College of Animal Science and Technology, Nanjing Agricultural University, Nanjing 210095, China.
College of Animal Science and Technology, Nanjing Agricultural University, Nanjing 210095, China
Development. 2019 Feb 4;146(3):dev171280. doi: 10.1242/dev.171280.
Cytoskeletal dynamics are involved in multiple cellular processes during oocyte meiosis, including spindle organization, actin-based spindle migration and polar body extrusion. Here, we report that the vesicle trafficking protein Rab23, a GTPase, drives the motor protein Kif17, and that this is important for spindle organization and actin dynamics during mouse oocyte meiosis. GTP-bound Rab23 accumulated at the spindle and promoted migration of Kif17 to the spindle poles. Depletion of Rab23 or Kif17 caused polar body extrusion failure. Further analysis showed that depletion of Rab23/Kif17 perturbed spindle formation and chromosome alignment, possibly by affecting tubulin acetylation. Kif17 regulated tubulin acetylation by associating with αTAT and Sirt2, and depletion of Kif17 altered expression of these proteins. Moreover, depletion of Kif17 decreased the level of cytoplasmic actin, which abrogated spindle migration to the cortex. The tail domain of Kif17 associated with constituents of the RhoA-ROCK-LIMK-cofilin pathway to modulate assembly of actin filaments. Taken together, our results demonstrate that the Rab23-Kif17-cargo complex regulates tubulin acetylation for spindle organization and drives actin-mediated spindle migration during meiosis.
细胞骨架动力学参与卵母细胞减数分裂过程中的多个细胞过程，包括纺锤体组织、基于肌动蛋白的纺锤体迁移和极体挤出。在这里，我们报告囊泡转运蛋白 Rab23（一种 GTPase）驱动马达蛋白 Kif17，这对于小鼠卵母细胞减数分裂过程中的纺锤体组织和肌动蛋白动力学很重要。结合 GTP 的 Rab23 在纺锤体上积累，并促进 Kif17 向纺锤体极迁移。Rab23 或 Kif17 的耗竭导致极体挤出失败。进一步的分析表明，Rab23/Kif17 的耗竭扰乱了纺锤体的形成和染色体的排列，可能是通过影响微管蛋白乙酰化。Kif17 通过与 αTAT 和 Sirt2 结合来调节微管蛋白乙酰化，而 Kif17 的耗竭改变了这些蛋白质的表达。此外，Kif17 的耗竭降低了细胞质肌动蛋白的水平，从而阻止了纺锤体向皮质的迁移。Kif17 的尾部结构域与 RhoA-ROCK-LIMK-肌动蛋白丝结合蛋白途径的成分结合，调节肌动蛋白丝的组装。总之，我们的结果表明，Rab23-Kif17-货物复合物调节微管蛋白乙酰化以进行纺锤体组织，并在减数分裂过程中驱动肌动蛋白介导的纺锤体迁移。
