Microreviews
Mek1/Mre4 is a master regulator of meiotic recombination in budding yeast
Nancy M. Hollingsworth
This article comments on work published by Chen et al. (PLoS BIol, 2015), showing that the meiosis specific kinase Mek1 indirectly regulates the crossover/non-crossover decision between homologs as well as genetic interference and suggests Mek1 to be a "master regulator" of meiotic recombination in budding yeast.
Shaping meiotic chromosomes with SUMO: a feedback loop controls the assembly of the synaptonemal complex in budding yeast
Hideo Tsubouchi1, Bilge Argunhan1 and Tomomi Tsubouchi2
This article comments on work published by Leung et al. (J Cell Biol, 2015), which shows that the formation of the meiosis-specific synaptonemal complex is controlled through SUMOylation of a regulator required for the assembly of transverse filaments, implicating the involvement of a positive feedback loop in the control of synaptonemal complex assembly.
Learning epigenetic regulation from mycobacteria
Sanjeev Khosla1, Garima Sharma1,2 and Imtiyaz Yaseen1,2
This article comments on work published by Koshla et al. (Nat Commun, 2015), which shows that pathogenic Mycobacterium tuberculosis has evolved strategies to hijack the epigenetic regulation of host transcripton for its own survival.
Biofilm assembly becomes crystal clear – filamentous bacteriophage organize the Pseudomonas aeruginosa biofilm matrix into a liquid crystal
Patrick R. Secor1, Laura K. Jennings1, Lia A. Michaels1, Johanna M. Sweere2, Pradeep K. Singh1, William C. Parks3, Paul L. Bollyky2
This article comments on work published by Secor et al. (Host Cell & Microbe, 2015), which highlights a previously unknown role for filamentous Pf phage in organizing the P. aeruginosa biofilm matrix into a liquid crystalline structure. These findings help ground our understanding of biofilm formation within established paradigms of soft matter physics
Spermidine cures yeast of prions
Shaun H. Speldewinde, and Chris M. Grant
This article comments on work published by Speldewinde and Grant (Mol Biol Cell, 2015), which found that spermidine, a polyamine that has been used to increase autophagic flux, acts as a protective agent which prevents spontaneous prion formation in yeast.
Histone deacetylases: revealing the molecular base of dimorphism in pathogenic fungi
Alberto Elías-Villalobos1,2, Dominique Helmlinger2 and José I. Ibeas1
Fungi, as every living organism, interact with the external world and have to adapt to its fluctuations. For pathogenic fungi, such interaction involves adapting to the hostile environment of their host. Survival depends on the capacity of fungi to detect and respond to external stimuli, which is achieved through a tight and efficient genetic control. Elías-Villalobos et al. propose that histone acetylation is critical to the proper timing and induction of transcription of the genes encoding factors that coordinate changes in morphology with pathogenesis.
Complex regulation of the sirtuin-dependent reversible lysine acetylation system of Salmonella enterica
Kristy L. Hentchel1,2 and Jorge C. Escalante-Semerena1
The extensive involvement of the reversible lysine acylation (RLA) system in metabolism has attracted the attention of investigators interested in understanding the fundamentals of prokaryotic and eukaryotic cell function. Here the authors discuss the implications of recently reported work performed in the enteropathogen Salmonella enterica (mBio (2015) 6(4):e00891-15), which provided the first insights into the integration of the transcriptional regulation of genes encoding the RLA system with the acs gene encoding the central metabolic enzyme acetyl-CoA synthetase (Acs).
A bacterial volatile signal for biofilm formation
Yun Chen2, Kevin Gozzi1, and Yunrong Chai1
Bacteria constantly monitor the environment they reside in and respond to potential changes in the environment through a variety of signal sensing and transduction mechanisms in a timely fashion. In their recent study (Chen, et al. mBio (2015), 6: e00392-15), the authors demonstrated that the soil bacterium Bacillus subtilis uses acetic acid as a volatile signal to coordinate the timing of biofilm formation within physically separated cells in the community. They also showed that the bacterium possesses an intertwined gene network to produce, secrete, sense, and respond to acetic acid, in stimulating biofilm formation.
Intracellular phase for an extracellular bacterial pathogen: MgtC shows the way
August 13, 2015
This article discusses the article "A macrophage subversion factor is shared by intracellular and extracellular pathogens" by Belon et al. (PLoS Pathogens 11(6): e1004969, 2015).
The role of transcriptional ‘futile cycles’ in autophagy and microbial pathogenesis
July 30, 2015
Eukaryotic cells utilize macroautophagy (hereafter autophagy) to recycle cellular materials during nutrient stress. Target of rapamycin (Tor) is a central regulator of this process, acting by post-translational mechanisms, phosphorylating preformed autophagy-related (Atg) proteins to repress autophagy during log-phase growth. A role for this regulatory process in fungal virulence was further demonstrated by showing that overexpression of the Dcp2-associated mRNA-binding protein Vad1 in the AIDS-associated pathogen Cryptococcus neoformans results in constitutive repression of autophagy even under starvation conditions as well as attenuated virulence in a mouse model. In summary, Tor-dependent post-transcriptional regulation of autophagy plays a key role in the facilitation of microbial pathogenesis.
Membrane depolarization-triggered responsive diversification leads to antibiotic tolerance
July 24, 2015
In this article, the authors discuss the article "Obg and membrane depolarization are part of a microbial bet-hedging strategy that leads to antibiotic tolerance", Verstraeten et al., Mol. Cell 2015 Jul 2; 59 (1): 9-21.
Evolutionary rewiring of bacterial regulatory networks
July 6, 2015
Bacteria have evolved complex regulatory networks that enable integration of multiple intracellular and extracellular signals to coordinate responses to environmental changes. However, our knowledge of how regulatory systems function and evolve is still relatively limited. There is often extensive homology between components of different networks, due to past cycles of gene duplication, divergence, and horizontal gene transfer, raising the possibility of cross-talk or redundancy. Consequently, evolutionary resilience is built into gene networks – homology between regulators can potentially allow rapid rescue of lost regulatory function across distant regions of the genome. This article discusses Taylor, et al. Science (2015), 347(6225), reporting mutations that facilitate cross-talk between pathways can contribute to gene network evolution, but which come with severe pleiotropic costs. Arising from this work are a number of questions surrounding how this phenomenon occurs.
Handcuffs for bacteria – NDP52 orchestrates xenophagy of intracellular Salmonella
May 21, 2015
This microreview discusses the article "Autophagy Receptor NDP52 Regulates Pathogen-Containing Autophagosome Maturation" by Verlhac et al. (2015), Cell Host Microbe.
Understanding grapevine-microbiome interactions: implications for viticulture industry
May 4, 2015
This microreview discusses the article "The soil microbiome influences grapevine-associated microbiota" by Zarraonaindia et al. (2015), MBio, which reports that the grapevine-associated microbiota depends on the soil microbiome.
Cytokinins beyond plants: synthesis by Mycobacterium tuberculosis
May 4, 2015
This microreview discusses "Proteasomal Control of Cytokinin Synthesis Protects Mycobacterium tuberculosis against Nitric Oxide" by Samanovic et al. (2015), Mol Cell.
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.
New roles for autophagy and spermidine in T cells
March 2, 2015
This microreview discusses the article "Autophagy is a critical regulator of memory CD8+ T cell formation" by Puleston et al. (2014), eLife.
Characterization of the Maf family of polymorphic toxins in pathogenic Neisseria species
March 2, 2015
In addition to harmless commensal species, Neisseria genus encompasses two pathogenic species, N. meningitidis (the meningococcus) and N. gonorrhoeae (the gonococcus), which are responsible for meningitis and genital tract infections, respectively. This microreview comments on the article "A new family of secreted toxins in pathogenic Neisseria species" by Jamet et al. (2015), PLoS Pathog.