Research Interests

Research in this laboratory is focused on molecular mechanisms of intracellular transport and organization of microtubule cytoskeleton. The model system that is being used is melanophores, pigment cells of lower vertebrates. The only function of these large cells is synchronous transport of thousands of membrane-bounded organelles, pigment granules, which rapidly move to the cell center to form a tight aggregate or redisperse uniformly throughout the cytoplasm. During aggregation, pigment granules move along microtubules by means of cytoplasmic dynein. Pigment dispersion involves initial rapid microtubule-dependent transport to the periphery by Kinesin II and subsequent slow diffusion-like movement along the randomly arranged actin filaments. Transport is regulated by Protein Kinase A (PKA) signaling cascade. Thus, melanophores provide a unique model system for the studies of the role of cytoskeleton in intracellular transport, mechanisms of switching between the two major transport systems, and regulation of activity of motor molecules by signal transduction mechanisms.

Two recent findings define the directions of current research. First, we have shown that in microsurgically produced cytoplasmic fragments of melanophores lacking the centrosome the radial array of microtubules rapidly forms and becomes positioned to the center. Thus, membrane organelles that are normally dragged by motors to the centrosome region may themselves play an active role in organization and maintenance of radial microtubules. Digital fluorescence microscopy, photobleaching , photoactivation and microinjection of motor-specific probes are being used to test the mechanisms of self-organization and self-centering of the radial microtubule array in the fragments. Second, we have demonstrated that during dispersion the pigment granules that initially move along microtubules switch tracks and continue motion along randomly arranged actin filaments. Thus, each pigment granule bears a member of each of the families of motor molecules: cytoplasmic dynein and a kinesin-like motors (specific for microtubules) and a myosin motor (specific for actin filaments). A combination of biochemical and molecular approaches are being used to test the hypothesis that the motor molecules interact and that regulation is achieved through phosphorylation of common subunits

Honors and Awards

1993 Academic degree Doctor of Sciences in Cell Biology, Supreme Attestation Committee of the Russia, (formal requirement for full professorship in Russia).

1994 Howard Huges Medical Institute Research Award for Eastern Europe.

Selected Publications

Rodionov, V.I., E.S.Nadezhdina, E.V.Leonova, E.A.Vaisberg, S.A.Kuznetsov, and V.I.Gelfand. 1985. Identification of a 100 kD protein associated with microtubules, intermediate filaments and coated vesicles in cultured cells. Exp. Cell Res. 159, 377-387.

Kuznetsov, S.A., V.I.Rodionov, E.S.Nadezhdina, D.B.Murphy and V.I.Gelfand. 1986. Identification of a 34-kD polypeptide as a light chain of microtubule-associated protein-1 (MAP-1) and its association with a MAP-1 peptide that binds to microtubules. J Cell Biol. 102, 1060-1066.

Rodionov, V.I., A.G.Vardanyan, V.F.Kamalov, and V.I.Gelfand. 1987. The movement of melanosomes in melanophore fragments obtained by laser microbeam irradiation. Cell Biol. Int. Rep. 11, 565-572.

Gyoeva, F.K., E.V.Leonova, V.I.Rodionov, and V.I.Gelfand. 1987. Vimentin intermediate filaments in fish melanophores. J. Cell Sci. 88, 649-655.

Rodionov, V.I., F.K.Gyoeva, A.S.Kashina, S.A.Kuznetsov, and V.I.Gelfand. 1990. Microtubule-associated proteins and microtubule-based translocators have different binding sites on tubulin molecule. J. Biol. Chem. 265, 5702-5707.

Rodionov, V.I., F.K.Gyoeva, and V.I.Gelfand. Kinesin is responsible for centrifugal movement of pigment granules in fish melanophores. 1991. Proc. Natl. Acad. Sci. USA 88, 4956-4960.

Rodionov, V.I., V.I.Gelfand, and G.G.Borisy. 1993. Kinesin-like molecules involved in spindle formation. J.Cell Sci. 106, 1179-1188.

Rodionov, V.I., F.K.Gyoeva, E.Tanaka, A.D. Bershadsky, J.M.Vasiliev, and V.I.Gelfand.1993. Microtubule-dependent control of cell shape and pseudopodial activity is inhibited by the antibody to kinesin motor domain. J. Cell Biol. 123, 1811-1820.

Rodionov, V.I.,S.-S.Lim, V.I.Gelfand, and G.G.Borisy. 1994. Microtubule dynamics in fish melanophores. J.Cell Biol. 126:1455-1464.

Rodionov, V.I., and G.G.Borisy. 1997. Microtubule treadmilling in vivo. Science 275, 215-218.

Rodionov, V.I., and G.G.Borisy. 1997. Self-centering activity of cytoplasm. Nature 386, 170-173.

Keating, T.J., J.P.Peloquin, V.I.Rodionov, D. Momcilovic, and G.G.Borisy. 1997. Microtubule release from the centrosome. Proc. Natl. Acad.Sci. USA 94:5078-5083.

Chang, S., V.I.Rodionov, G.G.Borisy, and S.V.Popov. 1998. Transport and turnover of microtubules in frog neurons depend on the pattern of axonal growth. J. Neurosci. 18: 821- 829.

Rodionov, V.I., A.J.Hope, T.S.Svitkina, and G.G.Borisy. 1998. Functional coordination of microtubule and actin based motility in melanophores. Curr. Biol. 8:165-168.

Rodionov, V.I., and Borisy, G.G. 1998. Self-centering in cytoplasmic fragments of melanophores. Mol. Biol. Cell 9:1613-1615.

Rodionov, V.I., E.S.Nadezhdina, and G.G.Borisy. 1999. Centrosomal control of microtubule dynamics. Proc.Natl. Acad. USA. 96:115-120.

Vorobjev, I.V., V.I.Rodionov, I.V.Maly, and G.G.Borisy . 1999. Contribution of plus and minus end pathways to microtubule turnover. J. Cell Sci. 112:2277-2289.

Borisy, G.G., and V.I.Rodionov. 1999. Lessons from the melanophore. FASEB Journal 13:S221-S224.

Rodionov, V.I., E.S.Nadezhdina, J.Peloquin, and G.G.Borisy. 2001. Digital fluorescence microscopy of cell cytoplasts with and without the centrosome. Meth. Cell Biol. 67:43-51.

Vorobjev, I.A, V.P.Malikov, and V.I.Rodionov. 2001. Self-organization of a radial microtubule array by dynein-dependent nucleation of microtubules. Proc. Natl. Acad. Sci. USA. 98:10160-10165.

Burakov, A.V., E.S.Nadezhdina, B.Slepchenko, and V.I.Rodionov. 2003. Centrosome positioning in interphase cells. J. Cell Biol.162:963-969.

V.Rodionov, J.Yi, A.Kashina, A.Oladipo, and S.P.Gross. 2003. Switching between microtubule- and actin-based transport systems in melanophores is controlled by cAMP levels. Curr. Biol. 13:1-20.

Cytrinbaum, E., V.Rodionov, and A.Mogilner. 2004. Computational model of dynein-dependent self-organization of microtubule asters. J. Cell Sci. 117:1381-1397.

Malikov, V.P., A.S.Kashina, and V.I.Rodionov. 2004. Cytoplasmic dynein nucleates microtubules to organize them into the radial array. Mol. Biol. Cell 15:2742-2749.

Kashina, A.S., E.S. Potekhina, I. V. Semenova, and V.I. Rodionov. 2004. Protein kinase A, which regulates intracellular transport, forms complexes with molecular motors on organelles. Curr. Biol. 14:1877-1881.

Snider, J., F.Lin, N.Zahedi, V.Rodionov, C.C.Yu, and S.P.Gross. 2004. Intracellular actin-based transport: how far you go depends on how often you switch. Proc. Natl. Acad. Sci. USA 101:13204-13209.

Bazu, S., V.Rodionov, M.Terasaki, and P.J.Campagnola. 2004. Multiphoton-excited microfabrication in live cells via Rose Bengal cross-linking of cytoplasmic proteins. Optics Lett. 30:159-161.

Zaliapin, I., I.Semenova, A.Kashina, and V.Rodionov. 2005. Multiscale trend analysis of microtubule transport in melanophores. Biophys. J. 88:4008-4016.

Kashina, A., and V.Rodionov. 2005. Intracellular organelle transport: few motors, many signals. Trends Cell Biol. 15:396-398.

Malikov, V., E.Cytrynbaum, A.Kashina, A.Mogilner, and V.Rodionov. 2005. Centering of a radial microtubule array by translocation along microtubules spontaneously nucleated in the cytoplasm. Nature Cell Biol. 7:1113-1118.