Identification of G-quadruplex structures that possess transcriptional regulating functions in the Dele and Cdc6 CpG islands.
BMC Mol Biol
; 18(1): 17, 2017 06 27.
Article
em En
| MEDLINE
| ID: mdl-28655335
ABSTRACT
BACKGROUND:
G-quadruplex is a DNA secondary structure that has been shown to play an important role in biological systems. In a previous study, we identified 1998 G-quadruplex-forming sequences using a mouse CpG islands DNA microarray with a fluorescent-labeled G-quadruplex ligand. Among these putative G-quadruplex-forming sequences, G-quadruplex formation was verified for 10 randomly selected sequences by CD spectroscopy and DMS footprinting analysis. In this study, the biological function of the 10 G-quadruplex-forming sequences in the transcriptional regulation has been analyzed using a reporter assay.RESULTS:
When G-quadruplex-forming sequences from the Dele and Cdc6 genes have been cloned in reporter vectors carrying a minimal promoter and the luciferase gene, luciferase expression is activated. This has also been detected in experiments applying a promoterless reporter vector. Mutational analysis reveals that guanine bases, which form the G-tetrads, are important in the activation. In addition, the activation has been found to decrease by the telomestatin derivative L1H1-7OTD which can bind to the G-quadruplex DNA. When Dele and Cdc6 CpG islands, containing the G-quadruplex-forming sequence, have been cloned in the promoterless reporter vector, the luciferase expression is activated. Mutational analysis reveals that the expression level is decreased by mutation on Dele G-quadruplex; however, increased by mutation on Cdc6 G-quadruplex.CONCLUSION:
Dele and Cdc6 G-quadruplex formation is significant in the transcriptional regulation. Dele and Cdc6 G-quadruplex DNA alone possess enhancer and promotor function. When studied in more complex CpG islands Dele G-quadruplex also demonstrates promotor activity, whereas Cdc6 G-quadruplex may possess a dual function of transcriptional regulation.Palavras-chave
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Transcrição Gênica
/
Proteínas Nucleares
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Regulação da Expressão Gênica
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Proteínas de Ciclo Celular
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Ilhas de CpG
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Proteínas Mitocondriais
/
Quadruplex G
Tipo de estudo:
Diagnostic_studies
Limite:
Animals
Idioma:
En
Revista:
BMC Mol Biol
Assunto da revista:
BIOLOGIA MOLECULAR
Ano de publicação:
2017
Tipo de documento:
Article
País de afiliação:
Japão