Commentary, News and thoughts

Staphylococcus aureus type I signal peptidase: essential or not essential, that’s the question

Wouter L.W. Hazenbos1, Elizabeth Skippington2 and Man-Wah Tan1

This article comments on work published by Morisaki et al. (mBio, 2016), which characterized a novel ABC transporter. This transporter apparently compensates for SpsB’s essential function by mediating alternative cleavage of a subset of proteins at a site distinct from the SpsB-cleavage site, leading to SpsB-independent secretion.

Transceptors as a functional link of transporters and receptors

George Diallinas

A relative newcomer in environment sensing are the so called transceptors, membrane proteins that possess both solute transport and receptor-like signaling activities. Now, the transceptor concept is further enlarged to include micronutrient sensing via the iron and zinc high-affinity transporters of Saccharomyces cerevisiae.

S. pombe placed on the prion map

Jacqueline Hayles

This article comments on work published by Sideri et al. (Microbial Cell, 2017), which identified the Ctr4 prion in S. pombe.

Using microbes as a key tool to unravel the mechanism of autophagy and the functions of the ATG proteins

Mario Mauthe1,2 and Fulvio Reggiori1,2

Microbes have served to discover and characterize unconventional functions of the ATG proteins, which are uncoupled from their role in autophagy. In our recent study, we have taken advantage of viruses as a screening tool to determine the extent of the unconventional functions of the ATG proteome and characterize one of them.

Autophagy: one more Nobel Prize for yeast

Andreas Zimmermann1, Katharina Kainz1, Aleksandra Andryushkova1, Sebastian Hofer1, Frank Madeo1,2 and Didac Carmona-Gutierrez1

The recent announcement of the 2016 Nobel Prize in Physiology or Medicine, awarded to Yoshinori Ohsumifor the discoveries of mechanisms governing autophagy, underscores the importance of intracellular degradation and recycling. Here we provide a quick historical overview that mirrors both the importance of autophagy as a conserved and essential process for cellular life and death as well as the crucial role of yeast in its mechanistic characterization.

Physiology, phylogeny, and LUCA

William F. Martin1,2, Madeline C. Weiss1, Sinje Neukirchen3, Shijulal Nelson-Sathi4, Filipa L. Sousa3

Genomes record their own history. But if we want to look all the way back to life's beginnings some 4 billion years ago, the record of microbial evolution that is preserved in prokaryotic genomes is not easy to read. The classical approach has been to look for genes that are universally distributed. Another approach is to make all trees for all genes, and sift out the trees where signals have been overwritten by lateral gene transfer. What is left ought to be ancient. If we do that, what do we find?

The curious case of vanishing mitochondria

Anna Karnkowska1 and Vladimír Hampl2

Due to their involvement in the energy metabolism, mitochondria are essential for most eukaryotic cells. Microbial eukaryotes living in low oxygen environments possess reduced forms of mitochondria, namely mitochondrion-related organelles (MROs). Recently, the first microbial eukaryote with neither mitochondrion nor MRO was characterized – Monocercomonoides sp. The discovery of such bona fide amitochondriate eukaryote broadens our knowledge about the diversity and plasticity of eukaryotic cells and provides a substantial contribution to our understanding of eukaryotic cell evolution.

Accumulation of metabolic side products might favor the production of ethanol in Pho13 knockout strains

Guido T. Bommer, Francesca Baldin & Emile Van Schaftingen

This article comments on work published by Collard et al. (Nat Chem Biol, 2016), which describes the discovery of a striking example illustrating the metabolite repair concept.

Sexually transmitted infections: old foes on the rise

Didac Carmona-Gutierrez1,*, Katharina Kainz1 and Frank Madeo1,2,*

Sexually transmitted infections (STIs) are commonly spread via sexual contact. It is estimated that one million STIs are acquired every day worldwide. Besides their impact on sexual, reproductive and neonatal health, they can cause disastrous and life-threatening complications if left untreated. In addition to this personal burden, STIs also represent a socioeconomic problem, deriving in treatment costs of tremendous proportions. Despite a substantial progress in diagnosis, treatment and prevention, the incidence of many common STIs is increasing, and STIs continue to represent a global public health problem and a major cause for morbidity and mortality. With this Special Issue, Microbial Cell provides an in-depth overview of the eight major STIs, covering all relevant features of each infection.

Previous Next

The complexities of bacterial-fungal interactions in the mammalian gastrointestinal tract

March 17, 2016

This article comments on work published by Lopez-Medina et al. (PLoS Pathog, 2015) and Fan et al. (Nat Med, 2015), which utilize an “artificial” niche, the antibiotic-treated gut with concomitant pathogenic microbe expansion, to gain insight in bacterial-fungal interactions in clinically common scenarios.

Gearing up for survival – HSP-containing granules accumulate in quiescent cells and promote survival

March 6, 2016

This article comments on work published by Lee et al. (Microbial Cell, 2016), which reports that distinct granules are formed in quiescent and non-quiescent cells, which determines their respective cell fates.

Yeast screening platform identifies FDA-approved drugs that reduce Aβ oligomerization

March 3, 2016

This article comments on work published by Park et al. (Microbial Cell, 2016), which discovered a number of small molecules capable of modulating Aβ aggregation in a yeast model.

Groupthink: chromosomal clustering during transcriptional memory

November 26, 2015

In this article, the authors comment on the study "NO1 transcriptional memory leads to DNA zip code-dependent interchromosomal clustering." by Brickner et al. (Microbial Cell, 2015), discussing the importance and molecular mechanisms of chromosomal clustering during transcriptional memory.

Yeast proteinopathy models: a robust tool for deciphering the basis of neurodegeneration

November 26, 2015

Protein quality control or proteostasis is an essential determinant of basic cell health and aging. Eukaryotic cells have evolved a number of proteostatic mechanisms to ensure that proteins retain functional conformation, or are rapidly degraded when proteins misfold or self-aggregate. This article discusses the use of budding yeast as a robust proxy to study the intersection between proteostasis and neurodegenerative disease.

Starting with a degron: N-terminal formyl-methionine of nascent bacterial proteins contributes to their proteolytic control

October 4, 2015

In this article, the author comments on the study "Formyl-methionine as a degradation signal at the N-termini of bacterial proteins." by Piatkov et al. (Microbial Cell, 2015), discussing a novel N-terminal degradation signal (N-degron) that targets nascent proteins for degradation in Escherichia coli by a new branch of the bacterial N-end rule pathway, termed the fMet/N-end rule pathway

Elongation factor-P at the crossroads of the host-endosymbiont interface

September 23, 2015

Elongation factor P (EF-P) is an ancient bacterial translational factor that aids the ribosome in polymerizing oligo-prolines. EF-P structurally resembles tRNA and binds in-between the exit and peptidyl sites of the ribosome to accelerate the intrinsically slow reaction of peptidyl-prolyl bond formation. Recent studies have identified in separate organisms, two evolutionarily convergent EF-P post-translational modification systems (EPMS), split predominantly between gammaproteobacteria, and betaproteobacteria. Here, the authors highlight the recent discoveries made regarding EPMSs, with a focus on how these incomplete modification pathways shape or have been shaped by the endosymbiont-host relationship.

Feelin’ it: Differential oxidative stress sensing mediated by Cyclin C

September 6, 2015

Microbial cells that live exposed directly to their environmental milieu are faced with the challenge of adapting to the dynamic stress conditions that will inevitably be encountered. These stress conditions may vary over wide ranges and the most efficient responses would be tuned to produce a proportional buffering change. A mild stress would most efficiently be dealt with by a mild metabolic reprogramming that would prevent serious damage. A more severe environmental challenge would demand a more dramatic cellular compensatory response.

Subverting lysosomal function in Trypanosoma brucei

August 2, 2015

This article discusses Koh et al. (2015) "The lysosomotropic drug LeuLeu-OMe induces lysosome disruption and autophagy-independent cell death in Trypanosoma brucei (Microbial Cell 2(8): 288-298).

Entamoeba histolytica – tumor necrosis factor: a fatal attraction

July 6, 2015

This article comments on the study "In Entamoeba histolytica, a BspA family protein is required for chemotaxis toward tumour necrosis factor" by Silvestre et al. (Microbial Cell, 2015).