Liu Yajun, Lee I-Ju, Sun Mingzhai, Lower Casey A, Runge Kurt W, Ma Jianjie, Wu Jian-Qiu
Department of Molecular Genetics, The Ohio State University, Columbus, OH 43210.
Department of Surgery, Davis Heart and Lung Research Institute, The Ohio State University, Columbus, OH 43210.
Mol Biol Cell. 2016 Aug 15;27(16):2528-41. doi: 10.1091/mbc.E16-03-0156. Epub 2016 Jul 6.
Rho GAPs are important regulators of Rho GTPases, which are involved in various steps of cytokinesis and other processes. However, regulation of Rho-GAP cellular localization and function is not fully understood. Here we report the characterization of a novel coiled-coil protein Rng10 and its relationship with the Rho-GAP Rga7 in fission yeast. Both rng10Δ and rga7Δ result in defective septum and cell lysis during cytokinesis. Rng10 and Rga7 colocalize on the plasma membrane at the cell tips during interphase and at the division site during cell division. Rng10 physically interacts with Rga7 in affinity purification and coimmunoprecipitation. Of interest, Rga7 localization is nearly abolished without Rng10. Moreover, Rng10 and Rga7 work together to regulate the accumulation and dynamics of glucan synthases for successful septum formation in cytokinesis. Our results show that cellular localization and function of the Rho-GAP Rga7 are regulated by a novel protein, Rng10, during cytokinesis in fission yeast.
Rho鸟苷酸酶激活蛋白（Rho GAPs）是Rho GTP酶的重要调节因子，Rho GTP酶参与胞质分裂的各个步骤及其他过程。然而，Rho - GAP细胞定位和功能的调控机制尚未完全明确。在此，我们报道了裂殖酵母中一种新型卷曲螺旋蛋白Rng10的特性及其与Rho - GAP Rga7的关系。rng10Δ和rga7Δ突变体在胞质分裂过程中均导致隔膜缺陷和细胞裂解。在间期，Rng10和Rga7共定位于细胞顶端的质膜上；在细胞分裂时，它们共定位于分裂位点。在亲和纯化和免疫共沉淀实验中，Rng10与Rga7发生物理相互作用。有趣的是，没有Rng10时，Rga7的定位几乎消失。此外，Rng10和Rga7共同作用，调节葡聚糖合酶的积累和动态变化，以确保胞质分裂过程中隔膜的成功形成。我们的结果表明，在裂殖酵母的胞质分裂过程中，Rho - GAP Rga7的细胞定位和功能受新型蛋白Rng10的调控。
