SUMO localizes to the central element of synaptonemal complex and is required for the full synapsis of meiotic chromosomes in budding yeast.
SUMO localizes to the central element of synaptonemal complex and is required for the full synapsis of meiotic chromosomes in budding yeast.
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DOI：
10.1371/journal.pgen.1003837
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发表时间：
2013
期刊：
影响因子：
4.5
通讯作者：
Macqueen AJ
中科院分区：
文献类型：
--
作者：
Voelkel-Meiman K;Taylor LF;Mukherjee P;Humphryes N;Tsubouchi H;Macqueen AJ
联会复合体（SC）是一种广泛保守的结构，它在减数分裂前期介导同源染色体的紧密排列，并在减数分裂I时为同源染色体的正确分离所必需。然而，SC架构和组装的基本细节仍然知之甚少。卷曲螺旋蛋白，Zip1，是唯一的组成部分，其安排在成熟SC的芽殖酵母已被广泛的特点。已经提出小泛素样调节剂SUMO通过将染色体轴与Zip1的C末端连接而在SC组装中起作用。然而，SUMO在SC结构中的作用还没有直接测试，因为缺乏SUMO的细胞是不能存活的。在这里，我们提供了直接的证据SUMO的功能，在SC大会。减数分裂smt3功能减少菌株显示减少的孢子形成，异常水平的交叉重组，减少SC组装。SC结构几乎不存在时，诱导在以后的减数分裂时间点在smt3功能降低的背景。使用结构照明显微镜，我们进一步确定SUMO在芽殖酵母SC结构中的位置。与以前的模型，定位SUMO Zip1的C末端附近，我们表明，SUMO位于SC中央区域的中线近Zip1的N末端，在一个子域称为“中央元素”。最近鉴定的SUMO化SC组分Ecm11也定位于SC中心元件。最后，我们表明，SUMO，Ecm11，甚至unSUMOylatable Ecm11表现出Zip1样的持续纳入先前建立的SC在减数分裂前期和SUMO和Ecm11的相对丰度与Zip1的丰度在不同Zip1含量的SC。我们讨论了一个模型，其中中心元件蛋白质是核心构建模块，稳定的SC附近Zip1的N末端的架构，SUMO化可能会发生后，如Ecm11到SC前体结构的组成部分纳入。减数分裂细胞周期使有性生殖的生物体能够产生具有一半染色体的生殖细胞。染色体倍性在减数分裂过程中由于同源染色体（同源物）之间建立的先前关联而降低。这样的关联，最终通过交换重组事件来确保，允许同源物实现相反的方向并在减数分裂I时彼此分离。一个多聚体蛋白质结构，联会复合体（SC），介导的亲密，纵向排列的同源物在减数分裂前期，并形成的背景下，其中交叉成熟。SC的三重结构被广泛保存，但其组成和结构在任何生物体中仍然不完全了解。小泛肽样调节剂（SUMO）定位于芽殖酵母中的SC。我们表明，SUMO是需要组装成熟的SC，我们还表明，SUMO和最近发现的SUMO化的蛋白质，Ecm11，是组成部分的核心元件子结构的芽殖酵母SC。我们的研究结果表明，SUMO和Ecm11是SC的核心积木，但我们的数据还表明，SUMO化可能发生后，Ecm11的纳入SC结构。最后，我们的研究强调结构照明作为一个强大的工具映射芽殖酵母SC的精细结构。
The synaptonemal complex (SC) is a widely conserved structure that mediates the intimate alignment of homologous chromosomes during meiotic prophase and is required for proper homolog segregation at meiosis I. However, fundamental details of SC architecture and assembly remain poorly understood. The coiled-coil protein, Zip1, is the only component whose arrangement within the mature SC of budding yeast has been extensively characterized. It has been proposed that the Small Ubiquitin-like MOdifier, SUMO, plays a role in SC assembly by linking chromosome axes with Zip1's C termini. The role of SUMO in SC structure has not been directly tested, however, because cells lacking SUMO are inviable. Here, we provide direct evidence for SUMO's function in SC assembly. A meiotic smt3 reduction-of-function strain displays reduced sporulation, abnormal levels of crossover recombination, and diminished SC assembly. SC structures are nearly absent when induced at later meiotic time points in the smt3 reduction-of-function background. Using Structured Illumination Microscopy we furthermore determine the position of SUMO within budding yeast SC structure. In contrast to previous models that positioned SUMO near Zip1's C termini, we demonstrate that SUMO lies at the midline of SC central region proximal to Zip1's N termini, within a subdomain called the “central element”. The recently identified SUMOylated SC component, Ecm11, also localizes to the SC central element. Finally, we show that SUMO, Ecm11, and even unSUMOylatable Ecm11 exhibit Zip1-like ongoing incorporation into previously established SCs during meiotic prophase and that the relative abundance of SUMO and Ecm11 correlates with Zip1's abundance within SCs of varying Zip1 content. We discuss a model in which central element proteins are core building blocks that stabilize the architecture of SC near Zip1's N termini, and where SUMOylation may occur subsequent to the incorporation of components like Ecm11 into an SC precursor structure. The meiotic cell cycle enables sexually reproducing organisms to generate reproductive cells with half their chromosome complement. Chromosome ploidy is reduced during meiosis by virtue of prior associations established between homologous chromosomes (homologs). Such associations, which are ultimately secured by crossover recombination events, allow homologs to achieve an opposing orientation and segregate from one another at meiosis I. A multimeric protein structure, the synaptonemal complex (SC), mediates the intimate, lengthwise alignment of homologs during meiotic prophase and forms the context in which crossovers mature. The SC's tripartite structure is widely conserved but its composition and architecture remain incompletely understood in any organism. The Small Ubiquitin-like MOdifier (SUMO) localizes to SC in budding yeast. We show that SUMO is required for assembling mature SC and we furthermore demonstrate that SUMO and the recently identified SUMOylated protein, Ecm11, are components of the central element substructure of the budding yeast SC. Our findings suggest that SUMO and Ecm11 are core building blocks of SC, yet our data also suggest that SUMOylation may occur subsequent to Ecm11's incorporation into the SC structure. Finally, our study highlights Structured Illumination as a powerful tool for mapping the fine structure of budding yeast SC.
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ECM11-GMC2复合物通过在发芽酵母中的横向丝组装来促进突发型复合物的形成。
影响因子：
4.5
作者：
Humphryes N;Leung WK;Argunhan B;Terentyev Y;Dvorackova M;Tsubouchi H
通讯作者：
Tsubouchi H
影响因子：
5.8
作者：
Davies OR;Maman JD;Pellegrini L
通讯作者：
Pellegrini L
影响因子：
4.5
作者：
Ho HC;Burgess SM
通讯作者：
Burgess SM
DOI：
10.1073/pnas.0500172102
发表时间：
2005-03-22
影响因子：
11.1
作者：
Anderson, LK;Royer, SM;Hawley, RS
通讯作者：
Hawley, RS
影响因子：
10.5
作者：
Benjamin, KR;Zhang, C;Herskowitz, I
通讯作者：
Herskowitz, I