulator of Eg5 in promoting microtubule polymerization. Moreover, we further demonstrated that B23 regulates microtubule dynamics by directly inhibiting Eg5 ATPase activity.
核仁磷酸蛋白/B23 是一种丰富的核仁蛋白，在细胞生长和增殖中发挥多种作用，但关于其调节微管动力学的功能研究甚少。在这里，我们报告 B23 可在细胞质中与驱动蛋白家族的 Eg5 直接相互作用。发现 B23 的 DNA/RNA 结合域和 Eg5 的马达域参与了它们的相互作用。体内和体外的证据均表明，B23 作为 Eg5 的上游调节剂，在促进微管聚合中起作用。此外，我们还进一步证明 B23 通过直接抑制 Eg5 ATP 酶活性来调节微管动力学。
