Disruption of the TCA cycle reveals an ATF4-dependent integration of redox and amino acid metabolism
- University of Cambridge, United Kingdom
- University of Edinburgh, United Kingdom
Abstract
The Tricarboxylic Acid Cycle (TCA) cycle is arguably the most critical metabolic cycle in physiology and exists as an essential interface coordinating cellular metabolism, bioenergetics, and redox homeostasis. Despite decades of research, a comprehensive investigation into the consequences of TCA cycle dysfunction remains elusive. Here, we targeted two TCA cycle enzymes, fumarate hydratase (FH) and succinate dehydrogenase (SDH), and combined metabolomics, transcriptomics, and proteomics analyses to fully appraise the consequences of TCA cycle inhibition (TCAi) in murine kidney epithelial cells. Our comparative approach shows that TCAi elicits a convergent rewiring of redox and amino acid metabolism dependent on the activation of ATF4 and the integrated stress response (ISR). Furthermore, we also uncover a divergent metabolic response, whereby acute FHi, but not SDHi, can maintain asparagine levels via reductive carboxylation and maintenance of cytosolic aspartate synthesis. Our work highlights an important interplay between the TCA cycle, redox biology and amino acid homeostasis.
Data availability
All the transcriptomics. proteomics and uncropped blots data have been deposited in Dryad.
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Label-free proteomics - thenoyltrifluoroacetone (TTFA)Dryad Digital Repository, doi:10.5061/dryad.h44j0zpkt.
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Label-free proteomics - fumarate hydratase inhibitor (FHIN-1)Dryad Digital Repository, doi:10.5061/dryad.fttdz08t9.
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TruSeq stranded mRNA - Atpenin A5 (AA5)Dryad Digital Repository, doi:10.5061/dryad.08kprr536.
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TruSeq stranded mRNA_Fumarate hydratase inhibitor (FHIN-1)Dryad Digital Repository, doi:10.5061/dryad.bk3j9kdcq.
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Western blot uncropped blotsDryad Digital Repository, doi:10.5061/dryad.08kprr537.
Article and author information
Author details
Christopher A Powell
Funding
Medical Research Council (MRC_MC_UU_12022/6.)
- Christian Frezza
H2020 European Research Council (ERC819920)
- Dylan Gerard Ryan
The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.
Copyright
© 2021, Ryan et al.
This article is distributed under the terms of the Creative Commons Attribution License permitting unrestricted use and redistribution provided that the original author and source are credited.
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Disruption of the TCA cycle reveals an ATF4-dependent integration of redox and amino acid metabolism
eLife 10:e72593.
https://doi.org/10.7554/eLife.72593
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