Calreticulin represses E-cadherin gene expression in Madin-Darby canine kidney cells via Slug.
Calreticulin (CRT) is a multifunctional Ca(2+)-binding molecular chaperone in the endoplasmic reticulum. In mammals, the expression level of CRT differs markedly in a variety of organs and tissues, suggesting that CRT plays a specific role in each cell type. In the present study, we focused on CRT functions in the kidney, where overall expression of CRT is quite low, and established CRT-overexpressing kidney epithelial cell-derived Madin-Darby canine kidney cells by gene transfection. We demonstrated that, in CRT-overexpressing cells, the morphology was apparently changed, and the original polarized epithelial cell phenotype was destroyed. Furthermore, CRT-overexpressing cells showed enhanced migration through Matrigel-coated Boyden chamber wells, compared with controls. E-cadherin expression was significantly suppressed at the protein and transcriptional levels in CRT-overexpressing cells compared with controls. On the other hand, the expression of mesenchymal protein markers, such as N-cadherin and fibronectin, was up-regulated. We also found that the expression of Slug, a repressor of the E-cadherin promoter, was up-regulated by overexpression of CRT through altered Ca(2+) homeostasis, and this led to enhanced binding of Slug to the E-box element in the E-cadherin promoter. Thus, we conclude that CRT regulates the epithelial-mesenchymal transition-like change of cellular phenotype by modulating the Slug/E-cadherin pathway through altered Ca(2+) homeostasis in cells, suggesting a novel function of CRT in cell-cell interaction of epithelial cells.
Hayashida
Yasushi
Y
Department of Biochemistry and Molecular Biology in Disease, Atomic Bomb Disease Institute, and Department of Urology, Nagasaki University Graduate School of Biomedical Sciences, 1-12-4 Sakamoto, Nagasaki 852-8523, Japan.
Urata
Yoshishige
Y
Muroi
Eiji
E
Kono
Takaaki
T
Miyata
Yasuyoshi
Y
Nomata
Koichiro
K
Kanetake
Hiroshi
H
Kondo
Takahito
T
Ihara
Yoshito
Y
D000818:Animals; D015820:Cadherins / Q000235:genetics / Q000378:metabolism*; D037282:Calreticulin / Q000235:genetics / Q000378:metabolism*; D002448:Cell Adhesion / Q000235:genetics / Q000502:physiology; D002460:Cell Line; D002465:Cell Movement / Q000235:genetics / Q000502:physiology; D048430:Cell Shape / Q000235:genetics / Q000502:physiology; D004285:Dogs; D004847:Epithelial Cells / Q000166:cytology / Q000378:metabolism*; D005786:Gene Expression Regulation / Q000235:genetics; D007668:Kidney / Q000166:cytology*; D012097:Repressor Proteins / Q000235:genetics / Q000378:metabolism; D013347:Subcellular Fractions / Q000378:metabolism
D015820:Cadherins; D037282:Calreticulin; D012097:Repressor Proteins