CAREER: Functional analysis of ubiquitin-mediated pathways controlling stem cell fate and tissue regeneration

正常的细胞功能依赖于蛋白质活性和寿命的持续调节。泛素连接酶是将小多肽泛素与其他蛋白质化学偶联以调节其功能或标记它们以进行破坏的酶。泛素标记控制广泛的关键细胞过程，如细胞分裂和细胞命运的决定在发展过程中。因此，某些泛素连接酶与许多人类疾病包括癌症有关。大多数动物都有大量的泛素连接酶（人类中约有600种），然而，我们对大多数这些酶的生物学功能或特异性蛋白质靶点知之甚少。本研究以真涡虫为模式生物，探讨泛素连接酶在干细胞组织再生中的作用。这些动物拥有大量的多能干细胞，赋予它们在受伤或截肢后再生所有组织的非凡能力。这项研究将确定基因编码的泛蛋白连接酶在涡虫和分析其功能的组织更新，使用遗传学，分子和显微镜相结合的方法。这些实验将揭示再生的各个方面所需的泛素连接酶基因。抑制动物中泛素连接酶基因功能的能力将与设计用于鉴定用泛素修饰的蛋白质中的改变的技术相结合。这项工作将有助于理解泛素连接酶的生物学作用和确定干细胞调节，组织再生或身体patterning.Dr. Zayas所需的细胞靶点的广泛目标是圣地亚哥州立大学（SDSU），西班牙裔服务机构的研究员和教育家。这个项目将开发一个实验室课程，将本科生与这里概述的研究相结合。将特别注意招收在科学方面代表性不足的学生参加这门课程。这些学生将接受指导，了解如何为多样化的科学职业做准备，以支持扩大STEM领域参与的努力。该提案的教育活动包括在当地K-12学校开展科学推广活动，以帮助激发社区对生物学的热情。

Normal cellular function relies on constant regulation of protein activity and longevity. Ubiquitin ligases are enzymes that chemically couple the small polypeptide ubiquitin to other proteins to regulate their function or mark them for destruction. Ubiquitin tagging controls a wide range of key cellular processes such as cell division and cell fate decisions during development. Consequently, certain ubiquitin ligases have been implicated in many human diseases including cancer. Most animals have a large number of ubiquitin ligases (approximately 600 in humans), however, we know very little about the biological functions or specific protein targets for the majority of these enzymes. This project investigates the role of ubiquitin ligases in stem cell-based tissue regeneration using planarian flatworms as model organisms. These animals possess a large population of pluripotent stem cells that bestow upon them the remarkable ability to regenerate all of their tissues after injury or amputation. This research will identify genes encoding ubiquitin ligases in planarians and analyze their function in tissue renewal using a combination of genetic, molecular, and microscopy approaches. These experiments will reveal ubiquitin ligase genes that are required for various aspects of regeneration. The ability to inhibit ubiquitin ligase gene function in the animal will be combined with technologies designed to identify alterations in proteins modified with ubiquitin. This work will contribute to the broad goal of understanding the biological roles of ubiquitin ligases and identifying cellular targets required for stem cell regulation, tissue regeneration or body patterning.Dr. Zayas is an investigator and educator at San Diego State University (SDSU), a Hispanic Serving Institution. This project will develop a laboratory course that will integrate undergraduate students with the research outlined here. Special attention will be given to recruiting students underrepresented in science to enroll in the course. These students will be mentored on how to prepare for diverse scientific careers to support efforts to broaden participation in STEM fields. The educational activities of this proposal include science outreach at local K-12 schools to help spark enthusiasm for biology in the community.