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(公共法律111-5)资助的。该奖项的研究目标是测量和模拟最近发现的胶原蛋白基因在形成海洋蓝藻的超群体中的力和纳米级结构-功能关系。在这个为期三年的项目过程中，研究人员和他们的学生将测试这样一个假设，即在这种光合作用、固氮的神经毒素产生生物中，胶原基因的表达在维持菌落完整性方面发挥了独特的机械作用。这一假说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的透射电子显微镜实验来验证。如果我们能够确定胶原蛋白在这个有机体中所起的假想的机械作用，我们不仅将获得对细胞群体的纳米级机制的有价值的见解，而且还将获得对蓝藻生态的有价值的见解。这种胶原蛋白的存在可能代表了发生在泥盆纪或志留纪时期的跨域基因转移事件，从脊椎动物等多细胞有机体(Layton等人，2008年J分子进化66 539-554)转移到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。在这种生物中发现的特定的胶原基因也有潜在的应用于组织工程，例如替代Matrigel，程序化的胶原表达，或加速伤口愈合。为期两周的NSF-RET式教师计划将于暑期在德雷克塞尔大学举行，通过与当地K12社区的联系，来自当地最有需求的高中的教师将更多地接触到细胞和蛋白质力学、进化和纳米技术方面的重要最新科学发现。

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.