Ypt11 functions in bud-directed transport of the Golgi by linking Myo2 to the coatomer subunit Ret2
Ypt11 functions in bud-directed transport of the Golgi by linking Myo2 to the coatomer subunit Ret2
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DOI：
10.1016/j.cub.2008.06.028
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发表时间：
2008-07-08
期刊：
影响因子：
9.2
通讯作者：
Yoda, Koji
中科院分区：
文献类型：
--
作者：
Arai, Seisuke;Noda, Yoichi;Yoda, Koji
酵母V类肌球蛋白Myo2在其遗传过程中将高尔基体运输到芽中[1]。然而，将高尔基体与Myo2联系起来的机制尚不清楚。在这里，我们报告了Ypt11，一个据说与Myo2相互作用的Rab GTP酶，与辅酶细胞复合体的一个亚单位Ret2结合。当Ypt11产量过高时，Ret2和高尔基标记Och1和Sft2在生长的芽中积累，并在母细胞中丢失。在产生与Ypt11亲和力降低的Ret2蛋白的ret2突变体中，在Ypt11的过量生产时没有观察到这种积累。在萌芽的某个阶段，已知用sec7-GFP标记的晚期高尔基体池在芽中呈极化分布[1]。我们发现，在ypt11 Delta突变体中没有观察到晚期高尔基池的这种极化。的确，用时空图像相关光谱(STICS)和光漂白中的荧光损失(FLIP)分析sec7-GFP的动力学表明，Ypt11是晚期高尔基体从母细胞向出芽细胞的矢量肌动蛋白依赖的运动所必需的。这些结果表明，Ypt11和Ret2是Myo2受体复合体的组成部分，该复合体在高尔基体遗传到生长芽的过程中发挥作用。
A yeast class V myosin Myo2 transports the Golgi into the bud during its inheritance [1]. However, the mechanism that links the Golgi to Myo2 is unknown. Here, we report that Ypt11, a Rab GTPase that reportedly interacts with Myo2, binds to Ret2, a subunit of the coatomer complex. When Ypt11 is overproduced, Ret2 and the Golgi markers, Och1 and Sft2, are accumulated in the growing bud and are lost in the mother cell. In a ret2 mutant that produces the Ret2 protein with reduced affinity to Ypt11, no such accumulation is observed upon overproduction of Ypt11. At a certain stage of budding, it is known that the late Golgi cisternae labeled with Sec7-GFP show polarized distribution in the bud [1]. We find that this polarization of late Golgi cisternae is not observed in the ypt11 Delta mutant. Indeed, analyses of Sec7-GFP dynamics with spatio-temporal image correlation spectroscopy (STICS) and fluorescence loss in photo-bleaching (FLIP) reveals that Ypt11 is required for the vectorial actin-dependent movement of the late Golgi from the mother cell toward the emerging bud. These results indicate that the Ypt11 and Ret2 are components of a Myo2 receptor complex that functions during the Golgi inheritance into the growing bud.