A distinct dimer configuration of a diatom Get3 forming a tetrameric complex with its tail-anchored membrane cargo.

BACKGROUND: Most tail-anchored (TA) membrane proteins are delivered to the endoplasmic reticulum through a conserved posttranslational pathway. Although core mechanisms underlying the targeting and insertion of TA proteins are well established in eukaryotes, their role in mediating TA protein biogenesis in plants remains unclear. We reported the crystal structures of algal arsenite transporter 1 (ArsA1), which possesses an approximately 80-kDa monomeric architecture and carries chloroplast-localized TA proteins. However, the mechanistic basis of ArsA2, a Get3 (guided entry of TA proteins 3) homolog in plants, for TA recognition remains unknown. RESULTS: Here, for the first time, we present the crystal structures of the diatom Pt-Get3a that forms a distinct ellipsoid-shaped tetramer in the open (nucleotide-bound) state through crystal packing. Pulldown assay results revealed that only tetrameric Pt-Get3a can bind to TA proteins. The lack of the conserved zinc-coordination CXXC motif in Pt-Get3a potentially leads to the spontaneous formation of a distinct parallelogram-shaped dimeric conformation in solution, suggesting a new dimer state for subsequent tetramerization upon TA targeting. Pt-Get3a nonspecifically binds to different subsets of TA substrates due to the lower hydrophobicity of its α-helical subdomain, which is implicated in TA recognition. CONCLUSIONS: Our study provides new insights into the mechanisms underlying TA protein shielding by tetrameric Get3 during targeting to the diatom's cell membrane.

Understanding the role of the state in dietary public health policymaking: a critical scoping review.

Despite evidence that dietary population health interventions are effective and widely accepted, they remain the topic of intense debate centring on the appropriate role of the state. This review sought to identify how the role of the state in intervening in individuals' food practices is conceptualized across a wide range of literatures. We searched 10 databases and 4 journals for texts that debated dietary population health interventions designed to affect individuals' health-affecting food practices. Two co-authors independently screened these texts for eligibility relative to inclusion and exclusion criteria. Thirty-five texts formed our final corpus. Through critical reflexive thematic analysis (TA), we generated 6 themes and 2 subthemes concerning choice, responsibility for health, balancing benefits and burdens of intervention, the use of evidence, fairness, and the legitimacy of the state's actions. Our analysis found that narratives that aim to prevent effective regulation are entrenched in academic literatures. Discourses that emphasized liberty and personal responsibility framed poor health as the result of 'lifestyle choices'. Utilitarian, cost-benefit rationales pervaded arguments about how to best balance the benefits and burdens of state intervention. Claims about fairness and freedom were used to evoke powerful common meanings, and evidence was used politically to bolster interests, particularly those of the food industry. This review identifies and critically analyses key arguments for and against population dietary public health policies. Our findings should motivate public health researchers and practitioners to avoid unreflexively embracing framings that draw on the languages and logics of free market economics.

Nanoemulsions of Hydroxysafflor Yellow A for Enhancing Physicochemical and In Vivo Performance.

Stroke was always a disease that threatened human life and health worldwide. We reported the synthesis of a new type of hyaluronic acid-modified multi-walled carbon nanotube. Then, we produced hydroxysafflor yellow A-hydroxypropyl-ß-cyclodextrin phospholipid complex water-in-oil nanoemulsion with hyaluronic acid-modified multi-walled carbon nanotubes and chitosan (HC@HMC) for oral treatment of an ischemic stroke. We measured the intestinal absorption and pharmacokinetics of HC@HMC in rats. We found that the intestinal absorption and the pharmacokinetic behavior of HC@HMC was superior to that of HYA. We measured intracerebral concentrations after oral administration of HC@HMC and found that more HYA crossed the blood-brain barrier (BBB) in mice. Finally, we evaluated the efficacy of HC@HMC in middle cerebral artery occlusion/reperfusion (MCAO/R)-injured mice. In MCAO/R mice, oral administration of HC@HMC demonstrated significant protection against cerebral ischemia-reperfusion injury (CIRI). Furthermore, we found HC@HMC may exert a protective effect on cerebral ischemia-reperfusion injury through the COX2/PGD2/DPs pathway. These results suggest that oral administration of HC@HMC may be a potential therapeutic strategy for the treatment of stroke.

Differences in energy and nutrient content of menu items served by large chain restaurants in the USA and the UK in 2018.

OBJECTIVE: To quantify the sector-wide energy and nutritional differences of both adult and children's restaurant menu items in the UK and the USA in 2018. DESIGN: Cross-sectional study. SETTING: Energy and nutritional information provided on restaurant websites. PARTICIPANTS: Menu items (n 40 902) served by forty-two large UK chains and ninety-six large USA chains. RESULTS: Mean absolute energy, fat and saturated fat values were higher in USA menu items. For example, the mean adjusted per-item differences of adult menu items between the USA and the UK were 45·6 kcal for energy and 3·2 g for fat. Comparable figures for children's menu items were 43·7 kcal and 4 g. Compared with UK menu items, USA adult menu items also had higher sugar content (3·2 g, 95 % CI (0·5, 6)), and children's menu items had higher Na content (181·1 mg, 95 % CI (108·4, 253·7)). Overall, 96·8 % of UK and 95·8 % of USA menu items exceeded recommended levels for at least one of Na, fat, saturated fat or sugars. CONCLUSIONS: Menu items served by large chain restaurants had higher mean absolute levels of energy, fat and saturated fat in the USA compared with the UK. UK adult menu items were also lower in sugars compared with the USA ones and children's items lower in Na. As more than 95 % of all items were considered to have high levels of at least one nutrient of public health concern in the USA and the UK, improvements in restaurant menu items are needed in both countries.

Prognostic factors and survival for malignant conjunctival melanoma and squamous cell carcinoma over four decades.

PURPOSE: To determine the epidemiology and survival of primary conjunctival malignant neoplasms. METHODS: Retrospective analysis of primary malignant conjunctival neoplasms using Surveillance, Epidemiology, and End Results database from 1973 to 2012. RESULTS: Of 1661 cases, the most common neoplasms are squamous cell carcinoma (SCC) at 54.8% and melanoma at 38.8%. Mean diagnostic age for melanoma was 62.1 compared to 65.5 years for SCC (p = 0.002). 52.2% of melanoma are male versus 77.4% of SCC (p < 0.001). For SCC only age (HR: 1.09, 95% CI:1.04-1.14) is a predictor of survival. For melanoma, age (HR: 1.07, 95% CI: 1.05-1.10), male sex (HR: 2.04, 95% CI: 1.16-3.60), T4 tumors (HR: 3.38, 95% CI: 1.17-9.80) and N1 status (HR: 8.69, 95% CI: 2.75-27.42) are all survival predictors. The 5 and 10-year overall survival (OS) estimates are not significantly different between SCC and melanoma, with 70% and 50% respectively for SCC, and 71% and 50% respectively for melanoma. Median survival time is worse for blacks (52 months) compared to whites (118 months) and Asians/Native Americans/Pacific Islanders (145 months), however race was not found to be a significant prognostic factor in multivariate analysis. Five-year survival are similar between decades 1973-1982 (66.2%), 1983-1992 (69.2%), 1993-2002 (71.3%) and 2003-2012 (70.2%). CONCLUSION: Age at diagnosis is a determinant of survival for both conjunctival SCC and melanoma. Male sex, T4 and N1 staging are also important prognostic factors for melanoma. With respect to overall survival, SCC and melanoma did not differ significantly.

Pore-size dependent THz absorption of nano-confined water.

We performed a THz absorption spectroscopy study on liquid water confined in mesoporous silica materials, MCM-41-S-18 and MCM-41-S-21, of two different pore sizes at room temperatures. We found that stronger confinement with a smaller pore size causes reduced THz absorption, indicating reduced water mobility due to confinement. Combined with recent theoretical studies showing that the microscopic structure of water inside the nanopores can be separated into a core water region and an interfacial water region, our spectroscopy analysis further reveals a bulk-water-like THz absorption behavior in the core water region and a solid-like THz absorption behavior in the interfacial water region.

Graphene-to-substrate energy transfer through out-of-plane longitudinal acoustic phonons.

Practically, graphene is often deposited on substrates. Given the major substrate-induced modification of properties and considerable energy transfer at the interface, the graphene-substrate interaction has been widely discussed. However, the proposed mechanisms were restricted to the two-dimensional (2D) plane and interface, while the energy conduction in the third dimension is hardly considered. Herein, we disclose the transfer of energy perpendicular to the interface of the combined system of the 2D graphene and the 3D base. More precisely, our observation of the energy dissipation of optically excited graphene via emitting out-of-plane longitudinal acoustic phonon into the substrate is presented. By applying nanoultrasonic spectroscopy with a piezoelectric nanolayer embedded in the substrate, we found that under photoexcitation by a femtosecond laser pulse graphene can emit longitudinal coherent acoustic phonons (CAPs) with frequencies over 1 THz into the substrate. In addition, the waveform of the CAP pulse infers that the photocarriers and sudden lattice heating in graphene caused modification of graphene-substrate bond and consequently generated longitudinal acoustic phonons in the substrate. The direct observation of this unexplored graphene-to-substrate vertical energy transfer channel can bring new insights into the understanding of the energy dissipation and limited transport properties of supported graphene.

Assessing the healthiness of menus of all out-of-home food outlets and its socioeconomic patterns in Great Britain.

Food environment research predominantly focuses on the spatial distribution of out-of-home food outlets. However, the healthiness of food choices available within these outlets has been understudied, largely due to resource constraints. In this study, we propose an innovative, low-resource approach to characterise the healthiness of out-of-home food outlets at scale. Menu healthiness scores were calculated for food outlets on JustEat, and a deep learning model was trained to predict these scores for all physical out-of-home outlets in Great Britain, based on outlet names. Our findings highlight the "double burden" of the unhealthy food environment in deprived areas where there tend to be more out-of-home food outlets, and these outlets tend to be less healthy. This methodological advancement provides a nuanced understanding of out-of-home food environments, with potential for automation and broad geographic application.

Effects and mechanisms of bisphenols exposure on neurodegenerative diseases risk: A systemic review.

Environmental bisphenols (BPs) pose a global threat to human health because of their extensive use as additives in plastic products. BP residues are increasing in various environmental media (i.e., water, soil, and indoor dust) and biological and human samples (i.e., serum and brain). Both epidemiological and animal studies have determined an association between exposure to BPs and an increased risk of neurodegenerative diseases (e.g., Parkinson's disease, Alzheimer's disease, and amyotrophic lateral sclerosis), including cognitive abnormalities and behavioral disturbances. Hence, understanding the biological responses to different BPs is essential for prevention, and treatment. This study provides an overview of the underlying pathogenic molecular mechanisms as a valuable basis for understanding neurodegenerative disease responses to BPs, including accumulation of misfolded proteins, reduction of tyrosine hydroxylase and dopamine, abnormal hormone signaling, neuronal death, oxidative stress, calcium homeostasis, and inflammation. These findings provide new insights into the neurotoxic potential of BPs and ultimately contribute to a comprehensive health risk evaluation.

Physical Activity Levels and Factors Affecting Them in Hospitalized Children With Leukemia.

BACKGROUND: Physical activity promotes healthy physical and mental development in children with leukemia. However, the level of physical activity in hospitalized children with leukemia and the factors that influence it are unknown. OBJECTIVES: The aims of this study were to understand the physical activity level of hospitalized children with leukemia and to explore the factors influencing it to provide a reference for physical activity assessment and intervention in such children. METHODS: A total of 133 hospitalized children with leukemia completed a general information questionnaire, the Chinese University of Hong Kong Physical Activity Rating for Children and Youth, and the Children's Social Anxiety Scale. A cross-sectional study was used to explore the effects of different variables on the children's activity levels. RESULTS: Among the study participants, 44.4% had a low-intensity activity level, 35.3% had a moderate-intensity activity level, and 20.3% had a high-intensity activity level, with a total physical activity rating of 3 (1, 6). Chemotherapy phase (P = .007), screen time (P = .001), and social anxiety (P = .012) were identified as influential factors. CONCLUSIONS: Our results showed that children with hospitalized leukemia had lower-intensity physical activity levels, especially in the chemotherapy phase of induction remission. Furthermore, screen time and social anxiety had negative effects on the children's activity levels. IMPLICATIONS FOR PRACTICE: According to the physical activity level of the children and the influencing factors, healthcare professionals should gradually improve children's mobility and promote their physical and mental health development through guidance and encouragement, and the development of personalized activity intervention programs.

Changes in the number of new takeaway food outlets associated with adoption of management zones around schools: A natural experimental evaluation in England.

By the end of 2017, 35 local authorities (LAs) across England had adopted takeaway management zones (or "exclusion zones") around schools as a means to curb proliferation of new takeaways. In this nationwide, natural experimental study, we evaluated the impact of management zones on takeaway retail, including unintended displacement of takeaways to areas immediately beyond management zones, and impacts on chain fast-food outlets. We used uncontrolled interrupted time series analyses to estimate changes from up to six years pre- and post-adoption of takeaway management zones around schools. We evaluated three outcomes: mean number of new takeaways within management zones (and by three identified sub-types: full management, town centre exempt and time management zones); mean number on the periphery of management zones (i.e. within an additional 100 m of the edge of zones); and presence of new chain fast-food outlets within management zones. For 26 LAs, we observed an overall decrease in the number of new takeaways opening within management zones. Six years post-intervention, we observed 0.83 (95% CI -0.30, -1.03) fewer new outlets opening per LA than would have been expected in absence of the intervention, equivalent to an 81.0% (95% CI -29.1, -100) reduction in the number of new outlets. Cumulatively, 12 (54%) fewer new takeaways opened than would have been expected over the six-year post-intervention period. When stratified by policy type, effects were most prominent for full management zones and town centre exempt zones. Estimates of intervention effects on numbers of new takeaways on the periphery of management zones, and on the presence of new chain fast-food outlets within management zones, did not meet statistical significance. Our findings suggest that management zone policies were able to demonstrably curb the proliferation of new takeaways. Modelling studies are required to measure the possible population health impacts associated with this change.

Changes in the number and outcome of takeaway food outlet planning applications in response to adoption of management zones around schools in England: A time series analysis.

Physical exposure to takeaway food outlets ("takeaways") is associated with poor diet and excess weight, which are leading causes of excess morbidity and mortality. At the end of 2017, 35 local authorities (LAs) in England had adopted takeaway management zones (or "exclusion zones"), which is an urban planning intervention designed to reduce physical exposure to takeaways around schools. In this nationwide, natural experimental study, we used interrupted time series analyses to estimate the impact of this intervention on changes in the total number of takeaway planning applications received by LAs and the percentage rejected, at both first decision and after any appeal, within management zones, per quarter of calendar year. Changes in these proximal process measures would precede downstream retail and health impacts. We observed an overall decrease in the number of applications received by intervention LAs at 12 months post-intervention (6.3 fewer, 95% CI -0.1, -12.5), and an increase in the percentage of applications that were rejected at first (additional 18.8%, 95% CI 3.7, 33.9) and final (additional 19.6%, 95% CI 4.7, 34.6) decision, the latter taking into account any appeal outcomes. This effect size for the number of planning applications was maintained at 24 months, although it was not statistically significant. We also identified three distinct sub-types of management zone regulations (full, town centre exempt, and time management zones). The changes observed in rejections were most prominent for full management zones (where the regulations are applied irrespective of overlap with town centres), where the percentage of applications rejected was increased by an additional 46.1% at 24 months. Our findings suggest that takeaway management zone policies may have the potential to curb the proliferation of new takeaways near schools and subsequently impact on population health.

Physicochemical Quality Retention during Cold Storage of Prepackaged Barramundi Meat Processed with a New Microwave-Assisted Induction Heating Technology.

Microwave-assisted induction heating (MAIH) is a composite microwave and induction heating to supply rapid and uniform heating of food. A recent study showed that the optimum MAIH heating condition for barramundi meat was 90 °C/110 s or 70 °C/130 s. This study examines whether the microwave-assisted induction heating (MAIH) technology (at 70 °C for 130 s or 90 °C for 110 s) can more effectively slow down the quality loss of barramundi meat during cold storage than the traditional boiling method (at 90 °C for 150 s). The results show that no microbial growth was observed in the three groups of heated barramundi meat samples during the 60 days of cold storage. However, the MAIH technology slowed down the increase in the total volatile basic nitrogen (TVBN) content more significantly than the boiling method. As the cold storage time increased, though, the L* (lightness), a* (redness), and W (whiteness) values decreased, while the b* (yellowness) and color difference (ΔE) values increased in the three treatment groups. However, the MAIH technology slowed down the decrease in the L*, a*, and W values more significantly, and produced a ΔE value smaller than the boiling method. Moreover, the MAIH technology ensured higher hardness and chewiness of the barramundi meat than the boiling method. Overall, the MAIH technology slowed down the quality loss of the barramundi meat and maintained better color and texture during cold storage.

Socioeconomic distribution of food outlet availability through online food delivery services in seven European countries: A cross-sectional study.

This area-level cross-sectional study examined online food outlet availability through the most popular online food delivery service platforms (OFDS) across seven European countries, and explored how this online food outlet availability was socioeconomically distributed. Data collection of online food outlet availability was automated in England, Italy, Luxembourg, the Netherlands, Portugal, Spain and Switzerland. We used a geographic information system to join online food outlet availability to socio-demographic information. Median number of food outlets delivering through OFDS was highest in England and lowest in Italy, Portugal and Spain. We also found that high-income areas have the greatest online food outlet availability in most countries. In England, areas with a middle income had the least online food outlets available and no income data was available for Switzerland. Further work is needed to understand drivers of disparities in online food outlet availability, as well as possible implications for public health.

The impact of parental overprotection on the emotions and behaviors of pediatric hematologic cancer patients: a multicenter cross-sectional study.

Background: Parental overprotection may have an impact on children's emotional and behavioral problems (EBPs). As pediatric hematologic cancer patients have compromised immune systems, parents of such children often worry excessively, interfering with their daily lives. Therefore, avoiding overprotection is crucial for the overall physical and mental health of pediatric hematologic cancer patients. Aims: The aim of this study was to examine the current status of EBPs in pediatric hematologic cancer patients and analyze their associated risk factors. Design: This work was a multicenter cross-sectional observational and correlational study. We collected data anonymously through parental questionnaires from three pediatric hematologic oncology hospitals in China. The Strengths and Difficulties Questionnaire, the Parental Overprotection Measure (POM) scale, and a general information survey designed by the research team were employed to assess children's EBPs, the degree of parental overprotection, as well as basic demographic and disease-related information. Chi-square tests and generalized linear mixed-effects regression analysis were used to analyze the factors influencing EBPs among the pediatric hematologic cancer patients. Setting and participants: Using a convenience sampling method, a total of 202 participants' parents were selected. All participants were invited to complete the questionnaire through one-on-one guidance. Results: Emotional symptoms accounted for the highest proportion of abnormal EBPs in children (27.72%), followed by peer problems (26.24%), prosocial behavior (25.74%), behavioral problems (14.36%), and total difficulties (13.86%). A minority of children had abnormal hyperactivity scores (4.95%). The results of a generalized linear mixed regression analysis showed that age, duration of illness, and parental overprotection were significant factors influencing abnormal EBPs in children (p < 0.05). A POM score threshold of 37 exhibited good sensitivity (74%) and specificity (90%) in predicting abnormal EBPs in children. Conclusion: Pediatric hematologic cancer patients under excessive parental protection are more prone to experiencing EBPs. Healthcare professionals should guide parents to reduce this excessive protection, thus mitigating the occurrence of EBPs in children.

Association between work content and musculoskeletal disorders among home caregivers: a cross-section study.

In Taiwan, over 80% of home caregivers have experienced musculoskeletal disorders (MSD) in the past year. Although MSDs in health care workers have been discussed in existing literature (e.g., in nursing staff), there is limited understanding of the association between MSD and the work content of home caregivers. This study aimed to investigate the correlation between the work content and MSD of home caregivers. This cross-sectional study was conducted in long-term care units in central Taiwan. A structured questionnaire was used to collect data, including basic information, work content survey, and information from the Nordic Musculoskeletal Questionnaire. Logistic regression analysis was used to examine the association between work content and MSD. A total of 149 home caregivers with a mean age of approximately 50.97 ± 9.80 years were recruited for the study. The frequency of transfer of toilet and wheelchair was significantly associated with shoulder discomfort, upper back discomfort, and wrists/hands discomfort. In addition, the frequency of passive range of motion exercise was significantly associated with elbows discomfort. The results of this study indicated that the highest risk factor for MSD was transfer of toilet and wheelchair followed by passive range of motion exercise.

Monitoring the Nutrient Composition of Food Prepared Out-of-Home in the United Kingdom: Database Development and Case Study.

BACKGROUND: Hand transcribing nutrient composition data from websites requires extensive human resources and is prone to error. As a result, there are limited nutrient composition data on food prepared out of the home in the United Kingdom. Such data are crucial for understanding and monitoring the out-of-home food environment, which aids policy making. Automated data collection from publicly available sources offers a potential low-resource solution to address this gap. OBJECTIVE: In this paper, we describe the first UK longitudinal nutritional database of food prepared out of the home, MenuTracker. As large chains will be required to display calorie information on their UK menus from April 2022, we also aimed to identify which chains reported their nutritional information online in November 2021. In a case study to demonstrate the utility of MenuTracker, we estimated the proportions of menu items exceeding recommended energy and nutrient intake (eg, >600 kcal per meal). METHODS: We have collated nutrient composition data of menu items sold by large chain restaurants quarterly since March 2021. Large chains were defined as those with 250 employees or more (those covered by the new calorie labeling policy) or belonging to the top 100 restaurants based on sales volume. We developed scripts in Python to automate the data collection process from business websites. Various techniques were used to harvest web data and extract data from nutritional tables in PDF format. RESULTS: Automated Python programs reduced approximately 85% of manual work, totaling 500 hours saved for each wave of data collection. As of January 2022, MenuTracker has 76,405 records from 88 large out-of-home food chains at 4 different time points (ie, March, June, September, and December) in 2021. In constructing the database, we found that one-quarter (24.5%, 256/1043) of large chains, which are likely to be subject to the United Kingdom's calorie menu labeling regulations, provided their nutritional information online in November 2021. Across these chains, 24.7% (16,391/66,295) of menu items exceeded the UK government's recommendation of a maximum of 600 kcal for a single meal. Comparable figures were 46.4% (29,411/63,416) for saturated fat, 34.7% (21,964/63,388) for total fat, 17.6% (11,260/64,051) for carbohydrates, 17.8% (11,434/64,059) for sugar, and 35.2% (22,588/64,086) for salt. Furthermore, 0.7% to 7.1% of the menu items exceeded the maximum daily recommended intake for these nutrients. CONCLUSIONS: MenuTracker is a valuable resource that harnesses the power of data science techniques to use publicly available data online. Researchers, policy makers, and consumers can use MenuTracker to understand and assess foods available from out-of-home food outlets. The methods used in development are available online and can be used to establish similar databases elsewhere.

Biosynthesis of Vitroprocines by α-Oxoamine Synthase and Oxidoreductase Identified from Vibrio sp. QWI-06.

A specific α-oxoamine synthase (VsAOS-2) and an oxidoreductase (VsOR) identified from marine Vibrio sp. QWI-06 were involved in the decarboxylative condensation of l-tyrosine to lauroyl-CoA following the reduction of the ketone group to form vitroprocine-type compound 1. The intermediates and products were characterized through HR-MS and their MS/MS fragmentations. This study reveals the biosynthetic pathway of vitroprocines and provides a useful model for elucidating the reaction mechanism underlying the production of amino acid-polyketide derivatives in microorganisms.

Structural insights into the substrate selectivity of α-oxoamine synthases from marine Vibrio sp. QWI-06.

Pyridoxal phosphate (PLP)-dependent α-oxoamine synthases are generally believed to be responsible for offloading and elongating polyketides or catalyzing the condensation of amino acids and acyl-CoA thioester substrates, such as serine into sphingolipids and cysteate into sulfonolipids. Previously, we discovered vitroprocines, which are tyrosine- and phenylalanine-polyketide derivatives, as potential new antibiotics from the genus Vibrio. Using bioinformatics analysis, we identified putative genes of PLP-dependent enzyme from marine Vibrio sp. QWI-06, implying a capability to produce amino-polyketide derivatives. One of these genes was cloned, and the recombinant protein, termed Vibrio sp. QWI-06 α-oxoamine synthases-1 (VsAOS1), was overexpressed for structural and biochemical characterization. The crystal structure of the dimeric VsAOS1 was determined at 1.8-Å resolution in the presence of L-glycine. The electron density map indicated a glycine molecule occupying the pyridoxal binding site in one monomer, suggesting a snapshot of the initiation process upon the loading of amino acid substrate. In mass spectrometry analysis, VsAOS1 strictly acted to condense L-glycine with C12 or C16 acyl-CoA, including unsaturated acyl analog. Furthermore, a single residue replacement of VsAOS1 (G243S) allowed the enzyme to generate sphingoid derivative when L-serine and lauroyl-CoA were used as substrates. Our data elucidate the mechanism of substrate binding and selectivity by the VsAOS1 and provide a thorough understanding of the molecular basis for the amino acid preference of AOS members.

DnaJ homolog Hdj2 facilitates Japanese encephalitis virus replication.

BACKGROUND: Japanese encephalitis virus (JEV) is a member of the mosquito-borne Flaviviridae family of viruses that causes human encephalitis. Upon infection of a new host, replication of viral RNA involves not only the viral RNA-dependent RNA polymerase (RdRp), but also host proteins. Host factors involved in JEV replication are not well characterized. RESULTS: We identified Hdj2, a heat-shock protein 40 (Hsp40)/DnaJ homolog, from a mouse brain cDNA library interacting with JEV nonstructural protein 5 (NS5) encoding viral RdRp using yeast two-hybrid system. Specific interaction of Hdj2 with NS5 was confirmed by coimmunoprecipitation and colocalization in JEV-infected cells. Overexpression of Hdj2 in JEV-infected cells led to an increase of RNA synthesis, and the virus titer was elevated approximately 4.5- to 10-fold. Knocking down of Hdj2 by siRNA reduced the virus production significantly. CONCLUSIONS: We conclude that Hdj2 directly associates with JEV NS5 and facilitates viral replication. This study is the first to demonstrate Hdj2 involved in JEV replication, providing insight into a potential therapeutic target and cell-based vaccine development of JEV infection.