Latest Articles
Research Article | Host-Microbe BiologyIdentification of Pneumococcal Factors Affecting Pneumococcal Shedding Shows that the dlt Locus Promotes Inflammation and TransmissionStreptococcus pneumoniae (the pneumococcus) is a common cause of respiratory tract and invasive infection. The overall effectiveness of immunization with the organism’s capsular polysaccharide depends on its ability to block colonization of the upper respiratory tract and thereby prevent host-to-host transmission. Because of the limited coverage of current...
Editor's Pick Research Article | Host-Microbe BiologyMouse Norovirus Infection Arrests Host Cell Translation Uncoupled from the Stress Granule-PKR-eIF2α AxisViruses hijack host machinery and regulate cellular homeostasis to actively replicate their genome, propagate, and cause disease. In retaliation, cells possess various defense mechanisms to detect, destroy, and clear infecting viruses, as well as signal to neighboring cells to inform them of the imminent threat. In this study, we demonstrate that the murine norovirus (MNV) infection stalls host protein translation and the production of...
Research Article | Molecular Biology and PhysiologyThe Lipid A 1-Phosphatase, LpxE, Functionally Connects Multiple Layers of Bacterial Envelope BiogenesisDephosphorylation of the lipid A 1-phosphate by LpxE in Gram-negative bacteria plays important roles in antibiotic resistance, bacterial virulence, and modulation of the host immune system. Our results demonstrate that in addition to removing the 1-phosphate from lipid A, LpxEs also dephosphorylate undecaprenyl pyrophosphate, an important metabolite for the synthesis of the essential envelope components, peptidoglycan and O-antigen....
Research Article | Host-Microbe BiologyPulmonary Iron Limitation Induced by Exogenous Type I IFN Protects Mice from Cryptococcus gattii Independently of T CellsCryptococcus neoformans and Cryptococcus gattii cause fatal infection in immunodeficient and immunocompetent individuals. While these fungi are sibling species, C. gattii infects very few AIDS patients, while...
Research Article | Host-Microbe BiologyNuclear Factor Y (NF-Y) Modulates Encystation in Entamoeba via Stage-Specific Expression of the NF-YB and NF-YC SubunitsThe human parasite Entamoeba histolytica is an important pathogen with significant global impact and is a leading cause of parasitic death in humans. Since only the cyst form can be transmitted, blocking encystation would prevent new infections, making the encystation pathway an attractive target for the development of new drugs. Identification of the genetic signals...
Commentary | Ecological and Evolutionary ScienceEarly Cyanobacteria and the Innovation of Microbial SunscreensMetabolism drives life; thus, understanding how and when various branches of metabolism evolved provides a critical piece to understanding how life has integrated itself into the geochemical cycles of our planet over billions of years.
Research Article | Molecular Biology and PhysiologyExtensive Epitranscriptomic Methylation of A and C Residues on Murine Leukemia Virus Transcripts Enhances Viral Gene ExpressionThe data presented in the present study demonstrate that MLV RNAs bear an exceptionally high level of the epitranscriptomic modifications m6A, m5C, and Nm, suggesting that these each facilitate some aspect of the viral replication cycle. Consistent with this hypothesis, we demonstrate that mutational removal of a subset of these m6A or m5C modifications from MLV transcripts inhibits MLV...
Research Article | Molecular Biology and PhysiologyThe Yeast PCNA Unloader Elg1 RFC-Like Complex Plays a Role in Eliciting the DNA Damage CheckpointThe Elg1protein forms an RFC-like complex in charge of unloading PCNA from chromatin during DNA replication and repair. Mutations in the ELG1 gene caused genomic instability in all organisms tested and cancer in mammals. Here we show that Elg1 plays a role in the induction of the DNA damage checkpoint, a cellular response to DNA damage. We show that this defect is due to a defect in the signal amplification process during...
Research Article | Ecological and Evolutionary ScienceTransient Replication in Specialized Cells Favors Transfer of an Integrative and Conjugative ElementBacterial evolution is driven to a large extent by horizontal gene transfer (HGT)—the processes that distribute genetic material between species rather than by vertical descent. The different elements and processes mediating HGT have been characterized in great molecular detail. In contrast, very little is known on adaptive features selecting HGT evolvability and fitness optimization. By studying the molecular behavior of an integrated...
Editor's Pick Research Article | Therapeutics and PreventionThe Landscape of Phenotypic and Transcriptional Responses to Ciprofloxacin in Acinetobacter baumannii: Acquired Resistance Alleles Modulate Drug-Induced SOS Response and Prophage ReplicationFluoroquinolones have been extremely successful antibiotics due to their ability to target multiple bacterial enzymes critical to DNA replication, the topoisomerases DNA gyrase and topo IV. Unfortunately, mutations lowering drug affinity for both enzymes are now widespread, rendering these drugs ineffective for many pathogens. To undermine this form of resistance, we examined how bacteria with target alterations differentially cope with...