Cellular and Molecular Mechanisms of Cytokinesis Mediated by the TIO Fused Kinase

植物和动物的细胞分裂是一个至关重要的过程，因为它为复杂的生长和发育提供了基础。在细胞分裂过程中，母细胞的遗传物质分裂成双胞胎子细胞核，通过细胞质分裂的过程分裂成单独的子细胞。植物和动物细胞使用不同的细胞分裂模式。在动物中，这涉及到一个挤压过程（“由外向内”模式），而在植物中，它涉及到建立一个新的内部分区（“由内向外”模式）。由于植物细胞“分裂”的特定方式的进化，以及这一过程对植物生长、作物和粮食生产的重要性，我们正试图了解这一过程在植物中是如何被调节的细节。为此，我们使用遗传筛选来鉴定重要模式植物拟南芥（拟南芥）花粉发育过程中细胞分裂所需的基因。这导致分离出二合一突变体，由于未能建立内部分裂壁，在一个共同的细胞质中产生两个核的花粉粒。我们克隆了在二合一突变体中突变的二合一基因，发现它与人类和果蝇中存在的FUSED基因密切相关。然而，与不参与细胞质分裂的动物不同，我们已经证明，在植物的整个生命周期中，植物的营养（绿色）和生殖部分都需要二合一细胞分裂，因此对植物的生长、发育和生存至关重要。在这项工作中，我们的目标是利用分子、遗传和细胞生物学方法了解二合一蛋白在细胞分裂过程中的重要作用。我们将研究制造二合一蛋白突变体的效果，看看它们与正常二合一蛋白相比的功能效率如何。我们将使用荧光蛋白来监测活细胞中参与构建新分裂壁的结构是如何组织的，以及突变的二合一蛋白如何影响这一过程。我们还将研究其他可以与二合一蛋白结合的蛋白质，这些蛋白质可能有助于二合一蛋白执行其任务。这项研究的结果将有助于我们在细胞和分子水平上解释TIO如何在植物细胞分裂过程中发挥作用。此外，这项工作还可以帮助我们解释一种古老的保守蛋白质如何在植物和动物的细胞生物学和生命周期中进化出独特的作用。

The division of cells in plants and animals is a vitally important process as it provides the building blocks for complex growth and development. During cell division the genetic material of the mother cell is divided into twin daughter nuclei that are split into separate daughter cells by a process known as cytokinesis. Plant and animal cells use different modes of cytokinesis. In animals this involves a pinching in process ('outside-in' mode), whereas in plants it involves building a new internal partition ('inside-out' mode). Because of the evolution of specific ways of 'splitting' plant cells and the importance of this process for plant growth, crop and food production, we are trying to understand the details of how this process is regulated in plants. To this end we have used genetic screens to identify genes that are required for cell division during pollen development in the important model plant species Arabidopsis thaliana (thale cress). This led to the isolation of two-in-one mutants that produce pollen grains with two nuclei in a common cytoplasm as a result of failure to build internal dividing walls. We have cloned the TWO-IN-ONE gene that is mutated in the two-in-one mutants and discovered that it is closely related to the FUSED gene that is present in humans and fruit flies. However unlike its animal counterparts that are not involved in cytokinesis, we have shown that TWO-IN-ONE is required for cytokinesis throughout the plant life cycle in vegetative (green) and reproductive parts of the plant and so is essential for plant growth, development and survival. In this work our objective is to understand how the TWO-IN-ONE protein is important in the cell division process using molecular, genetic and cell biology approaches. We will study the effect of making mutant forms of the TWO-IN-ONE protein to see how efficiently they function compared with the normal TWO-IN-ONE protein. We will use fluorescent proteins to monitor in living cells how the structures involved in building the new dividing wall are organised and how mutated TWO-IN-ONE proteins influences this process. We will also study other proteins that can bind with the TWO-IN-ONE protein that may help the TWO-IN-ONE protein to carry out its tasks. The outcome of this investigation will help us to explain at the cellular and molecular levels how TIO carries out its role in the plant cell division process. Moreover this work may also help us to explain how a conserved protein of ancient origin has evolved unique roles in the cell biology and life cycles of plants and animals.