Acylation of Superoxide Dismutase 1 (SOD1) at K122 Governs SOD1-Mediated Inhibition of Mitochondrial Respiration.

Published online

Journal Article

In this study, we employed proteomics to identify mechanisms of posttranslational regulation on cell survival signaling proteins. We focused on Cu-Zn superoxide dismutase (SOD1), which protects cells from oxidative stress. We found that acylation of K122 on SOD1, while not impacting SOD1 catalytic activity, suppressed the ability of SOD1 to inhibit mitochondrial metabolism at respiratory complex I. We found that deacylase depletion increased K122 acylation on SOD1, which blocked the suppression of respiration in a K122-dependent manner. In addition, we found that acyl-mimicking mutations at K122 decreased SOD1 accumulation in mitochondria, initially hinting that SOD1 may inhibit respiration directly within the intermembrane space (IMS). However, surprisingly, we found that forcing the K122 acyl mutants into the mitochondria with an IMS-targeting tag did not recover their ability to suppress respiration. Moreover, we found that suppressing or boosting respiration levels toggled SOD1 in or out of the mitochondria, respectively. These findings place SOD1-mediated inhibition of respiration upstream of its mitochondrial localization. Lastly, deletion-rescue experiments show that a respiration-defective mutant of SOD1 is also impaired in its ability to rescue cells from toxicity caused by SOD1 deletion. Together, these data suggest a previously unknown interplay between SOD1 acylation, metabolic regulation, and SOD1-mediated cell survival.

Full Text

Duke Authors

Cited Authors

  • Banks, CJ; Rodriguez, NW; Gashler, KR; Pandya, RR; Mortenson, JB; Whited, MD; Soderblom, EJ; Thompson, JW; Moseley, MA; Reddi, AR; Tessem, JS; Torres, MP; Bikman, BT; Andersen, JL

Published Date

  • October 15, 2017

Published In

Volume / Issue

  • 37 / 20

PubMed ID

  • 28739857

Pubmed Central ID

  • 28739857

Electronic International Standard Serial Number (EISSN)

  • 1098-5549

Digital Object Identifier (DOI)

  • 10.1128/MCB.00354-17

Language

  • eng

Conference Location

  • United States