Dynamic localization of a yeast development-specific PP1 complex during prospore membrane formation is dependent on multiple localization signals and complex formation.
Dynamic localization of a yeast development-specific PP1 complex during prospore membrane formation is dependent on multiple localization signals and complex formation.
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DOI：
10.1091/mbc.e17-08-0521
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发表时间：
2017-12-15
影响因子：
3.3
通讯作者：
Tachikawa H
中科院分区：
文献类型：
--
作者：
Nakamura TS;Numajiri Y;Okumura Y;Hidaka J;Tanaka T;Inoue I;Suda Y;Takahashi T;Nakanishi H;Gao XD;Neiman AM;Tachikawa H
酿酒酵母孢子膜的形成为理解从头成膜的机理提供了有力的模型。蛋白磷酸酶类型1，Glc7，和孢子形成特异性靶向亚基Gip1，利用多种定位信号进行动态定位，并在孢子形成过程中调节膜的生长。在酿酒酵母产孢量的发育过程中，形成一种称为前孢子膜的膜结构，这种膜结构从头开始形成，然后膨胀、延伸，最后形成圆形，最后成为孢子的质膜。GIP1编码蛋白磷酸酶1型的调节/靶向亚基，它是孢子形成所必需的。Gip1招募催化亚单位Glc7形成沿孢子膜形成的隔膜结构；然而，其定位和功能的分子基础尚不完全清楚。在这里，我们证明了Gip1动态地改变其定位，并且是孢子膜延伸所必需的。Gip1在孢子膜形成时首先与纺锤体结合，随着孢子膜的伸展而移动到孢子膜上，闭合后分布在孢子膜周围，最后移位到成熟孢子的细胞核中。缺失和突变分析显示，Gip1中的不同序列是不同定位和与Glc7相关所需的。与Glc7结合也是正确定位所必需的。值得注意的是，对Gip1的功能来说，定位在孢子膜上是重要的，但与Septins无关。此外，我们的遗传分析表明，Gip1-Glc7磷酸酶复合体与先前报道的Vps13、Spo71、Spo73途径平行地调节孢子膜的延伸。
Prospore membrane formation of Saccharomyces cerevisiae provides a powerful model for understanding the mechanisms of de novo membrane formation. Protein phosphatase type1, Glc7, and a sporulation-specific targeting subunit, Gip1, show dynamic localization using multiple localization signals and regulate membrane growth during sporulation. During the developmental process of sporulation in Saccharomyces cerevisiae, membrane structures called prospore membranes are formed de novo, expand, extend, acquire a round shape, and finally become plasma membranes of the spores. GIP1 encodes a regulatory/targeting subunit of protein phosphatase type 1 that is required for sporulation. Gip1 recruits the catalytic subunit Glc7 to septin structures that form along the prospore membrane; however, the molecular basis of its localization and function is not fully understood. Here we show that Gip1 changes its localization dynamically and is required for prospore membrane extension. Gip1 first associates with the spindle pole body as the prospore membrane forms, moves onto the prospore membrane and then to the septins as the membrane extends, distributes around the prospore membrane after closure, and finally translocates into the nucleus in the maturing spore. Deletion and mutation analyses reveal distinct sequences in Gip1 that are required for different localizations and for association with Glc7. Binding to Glc7 is also required for proper localization. Strikingly, localization to the prospore membrane, but not association with septins, is important for Gip1 function. Further, our genetic analysis suggests that a Gip1–Glc7 phosphatase complex regulates prospore membrane extension in parallel to the previously reported Vps13, Spo71, Spo73 pathway.