In this award from the Chemistry of Life Processes Program in the Chemistry Division, Dr. Irene Lee, from Case Western Reserve University, will develop a chemical biology approach to evaluating the contribution of ATP-dependent proteolysis in the maintenance of mitochondria homeostasis at a post-translational level. The mitochondrion is an important organelle that provides energy to sustain life. One of the key biochemical reactions is oxidative phosphorylation, which frequently generates reactive oxidizing species (ROS) as by-products. If allowed to accumulate, these ROS threaten the integrity of mitochondria by damaging the chemical integrity of lipids, nucleic acids and proteins in the organelles. In the matrix of mitochondria, protein quality control is presumably maintained by two energy dependent proteases, one of which is known as ClpXP (caseinolytic protease complex XP). Dr. Lee's work will generate selective substrates and inhibitors of human ClpXP to allow for evaluation of protease functions in mitochondrial protein lysates and intact mitochondria in the model cell line HeLa. Once proven to be effective, the strategy proposed in this study will find broad applications in generating tools to elucidate the roles played by non-proteasomal ATP-dependent proteases in the maintenance of cellular homeostasis in the future.
This project employs a multi-disciplinary approach to develop selective activity probes and inhibitors that will be used to address the physiological functions of a protease machine in mitochondria. Students will acquire training in enzyme kinetics, protein chemistry, liquid chromatography, mass spectrometry, chemical synthesis, solid phase peptide synthesis, fluorescence spectroscopy, protein purification and molecular cloning. These research activities provide excellent training opportunities to undergraduate and graduate students in chemical biology. Each graduate student in Dr. Lee's group will also be involved in undergraduate education, as each student will train and work with an undergraduate researcher for at least one semester. This endeavor is designed to provide graduate students teaching and mentoring experiences. Taken together, this project will provide students with the technical and social skills needed to enter a research or science education career. Additionally, all personnel working in the Lee group serve as volunteers to the National Youth Sports Program (NYSP), a summer program offered to children of low-income families in the Greater Cleveland area between the ages of 10 and 16. The Lee group teaches these children chemistry of daily life through experimentation with household chemicals and dry ice. This annual outreach activity has become a tradition in the Lee group, where undergraduate and graduate students learn to become more involved in the community and education for the underprivileged.
