Elevated FMR1 mRNA in premutation carriers is due to increased transcription

Details

Serval ID
serval:BIB_2C9D5467FCF6
Type
Article: article from journal or magazin.
Collection
Publications
Title
Elevated FMR1 mRNA in premutation carriers is due to increased transcription
Journal
RNA
Author(s)
Tassone F., Beilina A., Carosi C., Albertosi S., Bagni C., Li L., Glover K., Bentley D., Hagerman P. J.
ISSN
1355-8382 (Print)
ISSN-L
1355-8382
Publication state
Published
Issued date
04/2007
Volume
13
Number
4
Pages
555-62
Notes
Tassone, Flora
Beilina, Alexandra
Carosi, Chiara
Albertosi, Serena
Bagni, Claudia
Li, Lexin
Glover, Kira
Bentley, David
Hagerman, Paul J
eng
R01 GM058613/GM/NIGMS NIH HHS/
GM58613/GM/NIGMS NIH HHS/
PH40661/PH/PHPPO CDC HHS/
Research Support, N.I.H., Extramural
Research Support, Non-U.S. Gov't
2007/02/07 09:00
RNA. 2007 Apr;13(4):555-62. Epub 2007 Feb 5.
Abstract
Carriers of premutation alleles (55-200 CGG repeats) of the fragile X mental retardation 1 (FMR1) gene have levels of FMR1 mRNA that are elevated by as much as 10-fold in peripheral blood leukocytes and CNS tissue. The excess expanded-repeat mRNA, per se, is now believed to result in forms of clinical involvement that are largely restricted to premutation carriers, including the neurodegenerative disorder, fragile X-associated tremor/ataxia syndrome (FXTAS). Although evidence to date suggests that the elevated mRNA is not due to increased stability, the basis for the increase is not known. In the current study, we have determined the relative transcriptional activities of premutation and normal FMR1 alleles using a highly sensitive nuclear run-on assay that involves immunocapture of digoxigenin-modified run-on transcripts followed by PCR amplification of the nascent transcripts. Using the nuclear run-on approach, we demonstrate that the rate of run-on synthesis of FMR1 transcripts is increased in premutation alleles. The current run-on assay should be broadly applicable to studies of other genes with promoters of weak to moderate strength. The fraction of capped FMR1 mRNA remains unaltered for premutation transcripts, indicating that elevated message levels are not due to premature escape from the cotranscriptional capping process. We also show that, in contrast to the situation with myotonic dystrophy, there is no net nuclear sequestration of premutation FMR1 mRNA. Finally, we have demonstrated that AGG interruptions within the CGG repeat element do not influence FMR1 mRNA levels.
Keywords
Alleles, Fragile X Mental Retardation Protein/genetics/*metabolism, Fragile X Syndrome/genetics/*metabolism, *Heterozygote, Leukocytes, Mononuclear/metabolism, Nerve Tissue Proteins/genetics/*metabolism, Nucleic Acid Amplification Techniques, Polymerase Chain Reaction, RNA, Messenger/*metabolism, *Transcription, Genetic, Trinucleotide Repeat Expansion/genetics
Pubmed
Open Access
Yes
Create date
06/03/2017 17:23
Last modification date
20/08/2019 13:11
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