TY - JOUR
T1 - DDR1 regulates the stabilization of cell surface E-cadherin and E-cadherin-mediated cell aggregation
AU - Eswaramoorthy, Rajalakshmanan
AU - Wang, Chih Kuang
AU - Chen, Wen Cheng
AU - Tang, Ming Jer
AU - Ho, Mei Ling
AU - Hwang, Chi Ching
AU - Wang, Hui Min
AU - Wang, Chau Zen
PY - 2010/8
Y1 - 2010/8
N2 - 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.
AB - 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.
UR - http://www.scopus.com/inward/record.url?scp=77953642516&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=77953642516&partnerID=8YFLogxK
U2 - 10.1002/jcp.22134
DO - 10.1002/jcp.22134
M3 - Article
C2 - 20432435
AN - SCOPUS:77953642516
SN - 0021-9541
VL - 224
SP - 387
EP - 397
JO - Journal of Cellular Physiology
JF - Journal of Cellular Physiology
IS - 2
ER -