Commentary, Editorial
Starting with a degron: N-terminal formyl-methionine of nascent bacterial proteins contributes to their proteolytic control
R. Jürgen Dohmen
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
Andrei Rajkovic1, Anne Witzky2, William Navarre3, Andrew J. Darwin4 and Michael Ibba5
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
W. Scott Moye-Rowley
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
Sam Alsford
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
Serge Ankri
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).
Toxoplasma control of host apoptosis: the art of not biting too hard the hand that feeds you
Sébastien Besteiro
Toxoplasma gondii is an obligate intracellular parasite that is able to infect a multitude of different vertebrate hosts and can survive in virtually any nucleated cell. Here, the authors discuss the article "Toxoplasma gondii inhibits cytochrome c-induced caspase activation in its host cell by interference with holo-apoptosome assembly" by Graumann et al. (2015, Microbial Cell).
A safety catch for ornithine decarboxylase degradation
Christof Taxis
Feedback inhibition is a common mechanism to adjust the activity of an enzyme in accordance with the abundance of a product. This article comments on the study "Polyamines directly promote antizyme-mediated degradation of ornithine decarboxylase by the proteasome" by Beenukumar et al. (2015), Microbial Cell.
Fancy a gene? A surprisingly complex evolutionary history of peroxiredoxins.
Alena Zíková1,2, Miroslav Oborník1,2,3 and Julius Lukeš1,2,4
In this comment, the authors discuss the article "Prokaryotic ancestry and gene fusion of a dual localized peroxiredoxin in malaria parasites" (Djuika et al., Microbial Cell 2015).
Quorum protection, growth and survival
Ian G . Macreadie
For the growth of a cell culture, one inoculates not with one cell but with a quorum of cells. This most often a requirement, not just a convenience, and most of us take this for granted without question. Here this observation is re-examined to understand why a quorum may be required to grow cells. The importance of quorums may be widespread in the aspects of microbiology they affect. It is very likely that quorums are connected with and have a large impact on the determination of Minimal Inhibitory Concentrations. It is also possible that low cell density may adversely affect cell survival, however, this is an area where even less is known. The need for a quorum might affect other aspects of microbial cell culture, cell isolation and cell preservation. Effects also extend to mammalian cell culture. Here I seek to review studies that have been documented and speculate on how the information might be utilized in the future.
Using microbes as a key tool to unravel the mechanism of autophagy and the functions of the ATG proteins
December 30, 2016
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
December 5, 2016
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.
Sexually transmitted infections: old foes on the rise
September 4, 2016
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.
What’s old is new again: yeast mutant screens in the era of pooled segregant analysis by genome sequencing
April 4, 2016
This article comments on work published by Den Abt et al. (Microbial Cell, 2016), which identified genes involved in ethyl acetate formation in a yeast mutant screen based on a new approach combining repeated rounds of chemical mutagenesis and pooled segregant analysis by whole genome sequencing.
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.
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.
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
Transceptors as a functional link of transporters and receptors
March 1, 2017
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.