Abl family kinases are essential regulators of cell shape and movement. Genetic studies revealed functional interactions between Abl kinases and microtubules (MTs), but the mechanism by which Abl family kinases regulate MTs remains unclear. Here, we report that Abl2 directly binds to MTs and regulates MT behaviors. Abl2 uses its C-terminal half to bind MTs, an interaction mediated in part through electrostatic binding to tubulin C-terminal tails. Using purified proteins, we found that Abl2 binds growing MTs and promotes MT polymerization and stability. In cells, knockout of Abl2 significantly impairs MT growth, and this defect can be rescued via reexpression of Abl2. Stable reexpression of an Abl2 fragment containing the MT-binding domain alone was sufficient to restore MT growth at the cell edge. These results show Abl2 uses its C-terminal half to bind MTs and directly regulate MT dynamics.

中文翻译：

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通过直接结合 Abl 家族激酶调节 MT 动力学

Abl 家族激酶是细胞形状和运动的重要调节因子。遗传学研究揭示了 Abl 激酶和微管 (MT) 之间的功能相互作用，但 Abl 家族激酶调节 MT 的机制仍不清楚。在这里，我们报告 Abl2 直接与 MT 结合并调节 MT 行为。Abl2 使用其 C 端一半来结合 MT，这种相互作用部分是通过与微管蛋白 C 端尾部的静电结合介导的。使用纯化的蛋白质，我们发现 Abl2 结合生长中的 MT 并促进 MT 聚合和稳定性。在细胞中，Abl2 的敲除会显着损害 MT 的生长，并且可以通过 Abl2 的重新表达来挽救这种缺陷。单独含有 MT 结合结构域的 Abl2 片段的稳定再表达足以恢复 MT 在细胞边缘的生长。这些结果表明 Abl2 使用其 C 末端一半来结合 MT 并直接调节 MT 动态。