Stress-Dependent Coordination of Transcriptome and Translatome in Yeast (original) (raw)
Figure 4
Enhanced Ribosome Association and Activity of the Mitochondrial F1F0-ATPase by Low Doses of CFW
(A) Heat map representing relative changes of expression of 17 mitochondrial F1F0-ATPase components after mild stress treatments (blue–yellow color scale). Total: changes of steady-state mRNA levels, RA: change of ribosome associations. The gene names are indicated to the left, with the name of the corresponding subunit in parentheses.
(B) Structure of the mitochondrial F1F0-ATPase. Each component is colored according to changes in ribosome associations depicted in (A). The membrane-associated part (F0) uses a proton motive force to mechanically drive the soluble part (F1) that exhibits ATPase activity [78,79].
(C) Distribution of TIM11, ATP4, and ACT1 mRNAs in polysomal gradients obtained from untreated cells (upper panel), and from cells treated with CFW (lower panel). RNA was isolated from each fraction of the polysomal profile and quantified by RT-qPCR (see Materials and Methods).The mRNA level in each fraction was calculated as a percentage of the total; data and absorbance (254 nm) profiles from representative experiments are plotted. ACT1 is as a negative control mRNA that was not expected to alter ribosome association.
(D) Relative mitochondrial ATPase activity of drug-treated versus untreated control cells. Cells were treated with CFW (CFW) for 20 min; preincubated for 10 min with CHX prior to addition of CFW (CHX + CFW); or treated with CHX or menadione. The activity of purified mitochondria was normalized to the untreated control sample. Average activities are indicated with a dashed line, standard errors of the mean (SEM) with continuous lines. Single dots represent biologically independent experiments (double asterisks [**] indicate p < 0.01; a single asterisk [*] indicates p < 0.05).