203 Biology East
Department of Biology
Johns Hopkins University
3400 N. Charles Street
Baltimore, MD 21218-2685
Office 410 516-5373
Lab 410 516-5374, -0179
Departmental fax 410 516-5213
Ph.D.University of California, San Francisco
PostdoctoralWashington University, School of Medicine
Work in the Schroer lab addresses questions of cell motility: movement within the cell and movement of the cell as a whole. Our focus is on the microtubule cytoskeleton, the motors that power movement, and the cargo structures and molecules with which motors interact.
Much of our work is focused on the cytoplasmic dynein motor, specifically its “partner in crime”, dynactin. A multisubunit protein complex with an intriguing shape, dynactin acts as an adaptor that allows dynein to associate with its many subcellular cargoes. Dynein may provide the brawn for movement, but dynactin acts as the brain that controls dynein. Dynactin allows dynein to be targeted to different cellular structures at different times in development and the cell cycle, and also enhances dynein activity directly.
To better understand dynein and dynactin structure and function, we use many approaches, including biochemical, biophysical, molecular biological and microscopy-based techniques. To explore the in vivo functions of these and other molecules, we work in the model systems of fibroblasts, neurons, polarized epithelia and phagocytic cells, each of which allows us to study different aspects of motility. We study subcellular dynamics in real time using sophisticated live cell-imaging techniques.
3D averaged image of dynactin. (Imai et al., in preparation)
Cells that have been infected with pathogens can provide important new insights into host cell function, and also provide a link to the field of infectious disease. Our work with Salmonella has allowed us to learn more about how intracellular membranes interact with the cytoskeleton and is providing the lab with a fresh view of the molecular mechanisms that control protein trafficking in the endocytic and biosynthetic pathways.
Tubular late endosomes (green) in a Salmonella (red)-infected HeLa cell. (From Drecktrah et al., 2008)
Dreckrah, D, Levine-Wilkinson, S., Dam., T., Winfree, S. Knodler, L.A., Schroer, T.A., Steele-Mortimer, O. (2008) Dynamic behavior of Salmonella-induced membrane tubules in epithelial cells. Traffic, 9, 2117-2129.
Maier, K.C, Godfrey, J.E., Echeverri, C.J., Cheong, F.K., Schroer, T.A. (2008) Dynamitin mutagenesis reveals protein-protein interactions important for dynactin structure. Traffic, 9, 481-491.
Melkonian, K.A., Maier, K.C., Godfrey, J.E., Rodgers, M., Schroer, T.A., (2007) Mechanism of dynamitin-mediated disruption of dynactin, J. Biol. Chem. 282, 19355-19364.
Lai, S.K., Hida, K., Man, S.T., Chen, C., Machamer, C., Schroer, T.A., Hanes, J. (2007) Privileged delivery of polymer nanoparticles to the perinuclear region of live cells via a non-clathrin, non-degradative pathway. Biomaterials, 28, 2876-2884.
Berezuk, M.A., and Schroer, T.A. (2007). Dynactin is a processivity factor for kinesin-2. Traffic. 8:124-129.
Imai H, Narita A, Schroer TA, Maeda Y. (2006). Two-dimensional averaged images of the dynactin complex revealed by single particle analysis. J Mol Biol. Jun 16;359(4):833-9.
Pfister KK, Fisher EM, Gibbons IR, Hays TS, Holzbaur EL, McIntosh JR, Porter ME, Schroer TA, Vaughan KT, Witman GB, King SM, Vallee RB. (2005). Cytoplasmic dynein nomenclature. J Cell Biol. 71(3):411-3.
Schroer TA. (2004) Dynactin. Annu Rev Cell Dev Biol. 20:759-79. Review.
King SJ, Brown CL, Maier KC, Quintyne NJ, Schroer TA. (2003 ). Analysis of the dynein-dynactin interaction in vitro and in vivo. Mol. Biol Cell.14:5089-97.
Eckley, D.M. and Schroer, T.A.(2003) Interactions between the evolutionarily conserved, actin-related protein, Arp11, actin and Arp1. Mol. Biol. Cell, 14, 2645-2654.
Quintyne, N.J. and Schroer, T.A. (2002). Distinct cell cycle-dependent roles for dynactin and dynein at centrosomes. J. Cell Biol., 159, 245-254.
Salina, D., Boldoor, K., Eckley, D.M., Schroer, T.A., Rattner, J.B., Burke, B.(2002) Cytoplasmic dynein as a facilitator of nuclear envelope breakdown. Cell, 108, 97-107.
King, S.J. and Schroer, T.A. (2000). Dynactin increases the processivity of the cytoplasmic dynein motor. Nature Cell Biology, 2, 20-24.
2006 Alumni Association Excellence in Teaching Award from the Krieger School for a course on AIDS (020.347).