Role of CLASP2 in microtubule stabilization and the regulation of persistent motility
Role of CLASP2 in microtubule stabilization and the regulation of persistent motility
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DOI：
10.1016/j.cub.2006.09.065
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发表时间：
2006-11-21
期刊：
影响因子：
9.2
通讯作者：
Galjart, Niels
中科院分区：
文献类型：
--
作者：
Drabek, Ksenija;van Ham, Marco;Galjart, Niels
在运动成纤维细胞中，稳定的微管 (MT) 朝向细胞的前缘 (1]。这些极化 MT 阵列如何建立和维持，以及它们控制的细胞过程，一直是许多研究的主题。一些 MT“加端跟踪蛋白”或 + TIP [2]，已被提出来调节选择性 MT 稳定，包括 CLASP [3]，一种复合物 CLIP-170、IQGAP1、激活的 Cdc42 或 Rac1 [4]、APC、EB1 和 mDia1 的复合物 [5] 以及肌动蛋白-MT 交联因子 ACF7 [6]。通过在伤口愈合试验中使用小鼠胚胎成纤维细胞 (MEF)，我们在此表明 CLASP2 对于形成稳定的极化 MT 阵列是必需的，但 CLIP-170 和 APC-EB1 相互作用不是必需的。 CLASP2 缺陷的 MEF 的持续运动也受到阻碍。我们发现 ACF7 调节 HeLa 细胞中的皮质 CLASP 定位，表明它在 CLASP2 的上游发挥作用。基于荧光的方法表明 GFP-CLASP2 以双峰方式固定在细胞边缘附近的区域。我们的结果表明，区域 CLASP2 的固定化可以使 MT 稳定并促进成纤维细胞的定向持续运动。
In motile fibroblasts, stable microtubules (MTs) are oriented toward the leading edge of cells (1]. How these polarized MT arrays are established and maintained, and the cellular processes they control, have been the subject of many investigations. Several MT "plus-end-tracking proteins," or + TIPs [2], have been proposed to regulate selective MT stabilization, including the CLASPs [3], a complex of CLIP-170, IQGAP1, activated Cdc42 or Rac1 [4], a complex of APC, EB1, and mDia1 [5], and the actin-MT crosslinking factor ACF7 [6]. By using mouse embryonic fibroblasts (MEFs) in a wound-healing assay, we show here that CLASP2 is required for the formation of a stable, polarized MT array but that CLIP-170 and an APC-EB1 interaction are not essential. Persistent motility is also hampered in CLASP2-deficient MEFs. We find that ACF7 regulates cortical CLASP localization in HeLa cells, indicating it acts upstream of CLASP2. Fluorescence-based approaches show that GFP-CLASP2 is immobilized in a bimodal manner in regions near cell edges. Our results suggest that the regional immobilization of CLASP2 allows MT stabilization and promotes directionally persistent motility in fibroblasts.