Cyclin D1 is transcriptionally down-regulated by ZO-2 via an E box and the transcription factor c-Myc.
Recent reports have indicated the participation of tight junction (TJ) proteins in the regulation of gene expression and cell proliferation. Here, we have studied the role of zona occludens (ZO)-2, a TJ peripheral protein, in the regulation of cyclin D1 transcription. We found that ZO-2 down-regulates cyclin D1 transcription in a dose-dependent manner. To understand how ZO-2 represses cyclin D1 promoter activity, we used deletion analyses and found that ZO-2 negatively regulates cyclin D1 transcription via an E box and that it diminishes cell proliferation. Because ZO-2 does not associate directly with DNA, electrophoretic mobility shift assay and chromatin immunoprecipitation (ChIP) assay were used to identify the transcription factors mediating the ZO-2-repressive effect. c-Myc was found to bind the E box present in the cyclin D1 promoter, and the overexpression of c-Myc augmented the inhibition generated by ZO-2 transfection. The presence of ZO-2 and c-Myc in the same complex was further demonstrated by immunoprecipitation. ChIP and reporter gene assays using histone deacetylases (HDACs) inhibitors demonstrated that HDACs are necessary for ZO-2 repression and that HDAC1 is recruited to the E box. We conclude that ZO-2 down-regulates cyclin D1 transcription by interacting with the c-Myc/E box element and by recruiting HDAC1.
Huerta
Miriam
M
Departamentos de Genética y Biología Molecular and Fisiología, Biofísica y Neurociencias, Cinvestav-Zacatenco, México D.F. 07360, México.
Muñoz
Rodrigo
R
Tapia
Rocío
R
Soto-Reyes
Ernesto
E
Ramírez
Leticia
L
Recillas-Targa
Félix
F
González-Mariscal
Lorenza
L
López-Bayghen
Esther
E
D000818:Animals; D002460:Cell Line; D019938:Cyclin D1 / Q000235:genetics* / Q000378:metabolism*; D004285:Dogs; D015536:Down-Regulation / Q000235:genetics*; D024721:E-Box Elements; D006655:Histone Deacetylases / Q000378:metabolism; D006801:Humans; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism*; D008969:Molecular Sequence Data; D011401:Promoter Regions, Genetic; D011485:Protein Binding; D016271:Proto-Oncogene Proteins c-myc / Q000235:genetics / Q000378:metabolism*; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*; D014158:Transcription, Genetic / Q000235:genetics*; D062827:Zonula Occludens-2 Protein
D008565:Membrane Proteins; D016271:Proto-Oncogene Proteins c-myc; C569046:TJP2 protein, human; D014157:Transcription Factors; D062827:Zonula Occludens-2 Protein; D019938:Cyclin D1; D006655:Histone Deacetylases