Juan S. Bonifacino, Ph.D.
NIH Distinguished Investigator
Section on Intracellular Protein Trafficking
Bethesda, MD 20892-3758
Protein Sorting in the Endosomal-Lysosomal System
We investigate the molecular mechanisms by which transmembrane proteins (referred to as cargo) are sorted to different compartments of the endomembrane system in eukaryotic cells. The system consists of an array of membrane-enclosed organelles including the endoplasmic reticulum (ER), the Golgi apparatus, the trans-Golgi network (TGN), endosomes, lysosomes, lysosome-related organelles (LROs) (e.g., melanosomes), and various domains of the plasma membrane in polarized cells (e.g., epithelial cells and neurons). Transport of cargo between these compartments is mediated by carrier vesicles or tubules that bud from a donor compartment, translocate through the cytoplasm, and eventually fuse with an acceptor compartment. Work in our laboratory focuses on the molecular machineries that mediate these processes, including (1) sorting signals and adaptor proteins that select cargo proteins for packaging into the transport carriers, (2) microtubule motors that drive movement of the transport carriers and other organelles through the cytoplasm, and (3) tethering factors that promote fusion of the transport carriers to acceptor compartments. We study these machineries in the context of different intracellular transport pathways, including endocytosis, recycling to the plasma membrane, retrograde transport from endosomes to the TGN, biogenesis of lysosomes and LROs, and polarized sorting in epithelial cells and neurons. We apply knowledge gained from this research to the elucidation of disease protein trafficking diseases such as the pigmentation and bleeding disorder Hermansky-Pudlak syndrome (HPS) and the neuro-cutaneous disorder MEDNIK syndrome. In addition, we study how the molecular mechanisms of protein transport are exploited by intracellular pathogens such as HIV-1.
Dr. Juan Bonifacino received his doctoral degree in biochemistry from the University of Buenos Aires, Argentina, in 1981. He then moved to the NIH, where he pursued postdoctoral studies with Dr. Richard D. Klausner. He rose through the ranks to his current position as Associate Scientific Director for the Cell Biology and Neurobiology Branch, NICHD, NIH. In 2008, he was appointed NIH Distinguished Investigator. Since the early 1990s, Dr. Bonifacino's group has conducted research on signals and adaptor proteins that mediate protein sorting to endosomes and lysosomes. His group discovered new sorting signals and adaptor proteins, and applied this knowledge to the elucidation of the causes of various human diseases including the Hermansky-Pudlak syndrome type 2 and autosomal dominant polycystic liver disease. Dr. Bonifacino has served in various editorial capacities for the journals Developmental Cell, Molecular Cell, Molecular Biology of the Cell, Journal of Cell Biology, Journal of Biological Chemistry and Traffic. He is also the co-editor of the books Current Protocols in Cell Biology and Short Protocols in Cell Biology. He served as a member of the Council of the American Society for Cell Biology, and chaired various scientific conferences. He has delivered the Alex Novikoff, Leonardo Satz, and G. Burroughs Mider lectures, and is an Honorary Professor of Biological Chemistry at the University of Buenos Aires and a Sackler Lecturer at Tel Aviv University, Israel. His lab has trained over 70 postdoctoral fellows and students, most of whom have pursued careers in academic research.
Farías GG, Cuitino L, Guo X, Ren X, Jarnik M, Mattera R, Bonifacino JS. Signal-mediated, AP-1/clathrin-dependent sorting of transmembrane receptors to the somatodendritic domain of hippocampal neurons. Neuron. 2012;75(5):810-23.
Schindler C, Chen Y, Pu J, Guo X, Bonifacino JS. EARP is a multisubunit tethering complex involved in endocytic recycling. Nat Cell Biol. 2015;17(5):639-50.
Mattera R, Farías GG, Mardones GA, Bonifacino JS. Co-assembly of viral envelope glycoproteins regulates their polarized sorting in neurons. PLoS Pathog. 2014;10(5):e1004107.
Pu J, Schindler C, Jia R, Jarnik M, Backlund P, Bonifacino JS. BORC, a multisubunit complex that regulates lysosome positioning. Dev Cell. 2015;33(2):176-88.
Jain S, Farías GG, Bonifacino JS. Polarized sorting of the copper transporter ATP7B in neurons mediated by recognition of a dileucine signal by AP-1. Mol Biol Cell. 2015;26(2):218-28.
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This page was last updated on September 22nd, 2017