Vol. 04, 2017
Out with the old: Hsp90 finds amino acid residue more useful than co-chaperone protein
Abbey D. Zuehlke1 and Leonard Neckers1
This article comments on work published by Zuehlke et al (Nat Commun, 2017), which demonstrates that the function of one co-chaperone in yeast is replaced by posttranslational modification (PTM) of a single amino acid within Hsp90 in higher eukaryotes.
Having your cake and eating it – Staphylococcus aureus small colony variants can evolve faster growth rate without losing their antibiotic resistance
Gerrit Brandis1, Sha Cao1, Douglas L. Huseby1 and Diarmaid Hughes1
This article comments on work published by Cao et al. (mBio, 2027), which shows that Staphylococcus aureus can produce small colony variants (SCVs) that are challenging to detect and lead to persistent infections due to mutations affecting respiration and ATP production, with recent findings indicating various evolutionary paths for SCVs to increase growth rate while maintaining antibiotic resistance, suggesting greater adaptability and clinical challenge.
Cristae architecture is determined by an interplay of the MICOS complex and the F1FO ATP synthase via Mic27 and Mic10
Katharina Eydt1,2, Karen M. Davies3, Christina Behrendt4, Ilka Wittig1,5 and Andreas S. Reichert1,2,4,*
This article investigates the roles of MICOS subunits Mic27 and Mic10, revealing their antagonistic and cooperative interactions in crista junction formation and cristae membrane curvature, and proposes a model where F1FO-ATP synthase is connected to MICOS, influencing CJ formation.
The interplay between transcription and mRNA degradation in Saccharomyces cerevisiae
Subhadeep Das1, Debasish Sarkar2 and Biswadip Das1
This review summarizes how the integration of mRNA synthesis and degradation, mediated by specialized promoters and "coordinators," shapes the cellular transcriptome and plays a significant role in regulating gene expression profiles in various biological processes and potentially enhances evolutionary rates.
Inhibitors of glycosomal protein import provide new leads against trypanosomiasis
Vishal C. Kalel1, Leonidas Emmanouilidis2,3, Maciej Dawidowski2,3,4, Wolfgang Schliebs1, Michael Sattler2,3, Grzegorz M. Popowicz2,3, Ralf Erdmann1
This article comments on work published by Dawidowski et al. (Science, 2017), which provides the grounds for further development of the glycosome inhibitors into clinical candidates and validates the parasite protein-protein interactions as drug targets.
A new role for the nuclear basket network
Paola Gallardo1, Silvia Salas-Pino1 and Rafael R. Daga1
This article comments on work published by Salas-Pino et al. (J Cell Biol, 2017), which describes a novel function of the fission yeast nuclear basket component - the translocated promoter region (TPR) nucleoporin Alm1 - in proper localization of the proteasome to the nuclear envelope.
A genome-wide screen for FTY720-sensitive mutants reveals genes required for ROS homeostasis
Kanako Hagihara1, Kanako Kinoshita1, Kouki Ishida1, Shihomi Hojo1, Yoshinori Kameoka1, Ryosuke Satoh1, Teruaki Takasaki1 and Reiko Sugiura1
Fingolimod hydrochloride (FTY720) is an immune modulator for multiple sclerosis that also induces cancer cell apoptosis through reactive oxygen species generation, with a new study using fission yeast uncovering a gene network related to ROS homeostasis as a possible mechanism of FTY720's toxicity.
VAMP8 mucin exocytosis attenuates intestinal pathogenesis by Entamoeba histolytica
Steve Cornick1, France Moreau1, Herbert Y. Gaisano2, Kris Chadee1
This article comments on work published by Cornick et al. (mBio, 2017), which nominates SNARE-mediated exocytosis as the putative mechanism responsible for pathogen-induced mucus secretion from goblet cells.
Aminoglycoside resistance profile and structural architecture of the aminoglycoside acetyltransferase AAC(6’)-Im
Clyde A. Smith1, Monolekha Bhattacharya2, Marta Toth2, Nichole K. Stewart2 and Sergei B. Vakulenko2
AAC(6')-Im, a monofunctional acetyltransferase, imparts increased resistance to certain aminoglycosides compared to its bifunctional homolog AAC(6')-Ie, with structural studies revealing differences in substrate binding that explain the discrepancies in their enzymatic activity and resistance profiles.
Shutdown of interferon signaling by a viral-hijacked E3 ubiquitin ligase
Kaitlin A. Davis1 and John T. Patton2
This article comments on work published by Davis et al. (mBio, 2017), which describes molecular requirements that govern NSP1 recognition of β-TrCP, including an essential degron phosphorylation event, and the step-wise incorporation of NSP1 into hijacked cullin-RING E3 ligases (CRLs) that ubiquitinate and tag β-TrCP for degradation.
Post-transcriptional regulation of ribosome biogenesis in yeast
Isabelle C. Kos-Braun and Martin Koš
Microorganisms adapt to environmental changes by regulating their metabolism, and one key survival strategy is to decrease energy use during adverse conditions by halting ribosome production, with recent findings showing yeast can switch between pre-rRNA processing pathways in response to environmental shifts, adding complexity to ribosome biogenesis regulation.
Placeholder factors in ribosome biogenesis: please, pave my way
Francisco J. Espinar-Marchena, Reyes Babiano1 and Jesús de la Cruz
In ribosome synthesis, "placeholder" factors are crucial trans-acting elements that regulate the timing and assembly of ribosomal proteins, ensuring speed and accuracy in this intricate process by preventing premature interactions and guiding the proper formation of functional ribosomal subunits.
Insights from the redefinition of Helicobacter pylori lipopolysaccharide O-antigen and core-oligosaccharide domains
Hong Li1,2, Tiandi Yang3, Tingting Liao2, Aleksandra W. Debowski2,4, Hans-Olof Nilsson2, Stuart M. Haslam3, Anne Dell3, Keith A. Stubbs4, Barry J. Marshall2 and Mohammed Benghezal2,5
This article comments on work published by Li et al. (PloS Pathog, 2017), focusing on Helicobacter pylori infections. They are mostly asymptomatic but can lead to serious conditions, and H. pylori lipopolysaccharide (LPS) is crucial for colonization and persistence, making the study of its structure and biosynthesis pathway vital for understanding pathogenesis and developing treatments.
Evading plant immunity: feedback control of the T3SS in Pseudomonas syringae
Christopher Waite1, Jörg Schumacher1, Milija Jovanovic1, Mark Bennett1 and Martin Buck1
This article comments on work published by Waite et al. (mBio, 2017), which indicates that a negative autogenous control mechanism, where the sigma factor HrpL represses its own expression, permits the plant pathogen Pseudomonas syringae to fine-tune its type III secretion system, potentially reducing the elicitation of plant immunity and enhancing its ability to cause disease.
Microbial flora, probiotics, Bacillus subtilis and the search for a long and healthy human longevity
Facundo Rodriguez Ayala, Carlos Bauman, Sebastián Cogliati, Cecilia Leñini, Marco Bartolini and Roberto Grau
This article comments on work published by Donato et al. (Nat Commun, 2017), which reveals that the probiotic Bacillus subtilis extends the lifespan of Caenorhabditis elegans via mechanisms including the formation of biofilms and the production of signaling molecules like NO and CSF, suggesting a potential pathway through insulin-like signaling that could impact human longevity and age-related diseases.
Chlamydia trachomatis’ struggle to keep its host alive
Barbara S. Sixt1-4, Raphael H. Valdivia5, Guido Kroemer1-4,6-7
This article comments on work published by Sixt et al. (Cell Host Microbe, 2016), which analyzed a CpoS-deficient mutant yielding unique insights into the nature of cell-autonomous defense responses against Chlamydia.
New insights into the function of a versatile class of membrane molecular motors from studies of Myxococcus xanthus surface (gliding) motility
Tâm Mignot1 and Marcelo Nöllmann2
This article comments on work published by Faure et al. (Nature, 2016), which deciphers force transmission at focal adhesion complexes that are involved in gliding motility in bacteria.
Advancing host-directed therapy for tuberculosis: new therapeutic insights from the Toxoplasma gondii
Chul-Su Yang
This article comments on work published by Koh et al. (PLoS Pathog, 2017), which uncovered that infection-induced signaling pathways suggest possibilities for the development of novel therapeutic modalities for TB that target the intracellular signaling pathways permitting the replication of Mycobacterium tuberculosis (MTB).
Breaking the bilayer: OMV formation during environmental transitions
Katherine E. Bonnington, Meta J. Kuehn
This article comments on work published by Bonnington & Kuehn (MBio, 2016), which shows how gram-negative bacteria maintain the barrier properties of the outer membrane (OM) in a wide array of physiological conditions despite their inability to degrade lipopolysaccharide (LPS) and protein material present in the outer leaflet of the OM.
Uncovering the hidden: complexity and strategies for diagnosing latent tuberculosis
Mario Alberto Flores-Valdez
This editorial postulates that advanced proteomic and transcriptomic techniques are evolving and may enhance the detection of latent tuberculosis, thereby distinguishing true M. tuberculosis infections from other conditions, which is vital for controlling potential reactivation and transmission.
The Yin & Yang of Mitochondrial Architecture – Interplay of MICOS and F1Fo-ATP synthase in cristae formation
Heike Rampelt1 and Martin van der Laan2
This Editorial posits that mitochondrial cristae architecture is shaped by the interplay of MICOS and ATP synthase, with a recent study illuminating their roles in cristae formation and maintenance.
When a ribosomal protein grows up – the ribosome assembly path of Rps3
Brigitte Pertschy
This article comments on two papers by Mitterer et al., which followed yeast protein Rps3, highlighting the sophisticated mechanisms for protein protection, nuclear transport, and integration into pre-ribosomal particles for final assembly with 40S subunits.
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.
A new role for the nuclear basket network
November 28, 2017
This article comments on work published by Salas-Pino et al. (J Cell Biol, 2017), which describes a novel function of the fission yeast nuclear basket component - the translocated promoter region (TPR) nucleoporin Alm1 - in proper localization of the proteasome to the nuclear envelope.
A genome-wide screen for FTY720-sensitive mutants reveals genes required for ROS homeostasis
November 27, 2017
Fingolimod hydrochloride (FTY720) is an immune modulator for multiple sclerosis that also induces cancer cell apoptosis through reactive oxygen species generation, with a new study using fission yeast uncovering a gene network related to ROS homeostasis as a possible mechanism of FTY720's toxicity.
VAMP8 mucin exocytosis attenuates intestinal pathogenesis by Entamoeba histolytica
November 24, 2017
This article comments on work published by Cornick et al. (mBio, 2017), which nominates SNARE-mediated exocytosis as the putative mechanism responsible for pathogen-induced mucus secretion from goblet cells.
Aminoglycoside resistance profile and structural architecture of the aminoglycoside acetyltransferase AAC(6’)-Im
November 9, 2017
AAC(6')-Im, a monofunctional acetyltransferase, imparts increased resistance to certain aminoglycosides compared to its bifunctional homolog AAC(6')-Ie, with structural studies revealing differences in substrate binding that explain the discrepancies in their enzymatic activity and resistance profiles.
Shutdown of interferon signaling by a viral-hijacked E3 ubiquitin ligase
November 3, 2017
This article comments on work published by Davis et al. (mBio, 2017), which describes molecular requirements that govern NSP1 recognition of β-TrCP, including an essential degron phosphorylation event, and the step-wise incorporation of NSP1 into hijacked cullin-RING E3 ligases (CRLs) that ubiquitinate and tag β-TrCP for degradation.
Cross-species complementation of bacterial- and eukaryotic-type cardiolipin synthases
November 3, 2017
This article shows that cardiolipin is crucial for cellular respiration and membrane integrity, with cardiolipin synthase enzymes like TbCLS in Trypanosoma brucei being potential drug targets due to their essential role in survival. The study demonstrates TbCLS's ability to restore cardiolipin production in yeast, highlighting the specificity and potential co-localization required for cardiolipin synthesis and remodeling, and underscoring the differences between eukaryotic and prokaryotic cardiolipin synthase mechanisms.
Breaking the bad: Bacillus blocks fungal virulence factors
October 30, 2017
This article comments on work published by Mayer & Kronstad (mBio, 2017), which identified the soil bacterium, Bacillus safensis as a potent inhibitor of virulence factor production by two major fungal pathogens of humans, Cryptococcus neoformans, and Candida albicans.
The integrated stress response in budding yeast lifespan extension
October 24, 2017
This article summarizes how the budding yeast Saccharomyces cerevisiae has been instrumental in unraveling the molecular and cellular determinants of aging, and how the induction of cellular stress responses has been associated with experimental lifespan extension, thus underscoring the value of yeast as a model for developing potential aging therapies for humans.
Uncovering the hidden: complexity and strategies for diagnosing latent tuberculosis
October 24, 2017
This editorial postulates that advanced proteomic and transcriptomic techniques are evolving and may enhance the detection of latent tuberculosis, thereby distinguishing true M. tuberculosis infections from other conditions, which is vital for controlling potential reactivation and transmission.
The Yin & Yang of Mitochondrial Architecture – Interplay of MICOS and F1Fo-ATP synthase in cristae formation
Heike Rampelt1 and Martin van der Laan2
This Editorial posits that mitochondrial cristae architecture is shaped by the interplay of MICOS and ATP synthase, with a recent study illuminating their roles in cristae formation and maintenance.