Epiligrin, a new cell adhesion ligand for integrin alpha 3 beta 1 in epithelial basement membranes.
Epiligrin is a new glycoprotein in most epithelial basement membranes (BMs) and is a ligand for cell adhesion via integrin alpha 3 beta 1. In the extracellular matrix of human foreskin keratinocytes (HFKs), epiligrin contains three disulfide-bonded, glycoprotein subunits, E170, E145, and E135, based on molecular size in kilodaltons. Epiligrin, immunopurified with MAb P1E1, induced cell adhesion and localization of integrin alpha 3 beta 1 in focal adhesions (FAs). Cell adhesion to epiligrin was inhibited with an anti-alpha 3 beta 1 MAb. Epiligrin also colocalized with integrin alpha 6 beta 4 in hemidesmosome-like stable anchoring contacts (SACs). alpha 3 beta 1-FAs encircled alpha 6 beta 4-SACs in a complex adhesion structure. alpha 3 beta 1 and epiligrin localized in BM junctions of epithelial cells primarily in organs of endodermal/ectodermal origin. In epidermis, epiligrin was detected in the lamina lucida of BMs. alpha 3 beta 1 localized in plasma membranes of basal cells in contact with epiligrin and also in lateral/apical membranes. Epiligrin is the ligand of an adhesion super complex composed of alpha 3 beta 1-FAs and alpha 6 beta 4-SACs (hemidesmosomes).
Carter
W G
WG
Fred Hutchinson Cancer Research Center, University of Washington, Seattle 98104.
Ryan
M C
MC
Gahr
P J
PJ
D000911:Antibodies, Monoclonal; D001485:Basement Membrane / Q000502:physiology / Q000648:ultrastructure; D002448:Cell Adhesion; D002460:Cell Line; D002478:Cells, Cultured; D004848:Epithelium / Q000502:physiology / Q000648:ultrastructure; D005109:Extracellular Matrix / Q000502:physiology / Q000648:ultrastructure; D006801:Humans; D007231:Infant, Newborn; D016023:Integrins / Q000502:physiology*; D007365:Intercellular Junctions / Q000502:physiology; D015603:Keratinocytes / Q000166:cytology / Q000502:physiology* / Q000648:ultrastructure; D008024:Ligands; D046911:Macromolecular Substances; D008297:Male; D008562:Membrane Glycoproteins / Q000302:isolation & purification / Q000502:physiology*; D008854:Microscopy, Electron
D000911:Antibodies, Monoclonal; D016023:Integrins; D008024:Ligands; D046911:Macromolecular Substances; D008562:Membrane Glycoproteins