CAREER: Illuminating O-GlcNAc-Driven Functions of the Human Proteome

Wayne State University, Detroit MI

Investigators

Abstract

With the support of the Chemistry of Life Processes Program in the Division of Chemistry, Charlie Fehl from Wayne State University is developing tools that can be delivered specifically and rapidly and can elicit information on the effect of sugar modifications on any protein of interest. Currently, it is known that one third of the proteins in human cells are temporarily coated in sugars after eating carbohydrates, but the functions of those sugars are known for only about 3% of all human proteins. The elucidation of the functions of these proteins could be possible if one has the ability to determine the effects of high sugar on cellular proteins. This new knowledge is highly significant for the understanding of human metabolism and how our metabolism is regulated. The chemical tools being developed in this research could enable advancements in the study of sugar biology. Dr. Fehl’s work will focus on training students at multiple levels, from graduate and undergraduate students who will carry out the research as well as high school students whose participation in the project will enable them to become aware and informed about STEM career pathways. A key educational development is a “Lecture Exposure/Analysis of Data” (LEAD) modules that train undergraduates in hypothesis formation and hypothesis testing skills in the classroom using the data generated in the proposed experiments. This research project aims to build protein-specific assays that respond to high and low sugar levels using the “CRISPR” gene tagging system. Specifically, the Wayne State team will manipulate the sugar O-GlcNAc (O-linked N-acetylglucosamine), the major glucose- and nutrient-sensing molecule in all human cells. The three proposed assays are expected to reveal the stability, subcellular location, and overall cellular functions, respectively, of high vs. low O-GlcNAc on specific proteins tagged in these assays. Stability assays will focus on a set of O-GlcNAcylated kinases, which are major drivers of cell signaling that potentially responds to nutrient levels. Location assays will focus on a set known O-GlcNAcylated transcription factors, which are involved in regulating cellular functions. The “GlycoTag” system is expected to elevate O-GlcNAc levels on specific proteins in cells, making possible the measurement of the effects of these sugar modifications on cell metabolism, signaling, and survival. The results of these three new assays will be compiled into a functional database shared with the public and the scientific community. The data generated in this project are expected to rapidly advance knowledge of sugar-driven protein functions and provide new insights into how metabolic activities and homeostasis are regulated in human tissues. 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.