Regulation of the type II hemidesmosomal plaque assembly in intestinal epithelial cells.

Hemidesmosomes (HDs) are cellular junctions that anchor epithelial cells to the extracellular matrix (ECM) and are associated morphologically with the cytoskeleton. Hemidesmosomal molecular components include two proteins involved in linking intermediate filaments, HD1/plectin and BP230, and two transmembrane proteins, BP180 and the alpha6beta4 integrin, a laminin receptor. In cells lacking BP230 and BP180, HD1/plectin still associates with alpha6beta4 integrin, forming HD-like structures, called type II HDs. In the present study, we used an intestinal epithelial cell line that expresses HD1/plectin and the alpha6beta4 integrin to investigate the regulation of assembly of these proteins in type II HDs. These compounds were found to be clustered at sites of cell-ECM contact and their polarized localization was influenced by either cell confluency or extracellular matrix deposition. Conventional and immunoelectron microscopy showed that HD1/plectin and the beta4 integrin subunit are colocalized in an adhesion structure. Using cytoskeleton-disrupting drugs and confocal microscopy, we demonstrated that type II HDs are made up of numerous individual plaques whose assembly into a cluster requires actin filaments, but not microtubules.

Fontao L ，Stutzmann J ，Gendry P ，Launay JF ... -  《EXPERIMENTAL CELL RESEARCH》

Polarized expression of HD1: relationship with the cytoskeleton in cultured human colonic carcinoma cells.

Fontao L ，Dirrig S ，Owaribe K ，Kedinger M ，Launay JF ... -  《EXPERIMENTAL CELL RESEARCH》

Formation of hemidesmosome-like structures in the absence of ligand binding by the (alpha)6(beta)4 integrin requires binding of HD1/plectin to the cytoplasmic domain of the (beta)4 integrin subunit.

Nievers MG ，Kuikman I ，Geerts D ，Leigh IM ，Sonnenberg A ... -  《JOURNAL OF CELL SCIENCE》

Binding of integrin alpha6beta4 to plectin prevents plectin association with F-actin but does not interfere with intermediate filament binding.

Geerts D ，Fontao L ，Nievers MG ，Schaapveld RQ ，Purkis PE ，Wheeler GN ，Lane EB ，Leigh IM ，Sonnenberg A ... -  《-》

Linking integrin alpha6beta4-based cell adhesion to the intermediate filament cytoskeleton: direct interaction between the beta4 subunit and plectin at multiple molecular sites.

Rezniczek GA ，de Pereda JM ，Reipert S ，Wiche G ... -  《-》