Mutant SOD1 from spinal cord of G93A rats is destabilized and binds to inner mitochondrial membrane

Toni Ahtoniemi; Merja Jaronen; Velta Keksa-Goldsteine; Gundars Goldsteins; Jari Koistinaho

Neurobiology of Disease (Dec 2008)

Mutant SOD1 from spinal cord of G93A rats is destabilized and binds to inner mitochondrial membrane

Toni Ahtoniemi,
Merja Jaronen,
Velta Keksa-Goldsteine,
Gundars Goldsteins,
Jari Koistinaho

Affiliations

Toni Ahtoniemi: Department of Neurobiology, A. I. Virtanen Institute for Molecular Sciences, University of Kuopio, P.O. Box 1627, FIN-70211 Kuopio, Finland; Biocenter Kuopio, University of Kuopio, P.O.B. 1627, FIN-70211 Kuopio, Finland
Merja Jaronen: Department of Neurobiology, A. I. Virtanen Institute for Molecular Sciences, University of Kuopio, P.O. Box 1627, FIN-70211 Kuopio, Finland; Biocenter Kuopio, University of Kuopio, P.O.B. 1627, FIN-70211 Kuopio, Finland
Velta Keksa-Goldsteine: Department of Neurobiology, A. I. Virtanen Institute for Molecular Sciences, University of Kuopio, P.O. Box 1627, FIN-70211 Kuopio, Finland; Biocenter Kuopio, University of Kuopio, P.O.B. 1627, FIN-70211 Kuopio, Finland
Gundars Goldsteins: Department of Neurobiology, A. I. Virtanen Institute for Molecular Sciences, University of Kuopio, P.O. Box 1627, FIN-70211 Kuopio, Finland; Biocenter Kuopio, University of Kuopio, P.O.B. 1627, FIN-70211 Kuopio, Finland
Jari Koistinaho: Department of Neurobiology, A. I. Virtanen Institute for Molecular Sciences, University of Kuopio, P.O. Box 1627, FIN-70211 Kuopio, Finland; Biocenter Kuopio, University of Kuopio, P.O.B. 1627, FIN-70211 Kuopio, Finland; Department of Oncology, Kuopio University Hospital, Kuopio, Finland; Corresponding author. Department of Neurobiology, A. I. Virtanen Institute for Molecular Sciences, University of Kuopio, P.O. Box 1627, FIN-70211 Kuopio, Finland. Fax: +358 1716 3030.

Journal volume & issue: Vol. 32, no. 3
pp. 479 – 485

Abstract

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Mutations in Cu/Zn superoxide dismutase (SOD1) cause amyotrophic lateral sclerosis (ALS). Mechanisms of mutant SOD1 toxicity are unknown, but increased SOD1 activity can boost production of reactive oxygen species (ROS) in the mitochondrial intermembrane space (IMS). Using non-reducing SDS-PAGE we found that in G93A-SOD1 rats the mutant SOD1 was prominently destabilized only in the diseased spinal cord, where this mutant enzyme was also up regulated in the IMS with increased ability to bind the inner membrane of isolated non-transgenic mitoplasts. These mitoplasts increased ROS production when exposed to mutant SOD1 from the spinal cord at the presymptomatic stage. The levels of disulfide-reduced SOD1 peaked at the end stage of the disease, whereas protein disulfide isomerase (PDI), a chaperone capable of rearranging disulfide bonds between cysteine residues of SOD1, was increased prior to the end stage. IMS binding and increased ROS production by destabilized SOD1 may contribute to mitochondrial damage in G93A-SOD1 rats.

Published in Neurobiology of Disease

ISSN: 0969-9961 (Print); 1095-953X (Online)
Publisher: Elsevier
Country of publisher: United States
LCC subjects: Medicine: Internal medicine: Neurosciences. Biological psychiatry. Neuropsychiatry
Website: https://www.journals.elsevier.com/neurobiology-of-disease

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