B.A. Barnard College, New York, NY
Ph.D., University of California, San Diego
analysis of intercellular protein trafficking
My lab is interested in the mechanisms by which cells are able to send signals and share information with each other. Patterning of organs and specification of cell types requires intercellular signaling to communicate positional information and coordinate devlopment. The signaling molecules involved in these developmental events include small molecules, polypeptide ligands, and small RNAs. Surprisingly, in plants, transcription factors can also traffic from cell to cell and serve as signaling molecules . My research has concentrated on determining the mechanism by which the transcription factor, SHORT-ROOT (SHR), moves between specific cells in the Arabidopsis root (Figure 1) . We have shown that SHR movement is regulated and dynamic and uncovered an unexpected correlation between the ability of SHR to nuclear localize and to move . This correlation suggests a mechanistic requirement for nuclear localization in cell-to-cell transport, which may be similar to what has been demonstrated in mammalian systems for specific classes of proteins that traffic by unconventional secretion (ie do not use the usual ER to golgi route for export) [4-7]. Abnormal regulation of these proteins in mammals is associated with developmental abnormalities and cancer.
Using both cell biological and novel genomic techniques, including small molecule screens and inducible RNAi, we plan to identify and further characterize the mechanisms of intercellular protein movement in the Arabidopsis root. As tractable entry points into understanding the mechanisms of cell-to-cell signaling, we will use SHR and six recently characterized non-cell autonomous transcription factors. This research has the potential to elucidate protein movement not only between plant cells, but also the mechanisms of intercellular protein movement between animal cells, as there is emerging evidence that at least some of the trafficking machinery is conserved between these two kingdoms [4-7].
BIOL 221 - Molecular Biology and Genetics
BIOL 526 Experimental Methods in Molecular and Cell Biology
Gallagher, K.L., Paquette, A.J., Nakajima, K. and Benfey P.N. (2004). Mechanisms Regulating SHORT-ROOT Intercellular Movement. Curr. Biol 14: 1847-1851. (Faculty 1000
Gallagher, K.L. and Benfey, P.N. (2005). Not just another hole in the wall: understanding intercellular protein trafficking. Genes and Dev. 19: 189-195.
Cui, H., Levesque, M. P., Vernoux, T., Jung, J. W., Paquette, A. J., Gallagher, K. L., Wang, J. Y., Blilou, I., Scheres, B. and Benfey, P. N., (2007) An evolutionarily conserved mechanism delimiting SHR movement defines a single layer of endodermis in plants. Science, 316(5823): p. 421-5.
Gallagher, K.L., and Benfey, P. N., (2009) Both the conserved GRAS domain and nuclear localization are required for SHORT-ROOT movement. The Plant Journal, 57: 785-797
Wright, A. J., Gallagher, K.L. and Smith, L.G., (2009) discordia1 and alternative discordia1 are needed for PPB formation in maize and encode phosphatase regulatory subunits. Plant Cell, 21:234-247
Wu, S. and Gallagher K.L. (2011). Mobile protein signals in plant development. Current Opinion in Plant Biology 14 (5):563-570. (Cover Article)
Koizumi, K ., Wu, S., MacRae-Crerar, A., and Gallagher, K.L. (2011). An essential protein thatinteracts with endosomes and promotes movement of the SHORT-ROOT transcription factor.Current Biology 21 (18):1559-1564. (Faculty of 1000 selection)
Vatén, A., Dettmer, J., Wu, S., Stierhof, Y., Roberts, C.J., Yadav, S.R., Miyashimal, S.,Campilho, A., Bulone, V., Lichtenberger, R., Lehesrantal, S., Mahonen, A.P., Kim, J.Y., Sauer,N., Scheres, B., Carlsbecker, A., Gallagher, K.L., and Helariutta, Y. (2011) Callose biosynthesisregulates symplastic molecular traffic during root development. Developmental Cell 21 (6): 1144-1155. (Faculty of 1000 selection) (Featured in Science Daily, Dec. 12, 2011).
Wu, S. Koizumi, K. MacRae-Crerar, A. and Gallagher, K.L. (2011). Assessing the utility ofphotoswitchable fluorescent proteins for tracking intercellular protein movement in the Arabidopsis root. PLoS ONE 6(11) e27536. (Faculty of 1000 selection) (Selected by the illuminated plant cell as paper of the month, Feb 2012)
Wu, S., Baskin, T. and Gallagher, K.L. (2012) Preparing well oriented longitudinal sections ofArabidopsis thaliana roots for light or transmission electron microscopy. Nature Protocols 7(6):1113-24.
Koizumi, K., Hayashi, T., Wu, S., Gallagher, K.L. (2012) The SHORT-ROOT protein acts as a mobile, dose-dependent signal in patterning the ground tissue. Proc Natl Acad Sci U S A. 109(32):13010-5. (Faculty 1000 selection)
Sang, Y., Silva-Ortega, C.O., Wu, S., Yamaguchi, N., Wu, M.F., Pfluger, J., Gillmor, S.,Gallagher, K.L.*, Wagner, D*. (2012) Mutations in two non-canonical Arabidopsis SWI2/SNF2 chromatin remodeling ATPases cause embryogenesis and stem cell maintenance defects. Plant J.Oct 13. * Co-corresponding authors
Wu, S. and Gallagher, K.L. (2012) Transcription Factors on the Move. Curr Opin Plant Biol. 15:645–651
Koizumi, K., Hayashi, T. and Gallagher, K.L. (2012) SCARECROW reinforces SHORT-ROOT signaling and inhibits periclinal cell divisions in the ground tissue by maintaining SHR at high levels in the endodermis. Plant Sign & Behavior 7 (12)
Wu, S. and Gallagher, K.L. (2012) Intact microtubules are required for the intercellular movement of the SHORT-ROOT transcription factor. Plant J. 2013 Jan 7
Koizumi, K. and Gallagher, K.L. (2012) Identification of SHRUBBY, a SHORT-ROOT and SCARECROW
interacting protein that controls root growth and patterning. Development. (In
Gallagher, K.L. (2012) Cellular Patterning of the Root Meristem: Genes and Signals. Plant Roots: The Hidden Half (In press).