Dataset Information

Loss of Cardiolipin Leads to Perturbation of Acetyl-CoA Synthesis.

ABSTRACT: Cardiolipin (CL), the signature phospholipid of mitochondrial membranes, plays an important role in mitochondrial processes and bioenergetics. CL is synthesized de novo and undergoes remodeling in the mitochondrial membranes. Perturbation of CL remodeling leads to the rare X-linked genetic disorder Barth syndrome, which shows disparities in clinical presentation. To uncover biochemical modifiers that exacerbate CL deficiency, we carried out a synthetic genetic array screen to identify synthetic lethal interactions with the yeast CL synthase mutant crd1?. The results indicated that crd1? is synthetically lethal with mutants in pyruvate dehydrogenase (PDH), which catalyzes the conversion of pyruvate to acetyl-CoA. Acetyl-CoA levels were decreased in the mutant. The synthesis of acetyl-CoA depends primarily on the PDH-catalyzed conversion of pyruvate in the mitochondria and on the PDH bypass in the cytosol, which synthesizes acetyl-CoA from acetate. Consistent with perturbation of the PDH bypass, crd1? cells grown on acetate as the sole carbon source exhibited decreased growth, decreased acetyl-CoA, and increased intracellular acetate levels resulting from decreased acetyl-CoA synthetase activity. PDH mRNA and protein levels were up-regulated in crd1? cells, but PDH enzyme activity was not increased, indicating that PDH up-regulation did not compensate for defects in the PDH bypass. These findings demonstrate for the first time that CL is required for acetyl-CoA synthesis, which is decreased in CL-deficient cells as a result of a defective PDH bypass pathway.

SUBMITTER: Raja V

PROVIDER: S-EPMC5247643 | biostudies-other | 2017 Jan

REPOSITORIES: biostudies-other

ACCESS DATA

Publications

Loss of Cardiolipin Leads to Perturbation of Acetyl-CoA Synthesis.

Raja Vaishnavi V Joshi Amit S AS Li Guiling G Maddipati Krishna Rao KR Greenberg Miriam L ML

The Journal of biological chemistry 20161209 3

Cardiolipin (CL), the signature phospholipid of mitochondrial membranes, plays an important role in mitochondrial processes and bioenergetics. CL is synthesized de novo and undergoes remodeling in the mitochondrial membranes. Perturbation of CL remodeling leads to the rare X-linked genetic disorder Barth syndrome, which shows disparities in clinical presentation. To uncover biochemical modifiers that exacerbate CL deficiency, we carried out a synthetic genetic array screen to identify synthetic ...[more]

PMID: 27941023

Similar Datasets

Project description:Cytosolic acetyl-coenzyme A is a precursor for many biotechnologically relevant compounds produced by Saccharomyces cerevisiae. In this yeast, cytosolic acetyl-CoA synthesis and growth strictly depend on expression of either the Acs1 or Acs2 isoenzyme of acetyl-CoA synthetase (ACS). Since hydrolysis of ATP to AMP and pyrophosphate in the ACS reaction constrains maximum yields of acetyl-CoA-derived products, this study explores replacement of ACS by two ATP-independent pathways for acetyl-CoA synthesis. After evaluating expression of different bacterial genes encoding acetylating acetaldehyde dehydrogenase (A-ALD) and pyruvate-formate lyase (PFL), acs1M-NM-^T acs2M-NM-^T S. cerevisiae strains were constructed in which A-ALD or PFL successfully replaced ACS. In A-ALD-dependent strains, aerobic growth rates of up to 0.27 h-1 were observed, while anaerobic growth rates of PFL-dependent S. cerevisiae (0.21 h-1) were stoichiometrically coupled to formate production. In glucose-limited chemostat cultures, intracellular metabolite analysis did not reveal major differences between A-ALD-dependent and reference strains. However, biomass yields on glucose of A-ALD- and PFL-dependent strains were lower than those of the reference strain. Transcriptome analysis suggested that reduced biomass yields were caused by acetaldehyde and formate in A-ALD- and PFL-dependent strains, respectively. Transcript profiles also indicated that a previously proposed role of Acs2 in histone acetylation is probably linked to cytosolic acetyl-CoA levels rather than to direct involvement of Acs2 in histone acetylation. While, for the first time, demonstrating that yeast ACS can be fully replaced by alternative reactions, this study demonstrates that further modifications are needed to achieve optimal in vivo efficiencies of the supply of acetyl-CoA as product precursor. To investigate the impact of introduced changes in native pathway of cytosolic acetyl-CoA formation in S. cerevisiae, a DNA microarray-based transcriptome analysis was performed on aerobic or anaerobic, glucose-limited chemostat cultures.

Dataset Information

Loss of Cardiolipin Leads to Perturbation of Acetyl-CoA Synthesis.

Publications

Loss of Cardiolipin Leads to Perturbation of Acetyl-CoA Synthesis.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure