Christopher Lewis Berger, Ph.D.
I received my Ph.D. in Biochemistry at the University of Minnesota in 1991, and did my post-doctoral research at the University of Pennsylvania. I have been on the faculty at the University of Vermont since 1994, with a primary appointment in Molecular Physiology & Biophysics and a secondary appointment in Biochemistry. I have been actively involved in the CMB Program, serving as the Program’s Director from 2003-2006, and am currently the Director of Graduate Education for the College of Medicine.
Axonal transport is a critical process in neurons required for the efficient delivery of organelles, proteins, nucleic acids, and small molecules synthesized in the cell body to their site of function in distal regions of the axon. Defects in any one of the protein components in the axonal transport machinery, which includes molecular motor such as kinesin and dynein, the microtubule tracks they move on, a variety of adapter molecules that link motor proteins to their intracellular cargo, and regulatory MAPs (microtubule associated proteins) such as tau, result in serious and often lethal neurodegenerative diseases, including Alzheimer’s, Parkinson’s, Huntington’s, and ALS. Our lab in interested in understanding the interplay between post-translational modifications on both kinesin and tubulin (the protein subunits of microtubules), and different isoforms of tau, in regulating axonal transport under both normal and pathological conditions. We use a combination of molecular biology, fluorescence spectroscopy, and super-resolution single molecule imaging techniques, in both in vitro and in vivo systems, to achieve our goals. Recent results suggest that structural differences in the underlying microtubule lattice dictate tau’s ability to inhibit kinesin-mediated axonal transport in an isoform-specific manner (McVicker et al. (2011) J. Biol. Chem. 286:42873). Current projects are focused on 1.) elucidating the mechanism by which isoforms of tau differentially effect kinesin motility on varied microtubule lattice structures 2.) correlating the in vivo distribution of tau isoforms with different functional effects on both kinesin and microtubules, 3.) understanding the functional consequences of specific point mutations and post-translational modifications in tau associated with known neuronal pathologies, and 4.) examining the role of tau or phosphorylation of the kinesin motor domain in regulating bidirectional transport of intracellular cargo driven by different kinesin family members and cytoplasmic dynein.
Stern JL, Lessard DV, Ali R, Berger CL (2017) Single-molecule imaging of Tau dynamics on the microtubule surface. Methods Cell Biol 141: 135-154.
Hoeprich GJ, Mickolajczyk KJ, Nelson SR, Hancock WO, Berger CL (2017) The axonal transport motor kinesin-2 navigates microtubule obstacles via protofilament switching. Traffic 18(5): 304-314.
Stern JL, Lessard DV, Hoeprich GJ, Morfini GA, Berger CL (2017) Phosphoregulation of Tau modulates inhibition of kinesin-1 motility. Mol Biol Cell 28(8): 1079-1087.
Hoeprich GJ, Thompson AR, McVicker DP, Hancock WO, Berger CL (2014) Kinesin’s neck-linker determines its ability to navigate obstacles on the microtubule surface. Biophys J 106(8): 1691-700.
McVicker DP, Hoeprich GJ, Thompson AR, Berger CL (2014) Tau interconverts between diffusive and stable populations on the microtubule surface in an isoform and lattice specific manner. Cytoskeleton (Hoboken) 71(3): 184-94.
Liu J, Berger CL, Morrical SW (2013) Kinetics of presynaptic filament assembly in the presence of single-stranded DNA binding protein and recombination mediator protein. Biochemistry 52(45): 7878-89.
Thompson AR, Hoeprich GJ, Berger CL (2013) Single-molecule motility: statistical analysis and the effects of track length on quantification of processive motion. Biophys J 104(12): 2651-61.
Biophysical Journal Editorial Board
NIH MSFC Study Section Member
Biophysical Society Council