Whitehead Institute for Biomedical Research, 455 Main Street, Cambridge, MA 02142, USA.
Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02142, USA.
Open Biol. 2018 Sep 26;8(9):180095. doi: 10.1098/rsob.180095.
Cytoplasmic dynein is a minus-end-directed microtubule-based motor that acts at diverse subcellular sites. During mitosis, dynein localizes simultaneously to the mitotic spindle, spindle poles, kinetochores and the cell cortex. However, it is unclear what controls the relative targeting of dynein to these locations. As dynein is heavily post-translationally modified, we sought to test a role for these modifications in regulating dynein localization. We find that dynein rapidly and strongly accumulates at mitotic spindle poles following treatment with NSC697923, a small molecule that inhibits the ubiquitin E2 enzyme, Ubc13, or treatment with PYR-41, a ubiquitin E1 inhibitor. Subsets of dynein regulators such as Lis1, ZW10 and Spindly accumulate at the spindle poles, whereas others do not, suggesting that NSC697923 differentially affects specific dynein populations. We additionally find that dynein relocalization induced by NSC697923 or PYR-41 can be suppressed by simultaneous treatment with the non-selective deubiquitinase inhibitor, PR-619. However, we did not observe altered dynein localization following treatment with the selective E1 inhibitor, TAK-243. Although it is possible that off-target effects of NSC697923 and PYR-41 are responsible for the observed changes in dynein localization, the rapid relocalization upon drug treatment highlights the highly dynamic nature of dynein regulation during mitosis.
细胞质动力蛋白是一种向微管负端定向的微管动力蛋白，在各种亚细胞部位发挥作用。在有丝分裂过程中，动力蛋白同时定位于有丝分裂纺锤体、纺锤体极、动粒和细胞皮层。然而，目前尚不清楚是什么控制了动力蛋白对这些位置的相对靶向。由于动力蛋白受到强烈的翻译后修饰，我们试图测试这些修饰在调节动力蛋白定位中的作用。我们发现，在用抑制泛素 E2 酶 Ubc13 的小分子 NSC697923 或泛素 E1 抑制剂 PYR-41 处理后，动力蛋白迅速且强烈地积累在有丝分裂纺锤体极。动力蛋白调节剂的亚群，如 Lis1、ZW10 和 Spindly，积累在纺锤体极，而其他则没有，这表明 NSC697923 对特定的动力蛋白群体有不同的影响。我们还发现，用 NSC697923 或 PYR-41 诱导的动力蛋白重定位可以被同时用非选择性去泛素酶抑制剂 PR-619 抑制。然而，在用选择性 E1 抑制剂 TAK-243 处理后，我们没有观察到动力蛋白定位的改变。尽管 NSC697923 和 PYR-41 的脱靶效应可能是观察到的动力蛋白定位变化的原因，但药物处理后动力蛋白的快速重定位突出了有丝分裂过程中动力蛋白调节的高度动态性质。
Zotero 插件
