Department of Biology
Department of Biology
University of Pennsylvania
221 Leidy Laboratory
Philadelphia, PA 19104
Phone: (215) 898-5736
Fax: (215) 898-8780
Position: Associate Professor
Mechanisms of cell motility and roles of the cytoskeleton in this process. Cytoskeleton may be considered as molecular hardware for motility, which is controlled by molecular "software", the signaling networks. The major question of my research is how the hardware works. The design of an unknown machine can be understood based on how its elements are structurally arranged, how they move during action, and what happens if some element is missing. My experimental approach is based on the same idea applied to cells and molecules. I use platinum replica electron microscopy (EM) to analyze the structural organization of the cytoskeleton at the nanometer scale level. Since EM is not applicable to living cells, to see the machinery in action I use correlative analysis, in which the dynamic observation of a cell is followed by EM of the same cell. This approach allows establishing functional connections between cytoskeletal dynamics and supramolecular organization. Functional perturbations of specific molecules give further insight into details of the molecular design of cellular motile machinery. A more specific focus of my current research is on the mechanisms of leading edge protrusion, which is driven by polymerization of actin. Lamellipodia and filopodia are the two major protrusive organelles with strikingly different design and different sets of molecular players. Although we were able to formulate the basic models for each of these organelles, many questions remain about their molecular design and specific roles of individual molecules. I address these questions in my research.
- A. Biyasheva, T. Svitkina, P. Kunda, B. Baum, and G. Borisy. Cascade pathway of filopodia formation downstream of SCAR. J. Cell Sci. 117:837-848. 2004.
- T. M. Svitkina, E. A. Bulanova, O. Y. Chaga, D. M. Vignjevic, S. Kojima, J. M. Vasiliev, and G. G. Borisy. Mechanism of filopodia initiation by reorganization of a dendritic network. J. Cell Biol., 160: 409-421. 2003.
- D. Vignjevic, D. Yarar, M.D. Welch, J. Peloquin, T. Svitkina, and G.G. Borisy. Formation of filopodial-like bundles in vitro from dendritic network. J. Cell Biol., 160: 951-962. 2003.
- J.E. Bear, T. M. Svitkina (equal contribution with J.E.Bear), M. Krause, D.A. Schafer, J.J. Loureiro, G.A. Strasser, I.V. Maly, O.Y. Chaga, J.A. Cooper, G.G. Borisy, and F.B. Gertler. Antagonism between Ena/VASP proteins and actin filament capping regulates fibroblast migration. Cell. 109:509-521. 2002.
- L.A. Cameron, T.M. Svitkina, D. Vignjevic, J.A. Theriot, and G.G. Borisy. Dendritic organization of actin comet tails. Curr. Biol. 11:130-135. 2001.
- J.H. Henson, T.M. Svitkina, A.R. Burns,H.E. Hughes, K.J. MacPartland, R. Nazarian, and G.G. Borisy. Two components of actin-based retrograde flow in sea urchin coelomocytes. Mol. Biol. Cell. 10:4075-4090. 1999.
- T.M. Svitkina and G.G. Borisy. Arp2/3 complex and actin depolymerizing factor/cofilin in dendritic organization and treadmilling of actin filament array in lamellipodia. J. Cell Biol. 145:1009-1026. 1999.
- T.M. Svitkina, A.B. Verkhovsky, K.M. McQuade, and G.G. Borisy. Analysis of the actin-myosin II system in fish epidermal keratocytes: mechanism of cell body translocation. J. Cell Biol. 139: 397-415. 1997.
- A.B. Verkhovsky, T.M. Svitkina, and G.G. Borisy. Polarity sorting of actin filaments in cytochalasin-treated fibroblasts. J. Cell Sci., 110:1693-1704. 1997.
- T.M. Svitkina, A.B. Verkovsky, and G.G. Borisy. Plectin sidearms mediate interaction of intermediate filaments with microtubules and other components of the cytoskeleton. J. Cell. Biol. 135:991-1007. 1996.
- A.B. Verkhovsky, T.M. Svitkina, and G.G. Borisy. Myosin II filament assemblies in the active lamella of fibroblasts: their morphogenesis and role in the formation of actin filament bundles. J. Cell Biol. 131:989-1002. 1995.
- T.M. Svitkina, A.B. Verkhovsky, and G.G. Borisy. Improved procedures for electron microscopic visualization of the cytoskeleton of cultured cells. J. Struct. Biol. 115:290-303. 1995.