Journal Article

Heterodimer formation of wild-type and amyotrophic lateral sclerosis-causing mutant Cu/Zn-superoxide dismutase induces toxicity independent of protein aggregation

Heidrun Witan, Andreas Kern, Ingrid Koziollek-Drechsler, Rebecca Wade, Christian Behl and Albrecht M. Clement

in Human Molecular Genetics

Volume 17, issue 10, pages 1373-1385
Published in print May 2008 | ISSN: 0964-6906
Published online January 2008 | e-ISSN: 1460-2083 | DOI: http://dx.doi.org/10.1093/hmg/ddn025
Heterodimer formation of wild-type and amyotrophic lateral sclerosis-causing mutant Cu/Zn-superoxide dismutase induces toxicity independent of protein aggregation

Show Summary Details

Preview

Recent studies provide evidence that wild-type Cu/Zn-superoxide dismutase (SOD1(hWT)) might be an important factor in mutant SOD1-mediated amyotrophic lateral sclerosis (ALS). In order to investigate its functional role in the pathogenesis of ALS, we designed fusion proteins of two SOD1 monomers linked by a polypeptide. We demonstrated that wild-type-like mutants, but not SOD1(G85R) homodimers, as well as mutant heterodimers including SOD1(G85R)-SOD1(hWT) display dismutase activity. Mutant homodimers showed an increased aggregation compared with the corresponding heterodimers in cell cultures and transgenic Caenorhabditis elegans, although SOD1(G85R) heterodimers are more toxic in functional assays. Our data show that (i) toxicity of mutant SOD1 is not correlated to its aggregation potential; (ii) dismutase-inactive mutants form dismutase-active heterodimers with SOD1(hWT); (iii) SOD1(hWT) can be converted to contribute to disease by forming active heterodimers. Therefore, we conclude that toxicity of mutant SOD1 is at least partially mediated through heterodimer formation with SOD1(hWT) in vivo and does not correlate with the aggregation potential of individual mutants.

Journal Article.  7011 words.  Illustrated.

Subjects: Genetics and Genomics

Full text: subscription required

How to subscribe Recommend to my Librarian

Users without a subscription are not able to see the full content. Please, subscribe or login to access all content.