Mechanisms of Septin Assembly and Dynamics

智力优点细胞骨架由基于蛋白质的聚合物制成，这些聚合物是适当的细胞结构和功能所需的。 这些聚合物网络作为机器和轨道来分离细胞成分，改变细胞形状，并作为蛋白质和膜支架。隔蛋白是细胞骨架的高度保守组分，对于细胞分裂、膜隔室和分泌等过程很重要。 Septin蛋白广泛表达于真菌和哺乳动物。 隔膜在细胞中聚集在一起，形成更高级的结构，如环、棒和纤维。 我们使用一种遗传上易于处理的模型丝状真菌（称为棉阿舒囊菌）来研究胞苷，因为它的持久性、动态性和基于胞苷的大型组装体特别适合显微镜和生化分析。 本项目的目标是解决目前尚不了解的Septin架构的三个关键方面：1。确定Septin丝在活细胞中是如何伸展和连接在一起的; 2.确定哪些因素控制细胞中隔膜组装在一起的位置;以及3.隔蛋白丝动力学的评价。该研究采用了新的单分子和偏振荧光成像，遗传突变分析和体外生化方法的组合。 该项目的实验解决了一个一般的细胞工程问题：如何在细胞的特定位置建立持久而动态的恒定大小的结构。 该项目将发现细胞在空间中组织自己以执行生长和分裂等生命功能的基本规则。 PI致力于培养本科生和研究生，并在社区中传播科学。作为本科细胞生物学的课程主任，PI将扩展她和她的研究小组使用Ashbya作为模型系统开发的基于探究的实验室单元。 在撰写并获得用于生物学课程的“clickers”补助金后，她开发了一系列问题，将基于讲座的细胞生物学课程转变为一个积极的学习空间，并将继续扩展和分享这个工具包与其他教师在未来的产品。在过去的五年里，PI已经在实验室培训了七名本科生，其中包括两名数学和计算机科学专业的女性和一名计算机科学专业的男性。 2010年夏天，一名本科生被授予REU，与伍兹霍尔海洋生物实验室的PI一起工作。 今年，两名达特茅斯的本科生在PI的实验室完成了荣誉论文，现在他们的作品都以第一作者的身份发表了。 她指导了两名女博士生，一名女博士后和一名女技术员，并有五名女性轮换学生，其中两名是拉丁裔。PI谈到了女性在科学和平衡科学和母性在校园内的许多场所，包括各种女生联谊会教师晚宴，在生物学本科社会面临的问题，和本科妇女在科学计划。 PI是2010年美国细胞生物学学会年会特别会议本科生参与者的主旨发言人。PI指导了两名教师学者博士后研究员，通过与他们共同教学并每周提供教学反馈来促进他们作为教师的发展。PI在她所在社区的晚间研讨会上谈到基础科学研究的重要性，并在中学科学课堂上谈到成为科学家的感觉。 PI实验室的研究生定期向当地高中学生和教师讲授光学显微镜的原理和我们实验室的研究。PI将通过继续开展上述活动，将培训、指导和当地社区参与编织到她的研究计划中。

Intellectual meritThe cytoskeleton is made of protein-based polymers that are required for proper cell structure and function. These polymer networks serve as machines and tracks to segregate cell components, change cell shape, and act as protein and membrane scaffolds. The septins are a highly conserved component of the cytoskeleton important for processes such as cell division, membrane compartments, and secretion. The septin proteins are widely expressed from fungi to mammals. Septins come together in cells to build higher-order structures such as rings, bars, and fibers. We use a genetically tractable model filamentous fungus called Ashbya gossypii to study septins because its persistent, dynamic and large septin-based assemblies are especially amenable to microscopy and biochemical analysis. The objectives of this project address three key aspects of septin architecture that are presently not understood: 1. Determination of how septin filaments polymerize and link together in living cells; 2. Identification of what factors control where septins are assembled together in cells; and 3. Evaluation of the dynamics of septin filaments. The research employs a combination of novel single molecule and polarized fluorescence imaging, genetic mutant analysis and in vitro biochemical approaches. The experiments in this project tackle a general cellular engineering problem: how to erect persistent, yet dynamic, structures of a constant size at specific locations in the cell. This project will discover basic rules cells use to organize themselves in space to carry out functions of life such as growth and division. Broader ImpactsThe PI is committed to training undergraduates and graduate students and communicating science in the community. As the course director for undergraduate Cell Biology, the PI will expand on an inquiry-based lab unit developed by her and her research group using Ashbya as a model system. After writing and receiving a grant for "clickers" to use in Biology classes, she has developed a series of questions to change the lecture based cell biology class into an active learning space and will continue to expand and share this tool kit with other faculty in future offerings. The PI has trained seven undergraduates in the lab in the last five years, including two female math and computer science majors and one male computer science major. One undergraduate was awarded an REU in the summer of 2010 to work with the PI at the Marine Biological Lab in Woods Hole. Two Dartmouth undergraduates completed honors theses in the PI's lab this year and both now have had their work published as first authors. She has mentored two female PhD students, one female post-doc and one female technician and has had five female rotation students, two of whom are Latina. The PI speaks about issues facing women in science and balancing science and motherhood at many venues on campus including various sorority faculty dinners, at the Biology undergraduate society, and the undergraduate Women in Science Program. The PI was the keynote speaker at the American Society for Cell Biology Annual Meeting Special Session for undergraduate participants in 2010. The PI has mentored two teacher-scholar post-doctoral fellows to facilitate their development as teachers by co-teaching with them and providing weekly feedback on their teaching. The PI speaks at evening seminars in her community about the importance of basic science research and has spoken to middle school science classrooms about what it is like to be a scientist. Graduate students in the PI's lab regularly teach local high school students and teachers about the principles of light microscopy and the research in our lab. The PI will weave training, mentoring and local community involvement into her research program through the continuation of these described activities.