Beta-catenin/LEF1 activated enamelin expression in ameloblast-like cells.
Enamelin is an ameloblast-specific matrix protein believed to play essential roles in enamel formation. However, mechanisms of enamelin transcription regulation are not clear. beta-Catenin/LEF1 is a key transcriptional complex involved in tooth development. In this study, the role of beta-catenin/LEF1 in enamelin expression was investigated. The 5'-flanking region of the mouse enamelin gene was analyzed and cloned. Co-transfection analysis and mutation assays revealed that two conserved LEF1 responsive elements located at -1002 and -597bp upstream of the enamelin translation initiation site could augment transcriptional activity of the enamelin. The interaction between the enamelin elements and beta-catenin/LEF1 was further confirmed by electrophoresis mobility shift assays and chromatin immunoprecipitation assays. In addition, LiCl treatment induced nuclear translocation of beta-catenin and elevated endogenous enamelin expression in mouse ameloblast-like cells. The results suggested that Wnt/beta-catenin signaling could function in enamelin gene expression by direct interaction through two conserved LEF1 responsive elements on the enamelin gene in ameloblast-like cells.
Tian
Hua
H
Department of Cariology and Endodontology, Peking University School and Hospital of Stomatology, Beijing 100081, China.
Lv
Ping
P
Ma
Kangtao
K
Zhou
Chunyan
C
Gao
Xuejun
X
D024506:5' Flanking Region / Q000235:genetics; D000565:Ameloblasts / Q000378:metabolism*; D000818:Animals; D002460:Cell Line; D003746:Dental Enamel Proteins / Q000235:genetics*; D024202:Electrophoretic Mobility Shift Assay; D051821:Lymphoid Enhancer-Binding Factor 1 / Q000378:metabolism*; D051379:Mice; D008813:Mice, Inbred ICR; D011401:Promoter Regions, Genetic; D014158:Transcription, Genetic; D015533:Transcriptional Activation; D051153:Wnt Proteins / Q000378:metabolism*; D051176:beta Catenin / Q000378:metabolism*
D003746:Dental Enamel Proteins; C497574:Lef1 protein, mouse; D051821:Lymphoid Enhancer-Binding Factor 1; D051153:Wnt Proteins; D051176:beta Catenin; C038456:tuftelin