PEXEL is a proteolytic maturation site for both exported and non-exported Plasmodium proteins

Obligate intracellular malaria parasites dramatically remodel their erythrocyte host through effector protein export to create a niche for survival. Most exported proteins contain a pentameric Plasmodium export element (PEXEL)/host-targeting motif that is cleaved in the parasite ER by the aspartic protease Plasmepsin V (PMV). This processing event exposes a mature N terminus required for translocation into the host cell and is not known to occur in non-exported proteins. Here, we report that the non-exported parasitophorous vacuole protein UIS2 contains a bona fide PEXEL motif that is processed in the P. falciparum blood stage. While the N termini of exported proteins containing the PEXEL and immediately downstream ~10 residues are sufficient to mediate translocation into the RBC, the equivalent UIS2 N terminus does not promote the export of a reporter. Curiously, the UIS2 PEXEL contains an unusual aspartic acid at the fourth position, which constitutes the extreme N-terminal residue following PEXEL cleavage (P1', RIL↓DE). Using a series of chimeric reporter fusions, we show that Asp at P1' is permissive for PMV processing but abrogates export. Moreover, mutation of this single UIS2 residue to alanine enables export, reinforcing that the mature N terminus mediates export, not PEXEL processing per se. Prompted by this observation, we further show that PEXEL sequences in the N termini of other non-exported rhoptry proteins are also processed, suggesting that PMV may be a more general secretory maturase than previously appreciated, similar to orthologs in related apicomplexans. Our findings provide new insight into the unique N-terminal constraints that mark proteins for export.IMPORTANCEHost erythrocyte remodeling by malaria parasite-exported effector proteins is critical to parasite survival and disease pathogenesis. In the deadliest malaria parasite Plasmodium falciparum, most exported proteins undergo proteolytic maturation via recognition of the pentameric Plasmodium export element (PEXEL)/host-targeting motif by the aspartic protease Plasmepsin V, which exposes a mature N terminus that is conducive for export into the erythrocyte host cell. While PEXEL processing is considered a unique mark of exported proteins, we demonstrate that PEXEL motifs are present and processed in non-exported proteins. Importantly, we show that specific residues at the variable fourth position of the PEXEL motif inhibit export despite being permissive for processing, reinforcing that features of the mature N terminus, and not PEXEL cleavage, identify cargo for export. This opens the door to further inquiry into the nature and evolution of the PEXEL motif.

Fates of Terrigenous Dissolved Organic Carbon in the Gulf of Maine

A significant amount of organic carbon is transported in dissolved form from soils to coastal oceans via inland water systems, bridging land and ocean carbon reservoirs. However, it has been discovered that the presence of terrigenous dissolved organic carbon (tDOC) in oceans is relatively limited. Therefore, understanding the fates of tDOC in coastal oceans is essential to account for carbon sequestration through land ecosystems and ensure accurate regional carbon budgeting. In this study, we developed a state-of-the-art modeling approach by coupling a land-to-ocean tDOC flux simulation model and a coastal tDOC tracking model to determine the potential fates of tDOC exported from three primary drainage basins in the Gulf of Maine (GoM). According to our findings, over half a year in the GoM, 56.4% of tDOC was mineralized. Biomineralization was responsible for 90% of that amount, with the remainder attributed to photomineralization. Additionally, 37% of the tDOC remained suspended in the GoM, and 6.6% was buried in the marine sediment.

Characterization of Molecular Chaperone GroEL as a Potential Virulence Factor in Cronobacter sakazakii

The molecular chaperone GroEL of C. sakazakii, a highly conserved protein encoded by the gene grol, has the basic function of responding to heat shock, thus enhancing the bacterium's adaptation to dry and high-temperature environments, which poses a threat to food safety and human health. Our previous study demonstrated that GroEL was found in the bacterial membrane fraction and caused a strong immune response in C. sakazakii. In this study, we tried to elucidate the subcellular location and virulent effects of GroEL. In live C. sakazakii cells, GroEL existed in both the soluble and insoluble fractions. To study the secretory mechanism of GroEL protein, a non-reduced Western immunoblot was used to analyze the form of the protein, and the result showed that the exported GroEL protein was mainly in monomeric form. The exported GroEL could also be located on bacterial surface. To further research the virulent effect of C. sakazakii GroEL, an indirect immunofluorescence assay was used to detect the adhesion of recombinant GroEL protein to HCT-8 cells. The results indicated that the recombinant GroEL protein could adhere to HCT-8 cells in a short period of time. The recombinant GroEL protein could activate the NF-κB signaling pathway to release more pro-inflammatory cytokines (TNF-α, IL-6 and IL-8), downregulating the expression of tight-junction proteins (claudin-1, occluding, ZO-1 and ZO-2), which collectively resulted in dose-dependent virulent effects on host cells. Inhibition of the grol gene expression resulted in a significant decrease in bacterial adhesion to and invasion of HCT-8 cells. Moreover, the deficient GroEL also caused slow growth, decreased biofilm formation, defective motility and abnormal filamentation of the bacteria. In brief, C. sakazakii GroEL was an important virulence factor. This protein was not only crucial for the physiological activity of C. sakazakii but could also be secreted to enhance the bacterium's adhesion and invasion capabilities.

Engineering RNA export for measurement and manipulation of living cells

A system for programmable export of RNA molecules from living cells would enable both non-destructive monitoring of cell dynamics and engineering of cells capable of delivering executable RNA programs to other cells. We developed genetically encoded cellular RNA exporters, inspired by viruses, that efficiently package and secrete cargo RNA molecules from mammalian cells within protective nanoparticles. Exporting and sequencing RNA barcodes enabled non-destructive monitoring of cell population dynamics with clonal resolution. Further, by incorporating fusogens into the nanoparticles, we demonstrated the delivery, expression, and functional activity of exported mRNA in recipient cells. We term these systems COURIER (controlled output and uptake of RNA for interrogation, expression, and regulation). COURIER enables measurement of cell dynamics and establishes a foundation for hybrid cell and gene therapies based on cell-to-cell delivery of RNA.

Proteomic analysis of fatty liver induced by starvation of medaka fish larvae

When medaka fish (Oryzias latipes) larvae are grown in the absence of exogenous nutrition, the liver becomes dark and positive to Oil Red O staining from 7 days post-hatch (dph). We determined the mechanism of this starvation-induced development of fatty liver by proteomic analysis using livers obtained from larvae grown in the presence or absence of 2% glucose at 5 dph. Results showed that changes in the expression levels of enzymes involved in glycolysis or the tricarboxylic acid cycle were modest, whereas the expression levels of enzymes involved in amino acid catabolism or β-oxidation of fatty acids were significantly elevated, suggesting that they become major energy sources under starvation conditions. Expression levels of enzymes for the uptake and β-oxidation of fatty acids as well as synthesis of triacylglycerol were elevated, whereas those for the synthesis of cholesterol as well as export of cholesterol and triacylglycerol were decreased under starvation conditions, which explains the accumulation of triacylglycerol in the liver. Our results provide the basis for future research to understand how gene malfunction(s) affects the development of fatty liver, which can lead to nonalcoholic steatohepatitis and then to liver cirrhosis.Key words: amino acid catabolism, β-oxidation, triacylglycerol, cholesterol, export.

[The development of medical tourism in conditions of globalization health care]

The article considers impact of process of health care globalization on development of medical tourism. The main trends in health care that drastically changes the situation in conditions of COVID-19 pandemic and implementation of digitization are presented. The normative legal base in force regulating medical services export is analyzed. The study of conditions of development of medical tourism in Russia is carried out. The directions of development of medical services export in modern conditions are considered. The enumeration of issues of global health care is formed. It is accepted to consider health care sector as a part of economics that is most isolated and attached to place of rendering and consumption of services. The outbreak of COVID-19 pandemic and active implementation of digital technologies into processes of organization of health care and medical care provision launched transformation and urged globalization. The conclusion is drew that actual society exists in epoch of globalization and digitization of health care sector. Nowadays, borders of states are not insurmountable obstacle for patients in need of high-tech medical care. The world market of medical tourism demonstrates trend to continuous growth and development permitting largest medical clusters to compete for attention of patients. The purpose of the study is in considering directions of development of medical tourism under the influence of process of health care globalization in modern society.

The role of income, exports and capital flows on domestic income growth: empirical evidence from Denmark

This article examines the long-term growth path of the Danish economy from 1980 to 2017. Various developments and changes have emerged over the years to determine the robustness and legitimacy of the balance of payments constrained growth model. One of these changes is that capital flows have an important role in the growth process. In this study, relative prices, exchange rate and capital flows are questioned as important determinants. The study uses autoregressive distributed lag (ARDL) methodology to determine the both short- and long-run relationships among the variables. The outcome reveals that all the variables have significant impacts on both the short-run and long-run growth of Denmark. In the light of these findings, considering that the annual real growth of the Danish economy is 1.75%, it can be concluded that this estimation is correct and is proportional to the growth rate of Denmark from 1980 to 2017. It would be a correct assessment to consider income, relative prices and capital flows as important determinants of the growth of the Danish economy on the demand side. Weakening confidence indices and worsening expectations in Danish export markets could quickly affect Danish exports and trade investment.

The Dicarboxylate Transporters from the AceTr Family and Dct-02 Oppositely Affect Succinic Acid Production in S. cerevisiae

Membrane transporters are important targets in metabolic engineering to establish and improve the production of chemicals such as succinic acid from renewable resources by microbial cell factories. We recently provided a Saccharomyces cerevisiae strain able to strongly overproduce succinic acid from glycerol and CO₂ in which the Dct-02 transporter from Aspergillus niger, assumed to be an anion channel, was used to export succinic acid from the cells. In a different study, we reported a new group of succinic acid transporters from the AceTr family, which were also described as anion channels. Here, we expressed these transporters in a succinic acid overproducing strain and compared their impact on extracellular succinic acid accumulation with that of the Dct-02 transporter. The results show that the tested transporters of the AceTr family hinder succinic acid accumulation in the extracellular medium at low pH, which is in strong contrast to Dct-02. Data suggests that the AceTr transporters prefer monovalent succinate, whereas Dct-02 prefers divalent succinate anions. In addition, the results provided deeper insights into the characteristics of Dct-02, showing its ability to act as a succinic acid importer (thus being bidirectional) and verifying its capability of exporting malate.

Retroviral RNA Processing

This review is an accompaniment to a Special Issue on “Retroviral RNA Processing”. It discusses post-transcriptional regulation of retroviruses, ranging from the ancient foamy viruses to more modern viruses, such as HIV-1, HTLV-1, Rous sarcoma virus, murine leukemia virus, mouse mammary tumor virus, and Mason-Pfizer monkey virus. This review is not comprehensive. However, it tries to address some of the major questions in the field with examples of how different retroviruses express their genes. It is amazing that a single primary RNA transcript can have so many possible fates: genomic RNA, unspliced mRNA, and up to 50 different alternatively spliced mRNAs. This review will discuss the sorting of RNAs for packaging or translation, RNA nuclear export mechanisms, splicing, translation, RNA modifications, and avoidance of nonsense-mediated RNA decay.

Human C1orf27 protein interacts with α2A-adrenergic receptor and regulates its anterograde transport

The molecular mechanisms underlying the anterograde surface transport of G protein–coupled receptors (GPCRs) after their synthesis in the endoplasmic reticulum (ER) are not well defined. In C. elegans, odorant response abnormal 4 has been implicated in the delivery of olfactory GPCRs to the cilia of chemosensory neurons. However, the function and regulation of its human homolog, C1orf27, in GPCR transport or in general membrane trafficking remain unknown. Here, we demonstrate that siRNA-mediated knockdown of C1orf27 markedly impedes the ER-to-Golgi export kinetics of newly synthesized α_2A-adrenergic receptor (α_2A-AR), a prototypic GPCR, with the half-time being prolonged by more than 65%, in mammalian cells in retention using the selective hooks assays. Using modified bioluminescence resonance energy transfer assays and ELISAs, we also show that C1orf27 knockdown significantly inhibits the surface transport of α_2A-AR. Similarly, C1orf27 knockout by CRISPR-Cas9 markedly suppresses the ER–Golgi-surface transport of α_2A-AR. In addition, we demonstrate that C1orf27 depletion attenuates the export of β₂-AR and dopamine D2 receptor but not of epidermal growth factor receptor. We further show that C1orf27 physically associates with α_2A-AR, specifically via its third intracellular loop and C terminus. Taken together, these data demonstrate an important role of C1orf27 in the trafficking of nascent GPCRs from the ER to the cell surface through the Golgi and provide novel insights into the regulation of the biosynthesis and anterograde transport of the GPCR family members.

Impact of Resource on Green Growth and Threshold Effect of International Trade Levels: Evidence from China

International trade levels can change the relationship between resource endowments and green economic growth. Therefore, this study tested the resource curse hypothesis from the perspective of green growth in China using provincial-level panel data for 2005–2017. Energy conservation and environmental improvement were considered under green growth to further analyze the regional mechanism of the resource curse. A panel threshold model was used to identify the impact of import and export threshold effects on the transformation of this mechanism. The resource curse hypothesis was found to be valid nationwide; it hindered green economic growth mainly by impeding energy conservation and curbing environmental improvement. In terms of regional differences in green growth, resource endowment had a positive impact on the eastern region, a negative impact on the central region, and no effect on the western region. When the levels of import and export trade exceeded the threshold values, the resource curse effect was enhanced by reducing energy conservation and weakened by promoting environmental improvement, respectively. Therefore, the Chinese government should establish a more reasonable import and export trade structure, promote changes to the energy structure and green technological innovation, and reduce the negative impact of resource endowment on green growth.

Cysteine String Protein Controls Two Routes of Export for Misfolded Huntingtin

Extracellular vesicles (EVs) are secreted vesicles of diverse size and cargo that are implicated in the cell-to-cell transmission of disease-causing-proteins in several neurodegenerative diseases. Mutant huntingtin, the disease-causing entity in Huntington's disease, has an expanded polyglutamine track at the N terminus that causes the protein to misfold and form toxic intracellular aggregates. In Huntington's disease, mutant huntingtin aggregates are transferred between cells by several routes. We have previously identified a cellular pathway that is responsible for the export of mutant huntingtin via extracellular vesicles. Identifying the EV sub-populations that carry misfolded huntingtin cargo is critical to understanding disease progression. In this work we expressed a form of polyglutamine expanded huntingtin (GFP-tagged 72Qhuntingtin^exon1) in cells to assess the EVs involved in cellular export. We demonstrate that the molecular chaperone, cysteine string protein (CSPα; DnaJC5), facilitates export of disease-causing-polyglutamine-expanded huntingtin cargo in 180-240 nm vesicles as well as larger 10-30 μm vesicles.

[Corrigendum] The role of VIT1/FBXO11 in the regulation of apoptosis and tyrosinase export from endoplasmic reticulum in cultured melanocytes

Following the publication of the above article, an interested reader drew to the authors' attention that the Transwell cell migration assay data shown in Fig. 4A appeared to be partly overlapping with data presented for experiments performed under different experimental conditions in Figs. 4D and E. The authors independently examined the figure and realized that inadvertent errors had been made during the assembly of Fig. 4; furthermore, owing to the time that has elapsed since this paper was published, the authors no longer had access to the original data. Accordingly, to further verify the conclusions reported in the study, the authors repeated these experiments, and the results obtained were found to be consistent with the original findings. The new version of Fig. 4 is shown below. The authors are grateful to the Editor of International Journal of Molecular Medicine for allowing them the opportunity to publish this Corrigendum, and apologize to the readership for any inconvenience caused. [the original article was published in International Journal of Molecular Medicine 26: 57-65, 2010; DOI: 10.3892/ijmm_00000435].

Untangling the Governance of Public Health Aspects of Manure in The Netherlands

The Netherlands is one of the most densely populated countries in terms of people and livestock and is the second largest exporter of agricultural products worldwide. As a result, the Netherlands has a manure surplus. Excess application of manure can lead to environmental problems; therefore, manure needs to be treated and discharged. Manure can contain zoonotic pathogens, but whether exposure to manure and manure treatment also poses a risk to public health is still unknown. This study analysed the regulations, relevant actors, and responsibilities in the complex system of manure and public health in the Netherlands. Interviews and system mapping have demonstrated interlinkages between environmental, economic, and health aspects. Constraints and opportunities for public health protection have been identified. This study reveals the complexity of the Dutch manure policy, its scattered responsibilities, the challenge to deal with uncertainties, and, most importantly, the need for a microbial risk assessment in order to adequately communicate and manage possible risks to protect the health of animals, the environment, and people.

Do Corneal Tissue Providers Inform Their Community That They Export Corneas? An Audit of Publicly Available Sector Websites

Aim

The exportation of corneas from one nation to another, for transplantation services, is responsible for 23% of all global transplants. Global allocation is possible because of the end-of-life donations from citizens and residents of export nations. To date, there is no information indicating if export nation donors are aware that their corneas may be exported, nor if organizations that export provide information regarding their export engagement to their community. To ascertain if and how exporters inform their community, we audited known export organization public websites.

Materials and Methods

We designed and conducted a double-blind audit of known exporting eye banks, eye tissue sharing and distributor organization websites.

Results

We audited 79 websites, from 9 nations. Of the 79, 46 (58.2%) did not mention corneal tissue exportation, 17 (21.5%) implied exportation, and 16 (10.2%) explicitly mentioned it. Of the 16 that mentioned they exported, 75% (12/16) provided information regarding their export license, and 12.5% (2/16) indicated partnership with a third party. We could not locate information explaining how organizations decided on how and to whom they export.

Discussion

Organizations that export corneal tissue across national borders do not share sufficient information regarding their export activities on their website. The general public and donors within export nations may not be aware that this practice occurs or could occur with their donation. Export organizations and the eye tissue sector must evaluate their communication strategies and collaborate, preferably nationally, to develop publicly appropriate information regarding corneal tissue exportation.

Roles and Cellular Localization of GBP2 and NAB2 During the Blood Stage of Malaria Parasites

The quality control and export of mRNA by RNA-binding proteins are necessary for the survival of malaria parasites, which have complex life cycles. Nuclear poly(A) binding protein 2 (NAB2), THO complex subunit 4 (THO4), nucleolar protein 3 (NPL3), G-strand binding protein 2 (GBP2) and serine/arginine-rich splicing factor 1 (SR1) are involved in nuclear mRNA export in malaria parasites. However, their roles in asexual and sexual development, and in cellular localization, are not fully understood. In this study using the rodent malaria parasite, Plasmodium berghei, we found that NAB2 and SR1, but not THO4, NPL3 or GBP2, played essential roles in the asexual development of malaria parasites. By contrast, GBP2 but not NPL3 was involved in male and female gametocyte production. THO4 was involved in female gametocyte production, but had a lower impact than GBP2. In this study, we focused on GBP2 and NAB2, which play important roles in the sexual and asexual development of malaria parasites, respectively, and examined their cellular localization. GBP2 localized to both the nucleus and cytoplasm of malaria parasites. Using immunoprecipitation coupled to mass spectrometry (IP-MS), GBP2 interacted with the proteins ALBA4, DOZI, and CITH, which play roles in translational repression. IP-MS also revealed that phosphorylated adapter RNA export protein (PHAX) domain-containing protein, an adaptor protein for exportin-1, also interacted with GBP2, implying that mRNA export occurs via the PHAX domain-containing protein pathway in malaria parasites. Live-cell fluorescence imaging revealed that NAB2 localized at the nuclear periphery. Moreover, IP-MS indicated that NAB2 interacted with transportin. RNA immunoprecipitation coupled to RNA sequencing revealed that NAB2 bound directly to 143 mRNAs, including those encoding 40S and 60S ribosomal proteins. Our findings imply that malaria parasites use an evolutionarily ancient mechanism conserved throughout eukaryotic evolution.

Heterogeneous Driving Factors of Carbon Emissions Embedded in China's Export: An Application of the LASSO Model

With the steady growth of CO₂ emissions embedded in trade, the driving forces of emissions have attracted extensive attention. Most of the literature has verified a bundle of the influential factors; however, further analyses are necessary to understand the predominant and heterogeneous driving factors in different economies and/or industries. Accordingly, by applying the multiregional input-output (MRIO) model, this article firstly evaluates the embodied carbon emissions of China's export from 1992 to 2020 in total volumes and by 14 industries. Then, the Least Absolute Shrinkage and Selection Operator (LASSO) estimations allow us to discover that urbanization, technology update and gross domestic product (GDP) are the leading three prioritizing factors in generating China's export emissions. Interestingly, this paper discovers that raising the proportion of female parliamentarians contributes to an abatement of emissions. Furthermore, the empirical results suggest that the heterogeneities of those factors do exist among industries. For example, the percentage of females in parliaments turns out to have a larger effect among labor-intensive industries only. In facing with rapid globalization and economic development of China, this paper provides important policy implications towards specific industries in terms of mitigating trade emissions. It guides policy-makers to achieve "carbon neutrality" by avoiding carbon leakage in net-export countries such as China.

Protecting antiquities in early modern Rome: the papal edicts as paradigms for the heritage safeguard in Europe

The edicts issued in Rome between the fifteenth and the eighteenth centuries are the earliest legislation conceived for the preservation and supervision of heritage in Europe. Not only did such regulations aim to protect monuments, antiquities, and - at a later stage - paintings from the risks of damage and deterioration, but also established a legal framework against their illegal exportation and excavation.  In this study the gradual development of this vast corpus of legislation is considered within the variations of artistic scholarship, legal knowledge, artistic taste, and the art market in Europe between 1400s and 1700s. The mutual implications of juridical constructs and practices of supervision are evaluated together with interdisciplinary factors - such as the rise of collections and museums - to shed light on the development of the concepts of 'heritage protection' in early modern Rome. Specific analysis will also involve the gradual expansion of the definition of 'antiquity' and 'artefact' in papal legislation, as well as the establishment of innovative instruments to prevent and circumvent misdemeanours.  One final consideration is given to the launch of local procedures of heritage protection in other states in Europe. Considering the cultural and historical backgrounds of each individual place, this study will demonstrate that the idea of safeguarding what was thought of as 'collective heritage' emerged consistently in eighteenth-century Europe following the paradigms of the papal edicts.

Modeling and Forecasting Foreign Trade Values in Medical Devices

OBJECTIVES

Forecasting foreign trade values can be a good guidance to enable policymakers to introduce efficient instruments to regulate the medical device market. The purpose of this study is to forecast Turkey's medical device export and import values for the next 5 years.

METHODS

To that end, we identified the universal HS-6 commodity codes associated with medical devices, and then retrieved foreign trade data from the ITC Trademap database. We proposed Box-Jenkins autoregressive integrated moving average model in forecasting foreign trade values for upcoming years.

RESULTS

Turkey's foreign trade analysis has shown there is a 14% decrease in import and 21% increase in export in past 5 years. The Asian region is the main target market in medical device export with the rate of 42.8%, and most importers of Turkey are located in Europe region. The results show that the total value of imports is expected to reach $1.78 billion, and the total value of exports is expected to reach $720 million by 2023.

CONCLUSIONS

It is concluded that Turkey may have a larger medical device market in the next 5 years, which provides an appropriate environment for investment. We believe that the results are promising and our approach can be adopted in other countries.

Targeted expression of the arsenate reductase HAC1 identifies cell type specificity of arsenic metabolism and transport in plant roots

High Arsenic Concentration 1 (HAC1), an Arabidopsis thaliana arsenate reductase, plays a key role in arsenate [As(V)] tolerance. Through conversion of As(V) to arsenite [As(III)], HAC1 enables As(III) export from roots, and restricts translocation of As(V) to shoots. To probe the ability of different root tissues to detoxify As(III) produced by HAC1, we generated A. thaliana lines expressing HAC1 in different cell types. We investigated the As(V) tolerance phenotypes: root growth, As(III) efflux, As translocation, and As chemical speciation. We showed that HAC1 can function in the outer tissues of the root (epidermis, cortex, and endodermis) to confer As(V) tolerance, As(III) efflux, and limit As accumulation in shoots. HAC1 is less effective in the stele at conferring As(V) tolerance phenotypes. The exception is HAC1 activity in the protoxylem, which we found to be sufficient to restrict As translocation, but not to confer As(V) tolerance. In conclusion, we describe cell type-specific functions of HAC1 that spatially separate the control of As(V) tolerance and As translocation. Further, we identify a key function of protoxylem cells in As(V) translocation, consistent with the model where endodermal passage cells, above protoxylem pericycle cells, form a 'funnel' loading nutrients and potentially toxic elements into the vasculature.

Environmental Regulation and Exports: Evidence from the Comprehensive Air Pollution Policy in China

The impact of environmental regulation has been an important topic. Based on the Chinese Custom Database and China City Statistical Yearbook, this paper investigates the effect of environmental regulation on export values and explores potential mechanisms and heterogeneous effects. Taking advantage of China’s first comprehensive air pollution prevention and control plan, the Air Pollution Control in Key Zones policy, as a quasi-natural experiment, we employ the difference-in-differences method to examine the causal relationship between environmental regulation and exports. We find the statistically significant and negative effect of environmental regulation on exports at the city level. Moreover, we find that the potential mechanism is the change in export values caused by firm entry and exit, especially by exiters, rather than the change in the number of exporting firms in the city caused by firm entry and exit. In addition, we find the heterogeneous effects of environmental regulation based on the differences of environmental policy across cities and the Broad Economic Categories classification.

Inhibition of Plasmepsin V Activity Blocks Plasmodium falciparum Gametocytogenesis and Transmission to Mosquitoes

Plasmodium falciparum gametocytes infect mosquitoes and are responsible for malaria transmission. New interventions that block transmission could accelerate malaria elimination. Gametocytes develop within erythrocytes and activate protein export pathways that remodel the host cell. Plasmepsin V (PMV) is an aspartyl protease that is required for protein export in asexual parasites, but its function and essentiality in gametocytes has not been definitively proven, nor has PMV been assessed as a transmission-blocking drug target. Here, we show that PMV is expressed and can be inhibited specifically in P. falciparum stage I-II gametocytes. PMV inhibitors block processing and export of gametocyte effector proteins and inhibit development of stage II-V gametocytes. Gametocytogenesis in the presence of sublethal inhibitor concentrations results in stage V gametocytes that fail to infect mosquitoes. Therefore, PMV primes gametocyte effectors for export, which is essential for the development and fitness of gametocytes for transmission to mosquitoes.

Impacts of African Swine Fever on Pigmeat Markets in Europe

African Swine Fever (ASF) is a highly contagious animal disease which can cause disruptions in the international trade of pigs and products derived from pigs. During 2014-2019 ASF was introduced into several member states in the European Union (EU), including the Baltic states and Poland (2014), Czech Republic and Romania (2017), Belgium, Bulgaria and Hungary (2018), and Slovakia (2019). The objective of this study was to analyze how the ASF epidemic has contributed to the production, export, and prices of pigmeat and to the national pig inventory (number of pigs) in 11 EU member states. The data included country-level statistics on the pig markets and ASF outbreaks observed during 2010-2019. The data were first analyzed descriptively. Following this, a system of four equations was specified and estimated by using seemingly unrelated regression method. The results indicated that the consequences of ASF to the pigmeat markets are complex and may differ by country. They suggest that an ASF outbreak can reduce the production of pigmeat, export quantities and the national pig inventory in the short and medium term. On average, those new cases of ASF reduced the exports of pigmeat by close to 15% and the production quantity by more than 4% in the year after the cases had occurred, and the national pig inventory by 3-4% both in the current and the next year. However, only indirect effects on pigmeat prices were observed.

A Predictive Model for Assessing the Impact of the COVID-19 Pandemic on the Economies of Some Eastern European Countries

The paper seeks to develop a predictive model for assessing the impact of the (COVID-19) pandemic on the economies of Eastern Europe, taking into account quarantine measures. Functions of the dependence on the number of the infected populations in Eastern Europe on pandemic duration were calculated based on trend analysis. Factors affecting the intensity of disease and the number of infected persons have been determined. Integral model of their influence has been built using regression analysis. Based on the values of the factors, the number of infected people and the rate of infection were predicted for each of the Eastern European countries. The prognostic duration of the stage of exponential disease growth and the total duration of quarantine (epidemiological saturation point) are substantiated. The predicted decline in Eastern European GDP due to COVID-19 has been estimated based on the construction of a prognostic regression model. The results obtained can be used by state authorities and economic agents as a tool for active and preventive response. They can also serve as an example of the urgent need to develop, especially in non-standard situations, mechanisms and products of open innovation.

Amino Acid Transporters in Plants: Identification and Function

Amino acid transporters are the main mediators of nitrogen distribution throughout the plant body, and are essential for sustaining growth and development. In this review, we summarize the current state of knowledge on the identity and biological functions of amino acid transporters in plants, and discuss the regulation of amino acid transporters in response to environmental stimuli. We focus on transporter function in amino acid assimilation and phloem loading and unloading, as well as on the molecular identity of amino acid exporters. Moreover, we discuss the effects of amino acid transport on carbon assimilation, as well as their cross-regulation, which is at the heart of sustainable agricultural production.

Piggybacking on Classical Import and Other Non-Classical Mechanisms of Nuclear Import Appear Highly Prevalent within the Human Proteome

One of the most conserved cellular pathways among eukaryotes is the extensively studied classical protein nuclear import pathway mediated by importin-α. Classical nuclear localization signals (cNLSs) are recognized by importin-α and are highly predictable due to their abundance of basic amino acids. However, various studies in model organisms have repeatedly demonstrated that only a fraction of nuclear proteins contain identifiable cNLSs, including those that directly interact with importin-α. Using data from the Human Protein Atlas and the Human Reference Interactome, and proteomic data from BioID/protein-proximity labeling studies using multiple human importin-α proteins, we determine that nearly 50% of the human nuclear proteome does not have a predictable cNLS. Surprisingly, between 25% and 50% of previously identified human importin-α cargoes do not have predictable cNLS. Analysis of importin-α cargo without a cNLS identified an alternative basic rich motif that does not resemble a cNLS. Furthermore, several previously suspected piggybacking proteins were identified, such as those belonging to the RNA polymerase II and transcription factor II D complexes. Additionally, many components of the mediator complex interact with at least one importin-α, yet do not have a predictable cNLS, suggesting that many of the subunits may enter the nucleus through an importin-α-dependent piggybacking mechanism.

The RNA-binding protein hnRNPU regulates the sorting of microRNA-30c-5p into large extracellular vesicles

The transfer of microRNAs (miRs) via extracellular vesicles (EVs) is a functionally relevant mechanism of intercellular communication that regulates both organ homoeostasis and disease development. Little is known about the packaging of miRs into EVs. Previous studies have shown that certain miRs are exported by RNA-binding proteins into small EVs, while for other miRs and for large EVs, in general, the export mechanisms remain unclear. Therefore, a proteomic analysis of endothelial cell-derived large EVs was performed, which revealed that heterogeneous nuclear ribonucleoprotein U (hnRNPU) is abundantly present in EVs. EVs were characterized by electron microscopy, immunoblotting and nanoparticle tracking analysis. Taqman microRNA array and single qPCR experiments identified specific miR patterns to be exported into EVs in an hnRNPU-dependent way. The specific role of hnRNPU for vesicular miR-sorting was confirmed independently by gain- and loss-of-function experiments. In our study, miR-30c-5p was the miR whose export was most significantly regulated by hnRNPU. Mechanistically, in silico binding analysis showed that the export of miRs into EVs depends on the binding efficiency of the respective miRs to hnRNPU. Among the exported miRs, a significant enrichment of the sequence motif AAMRUGCU was detected as a potential sorting signal. Experimentally, binding of miR-30c-5p to hnRNPU was confirmed independently by RNA-immunoprecipitation, electrophoretic mobility shift assay and reciprocally by miR-pulldown. Nuclear binding of miR-30c-5p to hnRNPU and subsequent stabilization was associated with a lower cytoplasmatic abundance and consequently reduced availability for vesicular export. hnRNPU-dependent miR-30c-5p export reduced cellular migration as well as pro-angiogenic gene expression in EV-recipient cells. In summary, hnRNPU retains miR-30c-5p and other miRs and thereby prevents their export into large EVs. The data presented provide a novel and functionally relevant mechanism of vesicular miR export.

Efficacy of Sulfuryl Fluoride Against Fourth-Instar Pecan Weevil (Coleoptera: Curculionidae) in Pecans for Quarantine Security

The efficacy of sulfuryl fluoride was evaluated for control of fourth-instar pecan weevil, Curculio caryae (Horn), at 25°C for a 24-h exposure. Larvae, collected as they naturally emerged from pecans, were used to artificially infest pecan nuts. Infested nuts were fumigated with six concentration by time (CT) treatment dosages of sulfuryl fluoride (0-750 g-h/m3) within air-tight, glass containers. The sulfuryl fluoride concentration in each fumigation container was analyzed 30 min after sulfuryl fluoride introduction and just prior to termination of the experiment. Mean sulfuryl fluoride CT dosages were calculated from sulfuryl fluoride measurements and were used for probit analysis. The lethal accumulated dosage (LAD99) of sulfuryl fluoride for pecan weevil was 1052.0 g-h/m3 with a 95% C.I. of 683.21-2,573.0 g-h/m3. For the confirmatory trial, we used two sulfuryl fluoride CT dosage treatments, 1,100 and 1,300 g-h/m3, and a nonfumigated control. All larvae were dead in both fumigation treatments by 14-d postfumigation. Due to higher mortality in the nonfumigated control in the confirmatory trial compared to that of the dose-response trial, 1300 g-h/m3 was selected as the sulfuryl fluoride CT dosage for a proposed quarantine treatment schedule. Fumigating pecans with sulfuryl fluoride can control larval pecan weevil infestations in commercially traded nuts and maintain compliance with quarantine regulations both within and outside the United States.

Economic thoughts on COVID‐19 for Canadian food processors

In this paper, I explore the potential effects of the COVID‐19 pandemic on Canadian food processors. First, COVID‐19 may have an impact on food processing economic activities because of supply and demand shocks. Second, the impact of COVID‐19 on food processing may depend on the type of products and the size of the processors. The effects of measures taken by the government to flatten the epidemiological curve on the economic activities of the food processing sector are uncertain.

The CzcCBA Efflux System Requires the CadA P-Type ATPase for Timely Expression Upon Zinc Excess in Pseudomonas aeruginosa

Zinc (Zn) is a trace element essential for life but can be toxic if present in excess. While cells have import systems to guarantee a vital Zn intracellular concentration, they also rely on export systems to avoid lethal Zn overload. In particular, the opportunistic pathogen Pseudomonas aeruginosa possesses four Zn export systems: CadA, CzcCBA, CzcD, and YiiP. In this work, we compare the importance for bacterial survival of each export system at high Zn concentrations. We show that the P-type ATPase CadA, and the efflux pump CzcCBA are the main efflux systems affecting the bacterium tolerance to Zn. In addition, cadA and czcCBA genes expression kinetics revealed a hierarchical organization and interdependence. In the presence of high Zn concentrations, cadA expression is very rapidly induced (<1 min), while czcCBA expression occurs subsequently (>15 min). Our present data show that the fast responsiveness of cadA to Zn excess is due to its transcriptional activator, CadR, which is constitutively present on its promoter and promptly activating cadA gene expression upon Zn binding. Moreover, we showed that CadA is essential for a timely induction of the CzcCBA efflux system. Finally, we observed an induction of cadA and czcCBA efflux systems upon phagocytosis of P. aeruginosa by macrophages, in which a toxic metal boost is discharged into the phagolysosome to intoxicate microbes. Importantly, we demonstrated that the regulatory link between induction of the CzcCBA system and the repression of the OprD porin responsible for carbapenem antibiotic resistance, is maintained in the macrophage environment.

Critical Role of Zur and SmtB in Zinc Homeostasis of Mycobacterium smegmatis

Zinc homeostasis is crucial for bacterial cells, since imbalances affect viability. However, in mycobacteria, knowledge of zinc metabolism is incomplete. Mycobacterium smegmatis (MSMEG) is an environmental, nonpathogenic Mycobacterium that is widely used as a model organism to study mycobacterial metabolism and pathogenicity. How MSMEG maintains zinc homeostasis is largely unknown. SmtB and Zur are important regulators of bacterial zinc metabolism. In mycobacteria, these regulators are encoded by an operon, whereas in other bacterial species, SmtB and Zur are encoded on separate loci. Here, we show that the smtB-zur operon is consistently present within the genus Mycobacterium but otherwise found only in Nocardia, Saccharothrix, and Corynebacterium diphtheriae By RNA deep sequencing, we determined the Zur and SmtB regulons of MSMEG and compared them with transcriptional responses after zinc starvation or excess. We found an exceptional genomic clustering of genes whose expression was strongly induced by zur deletion and zinc starvation. These genes encoded zinc importers such as ZnuABC and three additional putative zinc transporters, including the porin MspD, as well as alternative ribosomal proteins. In contrast, only a few genes were affected by deletion of smtB and zinc excess. The zinc exporter ZitA was most prominently regulated by SmtB. Moreover, transcriptional analyses in combination with promoter and chromatin immunoprecipitation assays revealed a special regulation of the smtB-zur operon itself: an apparently zinc-independent, constitutive expression of smtB-zur resulted from sensitive coregulation by both SmtB and Zur. Overall, our data revealed yet unknown peculiarities of mycobacterial zinc homeostasis.IMPORTANCE Zinc is crucial for many biological processes, as it is an essential cofactor of enzymes and a structural component of regulatory and DNA binding proteins. Hence, all living cells require zinc to maintain constant intracellular levels. However, in excess, zinc is toxic. Therefore, cellular zinc homeostasis needs to be tightly controlled. In bacteria, this is achieved by transcriptional regulators whose activity is mediated via zinc-dependent conformational changes promoting or preventing their binding to DNA. SmtB and Zur are important antagonistically acting bacterial regulators in mycobacteria. They sense changes in zinc concentrations in the femtomolar range and regulate transcription of genes for zinc acquisition, storage, and export. Here, we analyzed the role of SmtB and Zur in zinc homeostasis in Mycobacterium smegmatis Our results revealed novel insights into the transcriptional processes of zinc homeostasis in mycobacteria and their regulation.

NXF1 and CRM1 nuclear export pathways orchestrate nuclear export, translation and packaging of murine leukaemia retrovirus unspliced RNA

Cellular mRNAs are exported from the nucleus as fully spliced RNAs. Proofreading mechanisms eliminate unprocessed and irregular pre-mRNAs to control the quality of gene expression. Retroviruses need to export partially spliced and unspliced full-length RNAs to the cytoplasm where they serve as templates for protein synthesis and/or as encapsidated RNA in progeny viruses. Genetically complex retroviruses such as HIV-1 use Rev-equivalent proteins to export intron-retaining RNA from the nucleus using the cellular CRM1-driven nuclear export machinery. By contrast, genetically simpler retroviruses such as murine leukaemia virus (MLV) recruit the NXF1 RNA export machinery. In this study, we reveal for the first time that MLV hijacks both NXF1 and CRM1-dependent pathways to achieve optimal replication capacity. The CRM1-pathway marks the MLV full-length RNA (FL RNA) for packaging, while NXF1-driven nuclear export is coupled to translation. Thus, the cytoplasmic function of the viral RNA is determined early in the nucleus. Depending on the nature of ribonucleoprotein complex formed on FL RNA cargo in the nucleus, the FL RNA will be addressed to the translation machinery sites or to the virus-assembly sites at the plasma membrane.

The Cellular Location of Rad23, a Polyubiquitin Chain-Binding Protein, Plays a Key Role in Its Interaction with Substrates of the Proteasome

Well-studied structural motifs in Rad23 have been shown to bind polyubiquitin chains and the proteasome. These domains are predicted to enable Rad23 to transport polyubiquitylated (polyUb) substrates to the proteasome (Chen and Madura, 2002 [1]). The validation of this model, however, has been hindered by the lack of specific physiological substrates of Rad23. We report here that Rad23 can bind Ho-endonuclease (Ho-endo), a nuclear protein that initiates mating-type switching in Saccharomyces cerevisiae. We observed that the degradation of Ho-endo required export from the nucleus, in agreement with a previous report (Kaplun et al., 2003 [2]), and suggests that Rad23 can traffic proteins out of the nucleus. In agreement, the subcellular distribution of Rad23 is noticeably altered in genetic mutants that disrupt nucleocytoplasmic trafficking. Significantly, the location of Rad23 affected its binding to polyUb substrates. Mutations in nuclear export stabilized substrates, and caused accumulation in the nucleus. Importantly, Rad23 also accumulated in the nucleus in an export mutant, and bound to higher levels of polyUb proteins. In contrast, Rad23 is localized in the cytosol in rna1-1, a nucleocytoplasmic transport mutant, and it forms reduced binding to polyUb substrates. These and other studies indicate that substrates that are conjugated to polyubiquitin chains in the nucleus may rely on an export-dependent mechanism to be degraded by the proteasome. The evolutionary conservation of Rad23 and similar substrate-trafficking proteins predicts an important role for export in the turnover of nuclear proteins.

A robust fractionation method for protein subcellular localization studies in Escherichia coli

Fractionation in Gram-negative bacteria is used to identify the subcellular localization of proteins, in particular the localization of exported recombinant proteins. The process of cell fractionation can be fraught with cross-contamination issues and often lacks supporting data for fraction purity. Here, we compare three periplasm extraction and two cell disruption techniques in different combinations to investigate which process gives uncontaminated compartments from Escherichia coli. From these data, a robust method named PureFrac was compiled that gives pure periplasmic fractions and a superior recovery of soluble cytoplasmic proteins. The process extracts periplasm using cold osmotic shock with magnesium, prior to sonication and ultracentrifugation to separate the cytoplasm from insoluble material. This method handles cells cultivated in various conditions and allows preparation of active proteins in their respective compartments.

Quantification of ractopamine residues on and in beef digestive tract tissues

Ractopamine hydrochloride is a commercial beta-adrenergic agonist commonly used as a dietary supplement in cattle production for improved feed efficiency and growth promotion. Currently, regulatory target tissues (as approved in the New Animal Drug Application with Food and Drug Administration) for ractopamine residue testing are muscle and liver. However, other tissues have recently been subjected to testing in some export markets for U.S. beef, a clear disregard for scientific maximum residue limits associated with specific tissues. The overall goal of this study was to develop and validate an LC-MS/MS assay to determine whether detectable and quantifiable levels of ractopamine in digestive tract-derived edible offal items (i.e., abomasum, omasum, small intestine, and reticulum) of cattle resulted from tissue residues or residual ingesta contamination of exposed surfaces of tissues (rinsates). Tissue samples and corresponding rinsates from 10 animals were analyzed for parent and total ractopamine (tissue samples only). The lower limit of quantitation was between 0.03 and 0.66 ppb depending on the tissue type, and all tissue and rinsate samples tested had quantifiable concentrations of ractopamine. The highest concentrations of tissue-specific ractopamine metabolism (represented by higher total vs. parent ractopamine levels) were observed in liver and small intestine. Contamination from residual ingesta (represented by detectable ractopamine in rinsate samples) was only detected in small intestine, with a measured mean concentration of 19.72 ppb (±12.24 ppb). Taken together, these results underscore the importance of the production process and suggest that improvements may be needed to reduce the likelihood of contamination from residual ractopamine in digestive tract-derived edible offal tissues for market.

Mitochondrial Trafficking and Processing of Telomerase RNA TERC

Mitochondrial dysfunctions play major roles in many diseases. However, how mitochondrial stresses are relayed to downstream responses remains unclear. Here we show that the RNA component of mammalian telomerase TERC is imported into mitochondria, processed to a shorter form TERC-53, and then exported back to the cytosol. We found that the import is regulated by PNPASE, and the processing is controlled by mitochondrion-localized RNASET2. Cytosolic TERC-53 levels respond to changes in mitochondrial functions but have no direct effect on these functions. These findings uncover a mitochondrial RNA trafficking pathway and provide a potential mechanism for mitochondria to relay their functional states to other cellular compartments.

The L1 stalk is required for efficient export of nascent large ribosomal subunits in yeast

The ribosomal protein Rpl1 (uL1 in universal nomenclature) is essential in yeast and constitutes part of the L1 stalk which interacts with E site ligands on the ribosome. Structural studies of nascent pre-60S complexes in yeast have shown that a domain of the Crm1-dependent nuclear export adapter Nmd3, binds in the E site and interacts with Rpl1, inducing closure of the L1 stalk. Based on this observation, we decided to reinvestigate the role of the L1 stalk in nuclear export of pre-60S subunits despite previous work showing that Rpl1-deficient ribosomes are exported from the nucleus and engage in translation. Large cargoes, such as ribosomal subunits, require multiple export factors to facilitate their transport through the nuclear pore complex. Here, we show that pre-60S subunits lacking Rpl1 or truncated for the RNA of the L1 stalk are exported inefficiently. Surprisingly, this is not due to a measurable defect in the recruitment of Nmd3 but appears to result from inefficient recruitment of the Mex67-Mtr2 heterodimer.

Sequestration of macroalgal carbon: the elephant in the Blue Carbon room

Macroalgae form the most extensive and productive benthic marine vegetated habitats globally but their inclusion in Blue Carbon (BC) strategies remains controversial. We review the arguments offered to reject or include macroalgae in the BC framework, and identify the challenges that have precluded macroalgae from being incorporated so far. Evidence that macroalgae support significant carbon burial is compelling. The carbon they supply to sediment stocks in angiosperm BC habitats is already included in current assessments, so that macroalgae are de facto recognized as important donors of BC. The key challenges are (i) documenting macroalgal carbon sequestered beyond BC habitat, (ii) tracing it back to source habitats, and (iii) showing that management actions at the habitat lead to increased sequestration at the sink site. These challenges apply equally to carbon exported from BC coastal habitats. Because of the large carbon sink they support, incorporation of macroalgae into BC accounting and actions is an imperative. This requires a paradigm shift in accounting procedures as well as developing methods to enable the capacity to trace carbon from donor to sink habitats in the ocean.

[Analysis of characteristics and problems of international trade of wolfberry in China]

Wolfberry has important unique medical values as well as edible and commerce values. In this paper,we analyze the characteristics and problems of international trade of wolfberry based on the customs data between 2008 and 2017. During periods of these ten years,the wolfberry was mainly exported with a small proportions of imports. The total export volume increased steadily,reached 82 182. 08 tons and 696. 622 million dollars respectively. Wolfberry came from 31 provinces/autonomous regions and exported to 105 countries and regions through 21 ports. Most of the total exports of wolfberry flew to markets of Asia and Europe,the Ningxia autonomous region was the major export province. Large amount of wolfberry exported through Tianjin port. Compared with the export volume,the import is almost negligible,mainly coming from North Korea,almost all through Changchun port,Jilin province to enter the domestic market. There is a situation of"import of domestic goods". To enhance the international competitiveness of wolf berry industry,we must rely on the fundamental research of wolfberry,speed up the standardization process,strengthen the scientific and technological innovation in wolfberry products,improve the added value and profit of wolfberry.

Structural and Functional Variation in Outer Membrane Polysaccharide Export (OPX) Proteins from the Two Major Capsule Assembly Pathways Present in Escherichia coli

Capsular polysaccharides (CPSs) are virulence factors for many important pathogens. In Escherichia coli, CPSs are synthesized via two distinct pathways, but both require proteins from the outer membrane polysaccharide export (OPX) family to complete CPS export from the periplasm to the cell surface. In this study, we compare the properties of the OPX proteins from the prototypical group 1 (Wzy-dependent) and group 2 (ABC transporter-dependent) pathways in E. coli K30 (Wza) and E. coli K2 (KpsD), respectively. In addition, we compare an OPX from Salmonella enterica serovar Typhi (VexA), which shares structural properties with Wza, while operating in an ABC transporter-dependent pathway. These proteins differ in distribution in the cell envelope and formation of stable multimers, but these properties do not align with acylation or the interfacing biosynthetic pathway. In E. coli K2, murein lipoprotein (Lpp) plays a role in peptidoglycan association of KpsD, and loss of this interaction correlates with impaired group 2 capsule production. VexA also depends on Lpp for peptidoglycan association, but CPS production is unaffected in an lpp mutant. In contrast, Wza and group 1 capsule production is unaffected by the absence of Lpp. These results point to complex structure-function relationships between different OPX proteins.IMPORTANCE Capsules are protective layers of polysaccharides that surround the cell surface of many bacteria, including that of Escherichia coli isolates and Salmonella enterica serovar Typhi. Capsular polysaccharides (CPSs) are often essential for virulence because they facilitate evasion of host immune responses. The attenuation of unencapsulated mutants in animal models and the involvement of protein families with conserved features make the CPS export pathway a novel candidate for therapeutic strategies. However, appropriate "antivirulence" strategies require a fundamental understanding of the underpinning cellular processes. Investigating export proteins that are conserved across different biosynthesis strategies will give important insight into how CPS is transported to the cell surface.

Intracellular accumulation of staphylopine impairs the fitness of Staphylococcus aureus cntE mutant

Staphylococcus aureus exports staphylopine (StP), a broad-spectrum metallophore, via the CntE efflux pump. Here, the mechanism of the fitness defect in the ΔcntE mutant under metal depletion was investigated. Deletion of the StP exporter CntE results in a substantial growth defect, and disrupting the StP biosynthesis gene cntL restores growth of the ΔcntE mutant in metal-depleted media. High-resolution mass spectrometry revealed cytoplasmic accumulation of StP and the absence of extracellular StP in the ΔcntE mutant. The fitness defect of the ΔcntE mutant in mouse subcutaneous abscesses is largely due to StP accumulation. Expression of StP biosynthesis genes are upregulated in the ΔcntE mutant under metal starvation induction. In conclusion, failure to efflux StP results in intracellular StP accumulation and substantially impairs the fitness of S. aureus.

Mitochondria export iron-sulfur and sulfur intermediates to the cytoplasm for iron-sulfur cluster assembly and tRNA thiolation in yeast

Iron-sulfur clusters are essential cofactors of proteins. In eukaryotes, iron-sulfur cluster biogenesis requires a mitochondrial iron-sulfur cluster machinery (ISC) and a cytoplasmic iron-sulfur protein assembly machinery (CIA). Here we used mitochondria and cytoplasm isolated from yeast cells, and [³⁵S]cysteine to detect cytoplasmic Fe-³⁵S cluster assembly on a purified apoprotein substrate. We showed that mitochondria generate an intermediate, called (Fe-S)_int, needed for cytoplasmic iron-sulfur cluster assembly. The mitochondrial biosynthesis of (Fe-S)_int required ISC components such as Nfs1 cysteine desulfurase, Isu1/2 scaffold, and Ssq1 chaperone. Mitochondria then exported (Fe-S)_int via the Atm1 transporter in the inner membrane, and we detected (Fe-S)_int in active form. When (Fe-S)_int was added to cytoplasm, CIA utilized it for iron-sulfur cluster assembly without any further help from the mitochondria. We found that both iron and sulfur for cytoplasmic iron-sulfur cluster assembly originate from the mitochondria, revealing a surprising and novel mitochondrial role. Mitochondrial (Fe-S)_int export was most efficient in the presence of cytoplasm containing an apoprotein substrate, suggesting that mitochondria respond to the cytoplasmic demand for iron-sulfur cluster synthesis. Of note, the (Fe-S)_int is distinct from the sulfur intermediate called S_int, which is also made and exported by mitochondria but is instead used for cytoplasmic tRNA thiolation. In summary, our findings establish a direct and vital role of mitochondria in cytoplasmic iron-sulfur cluster assembly in yeast cells.

The Study of Effective Factors on Iran's Pharmaceutical Export Supply and Demand

The importance of drug as a valuable export product in the global economy becomes clearer every day. Understanding the problems of exports and factors affecting it, can be an important step to keep Iran's position in the world markets and further export development of this product. In this study, Iranian pharmaceutical exports' supply and demand functions were calculated using co-integration and error correction techniques through time series quarterly data of 2000-2014 in order to identify the factors affecting pharmaceutical exports (short run and long run relationships among the variables) and price and income elasticities. The long run price elasticity of demand of -2.28 indicates that an increase in Iran's export price relative to competitor's export price will have a negative impact on pharmaceutical export volume. Also, the long run income elasticity of foreign demand for pharmaceutical exports of Iran is 1.11. That is an increase in income of foreign countries will have a positive impact on Iran's pharmaceutical export. On the other hand, the long run price elasticity of export supply is 1.09, indicating that the supply of pharmaceutical export is sensitive to the relative price changes. In other words, an increase in export price relative to domestic price as well as an expansion of the pharmaceutical production capacity will increase its export supply. Being aware of the factors affecting the pharmaceutical exports can prepare the ground to develop the pharmaceutical industry and balance the supply and demand in the long run. Therefore, the results of this study can help Iran's policymakers and managers to choose a clearer path for the pharmaceutical trade policies.

Mechanisms of the anterograde trafficking of GPCRs: Regulation of AT1R transport by interacting proteins and motifs

Anterograde cell surface transport of nascent G protein-coupled receptors (GPCRs) en route from the endoplasmic reticulum (ER) through the Golgi apparatus represents a crucial checkpoint to control the amount of the receptors at the functional destination and the strength of receptor activation-elicited cellular responses. However, as compared with extensively studied internalization and recycling processes, the molecular mechanisms of cell surface trafficking of GPCRs are relatively less defined. Here, we will review the current advances in understanding the ER-Golgi-cell surface transport of GPCRs and use angiotensin II type 1 receptor as a representative GPCR to discuss emerging roles of receptor-interacting proteins and specific motifs embedded within the receptors in controlling the forward traffic of GPCRs along the biosynthetic pathway.

Nitrogen and phosphate metabolism in ectomycorrhizas

1047 I. Introduction 1047 II. Mobilization of soil N/P by ECM fungi 1048 III. N/P uptake 1048 IV. N/P assimilation 1049 V. N/P storage and remobilization 1049 VI. Hyphal N/P efflux at the plant-fungus interface 1052 VII. Conclusion and research needs 1054 Acknowledgements 1055 References 1055 SUMMARY: Nutrient homeostasis is essential for fungal cells and thus tightly adapted to the local demand in a mycelium with hyphal specialization. Based on selected ectomycorrhizal (ECM) fungal models, we outlined current concepts of nitrogen and phosphate nutrition and their limitations, and included knowledge from Baker's yeast when major gaps had to be filled. We covered the entire pathway from nutrient mobilization, import and local storage, distribution within the mycelium and export at the plant-fungus interface. Even when nutrient import and assimilation were broad issues for ECM fungi, we focused mainly on nitrate and organic phosphorus uptake, as other nitrogen/phosphorus (N/P) sources have been covered by recent reviews. Vacuolar N/P storage and mobilization represented another focus point of this review. Vacuoles are integrated into cellular homeostasis and central for an ECM mycelium at two locations: soil-growing hyphae and hyphae of the plant-fungus interface. Vacuoles are also involved in long-distance transport. We further discussed potential mechanisms of bidirectional long-distance nutrient transport (distances from millimetres to metres). A final focus of the review was N/P export at the plant-fungus interface, where we compared potential efflux mechanisms and pathways, and discussed their prerequisites.

Seeing Some One

This paper outlines a light approach to heavy issues of consciousness. The basic claim is that human minds are very much tailored to the requirements of action perception, that is, to what people see when they watch other people acting. I argue that the third-person perspective entailed in action perception offers an easy and more direct access to such enigmatic things as selfhood, intentionality, and agency than the first-person perspective does. In a sense, we get these things for free when we study action perception. I do not claim that the study of action perception can solve (or even dissolve) the enigmata entailed in consciousness. I do claim, however, that it sheds new light on relationships between one’s own mind and other minds.

Upstream Hedgehog signaling components are exported in exosomes of cervical cancer cell lines

AIM

To investigate export of Hedgehog pathway (Hh) proteins Patched1, Smoothened, Sonic hedgehog and Indian hedgehog in cervical cancer cell line (CaCx) exosomes.

METHODS

Exosomes were isolated and characterized by Western blotting, scanning electron microscopy and in a colorimetric assay. Nucleic acids (RNA, DNA) and protein content of exosomes were analyzed. Hh pathway proteins in exosomes were detected using Western blotting.

RESULTS

CaCx secrete bio-macromolecule (DNA, RNA and proteins) enriched exosomes. CaCx exosomes contained higher amount of RNA with respect to DNA. CaCx preferentially exported Hh proteins (Patched1, Smoothened,  Sonic hedgehog, Indian hedgehog) in their exosomes. Cellular uptake assay revealed rapid internalization of CaCx exosomes in human umbilical vein endothelial cells.

CONCLUSION

Our study showed that Hh proteins are exported in CaCx exosomes.

Subtle determinants of the nucleocytoplasmic partitioning of in vivo-transcribed RNase MRP RNA in Xenopus laevis oocytes

RNase MRP is a ribonucleoprotein originally identified on the basis of its ability to cleave RNA endonucleolytically from origins of mitochondrial DNA replication, rendering it a likely candidate for a role in priming leading-strand synthesis of mtDNA. In addition, a nuclear role for RNase MRP has been identified in yeast (Saccharomyces cerevisiae) ribosomal RNA processing. Consistent with a duality of function, RNase MRP has been localized to both mitochondria and nucleoli by in situ techniques. The RNA component of this ribonucleoprotein has been characterized from several different species. We previously cloned the gene for Xenopus laevis MRP RNA and showed that RNase MRP RNA is differentially expressed during amphibian development; in addition, the microinjected X. laevis RNase MRP RNA gene is correctly and efficiently transcribed in vivo. This article presents an analysis of the intracellular movement of in vivo-transcribed RNase MRP RNA in microinjected mature X. laevis oocytes. Although X. laevis MRP RNA is assembled into a ribonucleoprotein form and transported in an expected manner, human and mouse MRP RNAs exhibit markedly different transport patterns even though they are highly conserved in primary sequence. Furthermore, the only currently assigned protein (Th autoantigen) binding site in MRP RNA can be deleted without loss of nuclear export capacity. These results indicate that subtle determinants must exist for nucleocytoplasmic partitioning of this RNP and that the conserved Th autoantigen binding region appears unnecessary for the transit of in vivo-transcribed MRP RNA to the cytoplasm of mature X. laevis oocytes.

Monitoring and Simulating Environmental Asbestos Dispersion from a Textile Factory

Although workplace asbestos concentrations (AC) have been reported several times, the past environmental AC are relatively poorly studied. Due to the harmful effects of the asbestos industry, production has moved from early industrialized countries (Japan), to late industrialized countries (Korea), and finally to industrializing countries (Indonesia). The purpose of this study was to determine current occupational exposure levels and evaluate neighborhood environmental exposure levels in an Indonesian asbestos textile factory through collaboration among three generation of industrialized countries. Asbestos concentrations were measured inside and outside of the factory and compared with simulated data. ACs in the factory were similar to those of 1980s and 1990s levels in the Korean factory that transferred the machines. Environmental ACs were dispersed according to wind direction. There were no significant differences between monitored and simulated data, and correlation coefficients between downwind, upwind, and middle wind directions were high, with some statistical significance. This study can be used to estimate past environmental ACs to understand the causality of asbestos related diseases. Because of the small sample size and specific weather conditions, a large-scale study of various asbestos exposure sources, including asbestos cement factories, shipyards, and mines, and various atmospheric conditions is required.