The desmosome is an intercellular junction which plays an important role in adhesion of epithelial cells. The hemidesmosome appears to effect adherence of basal cells in certain epithelia to the basement zone (BMZ). The program described in this application is aimed at characterizing the adhesion molecules of the desmosome and the hemidesmosome. Desmosomes will be prepared from bovine epithelial tissues by standard procedures. The 9.5M urea insoluble fraction of desmosomes is enriched is desmosomal glycoprotein components i.e. polypeptides with a possible role in cell adhesion. Monoclonal and polyclonal antibodies will be generated against the components of this urea insoluble fraction. These antibody preparations will be used in immunofluorescence assays to determine the distribution of desmosomal components in a variety of epithelial tissues. In addition, these antibody preparations will be localized ultrastructurally by the immungold procedure. Furthermore, using a keratinocyte culture system in which desmosome formation can be manipulated by the extracellular Ca2+ levels, incorporation of components into assembling desmosomes will be monitored by immunofluorescence and by immunoelectron microscopy. Fab' fragments derived from these desmosomal antibodies will be used in cell adhesion assays using cultured keratinocytes and organ cultures of skin. A technique is described for the enrichment of the components of hemidesmosomes i.e. the removal of the epidermis from the underlying connective tissue following EDTA treatment results in the retention of hemidesmosomes along the BMZ. The hemidesmosomes will be removed from the BMZ by solubilization in urea/SDS and monoclonal antibody preparations directed against hemidesmosomal components will be raised. The distribution of hemidesmosomal antigens in a variety of tissue types will be determined by indirect immunofluorescence. The binding sites of these hemidesmosomal antigens will be determined at the ultrastructural level be immunogold localization. Attempts to monitor the formation of hemidesmosomes by immunofluorescence and immunoelectron microscopy will involve the use of cultured keratinocytes. Fab' fragments of the hemidesmosomal antibodies will also by assayed for their ability to inhibit the adhesion of cultured cells to substrata and/or inhibit the formation of hemidesmosomes in an in vitro organ system. These studies may support a hypothesis that these two organelles play a role in mediating the kinds of cell interactions which are essential for tissue morphogenesis and the maintenance of tissue integrity.

National Institute of Health (NIH)
National Institute of General Medical Sciences (NIGMS)
Research Project (R01)
Project #
Application #
Study Section
Cellular Biology and Physiology Subcommittee 1 (CBY)
Project Start
Project End
Budget Start
Budget End
Support Year
Fiscal Year
Total Cost
Indirect Cost
Northwestern University at Chicago
School of Medicine & Dentistry
United States
Zip Code
DeHart, Gregory W; Jones, Jonathan C R (2004) Myosin-mediated cytoskeleton contraction and Rho GTPases regulate laminin-5 matrix assembly. Cell Motil Cytoskeleton 57:107-17
deHart, Gregory W; Healy, Kevin E; Jones, Jonathan C R (2003) The role of alpha3beta1 integrin in determining the supramolecular organization of laminin-5 in the extracellular matrix of keratinocytes. Exp Cell Res 283:67-79
Gonzales, M; Weksler, B; Tsuruta, D et al. (2001) Structure and function of a vimentin-associated matrix adhesion in endothelial cells. Mol Biol Cell 12:85-100
Goldfinger, L E; Jiang, L; Hopkinson, S B et al. (2000) Spatial regulation and activity modulation of plasmin by high affinity binding to the G domain of the alpha 3 subunit of laminin-5. J Biol Chem 275:34887-93
Hopkinson, S B; Jones, J C (2000) The N terminus of the transmembrane protein BP180 interacts with the N-terminal domain of BP230, thereby mediating keratin cytoskeleton anchorage to the cell surface at the site of the hemidesmosome. Mol Biol Cell 11:277-86
Goldfinger, L E; Hopkinson, S B; deHart, G W et al. (1999) The alpha3 laminin subunit, alpha6beta4 and alpha3beta1 integrin coordinately regulate wound healing in cultured epithelial cells and in the skin. J Cell Sci 112 ( Pt 16):2615-29
Gonzales, M; Haan, K; Baker, S E et al. (1999) A cell signal pathway involving laminin-5, alpha3beta1 integrin, and mitogen-activated protein kinase can regulate epithelial cell proliferation. Mol Biol Cell 10:259-70
Chen, M; Marinkovich, M P; Jones, J C et al. (1999) NC1 domain of type VII collagen binds to the beta3 chain of laminin 5 via a unique subdomain within the fibronectin-like repeats. J Invest Dermatol 112:177-83
Hopkinson, S B; Findlay, K; deHart, G W et al. (1998) Interaction of BP180 (type XVII collagen) and alpha6 integrin is necessary for stabilization of hemidesmosome structure. J Invest Dermatol 111:1015-22
El-Ghannam, A; Starr, L; Jones, J (1998) Laminin-5 coating enhances epithelial cell attachment, spreading, and hemidesmosome assembly on Ti-6A1-4V implant material in vitro. J Biomed Mater Res 41:30-40

Showing the most recent 10 out of 35 publications