title: N-glycosylation controls the function of junctional adhesion molecule-A.
abstract: Junctional adhesion molecule-A (JAM-A) is an adherens and tight junction protein expressed by endothelial and epithelial cells. JAM-A serves many roles and contributes to barrier function and cell migration and motility, and it also acts as a ligand for the leukocyte receptor LFA-1. JAM-A is reported to contain N-glycans, but the extent of this modification and its contribution to the protein's functions are unknown. We show that human JAM-A contains a single N-glycan at N185 and that this residue is conserved across multiple mammalian species. A glycomutant lacking all N-glycans, N185Q, is able to reach the cell surface but exhibits decreased protein half-life compared with the wild- type protein. N-glycosylation of JAM-A is required for the protein's ability to reinforce barrier function and contributes to Rap1 activity. We further show that glycosylation of N185 is required for JAM-A-mediated reduction of cell migration. Finally, we show that N-glycosylation of JAM-A regulates leukocyte adhesion and LFA-1 binding. These findings identify N-glycosylation as critical for JAM-A's many functions.
authors.affiliation: Department of Cell Biology and Physiology and Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill, Chapel Hill, NC 27599 dwscott@email.unc.edu.
authors.forename: David W
authors.initials: DW
authors.lastname: Scott
authors.affiliation: Department of Cell Biology and Physiology and Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill, Chapel Hill, NC 27599.
authors.forename: Caitlin E
authors.initials: CE
authors.lastname: Tolbert
authors.affiliation: Department of Cell Biology and Physiology and Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill, Chapel Hill, NC 27599.
authors.forename: David M
authors.initials: DM
authors.lastname: Graham
authors.affiliation: Department of Cell Biology and Physiology and Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill, Chapel Hill, NC 27599.
authors.forename: Erika
authors.initials: E
authors.lastname: Wittchen
authors.affiliation: Department of Cell Biology and Physiology and Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill, Chapel Hill, NC 27599.
authors.forename: James E
authors.initials: JE
authors.lastname: Bear
authors.affiliation: Department of Cell Biology and Physiology and Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill, Chapel Hill, NC 27599 McAllister Heart Institute, University of North Carolina, Chapel Hill, Chapel Hill, NC 27599.
authors.forename: Keith
authors.initials: K
authors.lastname: Burridge
mesh_terms: D000595:Amino Acid Sequence; D018938:Caco-2 Cells; D002448:Cell Adhesion / Q000502:physiology; D015815:Cell Adhesion Molecules / Q000378:metabolism*; D002460:Cell Line; D002465:Cell Movement / Q000502:physiology; D042783:Endothelial Cells / Q000378:metabolism; D004847:Epithelial Cells / Q000378:metabolism; D006031:Glycosylation; D018922:HL-60 Cells; D061307:Human Umbilical Vein Endothelial Cells; D006801:Humans; D007962:Leukocytes / Q000378:metabolism; D008024:Ligands; D016169:Lymphocyte Function-Associated Antigen-1 / Q000378:metabolism; D061986:MCF-7 Cells; D008969:Molecular Sequence Data; D011134:Polysaccharides / Q000378:metabolism*; D011485:Protein Binding; D055503:Protein Multimerization; D011956:Receptors, Cell Surface / Q000378:metabolism*; D015398:Signal Transduction
chemical_list: D015815:Cell Adhesion Molecules; C407243:F11R protein, human; D008024:Ligands; D016169:Lymphocyte Function-Associated Antigen-1; D011134:Polysaccharides; D011956:Receptors, Cell Surface