DDR1 regulates the stabilization of cell surface E‐cadherin and E‐cadherin‐mediated cell aggregation

Abstract

The stabilization of cell surface E-cadherin is important for the maintenance of apical junction complexes and epithelial polarity. Previously, we reported that discoidin domain receptor 1 (DDR1) forms a complex with E-cadherin at adhesive contacts; however, the regulatory role of DDR1 in the stabilization of cell surface E-cadherin and E-cadherin-mediated cell behaviors remained undefined. To gain insight into these questions, we utilized two stable clones depleted for DDR1 via the small interfering RNA (siRNA) technique, and we over-expressed DDR1 in MDCK cells. We performed Western blotting, immunofluorescence analysis, flow cytometry, and cell aggregation studies to investigate the effect of DDR1 on cell surface E-cadherin. The results showed that both DDR1/2 and E-cadherin use their extracellular domains to form DDR/E-cadherin complexes. Neither the depletion nor the over-expression of DDR1 changed the expression level of E-cadherin in MDCK cells. Collagen disrupted the formation of E-cadherin complexes and caused E-cadherin to accumulate in the cytoplasm; however, over-expression of DDR1 stabilized E-cadherin on the cell surface and decreased its cytoplasmic accumulation. Furthermore, independently of collagen stimulation, the depletion of DDR1 resulted in a decrease in the level of cell surface E-cadherin, which consequently caused its cytoplasmic accumulation and decreased E-cadherin-mediated cell aggregation. These results indicate that DDR1 can increase the stability of cell surface E-cadherin and promote MDCK cell aggregation, which may be mediated through the formation of DDR1/E-cadherin complexes. Overall, these findings have implications for the physiological roles of DDR1 in association with the maintenance of both the adhesion junction and epithelial polarity.

Core epithelial-to-mesenchymal transition interactome gene-expression signature is associated with claudin-low and metaplastic breast cancer subtypes

“…Consistent with this finding, the proapoptosis gene BIK was down-regulated in all samples. In addition, genes with a Zeb1 binding site present in their promoters were enriched in the set of genes down-regulated by EMT, including the gene discoidin domain receptor 1 (DDR1), which encodes an RTK involved in E-cadherin localization and distinguishes basal A from basal B cell lines (42)(43)(44)(45), and the gene follistatin (FST), which is a TGF-β antagonist (Tables S2 and S3) (46)(47)(48).…”

Antitumor activity of 7RH, a discoidin domain receptor 1 inhibitor, alone or in combination with dasatinib exhibits antitumor effects in nasopharyngeal carcinoma cells

“…Cell adhesion is involved in a number of regulatory processes, including growth, differentiation, proliferation, migration and regeneration (30). In addition, adhesion exhibits a crucial function in the formation and maintenance of coherent multicellular structures.…”

Cancer Cell Invasion in Three-dimensional Collagen Is Regulated Differentially by Gα13 Protein and Discoidin Domain Receptor 1-Par3 Protein Signaling

“…For example, mouse embryonic fibroblasts from G␣ 13 -null mice are deficient in lysophosphatidic acid-stimulated cell migration (18). G␣ 13 , but not the closely related G␣ 12 , also mediates EGF-driven migration (18). In addition to regulating cell migration, G␣ 13 can weaken adherens junctions by binding to E-cadherin and displacing ␤-catenin from adherens junctions (19,20).…”

“…The collagen-binding protein discoidin domain receptor 1 (DDR1) has been shown to localize to cell-cell junctions and mediate cell-cell adhesion (10,11). In addition to regulating E-cadherin stability at the cell surface (12,13), DDR1, through its interaction with the Par3 polarity complex, can also regulate actin cytoskeleton dynamics (11).…”