1. Plant Cell Biology: Information Trafficking in Plants Professor Epel and his group have pioneered in the molecular and functional characterization of plasmodesmata (Pd), transwall membranous tunnels that regulate the intercellular trafficking of regulatory macromolecules. The Epel lab has developed techniques for isolation of Pd and for the identification of Pd components (2, 5). Furthermore, he and collaborators are intensely involved in the exploration of virus-host interactions (1,3,8,10) A new and very exciting extension of these studies is the finding that Pd conductivity is under developmental control (6). This basic systematic approach of our lab of isolating and characterizing components of Pd is essential to an understanding of Pd functioning and regulation. This approach will facilitate the isolations of other cellular components involved in targeting to Pd and will provide the tools necessary to identify the facultative components that provide Pd with selectivity, tissue specificity etc.. Projects in our lab: The isolation and characterization of Pd proteins using proteomic techniques. The cloning and sequencing of genes to all Pd proteins. A functional and molecular characterization of Arabidopsis Pd mutants. The characterization of developmental changes in the Pd. The molecular characterization of Pd proteins associated with each type of Pd The identification of Pd proteins involved in virus MP and Pd interactions. Selected publications: 1.Heinlein M, Epel BL, Padgett HS and Beachy RN (1995).Tobamovirus movement protein interacts with the cytoskeleton in infected cells. Science 270: 1983-1985. 2.Epel BL, Kuchuck B, Kotlizky G, Shurtz S, Erlanger M and Yahalom, A (1995). Isolation and characterization of plasmodesmata. Methods in Cell Biology. Vol 50. Eds. D.W. Galbraith, D.P. Bourque and H.J. Bohnert. Academic Press Inc. pp 237-253. 3.Epel BL, Padgett HS, Heinlein M and Beachy RN (1996). Plant virus movement protein dynamics probed with a movement protein fused to GFP. Gene 173:75-79. 4.Fenczik CS., Epel BL and Beachy RN (1996). Role of plasmodesmata and viral movement protein in spread of plant viruses. In-: Plant Gene Research: Signal Transduction in Plant Development. Springer-Verlag Wein New York pp 249-279. 5.Yahalom A, Lando R, Katz A and Epel BL (1998). A calcium-dependent protein kinase is associated with maize mesocotyl plasmodesmata. J Plant Physiol. 153:354-362. 6.Oparka KJ, Roberts AG, Boevink P, Santa Cruz S, Roberts I, Pradel KS, Imlau A, Sauer N, Kotlizky G and Epel B (1999). Simple, but not branched, plasmodesmata allow the non-specific trafficking of proteins in developing tobacco leaves. Cell: 97: 743-754. 7.Kotlizky G, Boulton MI, Pitaksutheepong C, Davies JW and Epel BL (2000). Intracellular and intercellular movement of maize streak geminivirus V1 and V2 proteins transiently expressed as green fluorescent protein fusions. Virology 274: 32-38. 8.Kotlizky G, Katz A,, van der Laak J, Boyko V, Lapidot M,. Beachy N, Heinlein M and Epel BL (2001). A dysfunctional movement protein of Tobacco mosaic virus interferes with targeting of wild-type movement protein to microtubules. MPMI 14: 895-904. 9. Aaziz R, Dinant S and Epel BL (2001). Plasmodesmata and plant cytoskeleton. Trends in Plant Sciences 6: 326-330. 10.Gafni Y and Epel BL (2002). The role of host and viral proteins in intra- and inter-cellular trafficking of geminiviruses. Physiol Mol Plant Path 60: 231-241. Professor Baruch Epel and his group