ABHD11 regulates 2-oxoglutarate abundance by protecting mitochondrial lipoylated proteins from lipid peroxidation damage
Peter SJ Bailey, Brian M Ortmann, Jack W Houghton, Ana S H Costa, Robin Antrobus, Christian Frezza, James A Nathan
Received Date: 9th January 20
2-oxoglutarate (2-OG or a-ketoglutarate) relates mitochondrial metabolism to cell function by modulating the activity of 2-OG dependent dioxygenases (2-OG DDs) involved in the hypoxia response and DNA/histone modifications. However, metabolic pathways that regulate these oxygen and 2-OG sensitive enzymes remain poorly understood. Here, using CRISPR Cas9 genome-wide mutagenesis to screen for genetic determinants of 2-OG levels, we uncover a redox sensitive mitochondrial lipoylation pathway, dependent on the mitochondrial hydrolase ABHD11, that signals changes in mitochondrial 2-OG metabolism to 2-OG DD function. ABHD11 loss or inhibition drives a rapid increase in 2-OG levels by impairing lipoylation of the 2-OG dehydrogenase complex (OGDHc) – the rate limiting step for mitochondrial 2-OG metabolism. Rather than facilitating lipoate conjugation, ABHD11 protects the catalytic lipoyl domain from lipid peroxidation products formed by oxidative damage, demonstrating a requirement for a lipoyl repair pathway in human cells, and highlighting how the redox sensitivity of lipoylation modulates 2-OG metabolism.
Read in full at bioRxiv.
This is an abstract of a preprint hosted on an independent third party site. It has not been peer reviewed but is currently under consideration at Nature Communications.