Two types of epithelial cell-cell junctions, desmosomes and adherens junctions, are important in maintaining the integrity of epithelium. Disruption of epidermal junctions results in inherited and acquired blistering diseases, but the mechanisms of the disruption are unknown. To learn more about component proteins and assembly of structurally important junctions, we have purified proteins from preparations of mammalian junctions from pig oral epithelium. One, a 37 kDa protein, has been cloned and sequenced and has been found to be highly homologous with a family of lectins, proteins with the ability to bind carbohydrates, in different species; no other junction protein has been found to be a member of this family of proteins. Studies with antibodies to the protein suggest strongly that the protein is present in adherens junctions and indicate that the protein has a restriction previously undescribed for junction proteins (a) primarily to the oral epithelium and (b) to only suprabasal cells within that epithelium. In other studies, we have also demonstrated for the first time the presence of adherens junctions in mammalian epidermis and have shown that these junctions are present in human skin. We plan to continue studies of adherens junctions in human skin and to further delineate the location of the 37 kDa probable adherens junction protein in epithelium. Since the cDNA sequence and amino acid sequence are highly homologous with a mammalian lectin, which binds lactose, we will determine whether the 37 kDa protein can bind to sugars, especially lactose. We will identify proteins to which this protein binds in junctions and will attempt to find and clone the cDNA for the human protein corresponding to the 37 kDa protein. To understand the structure of the gene for the 37 kDa protein and thereby relate it to a correlative human gene, we will clone and sequence the genomic DNA for the pig gene. Finally we will continue to define the structure and possible function of adherens junctions in human tissues with available antibodies and will use organ culture in an effort to upregulate these junctions. These studies will elucidate the structure and function of epithelial junctions and may demonstrate a new function, the binding of carbohydrate, in a structural protein of epithelial junctions. These studies will increase our understanding of the structure and function of these junctions and of their assembly from component proteins.

Agency
National Institute of Health (NIH)
Institute
National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS)
Type
Research Project (R01)
Project #
2R01AR025871-15
Application #
3155358
Study Section
General Medicine A Subcommittee 2 (GMA)
Project Start
1979-07-01
Project End
1998-06-30
Budget Start
1993-08-16
Budget End
1994-06-30
Support Year
15
Fiscal Year
1993
Total Cost
Indirect Cost
Name
University of North Carolina Chapel Hill
Department
Type
Schools of Medicine
DUNS #
078861598
City
Chapel Hill
State
NC
Country
United States
Zip Code
27599
Hu, P; O'Keefe, E J; Rubenstein, D S (2001) Tyrosine phosphorylation of human keratinocyte beta-catenin and plakoglobin reversibly regulates their binding to E-cadherin and alpha-catenin. J Invest Dermatol 117:1059-67
O'Keefe, E J; Hamilton, E H; Lee, S C et al. (1993) Trichohyalin: a structural protein of hair, tongue, nail, and epidermis. J Invest Dermatol 101:65S-71S
Chiu, M L; Jones, J C; O'Keefe, E J (1992) Restricted tissue distribution of a 37-kD possible adherens junction protein. J Cell Biol 119:1689-700
Petersen, M J; Woodley, D T; Stricklin, G P et al. (1992) Synthesis and regulation of keratinocyte collagenase. Matrix Suppl 1:192-7
Hamilton, E H; Sealock, R; Wallace, N R et al. (1992) Trichohyalin: purification from porcine tongue epithelium and characterization of the native protein. J Invest Dermatol 98:881-9
Feldman, S R; O'Keefe, E J (1991) Isolation of a partial clone of desmoplakin-1 by antibody screening of a lambda gt11 library. Am J Med Sci 301:151-6
Hamilton, E H; Payne Jr, R E; O'Keefe, E J (1991) Trichohyalin: presence in the granular layer and stratum corneum of normal human epidermis. J Invest Dermatol 96:666-72
O'Keefe, E; Payne Jr, R E (1991) Minoxidil: inhibition of proliferation of keratinocytes in vitro. J Invest Dermatol 97:534-6
Woodley, D T; Briggaman, R A; Herzog, S R et al. (1990) Characterization of ""neo-dermis"" formation beneath cultured human epidermal autografts transplanted on muscle fascia. J Invest Dermatol 95:20-6
Petersen, M J; Woodley, D T; Stricklin, G P et al. (1990) Enhanced synthesis of collagenase by human keratinocytes cultured on type I or type IV collagen. J Invest Dermatol 94:341-6

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