Human Asunder promotes dynein recruitment and centrosomal tethering to the nucleus at mitotic entry.
Human Asunder promotes dynein recruitment and centrosomal tethering to the nucleus at mitotic entry.
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DOI：
10.1091/mbc.e12-07-0558
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发表时间：
2012-12
影响因子：
3.3
通讯作者：
Lee LA
中科院分区：
文献类型：
--
作者：
Jodoin JN;Shboul M;Sitaram P;Zein-Sabatto H;Reversade B;Lee E;Lee LA
前期中心体与核表面的正确偶联对于有丝分裂事件的保真度至关重要。锚定在核表面的动力蛋白马达池介导了这一步骤。 Asunder 蛋白是人类培养细胞中动力蛋白定位以及在有丝分裂进入时将中心体束缚到细胞核所必需的。将动力蛋白马达募集到核表面是前期核-中心体耦合的重要步骤。在培养的人类细胞中，该动力蛋白池通过 RanBP2-Bicaudal D2 (BICD2) 和 Nup133-着丝粒蛋白 F (CENP-F) 网络锚定在核孔复合物上。我们之前报道过，asunder (asun) 基因是果蝇精母细胞中核周动力蛋白定位和雄性减数分裂 G2/M 时核-中心体耦合所必需的。我们在这里展示了哺乳动物 Asunder (ASUN) 蛋白的雄性种系表达拯救了 asun 果蝇，证明了功能的进化保守性。在培养的人类细胞中，我们发现 ASUN 下调会导致有丝分裂前期核周动力蛋白减少。 ASUN 丢失后的其他缺陷包括核-中心体解偶联、纺锤体异常和多核。 ASUN 和动力蛋白接头 lissencephaly 1 (LIS1) 的免疫共沉淀和重叠定位模式表明 ASUN 通过 LIS1 与细胞质中的动力蛋白相互作用。我们的数据表明 ASUN 通过不同于 BICD2 或 CENP-F 的机制控制动力蛋白定位。我们提出了一个模型，其中 ASUN 促进 G2/M 期动力蛋白的核周富集，从而促进 BICD2 和 CENP-F 介导的动力蛋白锚定到核孔复合物。
Proper coupling of centrosomes to the nuclear surface at prophase is essential for fidelity of mitotic events. A pool of dynein motors anchored to the nuclear surface mediates this step. The protein Asunder is required in human cultured cells for dynein localization and tethering of centrosomes to the nucleus at mitotic entry. Recruitment of dynein motors to the nuclear surface is an essential step for nucleus–centrosome coupling in prophase. In cultured human cells, this dynein pool is anchored to nuclear pore complexes through RanBP2–Bicaudal D2 (BICD2) and Nup133– centromere protein F (CENP-F) networks. We previously reported that the asunder (asun) gene is required in Drosophila spermatocytes for perinuclear dynein localization and nucleus–centrosome coupling at G2/M of male meiosis. We show here that male germline expression of mammalian Asunder (ASUN) protein rescues asun flies, demonstrating evolutionary conservation of function. In cultured human cells, we find that ASUN down-regulation causes reduction of perinuclear dynein in prophase of mitosis. Additional defects after loss of ASUN include nucleus–centrosome uncoupling, abnormal spindles, and multinucleation. Coimmunoprecipitation and overlapping localization patterns of ASUN and lissencephaly 1 (LIS1), a dynein adaptor, suggest that ASUN interacts with dynein in the cytoplasm via LIS1. Our data indicate that ASUN controls dynein localization via a mechanism distinct from that of either BICD2 or CENP-F. We present a model in which ASUN promotes perinuclear enrichment of dynein at G2/M that facilitates BICD2- and CENP-F-mediated anchoring of dynein to nuclear pore complexes.