Gadd45a regulates beta-catenin distribution and maintains cell-cell adhesion/contact.
Gadd45a, a growth arrest and DNA-damage gene, plays important roles in the control of cell cycle checkpoints, DNA repair and apoptosis. We show here that Gadd45a is involved in the control of cell contact inhibition and cell-cell adhesion. Gadd45a can serve as an adapter to enhance the interaction between beta-catenin and Caveolin-1, and in turn induces beta-catenin translocation to cell membrane for maintaining cell-cell adhesion/contact inhibition. This is coupled with reduction of beta-catenin in cytoplasm and nucleus following Gadd45a induction, which is reflected by the downregulation of cyclin D1, one of the beta-catenin targeted genes. Additionally, Gadd45a facilitates ultraviolet radiation-induced degradation of cytoplasmic and nuclear beta-catenin in a p53-dependent manner via activation of p38 kinase. These findings define a novel link that connects Gadd45a to cell-cell adhesion and cell contact inhibition, which might contribute to the role of Gadd45a in inhibiting tumorigenesis.
Ji
J
J
State Key Laboratory of Molecular Oncology, Cancer Institute, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, PR China.
Liu
R
R
Tong
T
T
Song
Y
Y
Jin
S
S
Wu
M
M
Zhan
Q
Q
D000818:Animals; D051242:Caveolin 1 / Q000235:genetics / Q000378:metabolism; D002448:Cell Adhesion / Q000502:physiology*; D018797:Cell Cycle Proteins / Q000235:genetics / Q000502:physiology*; D002462:Cell Membrane / Q000378:metabolism; D002467:Cell Nucleus / Q000378:metabolism; D002478:Cells, Cultured; D056741:Cyclin D; D016213:Cyclins / Q000235:genetics / Q000378:metabolism; D003593:Cytoplasm / Q000378:metabolism; D004622:Embryo, Mammalian / Q000166:cytology / Q000378:metabolism; D005347:Fibroblasts / Q000166:cytology / Q000378:metabolism; D005786:Gene Expression Regulation; D051379:Mice; D018345:Mice, Knockout; D009687:Nuclear Proteins / Q000235:genetics / Q000502:physiology*; D021381:Protein Transport; D016159:Tumor Suppressor Protein p53 / Q000235:genetics / Q000378:metabolism; D051176:beta Catenin / Q000235:genetics / Q000378:metabolism*; D048051:p38 Mitogen-Activated Protein Kinases / Q000378:metabolism; D000097642:GADD45 Proteins
D051242:Caveolin 1; D018797:Cell Cycle Proteins; D056741:Cyclin D; D016213:Cyclins; D009687:Nuclear Proteins; D016159:Tumor Suppressor Protein p53; D051176:beta Catenin; D048051:p38 Mitogen-Activated Protein Kinases; C499072:Gadd45a protein, mouse; D000097642:GADD45 Proteins