Research, Research Reports
Depletion of SNAP-23 and Syntaxin 4 alters lipid droplet homeostasis during Chlamydia infection
Tiago Monteiro-Brás1,2,3, Jordan Wesolowski1 and Fabienne Paumet1
This study reveals that the plasma membrane SNARE proteins SNAP-23 and Syntaxin 4 are crucial for Chlamydia trachomatis development by regulating lipid droplet homeostasis and supporting the formation of infectious progeny within host cells.
Yeast can express and assemble bacterial secretins in the mitochondrial outer membrane
Janani Natarajan1, Anasuya Moitra1, Sussanne Zabel1,§, Nidhi Singh2, Samuel Wagner2,3 and Doron Rapaport1
Secretins, essential components of bacterial secretion systems, can be expressed in yeast and show differential dependencies on mitochondrial import and assembly factors for membrane integration, suggesting diverse pathways for their assembly into the bacterial outer membrane.
Metabolic reprogramming of Salmonella infected macrophages and its modulation by iron availability and the mTOR pathway
Julia Telser1,2,#, Chiara Volani1,3,#, Richard Hilbe1,2, Markus Seifert1,2, Natascha Brigo1, Giuseppe Paglia4 and Günter Weiss1,2
This article shows that iron plays a critical role in both the immune response and metabolic reprogramming of macrophages during infection, influencing the TCA cycle and mTOR pathway, with implications for the growth of intracellular bacteria like Salmonella.
Transcriptomic and chemogenomic analyses unveil the essential role of Com2-regulon in response and tolerance of Saccharomyces cerevisiae to stress induced by sulfur dioxide
Patrícia Lage1,2, Belém Sampaio-Marques3,4, Paula Ludovico3,4, Nuno P. Mira5 and Ana Mendes-Ferreira1,2
This article shows that in the presence of sulfur dioxide (SO2), the transcription factor Com2 plays a critical role in the tolerance and response of Saccharomyces cerevisiae, affecting the expression of a majority of SO2-activated genes and contributing to the protection against stress induced by SO2 at an enologically relevant pH.
Network dynamics of the yeast methyltransferome
Guri Giaever1, Elena Lissina1 and Corey Nislow1
This article presents a systematic genetic analysis of methyltransferases (MTases) under normal and stress conditions, uncovering the complex and adaptive nature of the methyltransferome and discovering a potential connection between phospholipid methylation and histone methylation, suggesting interplay between lipid homeostasis and epigenetic regulation.
Functional link between mitochondria and Rnr3, the minor catalytic subunit of yeast ribonucleotide reductase
Isaac Corcoles-Saez1, Jean-Luc Ferat2, Michael Costanzo3, Charles M. Boone3 and Rita S. Cha1
This article shows that the carbon source affects the abundance of ribonucleotide reductase (RNR) subunits in yeast, with a novel Mec1 signaling axis regulating Rnr3 independently of known DNA damage response pathways, and reveals Rnr3's unexpected role in mitochondrial function.
Mitochondria-Associated Membranes (MAMs) are involved in Bax mitochondrial localization and cytochrome c release
Alexandre Légiot1, Claire Céré1, Thibaud Dupoiron1, Mohamed Kaabouni1, Nadine Camougrand1 and Stéphen Manon1
This study investigated the role of Mitochondria-Associated Membranes (MAMs) in the regulation of apoptosis by analyzing the localization and function of the pro-apoptotic protein Bax in yeast, finding that disruption of MAMs by deletion of the MDM34 gene affects Bax's mitochondrial localization and the release of cytochrome c.
Valine biosynthesis in Saccharomyces cerevisiae is regulated by the mitochondrial branched-chain amino acid aminotransferase Bat1
March 21, 2018
In Saccharomyces cerevisiae, the yeast, the Bat1 and Bat2 proteins, which are branched-chain amino acid aminotransferases, play distinct roles in valine biosynthesis and cell growth regulation, with Bat1 primarily located in the mitochondria and Bat2 in the cytosol, and the mitochondria being identified as the major site of valine biosynthesis in this yeast.
Microbial competition between Escherichia coli and Candida albicans reveals a soluble fungicidal factor
March 7, 2018
Localized and systemic fungal infections caused by Candida albicans can lead to significant mortality and morbidity. Here, Cabral et al. show that E. coli produces a soluble factor that kills C. albicans in a magnesium-dependent fashion such that depletion of available magnesium is essential for toxicity.
Impact of F1Fo-ATP-synthase dimer assembly factors on mitochondrial function and organismic aging
January 30, 2018
In aerobic organisms, mitochondrial F1Fo-ATP-synthase is the major site of ATP production. Here, Rampello et al. report on the role of the two dimer assembly factors PaATPE and PaATPG of the aging model Podospora anserina validating a model that links mitochondrial membrane remodeling to aging and identify specific molecular components triggering this process.
Yeast quiescence exit swiftness is influenced by cell volume and chronological age
December 6, 2017
Quiescence exit swiftness is crucial not only for micro-organisms in competition for an environmental niche, such as yeast, but also for the maintenance of tissue homeostasis in multicellular species. Here, Laporte et al. explore the effect of replicative and chronological age on Saccharomyces cerevisiae quiescence exit efficiency. Overall, their data illustrate that the quiescent state is a continuum evolving with time, early and deep quiescence being distinguishable by the cell’s proficiency to re-enter the proliferation cycle.
The neuroprotective steroid progesterone promotes mitochondrial uncoupling, reduces cytosolic calcium and augments stress resistance in yeast cells
May 31, 2017
Progesterone, known for its role in the reproductive system, also acts as a neurosteroid and has been suggested to aid recovery from traumatic brain injury; a study using yeast models shows that progesterone can protect against apoptosis, reduce oxidative stress and calcium spikes, and increase mitochondrial function, independent of traditional progesterone receptors or calcium transporters.
A simple microfluidic platform to study age-dependent protein abundance and localization changes in Saccharomyces cerevisiae
April 13, 2017
We have developed a user-friendly microfluidic system paired with a genetic approach to enrich and study ageing mother yeast cells, enabling the monitoring of protein abundance and localization changes during the crucial first half of their replicative lifespan, leading to the discovery of novel age-dependent protein behaviors.
The frequency of yeast [PSI+] prion formation is increased during chronological ageing
March 27, 2017
Aging is marked by a decline in cellular functions and the increased formation of the yeast [PSI+] prion, an altered translation termination factor, which suggests that autophagy suppresses age-related prion development. Interestingly, yeast cells that adopt the [PSI+] form exhibit better survival through aging, indicating that [PSI+] formation, linked to enhanced autophagy, may confer advantages such as reduced protein aggregation and improved cell viability.
A multigene family encoding surface glycoproteins in Trypanosoma congolense
March 2, 2017
Trypanosoma congolense, the causative agent of the most important livestock disease in Africa, expresses specific surface proteins involved in its parasitic lifestyle. By mining the T. congolense genome database, we identified a novel family of lectin-like glycoproteins (TcoClecs).
The transcription factors ADR1 or CAT8 are required for RTG pathway activation and evasion from yeast acetic acid-induced programmed cell death in raffinose
December 2, 2016
Yeast Saccharomyces cerevisiae grown on glucose undergoes programmed cell death (PCD) induced by acetic acid (AA-PCD), but evades PCD when grown in raffinose. This is due to concomitant relief of carbon catabolite repression (CCR) and activation of mitochondrial retrograde signaling. In this work, we investigated the relationships between the RTG and CCR pathways in the modulation of AA-PCD sensitivity under glucose repression or de-repression conditions. Our data show that simultaneous mitochondrial retrograde pathway activation and SNF1-dependent relief of CCR have a key role in central carbon metabolism reprogramming which modulates the yeast acetic acid-stress response.