615 Charles E young Dr. East
Los Angeles, CA 90095
Adjunct Assistant Professor, Neurobiology
Lars Dreier, Ph.D., joined the Department of Neurobiology as an Assistant Professor in 2006. He received his undergraduate degree in Biochemistry from the Free University at Berlin, Germany, and did his Ph.D. research in the Department of Cell Biology, Harvard Medical School, in the laboratory of Dr. Tom Rapoport, reconstituting the transport of secretory proteins through the Endoplasmic Reticulum (ER) membrane with purified membrane proteins and characterizing the formation of the ER membrane tubules in vitro. He did his postdoctoral training with Dr. Josh Kaplan at the University of California, Berkeley, where he described the ubiquitin-dependent degradation of glutamate receptors in neurons in C. elegans. The Dreier lab integrates cell biological and biochemical approaches to investigate the mechanisms of ubiquitin dependent degradation of cellular components. Defective degradation underlies various neurodegenerative diseases. One focus is on the degradation of damaged mitochondria by an autophagy mechanism that involves the ubiquitin ligase Parkin and protein kinase PINK1, two proteins defective in familial forms of Parkinson’s disease. Dr. Dreier has a joint appointment in the Department of Biological Chemistry.
How does the cell degrade cellular components?
Degradation of damaged, misfolded or aggregated proteins, and degradation of other cellular components like mitochondria, peroxisomes, ribosomes, lipid droplets, and intracellular bacteria is a crucial part of cellular metabolism and protects cells from accumulating defective components. Degradation starts by conjugating the small protein ubiquitin to these cellular components. Conjugated ubiquitin chains serve as signals for targeting to common downstream degradation machinery. How ubiquitination is regulated, how ubiquitination targets are recognized, and how ubiquitin chains promote degradation is not well understood.
Research in the Dreier lab is aimed at understanding the molecular mechanisms of these processes. One focus is on the degradation of damaged mitochondria, a process relevant to Parkinson’s and other neurodegenerative diseases. The Dreier lab has discovered a role for a family of proteins in the outer mitochondrial membrane called VDACs in targeting the ubiquitin ligase Parkin to damaged mitochondria. On mitochondria, Parkin promotes the formation several different types of ubiquitin chains (linked through different lysines of ubiquitin). Current research is aimed at identifying the proteins catalyzing the formation of these different ubiquitin chains, identifying proteins interacting with specific types of ubiquitin chains on damaged mitochondria and defining their role in mitochondrial degradation. Insights gained from these studies will be used to investigate the mechanisms for degradation of other cellular components.