Tricarboxylic acid cycle activity suppresses acetylation of mitochondrial proteins during early embryonic development in Caenorhabditis elegans

Kazumasa Hada, Keiko Hirota, Ai Inanobe, Koichiro Kako, Mai Miyata, Sho Araoi, Masaki Matsumoto, Reiya Ohta, Mitsuhiro Arisawa, Hiroaki Daitoku, Toshikatsu Hanada, Akiyoshi Fukamizu

Research output: Contribution to journalArticle

3 Citations (Scopus)

Abstract

The tricarboxylic acid (TCA) cycle (or citric acid cycle) is responsible for the complete oxidation of acetyl-CoA and formation of intermediates required for ATP production and other anabolic pathways, such as amino acid synthesis. Here, we uncovered an additional mechanism that may help explain the essential role of the TCA cycle in the early embryogenesis of Caenorhabditis elegans. We found that knockdown of citrate synthase (cts-1), the initial and rate-limiting enzyme of the TCA cycle, results in early embryonic arrest, but that this phenotype is not because of ATP and amino acid depletions. As a possible alternative mechanism explaining this developmental deficiency, we observed that cts-1 RNAi embryos had elevated levels of intracellular acetyl-CoA, the starting metabolite of the TCA cycle. Of note, we further discovered that these embryos exhibit hyperacetylation of mitochondrial proteins. We found that supplementation with acetylase-inhibiting polyamines, including spermidine and putrescine, counteracted the protein hyperacetylation and developmental arrest in the cts-1 RNAi embryos. Contrary to the hypothesis that spermidine acts as an acetyl sink for elevated acetyl-CoA, the levels of three forms of acetylspermidine, N1-acetylspermidine, N8-acetylspermidine, and N1,N8-diacetylspermidine, were not significantly increased in embryos treated with exogenous spermidine. Instead, we demonstrated that the mitochondrial deacetylase sirtuin 4 (encoded by the sir-2.2 gene) is required for spermidine’s suppression of protein hyperacetylation and developmental arrest in the cts-1 RNAi embryos. Taken together, these results suggest the possibility that during early embryogenesis, acetyl-CoA consumption by the TCA cycle in C. elegans prevents protein hyperacetylation and thereby protects mitochondrial function.

Original languageEnglish
Pages (from-to)3091-3099
Number of pages9
JournalJournal of Biological Chemistry
Volume294
Issue number9
DOIs
Publication statusPublished - Mar 1 2019

All Science Journal Classification (ASJC) codes

  • Biochemistry
  • Molecular Biology
  • Cell Biology

Fingerprint Dive into the research topics of 'Tricarboxylic acid cycle activity suppresses acetylation of mitochondrial proteins during early embryonic development in Caenorhabditis elegans'. Together they form a unique fingerprint.

  • Cite this

    Hada, K., Hirota, K., Inanobe, A., Kako, K., Miyata, M., Araoi, S., Matsumoto, M., Ohta, R., Arisawa, M., Daitoku, H., Hanada, T., & Fukamizu, A. (2019). Tricarboxylic acid cycle activity suppresses acetylation of mitochondrial proteins during early embryonic development in Caenorhabditis elegans. Journal of Biological Chemistry, 294(9), 3091-3099. https://doi.org/10.1074/jbc.RA118.004726