Human Molecular Genetics Advance Access originally published online on October 20, 2005
Human Molecular Genetics 2005 14(23):3661-3671; doi:10.1093/hmg/ddi394
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Induction of inclusion formation and disruption of lamin A/C structure by premutation CGG-repeat RNA in human cultured neural cells
1Department of Biochemistry and Molecular Medicine, University of California Davis, School of Medicine, Davis, CA 95616, USA, 2Departamento de Genetica, Facultad de Medicina, UDELAR, Montevideo, Uruguay and 3Children's Hospital of Orange County Research Institute, Orange, CA 92868, USA
* To whom correspondence should be addressed at: Department of Biochemistry and Molecular Medicine, University of California Davis, School of Medicine, One Shields Avenue, Davis, CA 95616, USA. Tel: +1 5307547266; Fax: +1 5307547269; Email: pjhagerman{at}ucdavis.edu
Received August 2, 2005; Accepted October 13, 2005
Fragile X-associated tremor/ataxia syndrome (FXTAS) is a neurodegenerative disorder that affects some adult carriers of pre-mutation alleles (55200 CGG repeats) of the fragile X mental retardation 1 (FMR1) gene. FXTAS is thought to be caused by a toxic gain-of-function of the expanded CGG-repeat FMR1 mRNA, which is found in the neuronal and astrocytic intranuclear inclusions associated with the disorder. Using a reporter construct with a FMR1 5' untranslated region harboring an expanded (premutation) CGG repeat, we have demonstrated that intranuclear inclusions can be formed in both primary neural progenitor cells and established neural cell lines. As with the inclusions found in post-mortem tissue, the inclusions induced by the expanded CGG repeat are
B-crystallin-positive; however, inclusions in culture are not associated with ubiquitin, indicating that incorporation of ubiquitinated proteins is a later event in the disease process. The absence of ubiquitinated proteins also argues against a model in which inclusion formation is due to a failure of the proteasomal degradative machinery. The presence of the expanded CGG repeat, as RNA, results in reduced cell viability as well as the disruption of the normal architecture of lamin A/C within the nucleus. This last observation, and the findings that lamin A/C is present in both the inclusions of FXTAS patients and the inclusions in cell culture, suggests that lamin A/C dysregulation may be a component of the pathogenesis of FXTAS; in particular, the CharcotMarieTooth-type neuropathy associated with FXTAS may represent a functional laminopathy.
![]()
CiteULike
Connotea
Del.icio.us What's this?
This article has been cited by other articles:
![]() |
K. Usdin The biological effects of simple tandem repeats: Lessons from the repeat expansion diseases Genome Res., July 1, 2008; 18(7): 1011 - 1019. [Abstract] [Full Text] [PDF] |
||||
![]() |
K. Soontarapornchai, R. Maselli, G. Fenton-Farrell, F. Tassone, P. J. Hagerman, D. Hessl, and R. J. Hagerman Abnormal Nerve Conduction Features in Fragile X Premutation Carriers Arch Neurol, April 1, 2008; 65(4): 495 - 498. [Abstract] [Full Text] [PDF] |
||||
![]() |
K. Amiri, R. J. Hagerman, and P. J. Hagerman Fragile X Associated Tremor/Ataxia Syndrome: An Aging Face of the Fragile X Gene Arch Neurol, January 1, 2008; 65(1): 19 - 25. [Full Text] [PDF] |
||||
![]() |
P. D. Ladd, L. E. Smith, N. A. Rabaia, J. M. Moore, S. A. Georges, R. S. Hansen, R. J. Hagerman, F. Tassone, S. J. Tapscott, and G. N. Filippova An antisense transcript spanning the CGG repeat region of FMR1 is upregulated in premutation carriers but silenced in full mutation individuals Hum. Mol. Genet., December 15, 2007; 16(24): 3174 - 3187. [Abstract] [Full Text] [PDF] |
||||
![]() |
F. Tassone, A. Beilina, C. Carosi, S. Albertosi, C. Bagni, L. Li, K. Glover, D. Bentley, and P. J. Hagerman Elevated FMR1 mRNA in premutation carriers is due to increased transcription RNA, April 1, 2007; 13(4): 555 - 562. [Abstract] [Full Text] [PDF] |
||||
![]() |
R. J. Osborne and C. A. Thornton RNA-dominant diseases Hum. Mol. Genet., October 15, 2006; 15(suppl_2): R162 - R169. [Abstract] [Full Text] [PDF] |
||||



