Regulation of cell diameter, For3p localization, and cell symmetry by fission yeast Rho-GAP Rga4p
Regulation of cell diameter, For3p localization, and cell symmetry by fission yeast Rho-GAP Rga4p
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DOI：
10.1091/mbc.e06-09-0883
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发表时间：
2007-06-01
影响因子：
3.3
通讯作者：
Verde, Fulvia
中科院分区：
文献类型：
--
作者：
Das, Maitreyi;Wiley, David J.;Verde, Fulvia
细胞尺寸和细胞对称的控制是发育和分化的关键。在这里，我们提供的证据表明，分裂糖菌的Rho-GAP Rga4p控制细胞尺寸。rga4 δ细胞直径更宽，长度更短，而Rga4p过表达导致生长细胞尖端直径减小。与细胞生长控制中的负作用一致，Rga4p蛋白以“紧身胸衣”模式定位于细胞侧面和未生长的细胞尖端。此外，rga4 δ细胞表现出与双胍同源蛋白For3p突变体相似的生长模式改变。与这些观察结果一致，Rga4p是For3p正常定位和肌动蛋白细胞骨架正常分布所必需的。我们发现Rga4p蛋白的不同结构域介导不同的形态功能。c端GAP结构域介导For3p定位到细胞尖端并维持细胞直径。相反，Rga4p的n端LIM同源结构域的过表达以for3p依赖的方式促进肌动蛋白电缆的形成。我们的研究表明，Rga4p与For3p相互作用，在控制细胞直径和细胞生长方面具有新的功能。
Control of cellular dimensions and cell symmetry are critical for development and differentiation. Here we provide evidence that the putative Rho-GAP Rga4p of Schizosaccharomyces pombe controls cellular dimensions. rga4 Delta cells are wider in diameter and shorter in length, whereas Rga4p overexpression leads to reduced diameter of the growing cell tip. Consistent with a negative role in cell growth control, Rga4p protein localizes to the cell sides in a "corset" pattern, and to the nongrowing cell tips. Additionally, rga4 Delta cells show an altered growth pattern similar to that observed in mutants of the formin homology protein For3p. Consistent with these observations, Rga4p is required for normal localization of For3p and for normal distribution of the actin cytoskeleton. We show that different domains of the Rga4p protein mediate diverse morphological functions. The C-terminal GAP domain mediates For3p localization to the cell tips and maintains cell diameter. Conversely, overexpression of the N-terminal LIM homology domain of Rga4p promotes actin cable formation in a For3p-dependent manner. Our studies indicate that Rga4p functionally interacts with For3p and has a novel function in the control of cell diameter and cell growth.