Interaction of a putative transcriptional regulatory protein and the thermo-inducible cts-52 mutant repressor in the Bacillus subtilis phage φ105 genome

A 144 amino acid residue cts-52 mutant repressor (mtcφ105) located in the EcoRI-F immunity region (immF) of Bacillus subtilis phage φ105 is involved in the control mechanism of a thermo-inducible expression system. Adjacent to the repressor gene, an open-reading frame, designated ORF4, encodes a polypeptide of 90 amino acid residues, which shares a 37% homology with the amino acid sequence of the repressor. On the basis of the protein sequence alignment, a DNA-binding α helix-β turn-α helix (HTH) motif was identified in the N-terminal region (residues 18-37) of the repressor as well as in the polypeptide of ORF4 (residues 22-41). In vivo expression of the mutant repressor and ORF4 were confirmed by real-time reverse transcriptase polymerase chain reaction (RT-PCR) and Western blot analysis. To study their DNA binding properties, the wild-type repressor (wtcφ105) and the mutant repressor mtcφ105, which has a Thr17 to Ile substitution, were overexpressed in Escherichia coli and purified for affinity assays. Their affinities towards six operator sites at various temperatures were elucidated by surface plasmon resonance (SPR). Our data showed that a temperature shift does not influence the wtcφ105-operators' binding affinity, while the binding of mtcφ105 to the operators was temperature sensitive. This explains how thermo-induction triggers the release of the mutant repressor and renders heterologous gene expression. Interestingly, mtcφ105 and ORF4 demonstrated a large affinity discrepancy towards individual operators at different temperatures. mRNA levels monitored by real-time RT-PCR indicated a suppression of mtcφ105 expression, but a stimulation of ORF4 transcription after thermo-induction. Our data suggested that ORF4 might be a counter protein to the phage repressor in the modulation of the two divergent-oriented promoters P M and P R within the immF region. © 2003 Elsevier Ltd. All rights reserved.postprin

Augmentation of 5-lipoxygenase activity and expression during dengue serotype-2 infection

published_or_final_versio

A dual protein expression system in Bacillus subtilis

We have developed a dual expression system for the simultaneous overexpression of two proteins in Bacillus subtilis. Two candidate genes, xylanase (xynA) and glucanase (bglS) from B. subtilis strain 168, which were engineered with independent Shine-Dalgarno (SD) sequences, were cloned in tandem into a transfer vector, which was then transformed into B. subtilis strain 1A304 (φ105MU331). The genes were under the transcriptional control of a strong promoter of a bacteriophage, φ105, where transcription was initiated upon thermal induction. Six constructs were made to compare the factors that affected the yields of the gene products. The expression level of each candidate gene was found to correspond to its position relative to the phage promoter, irrespective of the identity of the insert. The lower expression level of the second insert might have been due to limited resources for protein synthesis, a short half-life of the mRNA, or an early termination of the RNA polymerase. Curiously, gene duplications in tandem did not lead to further increase in production. © 2002 Elsevier Science (USA). All rights reserved.postprin

Anti-prion drug mPPIg5 inhibits PrP(C) conversion to PrP(Sc).

Prion diseases, also known as transmissible spongiform encephalopathies, are a group of fatal neurodegenerative diseases that include scrapie in sheep, bovine spongiform encephalopathy (BSE) in cattle and Creutzfeldt-Jakob disease (CJD) in humans. The 'protein only hypothesis' advocates that PrP(Sc), an abnormal isoform of the cellular protein PrP(C), is the main and possibly sole component of prion infectious agents. Currently, no effective therapy exists for these diseases at the symptomatic phase for either humans or animals, though a number of compounds have demonstrated the ability to eliminate PrPSc in cell culture models. Of particular interest are synthetic polymers known as dendrimers which possess the unique ability to eliminate PrP(Sc) in both an intracellular and in vitro setting. The efficacy and mode of action of the novel anti-prion dendrimer mPPIg5 was investigated through the creation of a number of innovative bio-assays based upon the scrapie cell assay. These assays were used to demonstrate that mPPIg5 is a highly effective anti-prion drug which acts, at least in part, through the inhibition of PrP(C) to PrP(Sc) conversion. Understanding how a drug works is a vital component in maximising its performance. By establishing the efficacy and method of action of mPPIg5, this study will help determine which drugs are most likely to enhance this effect and also aid the design of dendrimers with anti-prion capabilities for the future

Quality of private and public ambulatory health care in low and middle income countries: systematic review of comparative studies

Paul Garner and colleagues conducted a systematic review of 80 studies to compare the quality of private versus public ambulatory health care in low- and middle-income countries

Anyonic interferometry and protected memories in atomic spin lattices

Strongly correlated quantum systems can exhibit exotic behavior called topological order which is characterized by non-local correlations that depend on the system topology. Such systems can exhibit remarkable phenomena such as quasi-particles with anyonic statistics and have been proposed as candidates for naturally fault-tolerant quantum computation. Despite these remarkable properties, anyons have never been observed in nature directly. Here we describe how to unambiguously detect and characterize such states in recently proposed spin lattice realizations using ultra-cold atoms or molecules trapped in an optical lattice. We propose an experimentally feasible technique to access non-local degrees of freedom by performing global operations on trapped spins mediated by an optical cavity mode. We show how to reliably read and write topologically protected quantum memory using an atomic or photonic qubit. Furthermore, our technique can be used to probe statistics and dynamics of anyonic excitations.Comment: 14 pages, 6 figure

Relationship between Silent Gastroesophageal Reflux and Food Sensitization in Infants and Young Children with Recurrent Wheezing

It is known that early childhood wheezing associated with sensitization to allergens, including food, has an increased risk of developing asthma later during school age. Gastroesophageal reflux (GER) is well known to be associated with asthma. The purpose of this study was to determine whether there is an association between silent GER and food sensitization in infants and young children with recurrent wheezing. Eighty-five infants or young children with recurrent wheezing, and no gastrointestinal symptoms, underwent 24 hr esophageal pH monitoring, as well as total serum IgE and specific IgE testing for eggs and milk. Among the 85 subjects, 48.2% had significant GER. There was no significant difference in the GER between atopic and non-atopic recurrent wheezers (41.7% and 50.8%, respectively). The sensitization rate to food (eggs or milk) was 12.2% and 20.5% in the GER and non-GER groups, respectively and showed no statistically significant difference between the two groups (P=0.34). In conclusion, about half of infants and young children with recurrent wheezing and no gastrointestinal symptoms have silent GER. The silent GER may not contribute to food sensitization in infants and young children with recurrent wheezing

Ecosystem service provision by marine habitats in Southeast Asia

Southeast Asia is an area of rich marine biodiversity providing a host of ecosystem services that contribute to the well-being of coastal communities and beyond. Sustainable management of ecosystems and the services they provide requires a good understanding of their underlying ecological functions and processes. This understanding can be gained through the rigorous assessment of studies identifying and quantifying ecological functions and ecosystem services. The aims of this study were to review the ecosystem services provided by marine and coastal habitats in Southeast Asia. The ecosystem service potential was scored for each habitat. The review was focused on nine key marine and coastal habitats, identified across four case study sites in Southeast Asia, contributing 18 marine relevant ecosystem services. The approach comprised a literature review supplemented with observations from experts from the case study areas. The four case study sites consist of three Man and Biosphere Reserves in Southeast Asia: Palawan in the Philippines, Cu Lao Cham- Hoi An in Viet Nam, Take-Bonerate Kepulauan Selayar in Indonesia, and a recently gazetted marine protected area, the Tun Mustapha Marine Park in Malaysia (Figure 1). The nine key habitats (eight benthic and one pelagic) covered in this review, identified as highly relevant for most case study sites, were mangrove forests, coral reefs, seagrass meadows, sand, mud, rock, coarse substratum, pelagic and modified habitats. Further division of these habitats into sub-habitats on the basis of biological type and substrate type was used to capture data on differential provision of ecosystem services within the broad habitat types. To ensure relevance in the four case study sites, firstly an ecosystem services typology was created tailored to these sites. After exploring several ecosystem service typologies, our final classification was adapted from the Common International Classification of Ecosystem services (CICES) V4.3 because it was considered to be most relevant to the objectives of this task. Provisioning, regulation and maintenance, and cultural services were assessed. Provisioning services focused on food for consumption by humans from plants, pelagic animals, demersal fish and invertebrates; energy from harvested plants; other materials from plants and animals, such as fibres, building and housing materials, medicines, decoration, handicrafts and souvenirs; and genetic material from plants and animals (including seeds, spat, spores, whole plants or animals, individual genes), for example seed or brood-stock collection for aquaculture and mangrove replanting and new plantations. Regulation and maintenance services assessed were treatment and assimilation of wastes or toxic substances; coastal erosion control; water flow regulation contributing to dampening the intensity of storm, floods, tsunamis, and hurricanes and the maintenance of localized water flows such as coastal current structures; maintenance of nursery,reproduction and feeding habitats; maintenance of critical habitats for charismatic species such as turtles, dugongs, cetaceans, sharks, seahorses, bats, fireflies, birds, monkeys, orchids and other epiphytes; and climate regulation through impacts on the hydrological cycle, temperature regulation, and the contribution to regulation of climate-influencing gases in the atmosphere, for example through carbon sequestration and long-term, decadal storage. Cultural services examined included uses of habitats as places for active and passive recreation; ceremonial activities; creative activities; and knowledge-based activities, such as educational activities, and citizen science or community environmental activities. The comprehensive literature review included peer-reviewed scientific research literature as well as grey literature such as government and other reports. To ensure a wide breadth of coverage, the research focused on studies from Southeast Asia. When no evidence was found in the literature, evidence was sought from experts, and where useful, was accompanied by observations from the authors in their respective case study sites. The evidence gathered was used to assess the potential of each habitat to provide an ecosystem service, rather than to assess the actual provision of ecosystem services from each case study site. This important distinction allows the differentiation between services provided by the ecosystem (i.e. the potential supply of ecosystem services that a habitat could deliver) and (achieved or used) benefits (i.e. the demand for ecosystem services). The knowledge gained from the literature, local and regional reports, together with observations from the study team and experts, was critically assessed using a robust methodology that captured different types of information together with a confidence score for the supporting evidence. The contribution of each habitat to each ecosystem service was then scored relative to other habitats. Our objective was to provide baseline information to enable better understanding of the ecosystem services arising from marine and coastal habitats in SE Asia. This provides a foundation for future assessments of natural capital and ecosystem services which may be used to inform sustainable management. The report will serve as a useful reference to many different readers. Regulators, managers of marine sites and policy makers might use this report to inform their management choices. This should enable more sustainable use of the marine environment and maximise the ecosystem service provision of all types of services addressed in this study. Stakeholders of the marine environment such as fisherfolk or residents might use this report to help them engage in management processes, to gain deeper understanding of the marine environment or confirm their observations of the marine environment. Academics can use it as a reference source or a base for further studies, in particular for valuation studies or when considering the trade-offs between ecosystem services in marine and coastal habitats. Finally, it is hoped that this report may bring a new appreciation and understanding of the marine environment and the life support it provides to society and inspire readers to improve management of the marine environment. This report is one of the outputs of the UK Research and Innovation’s Global Challenges Research Fund (UKRI GCRF) Blue Communities Programme (GCRF Blue Communities Global Challenges Research Fund via the United Kingdom Research and Innovation (UKRI) under grant agreement reference NE/P021107/1, www.blue-communities.org), which aims to “build capacity for sustainable interactions with marine ecosystems for the benefit of the health, well-being, food security and livelihoods of coastal communities in SE Asia”. GCRF Blue Communities is developing interdisciplinary research capability and lasting collaborations that can facilitate innovative application of integrated planning in the marine environment and respond to the UN Sustainable Development Goals of ‘no poverty’, ‘zero hunger’, ‘good health and well-being’ for coastal communities as well as ‘conserve and sustainably use the oceans, seas and marine resources for sustainable development’ through the sustainable use of marine resources

Heme oxygenase-1 derived carbon monoxide suppresses Aβ1-42 toxicity in astrocytes

Neurodegeneration in Alzheimer’s disease (AD) is extensively studied, and the involvement of astrocytes and other cell types in this process has been described. However, the responses of astrocytes themselves to amyloid β peptides ((Aβ; the widely accepted major toxic factor in AD) is less well understood. Here, we show that Aβ(1-42) is toxic to primary cultures of astrocytes. Toxicity does not involve disruption of astrocyte Ca2+ homeostasis, but instead occurs via formation of the toxic reactive species, peroxynitrite. Thus, Aβ(1-42) raises peroxynitrite levels in astrocytes, and Aβ(1-42) toxicity can be inhibited by antioxidants, or by inhibition of nitric oxide (NO) formation (reactive oxygen species (ROS) and NO combine to form peroxynitrite), or by a scavenger of peroxynitrite. Increased ROS levels observed following Aβ(1-42) application were derived from NADPH oxidase. Induction of heme oxygenase-1 (HO-1) protected astrocytes from Aβ(1-42) toxicity, and this protective effect was mimicked by application of the carbon monoxide (CO) releasing molecule CORM-2, suggesting HO-1 protection was attributable to its formation of CO. CO suppressed the rise of NADPH oxidase-derived ROS caused by Aβ(1-42). Under hypoxic conditions (0.5% O2, 48h) HO-1 was induced in astrocytes and Aβ(1-42) toxicity was significantly reduced, an effect which was reversed by the specific HO-1 inhibitor, QC-15. Our data suggest that Aβ(1-42) is toxic to astrocytes, but that induction of HO-1 affords protection against this toxicity due to formation of CO. HO-1 induction, or CO donors, would appear to present attractive possible approaches to provide protection of both neuronal and non-neuronal cell types from the degenerative effects of AD in the central nervous system