Journal article
Progressive aggregation despite chaperone associations of a mutant SOD1-YFP in transgenic mice that develop ALS
Proceedings of the National Academy of Sciences - PNAS, Vol.106(5), pp.1392-1397
02/03/2009
DOI: 10.1073/pnas.0813045106
PMCID: PMC2631083
PMID: 19171884
Abstract
Recent studies suggest that superoxide dismutase 1 (SOD1)-linked amyotrophic lateral sclerosis results from destabilization and misfolding of mutant forms of this abundant cytosolic enzyme. Here, we have tracked the expression and fate of a misfolding-prone human SOD1, G85R, fused to YFP, in a line of transgenic G85R SOD1-YFP mice. These mice, but not wild-type human SOD1-YFP transgenics, developed lethal paralyzing motor symptoms at 9 months. In situ RNA hybridization of spinal cords revealed predominant expression in motor neurons in spinal cord gray matter in all transgenic animals. Concordantly, G85R SOD-YFP was diffusely fluorescent in motor neurons of animals at 1 and 6 months of age, but at the time of symptoms, punctate aggregates were observed in cell bodies and processes. Biochemical analyses of spinal cord soluble extracts indicated that G85R SOD-YFP behaved as a misfolded monomer at all ages. It became progressively insoluble at 6 and 9 months of age, associated with presence of soluble oligomers observable by gel filtration. Immunoaffinity capture and mass spectrometry revealed association of G85R SOD-YFP, but not WT SOD-YFP, with the cytosolic chaperone Hsc70 at all ages. In addition, 3 Hsp110's, nucleotide exchange factors for Hsp70s, were captured at 6 and 9 months. Despite such chaperone interactions, G85R SOD-YFP formed insoluble inclusions at late times, containing predominantly intermediate filament proteins. We conclude that motor neurons, initially “compensated” to maintain the misfolded protein in a soluble state, become progressively unable to do so.
Details
- Title: Subtitle
- Progressive aggregation despite chaperone associations of a mutant SOD1-YFP in transgenic mice that develop ALS
- Creators
- Jiou Wang - Howard Hughes Medical InstituteGeorge W Farr - Howard Hughes Medical InstituteCaroline J Zeiss - Section of Comparative Medicine, andDiego J Rodriguez-Gil - Department of Neurosurgery, Yale University School of Medicine, New Haven, CT 06510Jean H Wilson - Section of Comparative Medicine, andKrystyna Furtak - Howard Hughes Medical InstituteD. Thomas Rutkowski - Howard Hughes Medical Institute and Department of Biological Chemistry, University of Michigan Medical Center, Ann Arbor, MI 48109Randal J Kaufman - Howard Hughes Medical Institute and Department of Biological Chemistry, University of Michigan Medical Center, Ann Arbor, MI 48109Cristian I Ruse - Department of Chemical Physiology, The Scripps Research Institute, La Jolla, CA 92037John R Yates - Department of Chemical Physiology, The Scripps Research Institute, La Jolla, CA 92037Steve Perrin - ALS Therapeutic Development Institute, Cambridge, MA 02142; andMel B Feany - Department of Pathology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02115Arthur L Horwich - Howard Hughes Medical Institute
- Resource Type
- Journal article
- Publication Details
- Proceedings of the National Academy of Sciences - PNAS, Vol.106(5), pp.1392-1397
- DOI
- 10.1073/pnas.0813045106
- PMID
- 19171884
- PMCID
- PMC2631083
- NLM abbreviation
- Proc Natl Acad Sci U S A
- ISSN
- 0027-8424
- eISSN
- 1091-6490
- Publisher
- National Academy of Sciences
- Language
- English
- Date published
- 02/03/2009
- Academic Unit
- Anatomy and Cell Biology; Internal Medicine
- Record Identifier
- 9984094405202771
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