Signaling and cellular microbiology

Low phosphatase activity of LiaS and strong LiaR-DNA affinity explain the unusual LiaS to LiaR in vivo stoichiometry

LiaRS mediates Bacillus subtilis response to cell envelope perturbations. A third protein, LiaF, has an inhibitory role over LiaRS in the absence of stimulus. Together, LiaF and LiaRS form a three-component syste...

Authors: Shailee Jani, Karen Sterzenbach, Vijaya Adatrao, Ghazal Tajbakhsh, Thorsten Mascher and Dasantila Golemi-Kotra

PilG and PilH antagonistically control flagellum-dependent and pili-dependent motility in the phytopathogen Xanthomonas campestris pv. campestris

The virulence of the plant pathogen Xanthomonas campestris pv. campestris (Xcc) involves the coordinate expression of many virulence factors, including surface appendages flagellum and type IV pili, which are req...

Authors: Yan-Hua Qi, Li Huang, Guo-Fang Liu, Ming Leng and Guang-Tao Lu

Synergistic action of SPI-1 gene expression in Salmonella enterica serovar typhimurium through transcriptional crosstalk with the flagellar system

Salmonella enterica serovar Typhimurium is a common food-borne pathogen. S. enterica uses a type III secretion system encoded within Salmonella pathogenicity island 1 (SPI-1) to invade intestinal epithelial cells...

Authors: Selwan Hamed, Xiaoyi Wang, Riham M. Shawky, Mohamed Emara, Philip D. Aldridge and Christopher V. Rao

The conserved actinobacterial transcriptional regulator FtsR controls expression of ftsZ and further target genes and influences growth and cell division in Corynebacterium glutamicum

Key mechanisms of cell division and its regulation are well understood in model bacteria such as Escherichia coli and Bacillus subtilis. In contrast, current knowledge on the regulation of cell division in Actino...

Authors: Kim Julia Kraxner, Tino Polen, Meike Baumgart and Michael Bott

The dimerization interface in VraR is essential for induction of the cell wall stress response in Staphylococcus aureus: a potential druggable target

Staphylococcus aureus remains a medical challenge in the treatment of bacterial infections. It has acquired resistance to commonly used antibiotics, and to those considered to be the last weapons in treating stap...

Authors: Ghazal Tajbakhsh and Dasantila Golemi-Kotra

Induction of the immunoprotective coat of Yersinia pestis at body temperature is mediated by the Caf1R transcription factor

Thermal regulation of gene expression occurs in many microorganisms, and is mediated via several typical mechanisms. Yersinia pestis is the causative agent of the plague and spreads by zoonotic transfer from flea...

Authors: Abdulmajeed D. Al-Jawdah, Iglika G. Ivanova, Helen Waller, Neil D. Perkins, Jeremy H. Lakey and Daniel T. Peters

The possible molecular mechanisms of farnesol on the antifungal resistance of C. albicans biofilms: the regulation of CYR1 and PDE2

Farnesol has potential antifungal activity against Candida albicans biofilms, but the molecular mechanism of this activity is still unclear. Farnesol inhibits hyphal growth by regulating the cyclic AMP (cAMP) sig...

Authors: Shengyan Chen, Jinping Xia, Chengxi Li, Lulu Zuo and Xin Wei

Helicobacter pylori infection downregulates duodenal CFTR and SLC26A6 expressions through TGFβ signaling pathway

The pathogenesis of Helicobacter pylori (H. pylori) infection-induced duodenal ulcer remains to be elucidated. Duodenal mucosal bicarbonate secretion is the most important protective factor against acid-induced m...

Authors: Guorong Wen, Shili Deng, Wenfeng Song, Hai Jin, Jingyu Xu, Xuemei Liu, Rui Xie, Penghong Song and Biguang Tuo

Regulation of bacteria population behaviors by AI-2 “consumer cells” and “supplier cells”

Autoinducer-2 (AI-2) is a universal signal molecule and enables an individual bacteria to communicate with each other and ultimately control behaviors of the population. Harnessing the character of AI-2, two k...

Authors: Yufen Quan, Fankang Meng, Xinyu Ma, Xinhao Song, Xiao Liu, Weixia Gao, Yulei Dang, Yao Meng, Mingfeng Cao and Cunjiang Song

Hypothetical protein Cpn0423 triggers NOD2 activation and contributes to Chlamydia pneumoniae-mediated inflammation

Chlamydia pneumoniae (C. pneumoniae) is pathogenic to humans, by causing pulmonary inflammation or bronchitis in both adolescents and young adults. However, the molecular signals linki...

Authors: Hong-liang Chen, Guo-zhi Dai, An-wen Zhou, Ran-hui Li, Hong-xia Yuan, Jing Xiang, Xiao-xing You, Ou Ran and Yi-mou Wu

Effects of hepatitis C virus core protein and nonstructural protein 4B on the Wnt/β-catenin pathway

Hepatitis C virus (HCV) core protein and nonstructural protein 4B (NS4B) are potentially oncogenic. Aberrant activation of the Wnt/β-catenin signaling pathway is closely associated with hepatocarcinogenesis. W...

Authors: Xiao-Hua Jiang, Yu-Tao Xie, Ya-Ping Cai, Jing Ren and Tao Ma

Detailed analysis of c-di-GMP mediated regulation of csgD expression in Salmonella typhimurium

The secondary messenger cyclic di-GMP promotes biofilm formation by up regulating the expression of csgD, encoding the major regulator of rdar biofilm formation in Salmonella typhimurium. The GGDEF/EAL domain pro...

Authors: Irfan Ahmad, Annika Cimdins, Timo Beske and Ute Römling

Characterization of pneumococcal Ser/Thr protein phosphatase phpP mutant and identification of a novel PhpP substrate, putative RNA binding protein Jag

Reversible protein phosphorylation catalyzed by protein kinases and phosphatases is the primary mechanism for signal transduction in all living organisms. Streptococcus pneumoniae encodes a single Ser/Thr protein...

Authors: Aleš Ulrych, Nela Holečková, Jana Goldová, Linda Doubravová, Oldřich Benada, Olga Kofroňová, Petr Halada and Pavel Branny

Antimicrobial and anti-Quorum Sensing activities of selected medicinal plants of Ethiopia: Implication for development of potent antimicrobial agents

Traditional medicinal plants have been used as an alternative medicine in many parts of the world, including Ethiopia. There are many documented scientific reports on antimicrobial activities of the same. To o...

Authors: Ketema Bacha, Yinebeb Tariku, Fisseha Gebreyesus, Shibru Zerihun, Ali Mohammed, Nancy Weiland-Bräuer, Ruth A. Schmitz and Mulugeta Mulat

Vertebrate TFPI-2 C-terminal peptides exert therapeutic applications against Gram-negative infections

Tissue factor pathway inhibitor-2 (TFPI-2) is a serine protease inhibitor that exerts multiple physiological and patho-physiological activities involving the modulation of coagulation, angiogenesis, tumor inva...

Authors: Gopinath Kasetty, Emanuel Smeds, Emelie Holmberg, Louise Wrange, Selvi Adikesavan and Praveen Papareddy

Preferential production of G-CSF by a protein-like Lactobacillus rhamnosus GR-1 secretory factor through activating TLR2-dependent signaling events without activation of JNKs

Different species and strains of probiotic bacteria confer distinct immunological responses on immune cells. Lactobacillus rhamnosus GR-1 (GR-1) is a probiotic bacterial strain found in both the intestinal and ur...

Authors: Shahab Meshkibaf, Jӧrg Fritz, Marcelo Gottschalk and Sung Ouk Kim

Evidence of cAMP involvement in cellobiohydrolase expression and secretion by Trichoderma reesei in presence of the inducer sophorose

The signaling second messenger cyclic AMP (cAMP) regulates many aspects of cellular function in all organisms. Previous studies have suggested a role for cAMP in the regulation of gene expression of cellulolyt...

Authors: Karoline Maria Vieira Nogueira, Mariana do Nascimento Costa, Renato Graciano de Paula, Flávia Costa Mendonça-Natividade, Rafael Ricci-Azevedo and Roberto Nascimento Silva

Autoinducer-2 regulates Pseudomonas aeruginosa PAO1 biofilm formation and virulence production in a dose-dependent manner

Pseudomonas aeruginosa is an opportunistic pathogen that is the leading cause of iatrogenic infections in critically ill patients, especially those undergoing mechanical ventilation. I...

Authors: Hongdong Li, Xingyuan Li, Zhengli Wang, Yakun Fu, Qing Ai, Ying Dong and Jialin Yu

Mini-Tn7 vectors for stable expression of diguanylate cyclase PleD* in Gram-negative bacteria

The cyclic diguanylate (c-di-GMP) is currently considered an ubiquitous second messenger in bacteria that influences a wide range of cellular processes. One of the methodological approaches to unravel c-di-GMP...

Authors: Lorena Romero-Jiménez, David Rodríguez-Carbonell, María Trinidad Gallegos, Juan Sanjuán and Daniel Pérez-Mendoza

The Escherichia coli NarL receiver domain regulates transcription through promoter specific functions

The Escherichia coli response regulator NarL controls transcription of genes involved in nitrate respiration during anaerobiosis. NarL consists of two domains joined by a linker that wraps around the interdomain ...

Authors: Galit Katsir, Michael Jarvis, Martin Phillips, Zhongcai Ma and Robert P. Gunsalus

Altered motility of Caulobacter Crescentus in viscous and viscoelastic media

Motility of flagellated bacteria depends crucially on their organelles such as flagella and pili, as well as physical properties of the external medium, such as viscosity and matrix elasticity. We studied the ...

Authors: Yukun Gao, Marianna Neubauer, Alexander Yang, Nathan Johnson, Michael Morse, Guanglai Li and Jay X Tang

Activation of gab cluster transcription in Bacillus thuringiensis by γ-aminobutyric acid or succinic semialdehyde is mediated by the Sigma 54-dependent transcriptional activator GabR

Bacillus thuringiensis GabR is a Sigma 54-dependent transcriptional activator containing three typical domains, an N-terminal regulatory domain Per-ARNT-Sim (PAS), a central AAA⁺ (ATPases associated with differe...

Authors: Qi Peng, Min Yang, Wei Wang, Lili Han, Guannan Wang, Pengyue Wang, Jie Zhang and Fuping Song

Mitogen-activated protein kinase Hog1 is activated in response to curcumin exposure in the budding yeast Saccharomyces cerevisiae

Curcumin (CUR), an active polyphenol derived from the spice turmeric, has been traditionally used for centuries in ancient Indian medicine to treat a number of diseases. The physiological effects of CUR have b...

Authors: Gajendra Kumar Azad, Vikash Singh, Mayur Jankiram Thakare, Shivani Baranwal and Raghuvir Singh Tomar

SinR is a mutational target for fine-tuning biofilm formation in laboratory-evolved strains of Bacillus subtilis

Bacteria often form multicellular, organized communities known as biofilms, which protect cells from a variety of environmental stresses. During biofilm formation, bacteria secrete a species-specific matrix; in B...

Authors: Sara A Leiman, Laura C Arboleda, Joseph S Spina and Anna L McLoon

Interactions between an anti-sigma protein and two sigma factors that regulate the pyoverdine signaling pathway in Pseudomonas aeruginosa

Synthesis and uptake of pyoverdine, the primary siderophore of the opportunistic pathogen Pseudomonas aeruginosa, is dependent on two extra-cytoplasmic function (ECF) sigma factors, FpvI and PvdS. FpvI and PvdS a...

Authors: Rebecca J Edgar, Xin Xu, Matt Shirley, Anna F Konings, Lois W Martin, David F Ackerley and Iain L Lamont

Extracellular excystation and development of Cryptosporidium: tracing the fate of oocysts within Pseudomonas aquatic biofilm systems

Aquatic biofilms often serve as environmental reservoirs for microorganisms and provide them with a nutrient-rich growth environment under harsh conditions. With regard to Cryptosporidium, biofilms can serve as e...

Authors: Wan Koh, Andrew Thompson, Hanna Edwards, Paul Monis and Peta L Clode

A systematic analysis of the in vitro and in vivo functions of the HD-GYP domain proteins of Vibrio cholerae

The second messenger cyclic diguanylate (c-di-GMP) plays a central role in bacterial adaptation to extracellular stimuli, controlling processes such as motility, biofilm development, cell development and, in s...

Authors: Robert W McKee, Ankunda Kariisa, Benjamin Mudrak, Courtney Whitaker and Rita Tamayo

The effects of the natural enzyme, Pectinex Ultra SP-L, on human cell cultures and bacterial biofilms in vitro

Pectinex Ultra SP-L (Pectinex) is a microbial-derived enzyme that is used in the food industry and that has been shown to inhibit bacterial biofilms. It has been suggested that Pectinex may be useful in the ma...

Authors: Ian P Olwoch, Oppel B W Greeff, Gisela Jooné and Vanessa Steenkamp

Exploring early steps in biofilm formation: set-up of an experimental system for molecular studies

Bacterial biofilms are predominant in natural ecosystems and constitute a public health threat because of their outstanding resistance to antibacterial treatments and especially to antibiotics. To date, severa...

Authors: Marc Crouzet, Caroline Le Senechal, Volker S Brözel, Patricia Costaglioli, Christophe Barthe, Marc Bonneu, Bertrand Garbay and Sebastien Vilain

Cell death and ultrastructural alterations in Leishmania amazonensis caused by new compound 4-Nitrobenzaldehyde thiosemicarbazone derived from S-limonene

The treatment of leishmaniasis with pentavalent antimonials is problematic because of their toxicity. Investigations of potentially active molecules are important to discover less toxic drugs that are viable e...

Authors: Elizandra Aparecida Britta, Débora Botura Scariot, Hugo Falzirolli, Tânia Ueda-Nakamura, Cleuza Conceição Silva, Benedito Prado Dias Filho, Redouane Borsali and Celso Vataru Nakamura

Gingipains from Porphyromonas gingivalis play a significant role in induction and regulation of CXCL8 in THP-1 cells

Porphyromonas gingivalis is an important bacterial etiological agent involved in periodontitis. The bacterium expresses two kinds of cysteine proteases called gingipains: arginine gingipains (RgpA/B) and lysine ...

Authors: Kartheyaene Jayaprakash, Hazem Khalaf and Torbjörn Bengtsson

Functional significance of nuclear export and mRNA binding of meiotic regulator Spo5 in fission yeast

Meiotic cells undergo two rounds of nuclear division and generate gametes. Previous studies have indicated that a number of transcription factors modulate the transcriptome in successive waves during meiosis a...

Authors: Naoyuki Togashi, Akira Yamashita, Masamitsu Sato and Masayuki Yamamoto

The ColRS signal transduction system responds to the excess of external zinc, iron, manganese, and cadmium

The ColRS two-component system has been shown to contribute to the membrane functionality and stress tolerance of Pseudomonas putida as well as to the virulence of Pseudomonas aeruginosa and plant pathogenic Xant...

Authors: Kadi Ainsaar, Karl Mumm, Heili Ilves and Rita Hõrak

Human serum inhibits adhesion and biofilm formation in Candida albicans

Candida albicans can form biofilms on intravenous catheters; this process plays a key role in the pathogenesis of catheter infections. This study evaluated the effect of human serum (HS) on C. albicans biofilm f...

Authors: Xiurong Ding, Zhizhong Liu, Jianrong Su and Donghui Yan

Identification of a predicted partner-switching system that affects production of the gene transfer agent RcGTA and stationary phase viability in Rhodobacter capsulatus

Production of the gene transfer agent RcGTA in the α-proteobacterium Rhodobacter capsulatus is dependent upon the response regulator protein CtrA. Loss of this regulator has widespread effects on transcription in...

Authors: Ryan G Mercer and Andrew S Lang

Virstatin inhibits biofilm formation and motility of Acinetobacter baumannii

Acinetobacter baumannii has emerged as an opportunistic nosocomial pathogen causing infections worldwide. One reason for this emergence is due to its natural ability to survive in the hospital environment, which...

Authors: Yassine Nait Chabane, Mohamed Ben Mlouka, Stéphane Alexandre, Marion Nicol, Sara Marti, Martine Pestel-Caron, Jordi Vila, Thierry Jouenne and Emmanuelle Dé

Diffusible signal factor (DSF) quorum sensing signal and structurally related molecules enhance the antimicrobial efficacy of antibiotics against some bacterial pathogens

Extensive use of antibiotics has fostered the emergence of superbugs that are resistant to multidrugs, which becomes a great healthcare and public concern. Previous studies showed that quorum sensing signal DS...

Authors: Yinyue Deng, Amy Lim, Jasmine Lee, Shaohua Chen, Shuwen An, Yi-Hu Dong and Lian-Hui Zhang

The Vibrio cholerae diguanylate cyclase VCA0965 has an AGDEF active site and synthesizes cyclic di-GMP

Diguanylate cyclases (DGCs) regulate biofilm formation and motility in bacteria by synthesizing the second messenger cyclic di-GMP (c-di-GMP) in response to environmental stimuli. DGC enzymatic activity is bel...

Authors: Jessica L Hunter, Geoffrey B Severin, Benjamin J Koestler and Christopher M Waters

Lactobacillus GG restoration of the gliadin induced epithelial barrier disruption: the role of cellular polyamines

Celiac disease is characterized by enhanced intestinal paracellular permeability due to alterations of function and expression of tight junction (TJ) proteins including ZO-1, Claudin-1 and Occludin. Polyamines...

Authors: Antonella Orlando, Michele Linsalata, Maria Notarnicola, Valeria Tutino and Francesco Russo

The Escherichia coli uropathogenic-specific-protein-associated immunity protein 3 (Imu3) has nucleic acid -binding activity

The Escherichia coli uropathogenic-specific protein (Usp) is a bacteriocin-like genotoxin, active against mammalian cells and associated with E. coli strains that provoke pyelonephritis, prostatitis and bacteraem...

Authors: Miha Črnigoj, Zdravko Podlesek, Maruška Budič and Darja Žgur-Bertok

Characterization and resuscitation of ‘non-culturable’ cells of Legionella pneumophila

Legionella pneumophila is a waterborne pathogen responsible for Legionnaires’ disease, an infection which can lead to potentially fatal pneumonia. After disinfection, L. pneumophila has been detected, like many ...

Authors: Adrien Ducret, Maïalène Chabalier and Sam Dukan

Erratum to: identification of biofilm proteins in non-typeable Haemophilus influenzae

Authors: Timothy K Gallaher, Siva Wu, Paul Webster and Rodrigo Aguilera

C. albicansgrowth, transition, biofilm formation, and gene expression modulation by antimicrobial decapeptide KSL-W

Antimicrobial peptides have been the focus of much research over the last decade because of their effectiveness and broad-spectrum activity against microbial pathogens. These peptides also participate in infla...

Authors: Simon Theberge, Abdelhabib Semlali, Abdullah Alamri, Kai P Leung and Mahmoud Rouabhia

Cis-2-dodecenoic acid signal modulates virulence of Pseudomonas aeruginosa through interference with quorum sensing systems and T3SS

Cis-2-dodecenoic acid (BDSF) is well known for its important functions in intraspecies signaling in Burkholderia cenocepacia. Previous work has also established an important role of BDSF in interspecies and inter...

Authors: Yinyue Deng, Calvin Boon, Shaohua Chen, Amy Lim and Lian-Hui Zhang

Deletion of the HAMP domains from the histidine kinase CaNik1p of Candida albicans or treatment with fungicides activates the MAP kinase Hog1p in S. cerevisiae transformants

Microorganisms use two-component signal transduction (TCST) systems to regulate the response of the organism to changes of environmental conditions. Such systems are absent from mammalian cells and are thus of...

Authors: Mohammed El-Mowafy, Mahmoud M Bahgat and Ursula Bilitewski

Quorum sensing influences growth and photosynthetic membrane production in high-cell-density cultivations of Rhodospirillum rubrum

The facultative anoxygenic photosynthetic bacterium Rhodospirillum rubrum exhibits versatile metabolic activity allowing the adaptation to rapidly changing growth conditions in its natural habitat, the microaerob...

Authors: Lisa Carius, Anke B Carius, Matthew McIntosh and Hartmut Grammel

Chlamydia trachomatis homotypic inclusion fusion is promoted by host microtubule trafficking

The developmental cycle of the obligate intracellular pathogen Chlamydia is dependant on the formation of a unique intracellular niche termed the chlamydial inclusion. The inclusion is a membrane bound vacuole de...

Authors: Theresa S Richards, Andrea E Knowlton and Scott S Grieshaber

OmpR and RcsB abolish temporal and spatial changes in expression of flhD in Escherichia coli Biofilm

Biofilms are communities of bacteria that are characterized by specific phenotypes, including an increased resistance towards anti-microbials and the host immune system. This calls for the development of novel...

Authors: Priyankar Samanta, Emily R Clark, Katie Knutson, Shelley M Horne and Birgit M Prüß

Spatial distributions of Pseudomonas fluorescens colony variants in mixed-culture biofilms

The emergence of colony morphology variants in structured environments is being recognized as important to both niche specialization and stress tolerance. Pseudomonas fluorescens demonstrates diversity in both it...

Authors: Matthew L Workentine, Siyuan Wang, Howard Ceri and Raymond J Turner

Inhibiting biofilm formation by Klebsiella pneumoniae B5055 using an iron antagonizing molecule and a bacteriophage

Success of biofilm dwelling bacteria in causing persistent and chronic infections is attributed to their resistance towards antibiotics and immune defences. Free iron is critical for the growth of biofilm asso...

Authors: Sanjay Chhibber, Deepika Nag and Shruti Bansal