Ferroptosis Regulation by the NGLY1/NFE2L1 Pathway

Abstract

Ferroptosis is an oxidative form of non-apoptotic cell death whose transcriptional regulation is poorly understood. Capncollar (CNC) transcription factors including Nuclear Factor Erythroid-2 Related Factor 1 (NFE2L1/NRF1) and NFE2L2 (NRF2) are important regulators of oxidative stress responses. Here, we report that NFE2L1 expression inhibits ferroptosis, independent of NFE2L2. NFE2L1 inhibits ferroptosis by promoting expression of the key anti-ferroptotic lipid hydroperoxidase glutathione peroxidase 4 (GPX4). NFE2L1 abundance and function are regulated post-translationally by N-glycosylation. Functional maturation of NFE2L1 requires deglycosylation by cytosolic peptide:N-glycanase 1 (NGLY1). We find that loss of NGLY1 or NFE2L1 enhances ferroptosis sensitivity. Expression of wild-type NGLY1 but not a disease-associated NGLY1 mutant inhibits ferroptosis, and this effect is dependent on the presence of NFE2L1. Enhanced ferroptosis sensitivity in NFE2L1 and NFE2L2 knockout cells can be potently reverted by expression of an NFE2L1 mutant containing eight asparagine-to-aspartate protein sequence substitutions, which mimic NGLY1-catalyzed sequence editing. Enhanced ferroptosis sensitivity in NGLY1/NFE2L1 pathway mutants could also be reversed by overexpression of NFE2L2. These results suggest that ferroptosis sensitivity is regulated by NGLY1-catalyzed NFE2L1 deglycosylation, and highlight a broad role for CNC transcription factors in ferroptosis regulation. Significance StatementFerroptosis is an oxidative form of cell death whose biochemical regulation remains incompletely understood. NFE2L1/NRF1 is a capncollar (CNC) transcription factor whose role in ferroptosis regulation is unclear. Unlike the CNC family member NFE2L2/NRF2, NFE2L1 is an N-glycoprotein whose abundance is regulated by post-translational deglycosylation catalyzed by the enzyme peptide:N-glycanase 1 (NGLY1). Our results indicate that NGLY1-mediated NFE2L1 deglycosylation, resulting in editing of the NFE2L1 amino acid sequence, is necessary for NFE2L1 to inhibit ferroptosis. Mechanistically, NFE2L1 inhibits ferroptosis by via the anti-ferroptotic protein GPX4. This work demonstrates that CNC transcription factors beyond NFE2L2 can regulate ferroptosis. This work may suggest a role of misregulation of ferroptosis in NGLY1 deficiency, an ultrarare genetic disorder.