Research Initiation Award: Redox Regulated Phosphorylation of BCAT by PKC

Research Initiation Awards provide support for junior and mid-career faculty at Historically Black Colleges and Universities who are building new research programs or redirecting and rebuilding existing research programs. It is expected that the award helps to further the faculty member's research capability and effectiveness, improve research and teaching at the home institution, and involves undergraduate students in research experiences. The award to North Carolina Agricultural & Technical State University has potential to increase the understanding of the cell membrane. The proposed study intends to train undergraduate and graduate students in the study of an enzyme that affects cell membrane function. The PI will actively engage and recruit underrepresented minority students into the project so that the students may engage in cutting edge research. This activity will enhance the technical and critical thinking skills of students. The goal of this proposal is to study the PKCα-BCATc interaction via biochemical and biophysical methods. Previously the PI showed that the membrane localization of cytosolic human Branched-Chain Aminotransferase (BCATc) regulates the autophagosome synthesis which further regulates Alzheimer’s Disease (AD), and the membrane localization of BCATc is redox regulated by the Protein Kinase C α (PKCα) mediated phosphorylation. In this proposed work, the PI will identify the PKCα-mediated phosphorylation site in BCATc, express and purify the PKCα-phosphorylated BCATc, and solve the crystal structure of the phosphorylated BCATc to analyze the structural changes of BCATc triggered by the phosphorylation by PKCα. The work will analyze the structure of PKCα-BCATc complex via co-crystallization and other biophysical methods, e.g. SPRi to uncover the protein-protein interaction interface and further understand the mechanism of the phosphorylation process. The constructed model built from the project outcomes will enable the PI to understand the mechanism of how the redox-regulated phosphorylation of BCATc by PKCα regulates its conformational changes that further regulate its membrane localization. This is the first time that these interactions will be described at the molecular level, and this would be a significant contribution to the field and help advance the understanding of these two inter-related modes of BCATc regulation. 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.