bluuebunny/crossref_metadata_2025_split huggingface dataset:
Participation of Chromosome Segregation Protein ParAI ofVibrio choleraein Chromosome Replication
Authors: Kadoya Ryosuke , Baek Jong Hwan , Sarker Arnab , Chattoraj Dhruba K. 
Published: January 2011

ABSTRACTVibrio choleraecarries homologs of plasmid-borneparAandparBgenes on both of its chromosomes. Thepargenes help to segregate many plasmids and chromosomes. Here we have studied thepargenes ofV. choleraechromosome I. Earlier studies suggested that ParBI binds to the centromeric siteparSInear the origin of replication (oriI), andparSI-ParBI complexes are placed at the cell poles by ParAI. Deletion ofparAIandparSIcaused the origin-proximal DNA to be less polar. Here we found that deletion ofparBIalso resulted in a less polar localization oforiI. However, unlike the deletion ofparAI, the deletion ofparBIincreased theoriInumber. Replication was normal when bothparAIandparBIwere deleted, suggesting that ParBI mediates its action through ParAI. Overexpression of ParAI in aparABI-deleted strain also increased the DNA content. The results are similar to those found forBacillus subtilis, where ParA (Soj) stimulates replication and this activity is repressed by ParB (SpoOJ). As inB. subtilis, the stimulation of replication most likely involves the replication initiator DnaA. Our results indicate that control of chromosomal DNA replication is an additional function of chromosomalpargenes conserved across the Gram-positive/Gram-negative divide.
The MreB-Like Protein Mbl ofStreptomyces coelicolorA3(2) Depends on MreB for Proper Localization and Contributes to Spore Wall Synthesis
Authors: Heichlinger Andrea , Ammelburg Moritz , Kleinschnitz Eva-Maria , Latus Annette , Maldener Iris , Flärdh Klas , Wohlleben Wolfgang , Muth Günther 
Published: January 2011

ABSTRACTMost bacteria with a rod-shaped morphology contain an actin-like cytoskeleton consisting of MreB polymers, which form helical spirals underneath the cytoplasmic membrane to direct peptidoglycan synthesis for the elongation of the cell wall. In contrast, MreB ofStreptomyces coelicoloris not required for vegetative growth but has a role in sporulation. Besides MreB,S. coelicolorencodes two further MreB-like proteins, Mbl and SCO6166, whose function is unknown. Whereas MreB and Mbl are highly similar, SCO6166 is shorter, lacking the subdomains IB and IIB of actin-like proteins. Here, we showed that MreB and Mbl are not functionally redundant but cooperate in spore wall synthesis. Expression analysis by semiquantitative reverse transcription-PCR revealed distinct expression patterns.mreBandmblare induced predominantly during morphological differentiation. In contrast,sco6166is strongly expressed during vegetative growth but switched off during sporulation. All genes could be deleted without affecting viability. Even a ΔmreBΔmbldouble mutant was viable. Δsco6166had a wild-type phenotype. ΔmreB, Δmbl, and ΔmreBΔmblproduced swollen, prematurely germinating spores that were sensitive to various kinds of stress, suggesting a defect in spore wall integrity. During aerial mycelium formation, an Mbl-mCherry fusion protein colocalized with an MreB-enhanced green fluorescent protein (MreB-eGFP) fusion protein at the sporulation septa. Whereas MreB-eGFP localized properly in the Δmblmutant, Mbl-mCherry localization depended on the presence of a functional MreB protein. Our results revealed that MreB and Mbl cooperate in the synthesis of the thickened spore wall, while SCO6166 has a nonessential function during vegetative growth.
Domain Analysis of Protein P30 in
Mycoplasma pneumoniae
Cytadherence and Gliding Motility
Authors: Chang How-Yi , Jordan Jarrat L. , Krause Duncan C. 
Published: January 2011

ABSTRACT

The cell wall-less prokaryote
Mycoplasma pneumoniae
causes bronchitis and atypical pneumonia in humans. Mycoplasma attachment and gliding motility are required for colonization of the respiratory epithelium and are mediated largely by a differentiated terminal organelle. P30 is a membrane protein at the distal end of the terminal organelle and is required for cytadherence and gliding motility, but little is known about the functional role of its specific domains. In the current study, domain deletion and substitution derivatives of P30 were engineered and introduced into a P30 null mutant by transposon delivery to assess their ability to rescue P30 function. Domain deletions involving the extracellular region of P30 severely impacted protein stability and adherence and gliding function, as well as the capacity to stabilize terminal organelle protein P65. Amino acid substitutions in the transmembrane domain revealed specific residues uniquely required for P30 stability and function, perhaps to establish correct topography in the membrane for effective alignment with binding partners. Deletions within the predicted cytoplasmic domain did not affect P30 localization or its capacity to stabilize P65 but markedly impaired gliding motility and cytadherence. The larger of two cytoplasmic domain deletions also appeared to remove the P30 signal peptide processing site, suggesting a larger leader peptide than expected. We propose that the P30 cytoplasmic domain may be required to link P30 to the terminal organelle core, to enable the P30 extracellular domain to achieve a functional conformation, or perhaps both.
Regulation of Catalase-Peroxidase KatG Is OxyR Dependent and Fur Independent in
Caulobacter crescentus
Authors: Italiani Valéria C. S. , da Silva Neto José F. , Braz Vânia S. , Marques Marilis V. 
Published: January 2011

ABSTRACT

Most organisms that grow in the presence of oxygen possess catalases and/or peroxidases, which are necessary for scavenging the H
2
O
2
produced by aerobic metabolism. In this work we investigate the pathways that regulate the
Caulobacter crescentus katG
gene, encoding the only enzyme with catalase-peroxidase function in this bacterium. The transcriptional start site of the
katG
gene was determined, showing a short 5′ untranslated region. The
katG
regulatory region was mapped by serial deletions, and the results indicate that there is a single promoter, which is responsible for induction at stationary phase. An
oxyR
mutant strain was constructed; it showed decreased
katG
expression, and no KatG protein or catalase-peroxidase activity was detected in stationary-phase cell extracts, implying that OxyR is the main positive regulator of the
C. crescentus katG
gene. Purified OxyR protein bound to the
katG
regulatory region between nucleotides −42 and −91 from the transcription start site, as determined by a DNase I footprinting assay, and a canonical OxyR binding site was found in this region. Moreover, OxyR binding was shown to be redox dependent, given that only oxidized proteins bound adjacent to the −35 sequence of the promoter and the
katG
P1 promoter was activated by OxyR in an H
2
O
2
-dependent manner. On the other hand, this work showed that the iron-responsive regulator Fur does not regulate
C. crescentus katG
, since a
fur
mutant strain presented wild-type levels of
katG
transcription and catalase-peroxidase production and activity, and the purified Fur protein was not able to bind to the
katG
regulatory region.
Unusual Heme-Binding PAS Domain from YybT Family Proteins
Authors: Rao Feng , Ji Qiang , Soehano Ishin , Liang Zhao-Xun 
Published: January 2011

ABSTRACTYybT family proteins (COG3887) are functionally unknown proteins that are widely distributed among the firmicutes, including the human pathogensStaphylococcus aureusandListeria monocytogenes. Recent studies suggested that YybT family proteins are crucial for thein vivosurvival of bacterial pathogens during host infection. YybT family proteins contain an N-terminal domain that shares minimum sequence homology with Per-ARNT-Sim (PAS) domains. Despite the lack of an apparent residue for heme coordination, the putative PAS domains ofBsYybT andGtYybT, two representative members of the YybT family proteins fromBacillus subtilisandGeobacillus thermodenitrificans, respectively, are found to bindb-type heme with 1:1 stoichiometry. Heme binding suppresses the catalytic activity of the DHH/DHHA1 phosphodiesterase domain and the degenerate GGDEF domain. Absorption spectroscopic studies indicate that YybT proteins do not form stable oxyferrous complexes due to the rapid oxidation of the ferrous iron upon O2binding. The ferrous heme, however, forms a hexacoordinated complex with carbon monoxide (CO) and a pentacoordinated complex with nitric oxide (NO). The coordination of NO, but not CO, to the heme stimulates the phosphodiesterase activity. These results suggest that YybT family proteins function as stress-signaling proteins for monitoring cellular heme or the NO level by using a heme-binding PAS domain that features an unconventional heme coordination environment.
Enterococcus faecalis
Virulence Regulator FsrA Binding to Target Promoters
Authors: Del Papa María Florencia , Perego Marta 
Published: January 2011

ABSTRACT

The FsrABDC signal transduction system is a major virulence regulator in
Enterococcus faecalis
. The FsrC sensor histidine kinase, upon activation by the gelatinase biosynthesis-activating pheromone (GBAP) peptide encoded by the
fsrBD
genes, phosphorylates the FsrA response regulator required for the transcription of the
fsrBDC
and the
gelE
-
sprE
genes from the
fsrB
promoter and the
gelE
promoter, respectively. FsrA belongs to the LytTR family of proteins, which includes other virulence regulators, such as AgrA of
Staphylococcus aureus
, AlgR of
Pseudomonas aeruginosa
, and VirR of
Clostridium perfringens
. The LytTR DNA-binding domain that characterizes these proteins generally binds to two imperfect direct repeats separated by a number of bases that place the repeats on the same face of the DNA helix. In this study, we demonstrated that FsrA also binds to two imperfect direct repeats separated by 13 bp, based on the consensus sequence of FsrA, T/AT/CAA/GGGAA/G, which is consistent with the binding characteristics of LytTR domains.
Combinatorial Regulation of
fmgD
by MrpC2 and FruA during
Myxococcus xanthus
Development
Authors: Lee Jun-seok , Son Bongjun , Viswanathan Poorna , Luethy Paul M. , Kroos Lee 
Published: January 2011

ABSTRACT

Upon starvation, a dense population of rod-shaped
Myxococcus xanthus
bacteria coordinate their movements to construct mounds in which some of the cells differentiate to spherical spores. During this process of fruiting body formation, short-range C-signaling between cells regulates their movements and the expression of genes important for sporulation. C-signaling activates FruA, a transcription factor that binds cooperatively with another transcription factor, MrpC2, upstream of the
fmgA
and
fmgBC
promoters, activating transcription. We have found that a third C-signal-dependent gene, herein named
fmgD
, is subject to combinatorial control by FruA and MrpC2. The two proteins appear to bind cooperatively upstream of the
fmgD
promoter and activate transcription. FruA binds proximal to the
fmgD
promoter, as in the
fmgBC
promoter region, whereas MrpC2 binds proximal to the
fmgA
promoter. A novel feature of the
fmgD
promoter region is the presence of a second MrpC2 binding site partially overlapping the promoter and therefore likely to mediate repression. The downstream MrpC2 site appears to overlap the FruA site, so the two transcription factors may compete for binding, which in both cases appears to be cooperative with MrpC2 at the upstream site. We propose that binding of MrpC2 to the downstream site represses
fmgD
transcription until C-signaling causes the concentration of active FruA to increase sufficiently to outcompete the downstream MrpC2 for cooperative binding with the upstream MrpC2. This would explain why
fmgD
transcription begins later during development and is more dependent on C-signaling than transcription of
fmgA
and
fmgBC
.
Characteristics of people with recurrent ankle sprains: a systematic review with meta-analysis
Authors: Hiller Claire E , Nightingale Elizabeth J , Lin Chung-Wei Christine , Coughlan Garrett F , Caulfield Brian , Delahunt Eamonn 
Published: January 2011

ObjectiveTo examine whether people with recurrent ankle sprain, have specific physical and sensorimotor deficits.DesignA systematic review of journal articles in English using electronic databases to September 2009. Included articles compared physical or sensorimotor measures in people with recurrent (≥2) ankle sprains and uninjured controls.Main outcome groupsOutcome measures were grouped into: physical characteristics, strength, postural stability, proprioception, response to perturbation, biomechanics and functional tests. A meta-analysis was undertaken where comparable results within an outcome group were inconsistent.ResultsFifty-five articles met the inclusion criteria. Compared with healthy controls, people with recurrent sprains demonstrated radiographic changes in the talus, changes in foot position during gait and prolonged time to stabilisation after a jump. There were no differences in ankle range of motion or functional test performance. Pooled results showed greater postural sway when standing with eyes closed (SMD=0.9, 95% CI 0.4 to 1.4) or on unstable surfaces (0.5, 0.1 to 1.0) and decreased concentric inversion strength (1.1, 0.2 to 2.1) but no difference in evertor strength, inversion joint position sense or peroneal latency in response to a perturbation.ConclusionThere are specific impairments in people with recurrent ankle sprain but not necessarily in areas commonly investigated.
Injuries and illnesses of football players during the 2010 FIFA World Cup
Authors: Dvorak Jiri , Junge Astrid , Derman Wayne , Schwellnus Martin 
Published: January 2011

BackgroundThe incidence and characteristics of football injuries during matches in top-level international tournaments are well documented, but training injuries and illnesses during this period have rarely been studied.AimTo analyse the incidence and characteristics of injuries and illnesses incurred during the 2010 Fédération Internationale de Football Association (FIFA) World Cup.MethodsThe chief physicians of the 32 finalist teams reported daily all newly incurred injuries and illnesses of their players on a standardised medical report form.ResultsOut of 229 injuries reported, 82 match and 58 training injuries were expected to result in time loss, equivalent to an incidence of 40.1 match and 4.4 training injuries per 1000 h. Contact with another player was the most frequent cause of match (65%) and of training (40%) injuries. The most frequent diagnoses were thigh strain and ankle sprain. 99 illnesses of 89 (12%) players were reported. Illnesses were mainly infections of the respiratory or the digestive system. Most illnesses did not result in absence from training or match. The incidence of time-loss illnesses was 3.0 per 1000 player days.ConclusionThe incidence of match injuries during the 2010 FIFA World Cup was significantly lower than in the three proceeding World Cups. This might be a result of more regard to injury prevention, less foul play and stricter refereeing. Tackling skills and fair play need to be improved to prevent contact injuries in training and matches. Prevention of illness should focus on reducing the risk of infections by considering the common modes of transmission and environmental conditions.
Impact of pesticide exposure misclassification on estimates of relative risks in the Agricultural Health Study
Authors: Blair Aaron , Thomas Kent , Coble Joseph , Sandler Dale P , Hines Cynthia J , Lynch Charles F , Knott Charles , Purdue Mark P , Zahm Shelia Hoar , Alavanja Michael C R , Dosemeci Mustafa , Kamel Freya , Hoppin Jane A , Freeman Laura Beane , Lubin Jay H 
Published: January 2011

BackgroundThe Agricultural Health Study (AHS) is a prospective study of licensed pesticide applicators and their spouses in Iowa and North Carolina. We evaluate the impact of occupational pesticide exposure misclassification on relative risks using data from the cohort and the AHS Pesticide Exposure Study (AHS/PES).MethodsWe assessed the impact of exposure misclassification on relative risks using the range of correlation coefficients observed between measured post-application urinary levels of 2,4-dichlorophenoxyacetic acid (2,4-D) and a chlorpyrifos metabolite and exposure estimates based on an algorithm from 83 AHS pesticide applications.ResultsCorrelations between urinary levels of 2,4-D and a chlorpyrifos metabolite and algorithm estimated intensity scores were about 0.4 for 2,4-D (n=64), 0.8 for liquid chlorpyrifos (n=4) and 0.6 for granular chlorpyrifos (n=12). Correlations of urinary levels with kilograms of active ingredient used, duration of application, or number of acres treated were lower and ranged from −0.36 to 0.19. These findings indicate that a priori expert-derived algorithm scores were more closely related to measured urinary levels than individual exposure determinants evaluated here. Estimates of potential bias in relative risks based on the correlations from the AHS/PES indicate that non-differential misclassification of exposure using the algorithm would bias estimates towards the null, but less than that from individual exposure determinants.ConclusionsAlthough correlations between algorithm scores and urinary levels were quite good (ie, correlations between 0.4 and 0.8), exposure misclassification would still bias relative risk estimates in the AHS towards the null and diminish study power.
Quality control in upper gastrointestinal endoscopy: detection rates of gastric cancer in Oxford 2005–2008
Authors: Vradelis S , Maynard N , Warren B F , Keshav S , Travis S P L 
Published: January 2011

ABSTRACT

Background
Gastric cancer (GC) represents the sum of advanced gastric cancer (AGC) and early gastric cancer (EGC). Endoscopy (with biopsies) is the gold standard for detection of GC, but a false-negative rate of up to 19% is reported.

Aim
To determine whether patients with GC had had an oesophagogastroduodenoscopy (OGD) in the year preceding diagnosis that might reasonably have been expected to detect the cancer, as a measure of quality assurance of endoscopic practice.

Methods
Patients with histologically proven GC were identified from pathology records. Endoscopy reports and case notes were examined to identify any OGD before diagnosis, the interval and endoscopic findings. A false-negative OGD was defined as one where GC was neither suspected nor shown at pathology, but where a diagnosis of GC was made within 12 months.

Results
Between January 2005 and February 2008, 9764 OGDs were performed. GC was diagnosed in 74 patients (male/female ratio 2.89; median age 76, range 38–95). Nine (12%) patients had EGC. There were no differences in age, sex or symptoms between the EGC and AGC group. Sixty-eight of the 74 patients with GC (92%) presented with alarm symptoms. Ten of the 74 had had an OGD within 12 months before definitive diagnosis; all these were planned because of suspicious lesions. Significantly fewer biopsies were performed at OGDs preceding definitive diagnosis (median 2 (0–10) vs 6 (2–12); p=0.002).

Conclusion
False-negative rates of 0% (within 12 months) and 8% (within 3 years) for diagnosis of GC are reassuring, but an inadequate number of biopsies compromises the quality assurance of endoscopy. GC presents without alarm symptoms in &lt;10%.
An EGFR–Src–Arg–Cortactin Pathway Mediates Functional Maturation of Invadopodia and Breast Cancer Cell Invasion
Authors: Mader Christopher C. , Oser Matthew , Magalhaes Marco A. O. , Bravo-Cordero Jose Javier , Condeelis John , Koleske Anthony J. , Gil-Henn Hava 
Published: January 2011

AbstractInvasive carcinoma cells use specialized actin polymerization–driven protrusions called invadopodia to degrade and possibly invade through the extracellular matrix (ECM) during metastasis. Phosphorylation of the invadopodium protein cortactin is a master switch that activates invadopodium maturation and function. Cortactin was originally identified as a hyperphosphorylated protein in v-Src–transformed cells, but the kinase or kinases that are directly responsible for cortactin phosphorylation in invadopodia remain unknown. In this study, we provide evidence that the Abl-related nonreceptor tyrosine kinase Arg mediates epidermal growth factor (EGF)–induced cortactin phosphorylation, triggering actin polymerization in invadopodia, ECM degradation, and matrix proteolysis–dependent tumor cell invasion. Both Src and Arg localize to invadopodia and are required for EGF-induced actin polymerization. Notably, Arg overexpression in Src knockdown cells can partially rescue actin polymerization in invadopodia while Src overexpression cannot compensate for loss of Arg, arguing that Src indirectly regulates invadopodium maturation through Arg activation. Our findings suggest a novel mechanism by which an EGFR–Src–Arg–cortactin pathway mediates functional maturation of invadopodia and breast cancer cell invasion. Furthermore, they identify Arg as a novel mediator of invadopodia function and a candidate therapeutic target to inhibit tumor invasion in vivo. Cancer Res; 71(5); 1730–41. ©2011 AACR.
Oncogenic Synergism between ErbB1, Nucleolin, and Mutant Ras
Authors: Farin Keren , Schokoroy Sari , Haklai Roni , Cohen-Or Ifat , Elad-Sfadia Galit , Reyes-Reyes Merit E. , Bates Paula J. , Cox Adrienne D. , Kloog Yoel , Pinkas-Kramarski Ronit 
Published: January 2011

Abstract
Alterations in the ErbB family of growth factor receptors, their signaling components, and mutational activation of Ras proteins are major contributors to malignant transformation. Recently, mutant Ras was shown to be capable of activating ErbB receptors in a ligand-independent manner. Furthermore, it was observed that nucleolin, a transcriptional regulator and ribosome biogenesis factor, can bind both K-Ras and the cytoplasmic tail of ErbB receptors to enhance ErbB receptor activation. However, the functional significance of these interactions to cancer pathogenesis has not been probed. Here, we show that endogenous nucleolin interacts simultaneously in vivo with endogenous Ras and ErbB1 (EGFR) in cancer cells. The C-terminal 212 amino acids of nucleolin were determined to be sufficient to interact with ErbB1 and all Ras protein isoforms (H-, N-, and K-Ras). Nucleolin partially colocalizes with Ras at the plasma membrane. Moreover, activated but not wild-type Ras facilitates nucleolin interaction with ErbB1 and stabilizes ErbB1 receptor levels. Most importantly, these three oncogenes synergistically facilitate anchorage-independent cell growth in vitro and tumor growth in vivo. Our findings suggest strategies to target nucleolin as a general approach to inhibiting ErbB- and Ras-driven cancers. Cancer Res; 71(6); 2140–51. ©2011 AACR.