CAREER: Actin Cytoskeleton Biomechanics and Mechanobiology in Complex Cellular Environments

这个教师早期职业发展（CAREER）补助金将支持跨学科的研究和教育计划，以调查肌动蛋白细胞骨架的基本作用。 肌动蛋白细胞骨架是活细胞的基本结构组成部分，并且存在于复杂的环境中。肌动蛋白力学和结构的变化发生在响应环境压力，如拥挤。 这些变化与细胞生理学和疾病状态有关。PI和研究团队将使用蛋白质生物物理学和纳米级工具来测量肌动蛋白细胞骨架的机械和结构特性如何随着拥挤而变化。所获得的知识将影响包括细胞生理学和衰老在内的多个科学领域的广泛应用。将研究结果整合到独特设计的生物物理学教学法中，将使中央佛罗里达大学（UCF）的本科生和研究生受益。将为K-12学生的STEM教育和面向公众的外联活动开发教育材料。通过这个项目，PI将在UCF以及当地社区学院招募和培训代表性不足的少数民族学生。 PI还将指导年轻的女科学家，以培养她们在STEM领域的兴趣和职业生涯。 这些努力将有助于更多样化的科学工作者。肌动蛋白组装驱动许多重要的细胞过程，这些过程发生在拥挤和有限的细胞质中。尽管大分子拥挤效应的认识增加，但拥挤的细胞内环境沿着改变离子和渗透条件如何调节细胞骨架细丝力学和结构还没有很好地确定。这个CAREER项目的目标是确定不同的细胞内环境调节肌动蛋白细胞骨架的构象，力学和机械感应的分子机制。中心假设是，在细丝力学和构象的变化引起的拥挤或渗透压影响与肌动蛋白结合蛋白的相互作用，这反过来又可以改变细胞力学和生理。为了证明这一假设，这项工作将1）确定肌动蛋白丝和交联束的力学和构象如何在纳米级的拥挤环境中进行调制，2）评估细丝组装动力学和在拥挤环境中与肌动蛋白交联蛋白的相互作用，以及3）确定肌动蛋白细胞骨架如何响应几何约束，机械力和细胞环境因素，以及渗透应力。通过结合分子生物物理学和最先进的纳米级表征，这项工作将改变对细胞生理学和疾病状态的理解，即控制细胞物理化学，机械，和肌动蛋白细胞骨架的结构特性。分子和细胞生物科学部的分子生物物理学集群为该奖项提供了共同创始。该奖项反映了NSF的法定使命，并已被视为通过使用基金会的知识价值和更广泛的影响审查标准进行评估，

This Faculty Early Career Development (CAREER) grant will support an interdisciplinary research and education program to investigate the fundamental roles of the actin cytoskeleton. The actin cytoskeleton is an essential structural component of a living cell and exists in a complex environment. Changes in actin mechanics and structure occur in response to environmental stresses such as crowding. These changes are linked to cell physiology and disease states. The PI and research team will use protein biophysics and nanoscale tools to measure how the mechanical and structural properties of the actin cytoskeleton change with crowding. The knowledge gained will impact a broad range of applications in multiple scientific fields including cell physiology and aging. Integration of the research findings to a uniquely designed biophysics pedagogy will benefit undergraduate and graduate students at the University of Central Florida (UCF). Educational materials will be developed for STEM education of K-12 students and outreach activities for general public. Through this project, the PI will recruit and train underrepresented minority students at UCF as well as from local community colleges. The PI will also mentor young female scientists to foster their interests and careers in STEM. These efforts will contribute to a more diverse scientific workforce.Actin assembly drives many important cellular processes, which take place in a crowded and confined cytoplasm. Despite increased appreciation of macromolecular crowding effects, it is not well established how crowded intracellular environments, along with altering ionic and osmotic conditions, modulate cytoskeletal filament mechanics and structure. The goal of this CAREER project is to identify molecular mechanisms by which varying intracellular environments modulate the conformations, mechanics, and mechanosensing of actin cytoskeleton. The central hypothesis is that changes in filament mechanics and conformations induced by crowding or osmotic stress affect interactions with actin binding proteins, which in turn can alter cellular mechanics and physiology. To prove the hypothesis, the work will 1) determine how mechanics and conformations of actin filaments and crosslinked bundles are modulated in crowded environments at the nanoscale, 2) evaluate filament assembly dynamics and interactions with actin crosslinking proteins in crowded environments, and 3) determine how actin cytoskeleton responds to geometric constraints, mechanical forces, and cellular environmental factors, in addition to osmotic stress. By combining molecular biophysics and state-of-the-art nanoscale characterization, this work will transform the understanding of cell physiology and disease states in terms of the mechanisms that control the physicochemical, mechanical, and structural properties of actin cytoskeleton.The Molecular Biophysics cluster of the Division of Molecular and Cellular Biosciences provided cofounding for this award.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.