Research, Research Articles
Basal level of ppGpp coordinates Escherichia coli cell heterogeneity and ampicillin resistance and persistence
Paulina Katarzyna Grucela1 and Yong Everett Zhang1
The universal stringent response alarmone ppGpp (guanosine penta and tetra phosphates) plays a crucial role in various aspects of fundamental cell physiology (e.g., cell growth rate, cell size) and thus bacterial tolerance to and survival of external stresses, including antibiotics. In tihs study, we discuss the fundamental role of basal level of ppGpp in regulating cell homogeneity and ampicillin persistence.
Investigation of the acetic acid stress response in Saccharomyces cerevisiae with mutated H3 residues
Nitu Saha1, Swati Swagatika1 and Raghuvir Singh Tomar1
Yeast cells respond to acetic acid in diverse ways. Here, we have elucidated the deleterious effects of acetic acid on different histone mutants
The coenzyme B12 precursor 5,6-dimethylbenzimidazole is a flavin antagonist in Salmonella
Lahiru Malalasekara1 and Jorge C. Escalante-Semerena1,*
Here we investigated why 5,6-dimethylbenzimidazole (DMB) inhibits in S. Typhimurium. Briefly, we determined that the structural similarities of the substituted benzene ring of DMB with the isoalloxazine moiety of flavins is responsible for the deleterious effects of this CoB12 precursor.
Yeast gene KTI13 (alias DPH8) operates in the initiation step of diphthamide synthesis on elongation factor 2
Meike Arend1, Koray Ütkür1, Harmen Hawer1, Klaus Mayer2, Namit Ranjan3, Lorenz Adrian4, Ulrich Brinkmann2 and Raffael Schaffrath1
We show here that apart from its effector role for Elongator-dependent tRNA modification in yeast, Kti13 alias Dph8 also operates in step one of the diphthamide modification pathway.
GFP fusions of Sec-routed extracellular proteins in Staphylococcus aureus reveal surface-associated coagulase in biofilms
Dominique C. S. Evans1,2,#, Amanda B. Khamas1,#, Lisbeth Marcussen1, Kristian S. Rasmussen3, Janne K. Klitgaard3, Birgitte H. Kallipolitis3, Janni Nielsen1, Daniel E. Otzen1, Mark C. Leake2,4 and Rikke L. Meyer1,5
We show that msfGFP can be used to generate extracellular fluorescent fusion proteins in S. aureus, applicable for proteins that are secreted through the Sec pathway. When fused to coagulase, msfGFP did not hinder the biological function, and the fusion protein localised to the fibrin pseudocapsule surrounding clusters of S. aureus cells.
Atg1, a key regulator of autophagy, functions to promote MAPK activation and cell death upon calcium overload in fission yeast
Teruaki Takasaki1, Ryosuke Utsumi1, Erika Shimada1, Asuka Bamba1, Kanako Hagihara2, Ryosuke Satoh1, and Reiko Sugiura1
Here, we provide evidence that the fission yeast Atg1 regulates cell death responses upon intracellular calcium load in addition to its role in promoting Pmk1 MAPK.
Spontaneous mutations in CYC8 and MIG1 suppress the short chronological lifespan of budding yeast lacking SNF1/AMPK
February 19, 2018
Chronologically aging yeast cells are prone to adaptive regrowth, whereby mutants with a survival advantage spontaneously appear and re-enter the cell cycle in stationary phase cultures. Here, Magani et al. identified specific downstream SNF1 targets responsible for CLS extension during CR.
Production of poly-β-1,6-N-acetylglucosamine by MatAB is required for hyphal aggregation and hydrophilic surface adhesion by Streptomyces
February 12, 2018
In this article van Dissel et al. describe new insights to allow better control of liquid-culture morphology of streptomycetes, which may be harnessed to improve growth and industrial exploitation of these highly versatile natural product and enzyme producers.
Non-canonical regulation of glutathione and trehalose biosynthesis characterizes non-Saccharomyces wine yeasts with poor performance in active dry yeast production
January 26, 2018
Several yeast species, belonging to Saccharomyces and non-Saccharomyces genera, play fundamental roles during spontaneous must grape fermentation, and recent studies have shown that mixed fermentations, co-inoculated with S. cerevisiae and non-Saccharomyces strains, can improve wine organoleptic properties. Here, Gamero-Sandemetrio et al. present findings that non-canonical regulation of glutathione and trehalose biosynthesis could cause poor fermentative performance after active dry yeast (ADY) production, as it corroborates the corrective effect of antioxidant treatments, during biomass propagation, with both pure chemicals and food-grade argan oil.
Molecular signature of the imprintosome complex at the mating-type locus in fission yeast
January 16, 2018
Genetic and molecular studies have indicated that an epigenetic imprint at mat1, the sexual locus of fission yeast, initiates mating type switching. Here, Raimondi et al. characterized the recruitment of early players of mating type switching at the mat1 region and suggest a nucleoprotein protective structure defined as imprintosome.
A novel system to monitor mitochondrial translation in yeast
January 13, 2018
In this study Suhm et al. present a novel system to monitor mitochondrial translation by detection of mitochondrial GFP-translation through fluorescence microscopy and flow cytometry in functional mitochondria. This novel tool allows the investigation of the function and regulation of mitochondrial translation during stress signaling, aging and mitochondrial biogenesis.
Fat storage-inducing transmembrane (FIT or FITM) proteins are related to lipid phosphatase/phosphotransferase enzymes
December 28, 2017
Fat storage-inducing transmembrane (FIT or FITM) proteins have been implicated in the partitioning of triacylglycerol to lipid droplets and the budding of lipid droplets from the ER. Saccharomyces cerevisiae has two FITM homologues and the presented results suggest that Scs3p and Yft2p as well as FITMs in general are lipid phosphatase/phosphotransferase (LPT) enzymes involved in an as yet unknown critical step in phospholipid metabolism.
A versatile plasmid system for reconstitution and analysis of mammalian ubiquitination cascades in yeast
December 5, 2017
In this article Avagliano Trezza et al. describe a versatile vector system that allows the reconstitution of specific ubiquitination cascades in the model eukaryote Saccharomyces cerevisae (baker’s yeast) that provides a versatile tool to study complex post-translational modifications in a cellular setting.
Alcohols enhance the rate of acetic acid diffusion in S. cerevisiae : biophysical mechanisms and implications for acetic acid tolerance
December 1, 2017
Microbial cell factories with the ability to maintain high productivity in the presence of weak organic acids, such as acetic acid, are required in many industrial processes. This study demonstrates that the rate of acetic acid diffusion can be strongly affected by compounds that partition into the cell membrane, and highlights the need for considering interaction effects between compounds in the design of microbial processes.