Human Molecular Genetics Advance Access published online on June 2, 2004
Human Molecular Genetics, doi:10.1093/hmg/ddh172
© 2004 by Oxford University Press
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
1 Department of Biochemistry and Graduate Program in Genetics & Molecular Biology, Emory University School of Medicine, Atlanta, GA 30322
* To whom correspondence should be addressed. E-mail: dreines{at}emory.edu.
Fragile X syndrome is due to mutation of the FMR1 gene. The most common mutation is an expansion of a CGG repeat in the 5' UTR that triggers dense DNA methylation and formation of a heterochromatin-like structure which lead to transcriptional silencing. In vitro experiments have identified several transcription factors, including Sp1, Nrf-1, and USF1/2 as potential regulators of normal FMR1 promoter activity. Using CpG methylation-deficient Drosophila cells, we demonstrate in vivo that Nrf-1 and Sp1 are strong, synergistic activators of an unmethylated human FMR1-driven reporter, while USF1/2 and Max repress this activation. In addition, analyses of transcription factor activity upon DNA methylation of the reporter show that Sp1 activity was largely intact when the promoter was densely methylated, but Nrf-1 transactivation was very sensitive to dense methylation. Notably, Nrf-1 transactivation was relatively insensitive to methylation of cytosines only at its binding site. FMR1 reporter activity is also reduced in HeLa cells after expression of a short interfering RNA directed against endogenous Nrf-1. Using chromatin immunoprecipitation, we demonstrate directly that Sp1 and Nrf-1 occupy the human FMR1 promoter in vivo and these interactions are disrupted in fragile X patient cells. In addition, we discover that Max resides at the FMR1 promoter and show that USF1/2 but not c-Myc are present at endogenous FMR1. These findings provide the first direct in vivo evidence identifying the specific transcription factors that regulate FMR1.
Article
Occupancy and synergistic activation of the FMR1 promoter by Nrf-1 and Sp1 in vivo
2 Department of Biochemistry and Graduate Program in Genetics & Molecular Biology, Emory University School of Medicine, Atlanta, GA 30322; Department of Human Genetics, Emory University, Atlanta, GA
Abstract 
CiteULike 
Connotea 
Del.icio.us What's this?
This article has been cited by other articles:
|
|
 |
|
  J. Fu, J. Zhang, F. Jin, J. Patchefsky, K.-H. Braunewell, and A. J. Klein-Szanto Promoter Regulation of the Visinin-like Subfamily of Neuronal Calcium Sensor Proteins by Nuclear Respiratory Factor-1 J. Biol. Chem., October 2, 2009; 284(40): 27577 - 27586. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 S. J. Gray, J. Gerhardt, W. Doerfler, L. E. Small, and E. Fanning An Origin of DNA Replication in the Promoter Region of the Human Fragile X Mental Retardation (FMR1) Gene Mol. Cell. Biol., January 15, 2007; 27(2): 426 - 437. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 K. T. Smith, R. D. Nicholls, and D. Reines The gene encoding the fragile X RNA-binding protein is controlled by nuclear respiratory factor 2 and the CREB family of transcription factors Nucleic Acids Res., February 25, 2006; 34(4): 1205 - 1215. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
D. J. Mulvihill, K. N. Edamura, K. A. Hagerman, C. E. Pearson, and Y.-H. Wang Effect of CAT or AGG Interruptions and CpG Methylation on Nucleosome Assembly upon Trinucleotide Repeats on Spinocerebellar Ataxia, Type 1 and Fragile X Syndrome J. Biol. Chem., February 11, 2005; 280(6): 4498 - 4503. [Abstract] [Full Text] [PDF]
|
|