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

正常的细胞功能依赖于对蛋白质活性和寿命的持续调节。泛素连接酶是一种酶，它将小的多肽泛素与其他蛋白质化学偶联，以调节它们的功能或标记它们的破坏。泛素标记控制着广泛的关键细胞过程，如细胞分裂和发育过程中的细胞命运决定。因此，某些泛素连接酶与包括癌症在内的许多人类疾病有关。大多数动物都有大量的泛素连接酶(在人类中约有600种)，然而，我们对大多数这些酶的生物学功能或特定的蛋白质靶标知之甚少。本项目以陆生扁虫为模型生物，研究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，这些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。这项研究将确定编码泛素连接酶的基因，并结合遗传学、分子和显微镜方法分析它们在组织更新中的功能。这些实验将揭示再生的各个方面所需的泛素连接酶基因。抑制动物泛素连接酶基因功能的能力将与旨在识别泛素修饰蛋白质变化的技术相结合。这项工作将有助于了解泛素连接酶的生物学作用，并识别干细胞调节、组织再生或身体模式所需的细胞靶点。Zayas是圣地亚哥州立大学(SDSU)的研究员和教育家，SDSU是一家西班牙裔服务机构。这个项目将开发一门实验室课程，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报读这门课程。这些学生将被指导如何为不同的科学职业做准备，以支持在STEM领域扩大参与的努力。这项建议的教育活动包括在当地K-12学校进行科学推广，以帮助激发社区对生物的热情。

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.