RUI: Activity-based Mapping of Cellular Cathepsins B and L - An introduction to Chemical Biology in Undergraduate Curriculum

有了这个RUI奖，化学系的生命过程化学项目资助Sanjai Kumar教授研究在人类细胞中发现的两种重要酶的功能。细胞是一个复杂但高度组织的系统，其中数千个事件在任何给定时刻都以极高的精度协调。这些过程是由细胞的主要活动中心蛋白质精心编排的。据估计，人类细胞中的蛋白质总数在25万到100万之间。为不同的蛋白质分配单独的功能是一项具有挑战性的工作，特别是因为蛋白质可能是活跃的或不活跃的，这取决于细胞的状态。蛋白质的这种状态通常由一组称为蛋白水解酶的酶控制。人类基因组具有产生约550种蛋白酶的能力。这些蛋白酶在复杂的细胞环境中如何、为什么以及在哪里发挥作用仍然知之甚少。该项目涉及检测半胱氨酸组织蛋白家族中两种密切相关的酶：组织蛋白B和组织蛋白L。选择性探针是针对这些组织蛋白的，以便了解它们的功能。这一研究努力为研究生和本科生提供了实践研究经验的教育机会。实验室环境是为增强本科生和研究生的跨学科体验而设计的。此外，还有为纽约昆士伯勒社区学院和巴德高中早期学院的学生提供研究培训的外展活动。特别强调包括科学学科中代表性不足的群体的学生、妇女和退伍军人。人的半胱氨酸组织蛋白由11种酶组成，这些酶对维持细胞的动态平衡、生长、分化和存活非常重要。组织蛋白酶生物学的主要挑战之一是在给定的细胞环境中为单个酶分配特定的功能。这主要是因为已经证明在单个细胞类型中存在几个功能冗余和重叠的底物特异性。由于新合成的细胞组织蛋白受到翻译后修饰的影响，从而导致其活性(从而功能)的改变，因此需要特定的研究工具来基于活动的询问活细胞中的细胞功能。该项目正在开发两种紧密相关的半胱氨酸组织蛋白L和B的选择性无标记活性探针(TABP)。所开发的TABP用于区分和定量定位活的胰腺细胞和神经细胞中组织蛋白酶B和L的活性。从这些研究中获得的知识极大地促进了对涉及人类组织蛋白酶B和L的细胞过程的功能理解。

With this RUI award, the Chemistry of Life Processes Program in the Division of Chemistry is funding Professor Sanjai Kumar to investigate the function of two important enzymes found in human cells. A cell is a complex yet highly organized system where thousands of events are coordinated with great precision at any given moment. These processes are elegantly orchestrated by proteins, the main centers of activity of the cell. It is estimated that the total number of proteins in a human cell is between 250,000 to one million. Assigning individual functions to the various proteins is a challenging endeavor, especially since a protein may be active or inactive depending on the status of the cell. This status of a protein is often controlled by a group of enzymes known as proteases. The human genome has the capacity to produce about 550 proteases. How, why, and where these proteases function in the complex cellular environment remains poorly understood. This project involves examining two closely-related proteases of the cysteine cathepsin family of enzymes; cathepsin B and L. Selective probes are made to target these cathepsins so that their function can be understood. This research endeavor provides educational opportunities with hands-on research experience to graduate and undergraduate students. The laboratory environment is structured for an enhanced interdisciplinary experience for both undergraduate and graduate students. Additionally, there are outreach activities incorporating research training for students from Queensborough Community College and Bard High School Early College in New York. Special emphasis is given to include students from underrepresented groups in science disciplines, women, and veterans. Human cysteine cathepsins comprise a small group of eleven enzymes that are important in maintaining cell homeostasis, growth, differentiation, and survival. One of the main challenges of cathepsin biology is in assigning specific function to individual enzymes in a given cellular context. This is mainly because several functional redundancies and overlapping substrate specificities have been shown to exist in individual cell types. Since newly synthesized cellular cathepsins are subject to post-translational modifications, thereby leading to alteration of their activities (and hence function), specific investigative tools are needed for activity-based interrogation of cellular function in live cells. This project is developing selective tagless activity-based probes (TABPs) of two closely related cysteine cathepsins; cathepsin L and B. The developed TABPs are used in differential and quantitative mapping of cathepsin B and L activities in live pancreatic and neuronal cells. The knowledge gained from these studies significantly advances the functional understanding of cellular processes involving human cathepsin B and L.