Mechanistic studies of plasmodesmal permeability

该项目是生物学家和物理学家之间的多学科合作，旨在研究植物细胞用于调节细胞间通讯的分子机制。细胞必须相互沟通，以形成组织，并最终建立一个身体计划。与动物不同，植物细胞被细胞壁所包围，将细胞永久地锁定在它们的姐妹细胞上。因此，与动物相比，植物中的组织形成和细胞间的通讯是完全不同的。为了适应细胞壁的永久性，植物进化出了复杂的通道，调节细胞之间的分子运动。虽然这些通道在19世纪被发现，但要了解这些通道是如何运作的，以及是什么决定了它们是开放还是封闭，一直是非常具有挑战性的。这项研究将利用一种名为肌球蛋白VIII的蛋白质在发育的特定阶段在这些通道附近发现的发现。缺乏这种蛋白质的植物表现出图案缺陷，这可能是由于细胞间通讯受损造成的。通过研究这种分子如何与通道相互作用的性质，这项研究将为细胞间通讯的调节提供急需的见解，并对植物细胞和发育生物学领域产生广泛的影响。包括来自主要本科院校和研究型大学的本科生将进一步扩大研究的影响。本科生将共同努力，将定量细胞建模和分子细胞生物学，以回答细胞间通讯的基本问题。此外，还将制定一项针对中学年龄女孩的计划，以鼓励妇女参与STEM学科。胞间连丝是连接植物细胞以介导细胞间通讯的通道，目前在分子水平上对胞间连丝知之甚少。这些通道的研究一直具有挑战性，因为它们对植物的生存和发展至关重要。本计画将以苔藓小立碗藓（Physcomitrella patens）的细胞与发育生物学植物模型来探讨这个重要的发育问题。P. patens是唯一适合这些研究，因为它有一个简单的身体计划，是非常适合细胞生物学和遗传操纵。这项研究将建立在一个苔藓线的发展，其中包含一个单一的肌球蛋白VIII蛋白，肌动蛋白为基础的分子马达，定位于胞间连丝在只有一个横壁在特定的发展阶段，提供了一个长期需要的遗传和细胞系统来研究肌动蛋白和肌球蛋白如何调节胞间连丝的电导。使用定量显微镜和计算建模的组合，该项目将确定肌球蛋白VIII是否对细胞之间的分子运动产生影响。利用肌球蛋白VIII作为分子手柄，拟议的研究将确定调节胞间连丝功能的新途径，最终影响模式和发育。由于肌球蛋白VIII和肌动蛋白在苔藓和种子植物之间高度保守，这些研究有望确定控制细胞间通讯和组织模式的进化古老机制。

This project is a multi-disciplinary collaboration between a biologist and physicist to investigate the molecular mechanisms that plant cells use to regulate cell-to-cell communication. Cells must communicate with each other in order to form tissues and ultimately establish a body plan. In contrast to animals, plant cells are surrounded by walls permanently locking cells to their sister cells. Thus, tissue formation and cell-to-cell communication is quite different in plants compared to animals. To negotiate the permanence of the wall, plants have evolved intricate channels that mediate movement of molecules between cells. While these channels were identified in the 1800s, it has been very challenging to understand how these channels function, and what determines whether they are open or closed. The research here will capitalize on findings that a protein named myosin VIII is found near these channels during very specific stages of development. Plants lacking this protein exhibit patterning defects that likely result from impaired cell-to-cell communication. By investigating the nature of how this molecule interacts with the channels, this research will provide much needed insights into regulation of cell-to-cell communication, and have broad implications for the fields of plant cell and developmental biology. Including undergraduates from both a primarily undergraduate institution as well as a research university will further broaden the impact of the research. The undergraduates will work together to incorporate quantitative cellular modeling and molecular cell biology to answer fundamental questions in cell-to-cell communication. Additionally, a program for middle-school aged girls will be developed to encourage the participation of women in STEM disciplines.Plasmodesmata, the channels that connect plant cells to mediate cell-to-cell communication, are poorly understood at the molecular level. These channels have been challenging to study because they are absolutely essential for plant viability and development. This project will investigate this critical developmental problem in the cell and developmental biological plant model, the moss Physcomitrella patens. P. patens is uniquely suited for these studies as it has a simple body plan that is highly amenable to cell biological and genetic manipulation. This research will build upon the development of a moss line that contains a single myosin VIII protein, an actin-based molecular motor, which localizes to plasmodesmata at only one cross wall at a particular stage of development, providing a long-needed genetic and cellular system to study how actin and myosin may regulate the conductance of plasmodesmata. Using a combination of quantitative microscopy and computational modeling, this project will determine whether myosin VIII has an impact on the movement of molecules between cells. Taking advantage of myosin VIII as a molecular handle, the proposed research will identify new pathways regulating plasmodesmata function, ultimately impacting patterning and development. Since myosin VIII and actin are highly conserved between moss and seed plants, these studies are expected to identify evolutionarily ancient mechanisms controlling cell-to-cell communication and tissue patterning.