The transcriptional repressor Sum1p counteracts Sir2p in regulation of the actin cytoskeleton, mitochondrial quality control and replicative lifespan in Saccharomyces cerevisiae

January 18, 2016

Increasing the stability or dynamics of the actin cytoskeleton can extend lifespan in C. elegans and S. cerevisiae. Actin cables of budding yeast, bundles of actin filaments that mediate cargo transport, affect lifespan control through effects on mitochondrial quality control. Here, we report that Sum1p and Sir2p inversely regulate actin and mitochondrial maintenance, as well as lifespan.

Struggling for breath in Sherbrooke: 1st Symposium on “One mitochondrion, many diseases” in Sherbrooke, Québec, Canada, March 11th, 2015

May 20, 2015

This meeting report summarizes discussions during the "1st symposium on “One mitochondrion, many diseases," which took place in Sherbrooke in southern Québec in 2015.

Modeling human Coenzyme A synthase mutation in yeast reveals altered mitochondrial function, lipid content and iron metabolism

April 6, 2015

Mutations in nuclear genes associated with defective coenzyme A biosynthesis have been identified as responsible for some forms of neurodegeneration with brain iron accumulation (NBIA), namely PKAN and CoPAN. Yeast expressing a pathogenic mutation exhibited a temperature-sensitive growth defect in the absence of pantothenate and a reduced CoA content. Additional characterization revealed decreased oxygen consumption, reduced activities of mitochondrial respiratory complexes, higher iron content, increased sensitivity to oxidative stress and reduced amount of lipid droplets, thus partially recapitulating the phenotypes found in patients and establishing yeast as a potential model to clarify the pathogenesis underlying PKAN and CoPAN diseases.

Modeling non-hereditary mechanisms of Alzheimer disease during apoptosis in yeast

March 20, 2015

Impaired protein degradation and mitochondrial dysfunction are believed to contribute to neurodegenerative disorders, including Alzheimer disease (AD). This microreview comments on the article "Accumulation of Basic Amino Acids at Mitochondria Dictates the Cytotoxicity of Aberrant Ubiquitin" by Braun et al. (2015), Cell Rep.

Two distinct and competitive pathways confer the cellcidal actions of artemisinins

January 1, 2015

The biological actions of artemisinin (ART), an antimalarial drug derived from Artemisia annua, remain poorly understood and controversial. This article concludes that ARTs are endowed with two major and distinct types of properties: a potent and specific mitochondria-dependent reaction and a more general and less specific heme-mediated reaction. The competitive nature of these two actions could be explained by their shared source of the consumable ARTs, so that inhibition of the heme-mediated degradation pathway would enable more ARTs to be available for the mitochondrial action. These properties of ARTs can be used to interpret the divergent antimalarial and anticancer actions of ARTs.

Rewiring yeast acetate metabolism through MPC1 loss of function leads to mitochondrial damage and decreases chronological lifespan

November 18, 2014

This work shows that MPC1-deficient cells make up for their impairment in mitochondrial pyruvate with a metabolic rewiring which involves several intermediates of the mitochondrially localized TCA cycle and the cytosolic glyoxylate shunt but ultimately results in a pro-aging process.

The dual role of cyclin C connects stress regulated gene expression to mitochondrial dynamics

September 14, 2014

This work summarizes the role cyclin C plays in regulating stress-responsive transcription in the budding yeast Saccharomyces cerevisiae, including mitochondrial fission and regulated cell death.

Effect of paraquat-induced oxidative stress on gene expression and aging of the filamentous ascomycete Podospora anserina

June 22, 2014

In this article, paraquat is used to experimentally induce strong cellular oxidative stress in Podospora anserina wild-type cultures of different age, finding that this treatment has profound effects on gene expression, growth and lifespan.

Cell-autonomous mechanisms of chronological aging in the yeast Saccharomyces cerevisiae

May 27, 2014

This article critically analyzes recent advances in the understanding of cell-autonomous mechanisms of chronological aging in the budding yeast Saccharomyces cerevisiae. It proposes a concept of a biomolecular network underlying the chronology of cellular aging in yeast, whichposits that such network progresses through a series of lifespan checkpoints.

Live longer on MARS: a yeast paradigm of mitochondrial adaptive ROS signaling in aging

April 23, 2014

In this article, the potential relevance of Mitochondrial Adaptive ROS Signaling (MARS) to the human disease Ataxia-Telangiectasia and as a potential anti-aging target is discussed.