Yeast growth in raffinose results in resistance to acetic-acid induced programmed cell death mostly due to the activation of the mitochondrial retrograde pathway

Biochim Biophys Acta. 2013 Dec;1833(12):2765-2774. doi: 10.1016/j.bbamcr.2013.07.017. Epub 2013 Jul 29.

Abstract

In order to investigate whether and how a modification of mitochondrial metabolism can affect yeast sensitivity to programmed cell death (PCD) induced by acetic acid (AA-PCD), yeast cells were grown on raffinose, as a sole carbon source, which, differently from glucose, favours mitochondrial respiration. We found that, differently from glucose-grown cells, raffinose-grown cells were mostly resistant to AA-PCD and that this was due to the activation of mitochondrial retrograde (RTG) response, which increased with time, as revealed by the up-regulation of the peroxisomal isoform of citrate synthase and isocitrate dehydrogenase isoform 1, RTG pathway target genes. Accordingly, the deletion of RTG2 and RTG3, a positive regulator and a transcription factor of the RTG pathway, resulted in AA-PCD, as shown by TUNEL assay. Neither deletion in raffinose-grown cells of HAP4, encoding the positive regulatory subunit of the Hap2,3,4,5 complex nor constitutive activation of the RTG pathway in glucose-grown cells due to deletion of MKS1, a negative regulator of RTG pathway, had effect on yeast AA-PCD. The RTG pathway was found to be activated in yeast cells containing mitochondria, in which membrane potential was measured, capable to consume oxygen in a manner stimulated by the uncoupler CCCP and inhibited by the respiratory chain inhibitor antimycin A. AA-PCD resistance in raffinose-grown cells occurs with a decrease in both ROS production and cytochrome c release as compared to glucose-grown cells en route to AA-PCD.

Keywords: 2,7-dihydrodichlorofluorescein diacetate; AA; Acetic acid; CCCP; DCF; GLU; H(2)DCH-DA; Mitochondria; N-acetyl cysteine; NAC; PCD; Programmed cell death; RAF; RTG; Raffinose; Retrograde pathway; TMRM; TUNEL; WT; Yeast; acetic acid; carbonyl cyanide m-chlorophenylhydrazone; cyt c; cytochrome c; dichlorophluoresceine; glucose-grown; programmed cell death; raffinose-grown; retrograde; terminal deoxynucleotidyl transferase (TdT)-mediated dUTP nick end labelling; tetramethylrhodamine methyl ester; wild type.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acetic Acid / pharmacology*
  • Apoptosis / drug effects*
  • Cytochromes c / metabolism
  • Gene Deletion
  • Glucose / pharmacology
  • Hydrogen-Ion Concentration / drug effects
  • Immunoblotting
  • Intracellular Space / drug effects
  • Intracellular Space / metabolism
  • Membrane Potential, Mitochondrial / drug effects
  • Mitochondria / drug effects
  • Mitochondria / metabolism*
  • Phosphorylation / drug effects
  • Raffinose / pharmacology*
  • Reactive Oxygen Species / metabolism
  • Saccharomyces cerevisiae / cytology
  • Saccharomyces cerevisiae / drug effects
  • Saccharomyces cerevisiae / growth & development*
  • Saccharomyces cerevisiae Proteins / metabolism
  • Signal Transduction / drug effects*

Substances

  • Reactive Oxygen Species
  • Saccharomyces cerevisiae Proteins
  • Cytochromes c
  • Glucose
  • Raffinose
  • Acetic Acid