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Bacterial signal transduction

Justin L Luebke, Daniel S Eaton, Joseph R Sachleben, Sean Crosson
Bacterial signal transduction systems commonly use receiver (REC) domains, which regulate adaptive responses to the environment as a function of their phosphorylation state. REC domains control cell physiology through diverse mechanisms, many of which remain understudied. We have defined structural features that underlie activation of the multi-domain REC protein, PhyR, which functions as an anti-anti-σ factor and regulates transcription of genes required for stress adaptation and host-microbe interactions in Alphaproteobacteria...
October 20, 2017: Molecular Microbiology
Youyun Yang, Alan Wolfe, X Frank Yang
Posttranslational modification (PTM) of proteins has emerged as a major regulatory mechanism in all three domains of life. One emerging PTM is Nε-lysine acetylation-the acetylation of the epsilon amino group of lysine residues. Nε-lysine acetylation is known to regulate multiple cellular processes. In eukaryotes, it regulates chromatin structure, transcription, metabolism, signal transduction, and the cytoskeleton. Recently, multiple groups have detected Nε-lysine acetylation in diverse bacterial phyla, but no work on protein acetylation in Borrelia burgdorferi has been reported...
2018: Methods in Molecular Biology
Markus Blaess, Nelly Bibak, Ralf A Claus, Matthias Kohl, Gabriel A Bonaterra, Ralf Kinscherf, Stefan Laufer, Hans-Peter Deigner
Ceramide generation is involved in signal transduction of cellular stress response, in particular during stress-induced apoptosis in response to stimuli such as minimally modified Low-density lipoproteins, TNFalpha and exogenous C6-ceramide. In this paper we describe 48 diverse synthetic products and evaluate their lysosomotropic and acid sphingomyelinase inhibiting activities in macrophages. A stimuli-induced increase of C16-ceramide in macrophages can be almost completely suppressed by representative compound NB 06 providing an effective protection of macrophages against apoptosis...
September 21, 2017: European Journal of Medicinal Chemistry
Yongfei Cai, Mingyang Su, Ashfaq Ahmad, Xiaojie Hu, Jiayan Sang, Lingyuan Kong, Xingqiang Chen, Chen Wang, Jianwei Shuai, Aidong Han
Two-component systems (TCSs) are key elements in bacterial signal transduction in response to environmental stresses. TCSs generally consist of sensor histidine kinases (SKs) and their cognate response regulators (RRs). Many SKs exhibit autokinase, phosphoryltransferase and phosphatase activities, which regulate RR activity through a phosphorylation and dephosphorylation cycle. However, how SKs perform different enzymatic activities is poorly understood. Here, several crystal structures of the minimal catalytic region of WalK, an essential SK from Lactobacillus plantarum that shares 60% sequence identity with its homologue VicK from Streptococcus mutans, are presented...
October 1, 2017: Acta Crystallographica. Section D, Structural Biology
Zhicheng Long, Bryan Quaife, Hanna Salman, Zoltán N Oltvai
Bacteria are able to coordinate their movement, growth and biochemical activities through cell-cell communication. While the biophysical mechanism of bacterial chemotaxis has been well understood in individual cells, the role of communication in the chemotaxis of bacterial populations is not clear. Here we report experimental evidence for cell-cell communication that significantly enhances the chemotactic migration of bacterial populations, a finding that we further substantiate using numerical simulations...
October 9, 2017: Scientific Reports
James A McCubrey, Stephen L Abrams, Kvin Lertpiriyapong, Lucio Cocco, Stefano Ratti, Alberto M Martelli, Saverio Candido, Massimo Libra, Ramiro M Murata, Pedro L Rosalen, Paolo Lombardi, Giuseppe Montalto, Melchiorre Cervello, Agnieszka Gizak, Dariusz Rakus, Linda S Steelman
Over the past fifty years, society has become aware of the importance of a healthy diet in terms of human fitness and longevity. More recently, the concept of the beneficial effects of certain components of our diet and other compounds, that are consumed often by different cultures in various parts of the world, has become apparent. These "healthy" components of our diet are often referred to as nutraceuticals and they can prevent/suppress: aging, bacterial, fungal and viral infections, diabetes, inflammation, metabolic disorders and cardiovascular diseases and have other health-enhancing effects...
October 3, 2017: Advances in Biological Regulation
Nazanin Hosseinkhan, Zaynab Mousavian, Ali Masoudi-Nejad
Pseudomonas aeruginosa and Staphylococcus aureus are two evolutionary distant bacterial species that are frequently isolated from persistent infections such as chronic infectious wounds and severe lung infections in cystic fibrosis patients. To the best of our knowledge no comprehensive genome scale co-expression study has been already conducted on these two species and in most cases only the expression of very few genes has been the subject of investigation. In this study, in order to investigate the level of expressional conservation between these two species, using heterogeneous gene expression datasets the weighted gene co-expression network analysis (WGCNA) approach was applied to study both single and cross species genome scale co-expression patterns of these two species...
October 4, 2017: Gene
Fufa Qu, Zhiming Xiang, Yingli Zhou, Yanping Qin
Tumor necrosis factor (TNF) receptor-associated factor 2 (TRAF2) is a member of the TRAF superfamily that acted as a key signal transduction protein and has been implicated in inflammatory and apoptosis processes in mammals. However, identification of TRAF2s in invertebrates is very limited and its function, in particular that under immune challenges, is still unknown. In this report, a molluscan TRAF2 gene (referred to as AwTRAF2) was cloned and characterized from the freshwater bivalve, Anodonta woodiana...
October 3, 2017: Fish & Shellfish Immunology
Qian Liu, Xu Dan, Shigui Jiang, Jianhua Huang, Falin Zhou, Yang Qibin, Jiang Song, Lishi Yang
Toll receptors are important pathogen recognition receptors (PRRs) in shrimps, which play a vital role in defending against virus and bacterial challenge. In this paper, the characterization and functional analysis of a Toll9 receptor gene from Penaeus monodon was performed in HEK293T cells. Data showed that PmToll9 can activate the NF-κB promoter activities of TLR pathway, while ISRE and IFN-β promoter cannot be activated obviously in HEK293T cells using dual-luciferase reporter system. The downstream immune factors of IL-8, IκB-α, and TRAF6 were activated by PmToll9 and IL-8 showed the most significant up-regulation in expression levels, indicating the activities of NF-κB can be mediated by PmToll9...
October 2, 2017: Gene
Xiong Zheng, Yinglong Su, Yinguang Chen, Haining Huang, Qiuting Shen
Functionalized single-walled carbon nanotubes (f-SWNTs) are widely used in many fields due to the unique structure and the excellent properties. Although these nanomaterials have been reported to enable to cause negative effects on denitrifying bacteria once they enter the environment, the toxic behaviors and regulatory mechanisms of f-SWNTs to denitrification remain unclear. In this study, the denitrification performance of a model denitrifier exposed to pristine and functionalized SWNTs was investigated, and the global transcriptional responses were comprehensively explored by RNA-seq and weighted gene-coexpression network analysis (WGCNA)...
September 24, 2017: Science of the Total Environment
Shouting Cheng, Fangfang Wang, Wei Qian
cyclic di-GMP (c-di-GMP) is a universal second messenger in bacterial cells. It regulates various biological processes such as biofilm development, pathogenicity, motility, exopolysaccharide (EPS) production and cell cycle. The second messenger exerts its function by binding to effectors, such as riboswitches and proteins. However, due to the diverse conformations of c-di-GMP, its effectors are hardly to be predicted by homology search. Identification of c-di-GMP effectors is the initial step to investigate its regulatory function in bacterial signal transduction, however, it remains to be a technically difficult task...
September 25, 2017: Sheng Wu Gong Cheng Xue Bao, Chinese Journal of Biotechnology
Bruna C Lustri, Vanessa Sperandio, Cristiano G Moreira
Intestinal bacteria employ microbial metabolites from the microbiota and chemical signaling during cell-to-cell communication to regulate several cellular functions. Pathogenic bacteria are extremely efficient in orchestrating their response to these signals through complex signaling transduction systems. Precise coordination and interpretation of these multiple chemical cues is important within the gastrointestinal (GI) tract. Enteric foodborne pathogens such as enterohemorrhagic Escherichia coli (EHEC) and Salmonella enterica serovar Typhimurium, or the surrogate murine infection model for EHEC, Citrobacter rodentium, are all examples of microorganisms that modulate expression of their virulence repertoire in response to signals from the microbiota or the host, such as Autoinducer-3 (AI-3), epinephrine (Epi) and norepinephrine (NE)...
September 25, 2017: Infection and Immunity
Sisi Yang, Qiuhua Li, Yinnan Mu, Jingqun Ao, Xinhua Chen
Interferon gamma (IFN-γ) is a T helper cell type 1 (Th1) cytokine that plays important roles in almost all phases of immune and inflammatory responses. Although IFN-γ gene in large yellow croaker Larimichthys crocea has been reported, little is known about its bioactivity. In this study, large yellow croaker IFN-γ (LycIFN-γ) gene was found to be constitutively expressed in all tissues tested, with the highest levels in blood and heart. Based on stimulation with polyinosinic-polycytidylic acid [poly (I:C)] or inactivated trivalent bacterial vaccine, LycIFN-γ mRNA was significantly increased in spleen and head kidney tissues...
September 20, 2017: Fish & Shellfish Immunology
Sheng Wang, Bin Yin, Haoyang Li, Bang Xiao, Kai Lǚ, Chiguang Feng, Jianguo He, Chaozheng Li
LvMKK4, a homologue of the mammalian mitogen-activated protein kinase kinase 4 (MKK4), was isolated and identified from Litopenaeus vannamei in the present study. The full-length cDNA of LvMKK4 is 1947 bp long, with an open reading frame (ORF) of 1185 bp encoding a putative protein of 388 amino acids. LvMKK4 contains several characteristic domains such as D domain, SIAKT motif and kinase domain, all of which are conserved in MAP kinase kinase family. Like mammalian MKK4 but not Drosophila MKK4, LvMKK4 could bind to, phosphorylate and activate p38 MAPK, which provided some insights into the signal transduction mechanism of MKK4-p38 cascade in invertebrates...
September 19, 2017: Developmental and Comparative Immunology
Eugenia Kress, Julika Merres, Lea-Jessica Albrecht, Sven Hammerschmidt, Thomas Pufe, Simone C Tauber, Lars-Ove Brandenburg
BACKGROUND: Antimicrobial peptides are important components of the host defence with a broad range of functions including direct antimicrobial activity and modulation of inflammation. Lack of cathelin-related antimicrobial peptide (CRAMP) was associated with higher mortality and bacterial burden and impaired neutrophil granulocyte infiltration in a model of pneumococcal meningitis. The present study was designed to characterize the effects of CRAMP deficiency on glial response and phagocytosis after exposure to bacterial stimuli...
September 16, 2017: Cell Communication and Signaling: CCS
Bethany A Weigele, Robert C Orchard, Alyssa Jimenez, Gregory W Cox, Neal M Alto
Membrane-bound organelles serve as platforms for the assembly of multi-protein complexes that function as hubs of signal transduction in eukaryotic cells. Microbial pathogens have evolved virulence factors that reprogram these host signaling responses, but the underlying molecular mechanisms are poorly understood. Here we test the ability of ~200 type III and type IV effector proteins from six Gram-negative bacterial species to interact with the eukaryotic plasma membrane and intracellular organelles. We show that over 30% of the effectors localize to yeast and mammalian cell membranes, including a subset of previously uncharacterized Legionella effectors that appear to be able to regulate yeast vacuolar fusion...
September 14, 2017: Nature Communications
Ahmad Ali-Ahmad, Firas Fadel, Corinne Sebban-Kreuzer, Moly Ba, Gauthier Dangla Pélissier, Olivier Bornet, Françoise Guerlesquin, Yves Bourne, Christophe Bordi, Florence Vincent
Pseudomonas aeruginosa is an opportunistic pathogenic bacterium responsible for both acute and chronic infections and has developed resistance mechanisms due to its ability to promote biofilm formation and evade host adaptive immune responses. Here, we investigate the functional role of the periplasmic detector domain (GacSPD) from the membrane-bound GacS histidine kinase, which is one of the key players for biofilm formation and coordination of bacterial lifestyles. A gacS mutant devoid of the periplasmic detector domain is severely defective in biofilm formation...
September 12, 2017: Scientific Reports
James A Hoch
This is a tale of how technology drove the discovery of the molecular basis for signal transduction in the initiation of sporulation in Bacillus subtilis and in bacterial two-component systems. It progresses from genetics to cloning and sequencing to biochemistry to structural biology to an understanding of how proteins evolve interaction specificity and to identification of interaction surfaces by statistical physics. This is about how the people in my laboratory accomplished this feat; without them little would have been done...
September 8, 2017: Annual Review of Microbiology
Krishnanand Mishra, Ghazi Alsbeih
The search for efficient radioprotective agents to protect from radiation-induced toxicity, due to planned or accidental radiation exposure, is still ongoing worldwide. Despite decades of research and development of widely different biochemical classes of natural and derivative compounds, a safe and effective radioprotector is largely unmet. In this comprehensive review, we evaluated the evidence for the radioprotective performance of classical thiols, vitamins, minerals, dietary antioxidants, phytochemicals, botanical and bacterial preparations, DNA-binding agents, cytokines, and chelators including adaptogens...
October 2017: 3 Biotech
Haigang Ma, Jie Chen, Zhenzhen Zhang, Ling Ma, Zeyu Yang, Qinglu Zhang, Xianghua Li, Jinghua Xiao, Shiping Wang
Mitogen-activated protein kinase (MAPK) cascades, with each cascade consisting of a MAPK kinase kinase (MAPKKK), a MAPK kinase (MAPKK), and a MAPK, have important roles in different biological processes. However, the signal transduction in rice MAPK cascades remains to be elucidated. We show that the structural non-canonical MAPKK, MPKK10.2, enhances rice resistance to Xanthomonas oryzae pv. oryzicola (Xoc), which causes bacterial streak disease, and increases rice tolerance to drought stress by phosphorylating and activating two MAPKs, MPK6 and MPK3, respectively...
August 30, 2017: Plant Journal: for Cell and Molecular Biology
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