[ Research Interests ] [ Representative Publications ]

Trina A. Schroer Professor Department of Biology B.S. Stanford University Ph.D. University of California, San Francisco Postdoctoral Washington University, School of Medicine

Department of Biology Johns Hopkins University 3400 North Charles Street Baltimore, MD 21218-2685 U.S.A. Office Telephone: Lab Telephone: Lab Fax: Email: 410.516.5373 410.516.5374,0179 410.516.5375 schroer@jhu.edu Office- Mudd 220

Research Interests Microtubule-Based Motors and Cytoarchitecture My lab is interested in how microtubule-based motors contribute to a subcellular organization and motility. Our work focuses on the motor, cytoplasmic dynein, and its activator, dynactin. Together, these proteins provide the majority of minus end-directed motor activity in interphase cells. Dynein and dynactin drive the centripetal movement of the endomembrane systems that support membrane protein biosynthesis and recycling, and also contribute significantly to the organization of the microtubule cytoskeleton during interphase and mitosis. Both dynein and dynactin are large, multisubunit complexes. Dynein provides the "brawn" for movement, while dynactin acts as the "brains" that controls motility, serving as both a linker between dynein and its cargoes, and as a processivity factor that allows dynein to move over longer distances. Because dynein's cargoes include structures as diverse as membranes, microtubules, chromosomes and possibly cell signaling molecules, we are interested in understanding the mechanisms by which dynactin interacts with each. To better understand dynein and dynactin structure and function, our lab has taken broad approach, using biochemical,biophysical, molecular biological and microscopy-based techniques. To study dynactin function in vivo, we work in the model systems of fibroblasts, neurons, polarized epithelia and phagocytic cells, each of which highlights a different type of dynein-based motility. Using sophisticated microscopy techniques, we study subcellular dynamics in vivo and in vitro. Biochemical and molecular biological methods have provided us with large quantities of native dynactin and recombinant subunits for enzymological, structural and biophysical studies. These efforts have provided a clear picture of dynactin subunit organization. The dynein and cargo binding subdomains of dynactin have been identified and we are in the process of defining cargo receptors and the molecular details of the dynein-dynactin and dynactin-microtubule interaction. Representative Publications Berezuk, M.A., and Schroer, T.A. 2007. Dynactin is a processivity factor for kinesin-2. Traffic. 8:124-129. Schramm B, de Haan CA, Young J, Doglio L, Schleich S, Reese C, Popov AV, Steffen W, Schroer T, Locker JK. (2006). Vaccinia-Virus-Induced Cellular Contractility Facilitates the Subcellular Localization of the Viral Replication Sites. Traffic. 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. Brown CL, Maier KC, Stauber T, Ginkel LM, Wordeman L, Vernos I, Schroer TA. (2005). Kinesin-2 is a motor for late endosomes and lysosomes. Traffic. (12):1114-24. 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. Berezuk, M., and Schroer, T.A. (2004). Isolation and characterization of native kinesin II from brain. Traffic, 5, 503-513. 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(12):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. Goodson HV, Skube SB, Stalder R, Valetti C, Kreis TE, Morrison EE, Schroer TA.(2003) CLIP-170 interacts with dynactin complex and the APC-binding protein EB1 by different mechanisms. Cell Motil Cytoskeleton. 55(3):156-73. 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. Habermann, A., Schroer, T.A., Griffiths, G. and Burkhardt, J. K. (2001)  Immunolocalization of cytoplasmic dynein and dynactin subunits in cultured macrophages:  Enrichment on early endocytic organelles, J. Cell Sci., 114, 229-240. Schroer, T.A,. (2001)  Microtubules don and doff their caps:  dynamic attachments at microtubule ends.  Curr. Op. Cell Biol., 13, 92-93. King, S.J. and Schroer, T.A. (2000). Dynactin increases the processivity of the cytoplasmic dynein motor. Nature Cell Biology, 2, 20-24.

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