|
Cell Signaling, Pattern Formation, Growth Control, Cell Movement, Developmental Glycobiology Control of Tissue Patterning and Growth During Development Research in my laboratory is directed toward understanding the regulation and coordination of tissue patterning, growth, and morphogenesis during animal development. Much of our research takes advantage of the powerful genetic, molecular, and cellular techniques available in Drosophila melanogaster, which facilitate both gene discovery and the analysis of gene function. One major focus of our current research is the Notch signaling pathway. Our interest in Notch began with investigations of the fringe gene, which encodes a glycosyltransferase that modulates Notch signaling. The Notch gene encodes a receptor protein that mediates a wide range of cell fate decisions during animal development. In humans, aberrant Notch signaling has been linked to leukemia (TAN-1), a congenital syndrome associated with stroke and dementia (CADASIL), a congenital syndrome associated with liver, cardiovascular, and skeletal defects (Alagille), and a congenital syndrome associated with axial skeletal defects (spondylocostal dysostosis). Recently we have begun a new research initiative in developmental glycobiology. This project takes advantage of the genetics and genomics of Drosophila to identify functions for protein glycosylation in regulating cell signaling and cell adhesion, particularly those related to the Notch pathway. The mechanisms involved in the development of the Drosophila wing are another focus of our research. Many of the basic molecular and cellular mechanisms involved in wing development are shared with tissues in other organisms. This work began with the scalloped gene, which encodes a member of the TEA/ATTS-domain family of transcription factors. Scalloped functions downstream of Notch signaling during development of the Drosophila wing and acts as an intermediary between the signaling pathways that pattern the wing and the regulation of wing growth. Fringe, a Glycosyltransferase That Modulates Notch Signaling The fringe gene was first identified as a gene involved in signaling interactions between dorsal and ventral cells that are essential for the growth and patterning of the Drosophila wing imaginal disc. Fringe inhibits the activation of Notch by one ligand, Serrate, and potentiates the activation of Notch by another ligand, Delta. This modulation of Notch signaling positions and restricts Notch activation to the dorsal-ventral border of the developing Drosophila wing. Because of our interest in developmental mechanisms, and to investigate whether our understanding of fringe function in the Drosophila wing reflected general principles of fringe-dependent cell signaling, we undertook a series of studies of fringe function in different tissues. Through these studies, we (and others) have found that fringe -related genes are present in mammals and play essential roles in the development of many other tissues. Indeed, because of the key role of fringe in positioning sites of Notch activation, our studies have proved valuable for identifying and characterizing different functions of Notch signaling during development. Our research efforts have also been directed toward a better understanding of the biochemical function and regulation of Fringe proteins. In collaboration with Bob Haltiwanger (State University of New York at Stony Brook), Pamela Stanley (Albert Einstein College of Medicine), and Tom Vogt (Princeton University), we demonstrated that Fringe proteins possess a novel glycosyltransferase activity: they are fucose-specific b1,3 N-acetylglucosaminyltransferases that initiate elongation of O -linked fucose residues attached to epidermal growth factor (EGF)-like repeats. Both Notch and its ligands are substrates for Fringe, and evidence that Fringe-dependent elongation of O-linked fucose modulates Notch signaling has been obtained from assays in mammalian cells and in Drosophila . This is a novel example of modulation of a signaling event by differential receptor glycosylation. It leaves unanswered, however, the question of how these carbohydrate modifications influence the activation of Notch by its ligands. In addition, Notch and its ligands each contain multiple EGF modules in their extracellular domain that can be modified by Fringe. We are trying to determine which Fringe-catalyzed modifications are functionally important and how these modifications influence Notch activation. Developmental Glycobiology The biochemical characterization of Fringe has also led us to embark on a new avenue of research. Fringe catalyzes the second step in the formation of an O-linked tetrasaccharide. To assess the importance of specific carbohydrate structures on Notch, we have initiated genetic and biochemical studies in Drosophila on other glycosyltransferases predicted to be involved in the synthesis of this structure. Our studies are expected to reveal other potential roles for these glycosyltransferases in developing animals. We are extending these studies to investigations of other O-linked carbohydrates that may have important roles during development. Scalloped and Development of the Wing Imaginal Disc The growth of imaginal discs is controlled downstream of signaling molecules that are produced along the borders between compartments. The scalloped gene is regulated downstream of these compartment border signals in the wing and is expressed in a gradient, with the peak of expression at the dorsal-ventral boundary. All wing blade cells require the scalloped gene for their proliferation and viability. Both the expression pattern and requirements for wing growth of Scalloped are shared by another protein, Vestigial. In collaboration with John Bell (University of Alberta), we and others have shown that Scalloped and Vestigial bind to each other and function coordinately in vivo, forming a heterodimeric transcription factor that regulates wing identity, wing growth, and wing-specific gene expression. Our studies have also revealed two previously unrealized functions for scalloped and vestigial. First, in the hinge region of the wing, vestigial exerts a nonautonomous induction of expression of the Wnt protein Wingless. This and other observations point to novel signaling interactions between the wing blade and the wing hinge primordia. Second, clones of cells overexpressing vestigial exhibit altered cell affinities. These and other observations imply that vestigial -dependent cell adhesion may contribute to physical separation of the wing blade from the wing hinge and to a gradient of cell affinities along the proximal-distal axis of the wing. We are attempting to identify the molecular basis for the influences of scalloped and vestigial on cell proliferation, cell signaling, and cell affinity. Our research includes studies of known candidate cell signaling and cell adhesion molecules, as well as identification of new candidates using DNA microarrays. Recent Publications: Panin, V.M., Shao, L., Lei, L., Moloney, D.J., Irvine, K.D., and Haltiwanger, R.S. 2002.
Notch ligands are substrates for Protein O-fucosyltransferase-1 and Fringe. Grammont, M. and Irvine, K.D. 2002. Organizer activity of the polar cells during Drosophila oogenesis. Development, 129, 5131-5140. Nakamura, Y., Haines, N., Chen, J., Okajima, T., Furukawa, K., Urano, T., Stanley, P., Irvine, K.D., and Furukawa, K. 2002. Identification of a Drosophila gene encoding xylosylprotein ß4-galactosyltransferase that is essential for the synthesis of glycosaminoglycans and for morphogenesis. J. Biol. Chem., 277, 46280-46288. Okajima, T. and Irvine, K.D. 2002. Regulation of Notch signaling by O-linked fucose. Cell, 111, 893-904. Li, Y. Lei, L., Irvine, K.D. and Baker, N.E. 2003. Notch activity in neural cells triggered by a mutant allele with altered
glycosylation. Correia, T., Papayannopoulos, V., Panin, V., Woronoff, P., Jiang, J., Vogt T.F. and Irvine, K.D. 2003. Molecular genetic analysis of the glycosyltransferase Fringe in Drosophila. Proc. Nat. Acad. Sci. USA, 100, 6404-6409. Okajima, T., Xu, A. and Irvine, K.D. 2003. Modulation of Notch-ligand binding by Protein O-fucosyltransferase 1 and Fringe. J. Biol. Chem., 278 42340-42345. Haines, N. and Irvine, K.D. 2003. Glycosylation regulates the Notch signaling pathway. Nature Rev. Mole. Cell Biol., 4, 786-797. Lei, L., Xu, A., Panin, V. and Irvine, K. D. 2003. An O-fucose site in the ligand binding domain inhibits Notch activation. Development, 130, 6411-6421. Koles, K. Irvine, K. D., Panin, V. M. 2004. Functional characterization of Drosophila Sialyltransferase. J. Biol. Chem. 279, 4346-57. Cho, E. and Irvine, K.D. 2004. Action of fat, four-jointed, dachsous and dachs in distal-to-proximal wing signaling. Development, 131, 4489-4500. Haines, N. and Irvine, K.D. 2005. Functional analysis of Drosophila N-Acetlygalactosaminyltransferases. Glycobiology, 15, 335-346. Okajima, T., Xu, A., Lei, L. and Irvine, K.D. 2005. Chaperone Activity of Protein Major, R. and Irvine, K.D. 2005. Influence of Notch on dorsal-ventral compartmentalization and actin organization in the Drosophila wing. Xu, A. Lei, L., and Irvine, K.D. 2005. Regions of Drosophila Notch that contribute to ligand binding and the modulatory influence of Fringe. J. Biol. Chem., 280, 30158-30165. Rogulja, D. and Irvine, K.D. 2005 Regulation of cell proliferation by a morphogen gradient. Cell, 123, 449-461. Mao, Y., Rauskolb, C., Cho, E., Hu, W.-L., Hayter, H., Minihan, G., Katz, F.N., and Irvine, K.D. 2006. Dachs, an unconventional myosin that functions downstream of Fat to regulate
growth, affinity and gene expression in Drosophila. Cho, E., Feng, Y., Rauskolb, C., Maitra, S., Fehon, R., and Irvine, K.D. 2006. Delineation of a Fat tumor suppressor pathway. Nature Genetics 38, 1142-1150. Major, R. and Irvine, K.D. 2006. Localization and requirement for Myosin II at the dorsal-ventral compartment boundary of the Drosophila wing. Okajima, T. and Irvine, KD. (2002) Regulation of Notch Signaling by O-Linked Fucose. Cell111:893-904. Nakamura, Y., Haines, N., Chen, J., Okajima, T., Furukawa, K., Urano, T., Stanley, P., Irvine, K.D., and Furukawa, K. (2002) Identification of a Drosophila gene encoding xylosylprotein b4-galactosyltransferase that is essential for the synthesis of glycosaminoglycans and for morphogenesis. J. Biol. Chem 277:46280-46288. Grammont, M and Irvine, KD. (2002) Organizer activity of the polar cells during Drosophila oogenesis. Development 129:5131-5140. Panin VM, Shao L, Lei Liang, Moloney DJ, Irvine KD, and Haltiwanger RS.(2002) Notch ligands are substrates for EGF protein O-fucosyltransferase and Fringe. J. Biol. Chem 277: 29945-29952. Irvine K.D., and Rauskolb, C. (2001) Boundaries in development: formation and function. Annu Rev Cell Dev Biol. 17:189-214. Download PDF. Grammont, M. and Irvine, K.D. (2001) Fringe and the regulation and function of notch during early stages of Drosophila oogenesis. Development 128:2243-2253. Liu, X., Grammont, M. and Irvine, K.D. (2000) Roles for scalloped and vestigial in regulating cell affinity and interactions between the wing blade and the wing hinge. Developmental Biology 228: 287-303. Moloney, D. J., Panin, V. M., Johnston, S. H., Chen, J., Shao, L., Wilson, R., Wang, Y., Stanley, P., Irvine, K. D. Haltiwanger, R. S. and Vogt, T. F. (2000). Fringe is a glycosyltransferase that modifies Notch. Nature 406:369-375. Rauskolb C., Correia T., and Irvine K.D. (1999) Fringe-dependent separation of dorsal and ventral cells in the Drosophila wing. Nature. 401:476-80. Irvine K.D. (1999) Fringe, Notch, and making developmental boundaries. Curr Opin Genet Dev. 9:434-41. Rauskolb C, and Irvine K.D. (1999)
Notch-mediated segmentation and growth control of the
Drosophila leg. Panin V.M and Irvine K.D. (1998) Modulators of Notch signaling. Semin Cell Dev Biol. 9:609-17. Simmonds A.J., Liu X., Soanes K.H., Krause H.M., Irvine K.D., and Bell J.B.. (1998) Molecular interactions between Vestigial and Scalloped promote wing formation in Drosophila. Genes Dev. 12(24):3815-20. Papayannopoulos V., Tomlinson A., Panin V.M., Rauskolb C., and Irvine K.D. (1998) Dorsal-ventral signaling in the Drosophila eye. Science 281:2031-4. Irvine K.D. and Vogt T.F. (1997). Dorsal-ventral
signaling in limb development. Curr
Opin Cell Biol. 9(6): 867-876 Lab Members Aiguo
Xu, Research Specialist |
Research
Summary