signal transduction
Research Article | Molecular Biology and PhysiologyThe Unconventional Cytoplasmic Sensing Mechanism for Ethanol Chemotaxis in Bacillus subtilisEthanol is a chemoattractant for Bacillus subtilis even though it is not metabolized and inhibits growth. B. subtilis likely uses ethanol to find ethanol-fermenting microorganisms to utilize as prey. Two chemoreceptors sense ethanol: HemAT and McpB. HemAT’s myoglobin-like sensing domain directly...
Research Article | Molecular Biology and PhysiologyCyclic di-GMP Signaling in Bacillus subtilis Is Governed by Direct Interactions of Diguanylate Cyclases and Cognate ReceptorsSecond messengers are free to diffuse through the cells and to activate all responsive elements. Cyclic di-GMP (c-di-GMP) signaling plays an important role in the determination of the life style transition between motility and sessility/biofilm formation but involves numerous distinct synthetases (diguanylate cyclases [DGCs]) or receptor pathways that appear to act in an independent manner. Using...
Editor's Pick Research Article | Molecular Biology and PhysiologyHow Bacterial Chemoreceptors Evolve Novel Ligand SpecificitiesMany bacteria possess a large number of chemoreceptors that recognize a variety of different compounds. More than 60% of the genomes analyzed in this study contain paralogous chemoreceptors, suggesting that they emerge with high frequency. We provide first insight on how paralogous receptors have evolved and show that two chemoreceptors with a narrow ligand range have evolved from an ancestral protein with a broad chemoeffector spectrum...
Research Article | Molecular Biology and PhysiologyComprehensive Analysis of Aspergillus nidulans PKA Phosphorylome Identifies a Novel Mode of CreA RegulationThe cyclic AMP (cAMP)-dependent protein kinase A (PKA) signaling pathway is well conserved across eukaryotes, and previous work has shown that it plays an important role in regulating development, growth, and virulence in a number of fungi. PKA is activated in response to extracellular nutrients and acts to regulate metabolism and growth. While a number of components in the PKA pathway have been defined in filamentous fungi, current...
Research Article | Molecular Biology and PhysiologyCross Talk between Chemosensory Pathways That Modulate Chemotaxis and Biofilm FormationIn many bacteria, two or more homologous chemosensory pathways control several cellular functions, such as motility and gene regulation, in response to changes in the cell’s microenvironment. Cross talk between signal transduction systems is poorly understood; while generally it is considered to be undesired, in some instances it might be beneficial for coregulation of complex behaviors. We demonstrate that several receptors from the...
- Research ArticleProposed Role for KaiC-Like ATPases as Major Signal Transduction Hubs in Archaea
Little is currently known about signal transduction pathways in Archaea. Recent studies indicate that KaiC-like ATPases, known as key components of the circadian clock apparatus in cyanobacteria, are involved in the regulation of archaellum assembly and, likely, type IV pili and the gas vesicle system in Archaea. We performed comprehensive comparative genomic analyses of the KaiC family. A vast protein interaction...
- Research ArticleTIFA Signaling in Gastric Epithelial Cells Initiates the cag Type 4 Secretion System-Dependent Innate Immune Response to Helicobacter pylori Infection
H. pylori is a globally prevalent cause of gastric and duodenal ulcers and cancer. H. pylori antibiotic resistance is rapidly increasing, and a vaccine remains elusive. The earliest immune response to H. pylori is initiated by gastric epithelial cells and sets the stage for the subsequent immunopathogenesis. This study revealed that host TIFA and H. pylori-derived HBP are critical effectors of innate...