Read by QxMD icon Read

Bacterial signal transduction

Neeraj K Lal, Ugrappa Nagalakshmi, Nicholas K Hurlburt, Rosalva Flores, Aurelie Bak, Pyae Sone, Xiyu Ma, Gaoyuan Song, Justin Walley, Libo Shan, Ping He, Clare Casteel, Andrew J Fisher, Savithramma P Dinesh-Kumar
Plants employ cell-surface pattern recognition receptors (PRRs) to detect pathogens. Although phytohormones produced during PRR signaling play an essential role in innate immunity, a direct link between PRR activation and hormone regulation is unknown. EFR is a PRR that recognizes bacterial EF-Tu and activates immune signaling. Here we report that EFR regulates the phytohormone jasmonic acid (JA) through direct phosphorylation of a receptor-like cytoplasmic kinase, BIK1. The BIK1 structure revealed that the EFR-phosphorylated sites reside on a uniquely extended loop away from the BIK1 kinase core domain...
April 11, 2018: Cell Host & Microbe
Heikki Takala, Heli Lehtivuori, Oskar Berntsson, Ashley Hughes, Rahul Nanekar, Stephan Niebling, Matthijs Panman, Léocadie Henry, Andreas Menzel, Sebastian Westenhoff, Janne A Ihalainen
Phytochromes are photoreceptors in plants, fungi, and various microorganisms and cycle between metastable red light-absorbing (Pr) and far-red light-absorbing (Pfr) states. Their light responses are thought to follow a conserved structural mechanism that is triggered by isomerization of the chromophore. Downstream structural changes involve refolding of the so-called tongue extension of the phytochrome-specific GAF-related (PHY) domain of the photoreceptor. The tongue is connected to the chromophore by conserved DIP and PRxSF motifs and a conserved tyrosine, but the role of these residues in signal transduction is not clear...
April 5, 2018: Journal of Biological Chemistry
Adam James Waite, Nicholas W Frankel, Thierry Emonet
Living cells detect and process external signals using signaling pathways that are affected by random fluctuations. These variations cause the behavior of individual cells to fluctuate over time (behavioral variability) and generate phenotypic differences between genetically identical individuals (phenotypic diversity). These two noise sources reduce our ability to predict biological behavior because they diversify cellular responses to identical signals. Here, we review recent experimental and theoretical advances in understanding the mechanistic origin and functional consequences of such variation in Escherichia coli chemotaxis-a well-understood model of signal transduction and behavior...
April 4, 2018: Annual Review of Biophysics
Suyu Mei
Bacterial protein-protein interaction (PPI) networks are significant to reveal the machinery of signal transduction and drug resistance within bacterial cells. The database STRING has collected a large number of bacterial pathogen PPI networks, but most of the data are of low quality without being experimentally or computationally validated, thus restricting its further biomedical applications. In this work, we exploit the experimental data via four solutions to enhance the quality of M. tuberculosis H37Rv (MTB) PPI networks in STRING...
April 3, 2018: Journal of Proteome Research
Qian Wang, Yoon-Suk Kang, Abdullah Alowaifeer, Kaixiang Shi, Xia Fan, Lu Wang, Jonathan Jetter, Brian Bothner, Gejiao Wang, Timothy R McDermott
Environmental arsenic poisoning affects roughly 200 million people worldwide. The toxicity and mobility of arsenic in the environment is significantly influenced by microbial redox reactions, with arsenite (AsIII ) being more toxic than arsenate (AsV ). Microbial oxidation of AsIII to AsV is known to be regulated by the AioXSR signal transduction system and viewed to function for detoxification or energy generation. Here we show that AsIII oxidation is ultimately regulated by the phosphate starvation response (PSR), requiring the sensor kinase PhoR for expression of the AsIII oxidase structural genes aioBA...
March 25, 2018: Environmental Microbiology
Dehong Zheng, Bingbing Xue, Yanan Shao, Haoquan Yu, Xiaoyan Yao, Lifang Ruan
Two-component signal transduction system PhoBR regulates the adaptation to phosphate limitation and the virulence of many animal bacterial pathogens. However, PhoBR in phytopathogens has been rarely investigated. In this study, we found that PhoBR in Xanthomonas oryzae pv. oryzae (Xoo), the pathogen of rice bacterial leaf blight, also regulates the adaptation to phosphate starvation. Unexpectedly, rice leaves infected by phoBR-deleted mutant and wild-type PXO99A showed similar lesions, indicating that PhoBR is unnecessary for the virulence of Xoo...
March 25, 2018: Molecular Plant Pathology
Qinghua Zhang, Ce Ji, Jianfeng Ren, Qiuyue Zhang, Xuehong Dong, Yao Zu, Liang Jia, Weiming Li
Zebrafish embryo and larva represent a useful in vivo model for identification of host innate immune responses to bacterial infection. Vibrio parahaemolyticus is a typical zoonotic pathogen worldwide that causes acute gastroenteritis in humans and vibriosis in fishes. However, the mechanism of the innate immune response in the zebrafish larvae infected by V. parahaemolyticus has not been clear. We analysed the transcriptomic profile of 3 days post-fertilization (dpf) zebrafish larvae immersed in V. parahaemolyticus 13 (Vp13) strain suspension for 2 hr...
March 23, 2018: Journal of Fish Diseases
Chi Zhang, Rui He, Rongjing Zhang, Junhua Yuan
Bacterial chemotaxis is a canonical system for the study of signal transduction. One of the hallmarks of this system is its robust adaptive behavior. However, how fast the system adapts remains controversial. The adaptation time measured at the level of the kinase activity was tens of seconds, whereas that measured at the level of the flagellar motor was <10 s. The flagellar motor was recently shown to exhibit adaptive remodeling, its main physiological function being to provide a robust match between the chemoreceptor output and the motor input, whereas its adaptation timescale was thought to be too slow to contribute much to the overall adaptation timescale of the chemotaxis system...
March 13, 2018: Biophysical Journal
Anne-Marie Garnerone, Fernando Sorroche, Lan Zou, Céline Mathieu-Demazière, Chang Fu Tian, Catherine Masson-Boivin, Jacques Batut
An ongoing signal exchange fine-tunes the symbiotic interaction between rhizobia and legumes, ensuring the establishment and maintenance of mutualism. In a recently identified regulatory loop, endosymbiotic S. meliloti exert a negative feedback on root infection in response to unknown plant cues. Upon signal perception, three bacterial Adenylate Cyclases (ACs) of the inner membrane, CyaD1, CyaD2 and CyaK, synthesize the second messenger cAMP that, together with the cAMP-dependent Clr transcriptional activator, activates the expression of genes involved in root infection control...
March 12, 2018: Journal of Bacteriology
Mary K Phillips-Jones, Stephen E Harding
In this review, we discuss mechanisms of resistance identified in bacterial agents Staphylococcus aureus and the enterococci towards two priority classes of antibiotics-the fluoroquinolones and the glycopeptides. Members of both classes interact with a number of components in the cells of these bacteria, so the cellular targets are also considered. Fluoroquinolone resistance mechanisms include efflux pumps (MepA, NorA, NorB, NorC, MdeA, LmrS or SdrM in S. aureus and EfmA or EfrAB in the enterococci) for removal of fluoroquinolone from the intracellular environment of bacterial cells and/or protection of the gyrase and topoisomerase IV target sites in Enterococcus faecalis by Qnr-like proteins...
March 10, 2018: Biophysical Reviews
Hiraku Takada, Hirofumi Yoshikawa
The WalK/WalR two-component system (TCS), originally identified in Bacillus subtilis, is very highly conserved in gram-positive bacteria, including several important pathogens. The WalK/WalR TCS appears to be involved in the growth of most bacterial species encoding it. Previous studies have indicated conserved functions of this system, defining this signal transduction pathway as a crucial regulatory system for cell wall metabolism. Because of such effects on essential functions, this system is considered a potential target for anti-infective therapeutics...
March 7, 2018: Bioscience, Biotechnology, and Biochemistry
Vishal Mevada, Rajesh Patel, Bhoomi Patel, Rajesh Chaudhari
Since last several years, infection caused by Staphylococcus aureus is challenging to cure using conventional antibiotics. The organism is a Gram-positive bacterial pathogen that can cause serious diseases not only in humans but also in animals, such as various skin infections, pneumonia, endocarditis and toxin shock syndrome. This bacterium causes such diseases by producing macromolecules such as hemolysins, enterotoxins, proteases and toxic shock syndrome toxin (TSST-1). This organism had developed the multidrug resistance by acquiring MEC-A gene...
February 26, 2018: Computational Biology and Chemistry
Elodie Lesne, Elian Dupré, Marc F Lensink, Camille Locht, Rudy Antoine, Françoise Jacob-Dubuisson
Bordetella pertussis controls the expression of its virulence regulon through the two-component system BvgAS. BvgS is a prototype for a family of multidomain sensor kinases. In BvgS, helical linkers connect periplasmic Venus flytrap (VFT) perception domains to a cytoplasmic Per-Arnt-Sim (PAS) domain and the PAS domain to the dimerization/histidine phosphotransfer (DHp) domain of the kinase. The two linkers can adopt coiled-coil structures but cannot do so simultaneously. The first linker forms a coiled coil in the kinase mode and the second in the phosphatase mode, with the other linker in both cases showing an increase in dynamic behavior...
February 27, 2018: MBio
Ekaterina V Filippova, Bozena Zemaitaitis, Theint Aung, Alan J Wolfe, Wayne F Anderson
RcsB is a highly conserved transcription regulator of the Rcs phosphorelay system, a complex two-component signal transduction system (N. Majdalani and S. Gottesman, Annu Rev Microbiol 59:379-405, 2005; A. J. Wolfe, Curr Opin Microbiol 13:204-209, 2010,; D. J. Clarke, Future Microbiol 5:1173-1184, 2010, RcsB plays an important role in virulence and pathogenicity in human hosts by regulating biofilm formation. RcsB can regulate transcription alone or together with its auxiliary transcription regulators by forming heterodimers...
February 27, 2018: MBio
Xueye Ding, Qiang He, Fenglin Shen, Frederick W Dahlquist, Xiqing Wang
The histidine kinase CheA plays a central role in signal integration, conversion, and amplification in the bacterial chemotaxis signal transduction pathway. The kinase activity is regulated in chemotaxis signaling complexes formed via the interactions among CheA's regulatory domain (P5), the coupling protein CheW, and transmembrane chemoreceptors. Despite recent advancement in understanding of the architecture of the signaling complex, the molecular mechanism underlying this regulation remains elusive. An interdomain linker that connects the catalytic (P4) and regulatory domains of CheA may mediate regulatory signals from the P5/CheW/receptor interactions to the catalytic domain...
February 26, 2018: Journal of Bacteriology
Peixi Chang, Weitian Li, Guolin Shi, Huan Li, Xiaoqing Yang, Zechen Xia, Yuan Ren, Zhiwei Li, Huanchun Chen, Weicheng Bei
Streptococcus suis is a highly invasive pathogen that can cause sepsis and meningitis in pigs and humans. However, we have limited understanding of the mechanisms S. suis uses to evade innate immunity. To investigate the involvement of the two-component signal transduction system of S. suis in host immune defense, we examined the expression of 15 response regulators of S. suis following stimulation with polymorphonuclear leukocytes (PMNs). We found that several response regulators were significantly up-regulated including vraR...
February 23, 2018: Virulence
Anica Graf, Richard J Lewis, Stephan Fuchs, Martin Pagels, Susanne Engelmann, Katharina Riedel, Jan Pané-Farré
Lipoproteins are attached to the outer leaflet of the membrane by a di- or tri-acylglyceryl moiety and are thus positioned in the membrane-cell wall interface. Consequently, lipoproteins are involved in many surface associated functions, including cell wall synthesis, electron transport, uptake of nutrients, surface stress response, signal transduction, and they represent a reservoir of bacterial virulence factors. Inspection of 123 annotated Staphylococcus aureus genome sequences in the public domain revealed that this organism devotes about 2-3% of its coding capacity to lipoproteins, corresponding to about 70 lipoproteins per genome...
February 1, 2018: International Journal of Medical Microbiology: IJMM
Michael D Manson
Like all living organisms, bacteria must communicate with the world around them. As they typically live as single cells, the communication with their environment must occur at the cell membrane, both in moving molecules in and out and in transmitting information about their surroundings to response elements within the cell. This volume is devoted primarily to methods used to study either the behavior of bacteria in response to their environment or methods used to study events that involve signaling pathways that are initiated by events at the cell membrane...
2018: Methods in Molecular Biology
Joseph Jeswin, Min-Soo Joo, Ji-Min Jeong, Jin-Sol Bae, Kwang-Min Choi, Dong-Hee Cho, Son-Il Park, Chan-Il Park
Siglec-3/CD33 is a myeloid-specific inhibitory receptor that is expressed on cells of the immune system, where it is believed to play a regulatory role, modulating the inflammatory and immune responses. We characterized CD33 (RbCD33) in rock bream which is a transmembrane protein with two IG-like domains and a cytoplasmic tail. It has a deduced amino acid sequence of 390 residues and has tyrosine-based signaling motifs in the cytoplasmic tail. The RbCD33 mRNA was highly expressed in peripheral blood leukocytes and was also detected in the muscle, spleen, skin, head kidney, gills, trunk kidney, heart, stomach, brain, intestine and liver by quantitative real-time PCR...
February 7, 2018: Developmental and Comparative Immunology
Ruo-Lan Yang, Chao-Ying Deng, Jin-Wei Wei, Wei He, Ai-Ning Li, Wei Qian
Poplar, which is a dominant species in plant communities distributed in the northern hemisphere, is commonly used as a model plant in forestry studies. Poplar production can be inhibited by infections caused by bacteria, including Lonsdalea quercina subsp. populi, which is a Gram-negative bacterium responsible for bark canker disease. However, the molecular basis of the pathogenesis remains uncharacterized. In this study, we annotated the two-component signal transduction systems (TCSs) encoded by the L. quercina subsp...
February 9, 2018: Molecular Plant-microbe Interactions: MPMI
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"