ABSTRACT

Telomere-led chromosome movement or Rapid Prophase Movements (RPM) occur in meiotic prophase and is a conserved process required for proper homologous chromosome interactions. This type of active movements originates in the cytoplasm and is translated to the telomeres through the nuclear membrane. We highlight our recent advances in the engine generating RPMs in S. cerevisiae, with special emphasis in exonuclear components of the machinery. We demonstrate that Mps2 protein participates as a LINC complex component; we identify Myo2 motor protein, which interacts with Mps2 connecting telomeres to the actin cytoskeleton; and show that Csm4 is a regulator of the Mps2-Myo2 interaction and function. In this article we extend our observations regarding to the functional interaction of Mps2 and Csm4. We show that the Mps2-Csm4 fusion protein complement deficient sporulation and anaphase I entrance of a csm4 deletion strain, and partially complement RPM function. Overall, our results allow the construction of a complete model for the primary mechanism generating chromosome movements in budding yeast. Malfunction of this machinery results in impaired meiotic progression in different experimental models indicating its requirement for successful haploidization of the genome and species survival.

摘要

端粒主导的染色体运动或快速前期运动（RPM）发生在减数分裂前期，是适当的同源染色体相互作用所需的保守过程。这种类型的主动运动起源于细胞质，并通过核膜转化为端粒。我们着重介绍我们在酿酒酵母中生成RPM的引擎方面的最新进展，特别强调机械的核外组件。我们证明了Mps2蛋白作为LINC复杂成分参与；我们鉴定了Myo2运动蛋白，该蛋白与将端粒连接到肌动蛋白细胞骨架的Mps2相互作用。并表明Csm4是Mps2-Myo2相互作用和功能的调节剂。在本文中，我们将我们的观察扩展到Mps2和Csm4的功能相互作用。我们显示，Mps2-Csm4融合蛋白可弥补csm4缺失菌株的不足孢子形成和后期I入口，并部分补充RPM功能。总的来说，我们的结果允许构建一个完整的模型，用于建立发芽酵母中染色体运动的主要机制。