News & Events

Robert M. Hughes, Ph.D

Posted on October 9, 2020


Date - October 9, 2020
1:00 pm - 2:00 pm


Assistant Professor of Biological Chemistry
Department of Chemistry
East Carolina University
Talk Title: A “CofActor” Approach to Exploring Neurodegenerative Pathways in Living Cells


The biochemical hallmarks of neurodegenerative diseases (neural fibrils, clumps, and tangles; heightened reactive oxygen species (ROS); cofilin-actin rods) have presented numerous challenges for development of in vivo diagnostic tools. Biomarkers such as amyloid beta (Aβ) fibrils and Tau tangles in Alzheimer’s Disease (AD) are only accessible via invasive cerebrospinal fluid assay for peptide mass fingerprinting or post-mortem diagnosis, while ROS can be fleeting and thus challenging to monitor in vivo. While remaining a challenge for in vivo detection, the unique protein-protein interactions underlying these disease-specific biomarkers also present rich opportunities for the engineering of in vitro pathology-sensitive biosensors and bioactuators. These tools can be useful for the investigation of critical, early stage events in neurodegenerative diseases in both cellular and animal models, while potentially leading to advanced detection reagents with clinical applications. In this seminar, I will describe a light and redox-gated protein switch inspired by the phenomenon of cofilin-actin rod formation, which occurs in stressed neurons in the AD brain and following brain ischemia. By coupling the redox-sensitive interaction of cofilin and actin with the light responsive Cry2-CIB blue light switch, we have accomplished both light- and stress-gated control of this interaction. The resulting switch is referred to as the “CofActor” system. Site-directed mutagenesis of both cofilin and actin partners demonstrate which residues are critical for sustaining or abrogating the light and redox gated response. Furthermore, switch response varies depending on whether oxidative stress is generated via glycolytic inhibition or a combination of glycolytic inhibition and azide-induced oxidative stress. Finally, we demonstrate light and redox gated switch function in cultured hippocampal neurons. As a dual input biosensor, CofActor holds promise for the tracking of early stage events in neurodegeneration and the investigation of actin-binding protein interactions under oxidative and energetic stress.