Multiscale Structure-Function Relationships of Collagen in the Marine Cyanobacterium Trichodesmium erythraeum

该奖项是根据2009年美国复苏和再投资法案（公法111-5）资助的。该奖项的研究目标是测量和模拟最近在形成超集落的海洋蓝藻Trichodesmium erythraeum中发现的胶原基因的力和纳米级结构-功能关系。在这个为期三年的项目中，研究人员和他们的学生将测试一个假设，即在这种光合作用、固氮神经毒素产生的生物中，胶原蛋白基因的表达在维持菌落完整性方面起着独特的机械作用。该假设将通过静态和动态细胞培养、蛋白质分离和纯化、胶原基因敲除模型、原子力显微镜成像和纤维形成实验的透射电子显微镜来验证。如果我们能够建立胶原蛋白在这种生物体中所起的假设的机械作用，我们不仅将获得对细胞菌落纳米级力学的宝贵见解，而且还将获得对蓝藻生态学的宝贵见解。这种胶原蛋白在T erythraum中的存在可能代表了发生在泥盆纪或志留纪时期的域间基因转移事件，从脊椎动物等多细胞生物（Layton et al., 2008 J Molecular Evolution 66 539-554）转变为现代海洋细菌的祖先，赋予原核生物通过神经毒素浓度和鳃堵塞机制获得额外食物来源的能力。在该生物中发现的特异性胶原蛋白基因在组织工程中也有潜在的应用，如替代基质蛋白、程序化胶原蛋白表达或加速伤口愈合。通过在德雷塞尔大学举办的为期两周的nsf - ret式教师项目，扩展到当地K12社区。该项目将为当地最需要的高中教师提供机会，让他们更好地了解细胞和蛋白质力学、进化和纳米技术等领域的最新重要科学发现。

This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5).The research objective of this award is to measure and model the forces and nanoscale structure-function relationship of a recently discovered collagen gene within the ultra-colony forming marine cyanobacteria, Trichodesmium erythraeum. Over the course of this three-year project the investigators and their students will test the hypothesis that the expression of the collagen gene found in serves a unique mechanical role in maintaining colony integrity in this photosynthetic, nitrogen-fixing neurotoxin-producing organism. The hypothesis will be tested with static and dynamic cell culture, protein isolation and purification, a collagen gene knock-out model, atomic force microscopy imaging, and transmission electron microscopy of fibrillogenesis experiments. If we are able to establish the hypothesized mechanical role that collagen serves in this organism, we will not only gain valuable insights into the nanoscale mechanics of cell colonies, but also into cyanobacteria ecology. The presence of this collagen within T erythraeum may represent an interdomain gene transfer event that occurred during the Devonian or Silurian period from a multicellular organism such as a vertebrate (Layton et al., 2008 J Molecular Evolution 66 539-554), into an ancestor of modern marine bacteria, endowing a prokaryote with the ability to gain access to additional food sources via neurotoxin concentration and gill-clogging mechanisms. The specific collagen gene found in this organism also has potential applications for the tissue engineering, such as an alternative to Matrigel, programmed collagen expression, or accelerated wound healing. Outreach to the local K12 community through a 2-week NSF-RET-style teachers program to be held during the summer quarter at Drexel University will give teachers from local high schools with the greatest need, enhanced access to the important recent scientific discoveries in cell and protein mechanics, evolution and nanotechnology.