Human Molecular Genetics Advance Access published online on January 27, 2005
Human Molecular Genetics, doi:10.1093/hmg/ddi067
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
1 Laboratoire de Génétique et Physiologie du Développement, Developmental Biology Institute of Marseille, CNRS-INSERM-Université de la Méditerranée, Campus de Luminy, Case 907, F-13288 Marseille Cedex 9, France
* To whom correspondence should be addressed. Huntington's disease (HD) is a late onset heritable neurodegenerative disorder caused by expansion of a polyglutamine (polyQ) sequence in the protein Huntingtin (Htt). Transgenic models in mice have suggested that the motor and cognitive deficits associated to this disease are triggered by extended neuronal and possibly glial dysfunction, whereas neuronal death occurs late and selectively. Here we provide in vivo evidence that expanded polyQ peptides antagonize epidermal growth factor receptor (EGFR) signaling in Drosophila glia. We targeted the expression of the polyQ-containing domain of Htt or an extended polyQ peptide alone in a subset of Drosophila glial cells, where the only fly glutamate transporter, dEAAT1, is detected. This resulted in formation of nuclear inclusions, progressive decrease in dEAAT1 transcription and shortened adult lifespan, but no significant glial cell death. We observed that brain expression of dEAAT1 is normally sustained by the EGFR-Ras-extracellular signal-regulated kinase (ERK) signaling pathway, suggesting that polyQ could act by antagonizing this pathway. We found that the presence of polyQ peptides indeed abolished dEAAT1 upregulation by constitutively active EGFR, and potently inhibited EGFR-mediated ERK activation in fly glial cells. Long polyQ also limited the effect of activated EGFR on Drosophila eye development. Our results further indicate that the polyQ acts at an upstream step in the pathway, situated between EGFR and ERK activation. This suggests that disruption of EGFR signaling and ensuing glial cell dysfunction could play a direct role in the pathogenesis of HD and other polyQ diseases in humans.
Article
Expanded polyglutamine peptides disrupt EGF receptor signaling and glutamate transporter expression in Drosophila
2 Inserm U114, Collège de France, 11 place Marcellin-Berthelot, 75231 Paris Cedex 05, France
Serge Birman, E-mail: birman{at}ibdm.univ-mrs.fr
![]()
Abstract ![]()
CiteULike
Connotea
Del.icio.us What's this?
This article has been cited by other articles:
![]() |
D. S. Verbeek, J. Goedhart, L. Bruinsma, R. J. Sinke, and E. A. Reits PKC{gamma} mutations in spinocerebellar ataxia type 14 affect C1 domain accessibility and kinase activity leading to aberrant MAPK signaling J. Cell Sci., July 15, 2008; 121(14): 2339 - 2349. [Abstract] [Full Text] [PDF] |
||||
![]() |
S.-Y. Chou, J.-Y. Weng, H.-L. Lai, F. Liao, S. H. Sun, P.-H. Tu, D. W. Dickson, and Y. Chern Expanded-Polyglutamine Huntingtin Protein Suppresses the Secretion and Production of a Chemokine (CCL5/RANTES) by Astrocytes J. Neurosci., March 26, 2008; 28(13): 3277 - 3290. [Abstract] [Full Text] [PDF] |
||||
![]() |
J.-C. Lievens, M. Iche, M. Laval, C. Faivre-Sarrailh, and S. Birman AKT-sensitive or insensitive pathways of toxicity in glial cells and neurons in Drosophila models of Huntington's disease Hum. Mol. Genet., March 15, 2008; 17(6): 882 - 894. [Abstract] [Full Text] [PDF] |
||||
![]() |
A. Li, Z. Xie, Y. Dong, K. M. McKay, M. L. McKee, and R. E. Tanzi Isolation and characterization of the Drosophila ubiquilin ortholog dUbqln: in vivo interaction with early-onset Alzheimer disease genes Hum. Mol. Genet., November 1, 2007; 16(21): 2626 - 2639. [Abstract] [Full Text] [PDF] |
||||
![]() |
H. Varma, R. Cheng, C. Voisine, A. C. Hart, and B. R. Stockwell Inhibitors of metabolism rescue cell death in Huntington's disease models PNAS, September 4, 2007; 104(36): 14525 - 14530. [Abstract] [Full Text] [PDF] |
||||
![]() |
E. Scappini, T.-W. Koh, N. P. Martin, and J. P. O'Bryan Intersectin enhances huntingtin aggregation and neurodegeneration through activation of c-Jun-NH2-terminal kinase Hum. Mol. Genet., August 1, 2007; 16(15): 1862 - 1871. [Abstract] [Full Text] [PDF] |
||||
![]() |
J.-Y. Shin, Z.-H. Fang, Z.-X. Yu, C.-E. Wang, S.-H. Li, and X.-J. Li Expression of mutant huntingtin in glial cells contributes to neuronal excitotoxicity J. Cell Biol., December 19, 2005; 171(6): 1001 - 1012. [Abstract] [Full Text] [PDF] |
||||




