Hypoglycosylated E-cadherin promotes the assembly of tight junctions through the recruitment of PP2A to adherens junctions |
| |
Authors: | Mihai Nita-Lazar Janice Walker |
| |
Institution: | a Department of Molecular and Cell Biology, Boston University Medical Center, Boston, MA 02118, USA b Matrix and Morphogenesis Unit, Craniofacial Developmental Biology and Regeneration Branch, National Institute for Dental and Craniofacial Research, National Institutes of Health, Bethesda, MD, USA c Department of Pathology, Anatomy and Cell Biology, Thomas Jefferson University, Philadelphia, PA, USA |
| |
Abstract: | Epithelial cell-cell adhesion is controlled by multiprotein complexes that include E-cadherin-mediated adherens junctions (AJs) and ZO-1-containing tight junctions (TJs). Previously, we reported that reduction of E-cadherin N-glycosylation in normal and cancer cells promoted stabilization of AJs through changes in the composition and cytoskeletal association of E-cadherin scaffolds. Here, we show that enhanced interaction of hypoglycosylated E-cadherin-containing AJs with protein phosphatase 2A (PP2A) represents a mechanism for promoting TJ assembly. In MDCK cells, attenuation of cellular N-glycosylation with siRNA to DPAGT1, the first gene in the N-glycosylation pathway, reduced N-glycosylation of surface E-cadherin and resulted in increased recruitment of stabilizing proteins γ-catenin, α-catenin, vinculin and PP2A to AJs. Greater association of PP2A with AJs correlated with diminished binding of PP2A to ZO-1 and claudin-1 and with increased pools of serine-phosphorylated ZO-1 and claudin-1. More ZO-1 was found in complexes with occludin and claudin-1, and this corresponded to enhanced transepithelial resistance (TER), indicating physiological assembly of TJs. Similar maturation of AJs and TJs was detected after transfection of MDCK cells with the hypoglycosylated E-cadherin variant, V13. Our data indicate that E-cadherin N-glycans coordinate the maturity of AJs with the assembly of TJs by affecting the association of PP2A with these junctional complexes. |
| |
Keywords: | AJs adherens junctions CHO Chinese Hamster Ovary CNX calnexin ECs E-cadherin ectodomains ER endoplasmic reticulum F-actin filamentous actin MDCK Madin-Darby canine kidney PP2A protein phosphatase 2A TCL total cell lysate TER transepithelial resistance TJs tight junctions UPR unfolded protein response |
本文献已被 ScienceDirect 等数据库收录! |
|