Regulation of mitochondrial dynamics pathways in mammalian cells

PROJECT SUMMARY Mitochondria function is tightly regulated by a complex, intertwined machinery that dictates mitochondrial gross morphology, transport of organelles, inner membrane and cristae morphology, communication between adjacent mitochondria and contact with other organelles. These processes are collectively known as mitochondrial dynamics. My overall goal is to reach a comprehensive understanding on the mechanisms that govern mitochondrial dynamics and the interplay between mitochondrial transport with other aspects of mitochondrial and cellular biology. While the mechanisms of mitochondrial transport had been largely characterized in neurons, our recent advances showed that transport of energetically active mitochondria to the cortical cytoskeleton supports lamellipodia dynamics, fuels turnover of focal adhesion complexes and increases velocity and distance of random cell migration in epithelial cells. Because specialized cell types have unique spatiotemporal needs for mitochondria functions, a fundamental question is how similar are the mechanisms of mitochondrial movement between neurons and other cell types? Here we will focus on characterizing the function and regulation of alternative isoforms of trafficking proteins that are expressed in non-neuronal cells. Adding complexity to this picture, we have evidence of multifunctionality amongst trafficking proteins in non-neuronal cells. These novel functions include mitochondrial metabolism and mitochondrial signaling. This poses an important question: how are these multifunctional proteins regulated so single or double functions are enabled at a particular time and location? Overall, my research program will lead to discoveries on the regulation of mitochondrial trafficking and mitochondrial signaling pathways in non-neuronal cells. Because mitochondria are key organelles that maintain cellular homeostasis, and mitochondrial dysfunction are associated with neurological and metabolic diseases, cancer and aging, our advances have the potential to inform how to exploit these mechanisms for practical applications in medicine.