The export receptor Crm1 forms a dimer to promote nuclear export of HIV RNA.

Science.gov (United States)

Booth, David S; Cheng, Yifan; Frankel, Alan D

2014-12-08

The HIV Rev protein routes viral RNAs containing the Rev Response Element (RRE) through the Crm1 nuclear export pathway to the cytoplasm where viral proteins are expressed and genomic RNA is delivered to assembling virions. The RRE assembles a Rev oligomer that displays nuclear export sequences (NESs) for recognition by the Crm1-Ran(GTP) nuclear receptor complex. Here we provide the first view of an assembled HIV-host nuclear export complex using single-particle electron microscopy. Unexpectedly, Crm1 forms a dimer with an extensive interface that enhances association with Rev-RRE and poises NES binding sites to interact with a Rev oligomer. The interface between Crm1 monomers explains differences between Crm1 orthologs that alter nuclear export and determine cellular tropism for viral replication. The arrangement of the export complex identifies a novel binding surface to possibly target an HIV inhibitor and may point to a broader role for Crm1 dimerization in regulating host gene expression.

Nuclear Export of Messenger RNA

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Jun Katahira

2015-03-01

Full Text Available Transport of messenger RNA (mRNA from the nucleus to the cytoplasm is an essential step of eukaryotic gene expression. In the cell nucleus, a precursor mRNA undergoes a series of processing steps, including capping at the 5' ends, splicing and cleavage/polyadenylation at the 3' ends. During this process, the mRNA associates with a wide variety of proteins, forming a messenger ribonucleoprotein (mRNP particle. Association with factors involved in nuclear export also occurs during transcription and processing, and thus nuclear export is fully integrated into mRNA maturation. The coupling between mRNA maturation and nuclear export is an important mechanism for providing only fully functional and competent mRNA to the cytoplasmic translational machinery, thereby ensuring accuracy and swiftness of gene expression. This review describes the molecular mechanism of nuclear mRNA export mediated by the principal transport factors, including Tap-p15 and the TREX complex.

Nuclear Export of Messenger RNA

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Katahira, Jun

2015-01-01

Transport of messenger RNA (mRNA) from the nucleus to the cytoplasm is an essential step of eukaryotic gene expression. In the cell nucleus, a precursor mRNA undergoes a series of processing steps, including capping at the 5' ends, splicing and cleavage/polyadenylation at the 3' ends. During this process, the mRNA associates with a wide variety of proteins, forming a messenger ribonucleoprotein (mRNP) particle. Association with factors involved in nuclear export also occurs during transcription and processing, and thus nuclear export is fully integrated into mRNA maturation. The coupling between mRNA maturation and nuclear export is an important mechanism for providing only fully functional and competent mRNA to the cytoplasmic translational machinery, thereby ensuring accuracy and swiftness of gene expression. This review describes the molecular mechanism of nuclear mRNA export mediated by the principal transport factors, including Tap-p15 and the TREX complex. PMID:25836925

Optimizing the protein switch: altering nuclear import and export signals, and ligand binding domain

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Kakar, Mudit; Davis, James R.; Kern, Steve E.; Lim, Carol S.

2007-01-01

Ligand regulated localization controllable protein constructs were optimized in this study. Several constructs were made from a classical nuclear export signal (HIV-rev, MAPKK, or progesterone receptor) in combination with a SV40 T-antigen type nuclear import signal. Different ligand binding domains (LBDs from glucocorticoid receptor or progesterone receptor) were also tested for their ability to impart control over localization of proteins. This study was designed to create constructs which are cytoplasmic in the absence of ligand and nuclear in the presence of ligand, and also to regulate the amount of protein translocating to the nucleus on ligand induction. The balance between the strengths of import and export signals was critical for overall localization of proteins. The amount of protein entering the nucleus was also affected by the dose of ligand (10-100nM). However, the overall import characteristics were determined by the strengths of localization signals and the inherent localization properties of the LBD used. This study established that the amount of protein present in a particular compartment can be regulated by the use of localization signals of various strengths. These optimized localization controllable protein constructs can be used to correct for diseases due to aberrant localization of proteins. PMID:17574289

Identification of a functional, CRM-1-dependent nuclear export signal in hepatitis C virus core protein.

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Andrea Cerutti

Full Text Available Hepatitis C virus (HCV infection is a major cause of chronic liver disease worldwide. HCV core protein is involved in nucleocapsid formation, but it also interacts with multiple cytoplasmic and nuclear molecules and plays a crucial role in the development of liver disease and hepatocarcinogenesis. The core protein is found mostly in the cytoplasm during HCV infection, but also in the nucleus in patients with hepatocarcinoma and in core-transgenic mice. HCV core contains nuclear localization signals (NLS, but no nuclear export signal (NES has yet been identified.We show here that the aa(109-133 region directs the translocation of core from the nucleus to the cytoplasm by the CRM-1-mediated nuclear export pathway. Mutagenesis of the three hydrophobic residues (L119, I123 and L126 in the identified NES or in the sequence encoding the mature core aa(1-173 significantly enhanced the nuclear localisation of the corresponding proteins in transfected Huh7 cells. Both the NES and the adjacent hydrophobic sequence in domain II of core were required to maintain the core protein or its fragments in the cytoplasmic compartment. Electron microscopy studies of the JFH1 replication model demonstrated that core was translocated into the nucleus a few minutes after the virus entered the cell. The blockade of nucleocytoplasmic export by leptomycin B treatment early in infection led to the detection of core protein in the nucleus by confocal microscopy and coincided with a decrease in virus replication.Our data suggest that the functional NLS and NES direct HCV core protein shuttling between the cytoplasmic and nuclear compartments, with at least some core protein transported to the nucleus. These new properties of HCV core may be essential for virus multiplication and interaction with nuclear molecules, influence cell signaling and the pathogenesis of HCV infection.

Identification of a functional, CRM-1-dependent nuclear export signal in hepatitis C virus core protein.

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Cerutti, Andrea; Maillard, Patrick; Minisini, Rosalba; Vidalain, Pierre-Olivier; Roohvand, Farzin; Pecheur, Eve-Isabelle; Pirisi, Mario; Budkowska, Agata

2011-01-01

Hepatitis C virus (HCV) infection is a major cause of chronic liver disease worldwide. HCV core protein is involved in nucleocapsid formation, but it also interacts with multiple cytoplasmic and nuclear molecules and plays a crucial role in the development of liver disease and hepatocarcinogenesis. The core protein is found mostly in the cytoplasm during HCV infection, but also in the nucleus in patients with hepatocarcinoma and in core-transgenic mice. HCV core contains nuclear localization signals (NLS), but no nuclear export signal (NES) has yet been identified.We show here that the aa(109-133) region directs the translocation of core from the nucleus to the cytoplasm by the CRM-1-mediated nuclear export pathway. Mutagenesis of the three hydrophobic residues (L119, I123 and L126) in the identified NES or in the sequence encoding the mature core aa(1-173) significantly enhanced the nuclear localisation of the corresponding proteins in transfected Huh7 cells. Both the NES and the adjacent hydrophobic sequence in domain II of core were required to maintain the core protein or its fragments in the cytoplasmic compartment. Electron microscopy studies of the JFH1 replication model demonstrated that core was translocated into the nucleus a few minutes after the virus entered the cell. The blockade of nucleocytoplasmic export by leptomycin B treatment early in infection led to the detection of core protein in the nucleus by confocal microscopy and coincided with a decrease in virus replication.Our data suggest that the functional NLS and NES direct HCV core protein shuttling between the cytoplasmic and nuclear compartments, with at least some core protein transported to the nucleus. These new properties of HCV core may be essential for virus multiplication and interaction with nuclear molecules, influence cell signaling and the pathogenesis of HCV infection.

Nuclear Imprisonment: Viral Strategies to Arrest Host mRNA Nuclear Export

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Beatriz M. A. Fontoura

2013-07-01

Full Text Available Viruses possess many strategies to impair host cellular responses to infection. Nuclear export of host messenger RNAs (mRNA that encode antiviral factors is critical for antiviral protein production and control of viral infections. Several viruses have evolved sophisticated strategies to inhibit nuclear export of host mRNAs, including targeting mRNA export factors and nucleoporins to compromise their roles in nucleo-cytoplasmic trafficking of cellular mRNA. Here, we present a review of research focused on suppression of host mRNA nuclear export by viruses, including influenza A virus and vesicular stomatitis virus, and the impact of this viral suppression on host antiviral responses.

Nuclear Imprisonment: Viral Strategies to Arrest Host mRNA Nuclear Export

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Kuss, Sharon K.; Mata, Miguel A.; Zhang, Liang; Fontoura, Beatriz M. A.

2013-01-01

Viruses possess many strategies to impair host cellular responses to infection. Nuclear export of host messenger RNAs (mRNA) that encode antiviral factors is critical for antiviral protein production and control of viral infections. Several viruses have evolved sophisticated strategies to inhibit nuclear export of host mRNAs, including targeting mRNA export factors and nucleoporins to compromise their roles in nucleo-cytoplasmic trafficking of cellular mRNA. Here, we present a review of research focused on suppression of host mRNA nuclear export by viruses, including influenza A virus and vesicular stomatitis virus, and the impact of this viral suppression on host antiviral responses. PMID:23872491

eEF1A Mediates the Nuclear Export of SNAG-Containing Proteins via the Exportin5-Aminoacyl-tRNA Complex

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José Manuel Mingot

2013-11-01

Full Text Available Exportin5 mediates the nuclear export of double-stranded RNAs, including pre-microRNAs, adenoviral RNAs, and tRNAs. When tRNAs are aminoacylated, the Exportin5-aminoacyl (aa-tRNA complex recruits and coexports the translation elongation factor eEF1A. Here, we show that eEF1A binds to Snail transcription factors when bound to their main target, the E-cadherin promoter, facilitating their export to the cytoplasm in association with the aa-tRNA-Exportin5 complex. Snail binds to eEF1A through the SNAG domain, a protein nuclear export signal present in several transcription factor families, and this binding is regulated by phosphorylation. Thus, we describe a nuclear role for eEF1A and provide a mechanism for protein nuclear export that attenuates the activity of SNAG-containing transcription factors.

Nuclear export and import of human hepatitis B virus capsid protein and particles.

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Hung-Cheng Li

Full Text Available It remains unclear what determines the subcellular localization of hepatitis B virus (HBV core protein (HBc and particles. To address this fundamental issue, we have identified four distinct HBc localization signals in the arginine rich domain (ARD of HBc, using immunofluorescence confocal microscopy and fractionation/Western blot analysis. ARD consists of four tight clustering arginine-rich subdomains. ARD-I and ARD-III are associated with two co-dependent nuclear localization signals (NLS, while ARD-II and ARD-IV behave like two independent nuclear export signals (NES. This conclusion is based on five independent lines of experimental evidence: i Using an HBV replication system in hepatoma cells, we demonstrated in a double-blind manner that only the HBc of mutant ARD-II+IV, among a total of 15 ARD mutants, can predominantly localize to the nucleus. ii These results were confirmed using a chimera reporter system by placing mutant or wild type HBc trafficking signals in the heterologous context of SV40 large T antigen (LT. iii By a heterokaryon or homokaryon analysis, the fusion protein of SV40 LT-HBc ARD appeared to transport from nuclei of transfected donor cells to nuclei of recipient cells, suggesting the existence of an NES in HBc ARD. This putative NES is leptomycin B resistant. iv We demonstrated by co-immunoprecipitation that HBc ARD can physically interact with a cellular factor TAP/NXF1 (Tip-associated protein/nuclear export factor-1, which is known to be important for nuclear export of mRNA and proteins. Treatment with a TAP-specific siRNA strikingly shifted cytoplasmic HBc to nucleus, and led to a near 7-fold reduction of viral replication, and a near 10-fold reduction in HBsAg secretion. v HBc of mutant ARD-II+IV was accumulated predominantly in the nucleus in a mouse model by hydrodynamic delivery. In addition to the revised map of NLS, our results suggest that HBc could shuttle rapidly between nucleus and cytoplasm via a novel

Regulation of RNA-binding proteins affinity to export receptors enables the nuclear basket proteins to distinguish and retain aberrant mRNAs.

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Soheilypour, M; Mofrad, M R K

2016-11-02

Export of messenger ribonucleic acids (mRNAs) into the cytoplasm is a fundamental step in gene regulation processes, which is meticulously quality controlled by highly efficient mechanisms in eukaryotic cells. Yet, it remains unclear how the aberrant mRNAs are recognized and retained inside the nucleus. Using a new modelling approach for complex systems, namely the agent-based modelling (ABM) approach, we develop a minimal model of the mRNA quality control (QC) mechanism. Our results demonstrate that regulation of the affinity of RNA-binding proteins (RBPs) to export receptors along with the weak interaction between the nuclear basket protein (Mlp1 or Tpr) and RBPs are the minimum requirements to distinguish and retain aberrant mRNAs. Our results show that the affinity between Tpr and RBPs is optimized to maximize the retention of aberrant mRNAs. In addition, we demonstrate how the length of mRNA affects the QC process. Since longer mRNAs spend more time in the nuclear basket to form a compact conformation and initiate their export, nuclear basket proteins could more easily capture and retain them inside the nucleus.

Inhibition of CRM1-mediated nuclear export of transcription factors by leukemogenic NUP98 fusion proteins.

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Takeda, Akiko; Sarma, Nayan J; Abdul-Nabi, Anmaar M; Yaseen, Nabeel R

2010-05-21

NUP98 is a nucleoporin that plays complex roles in the nucleocytoplasmic trafficking of macromolecules. Rearrangements of the NUP98 gene in human leukemia result in the expression of numerous fusion oncoproteins whose effect on nucleocytoplasmic trafficking is poorly understood. The present study was undertaken to determine the effects of leukemogenic NUP98 fusion proteins on CRM1-mediated nuclear export. NUP98-HOXA9, a prototypic NUP98 fusion, inhibited the nuclear export of two known CRM1 substrates: mutated cytoplasmic nucleophosmin and HIV-1 Rev. In vitro binding assays revealed that NUP98-HOXA9 binds CRM1 through the FG repeat motif in a Ran-GTP-dependent manner similar to but stronger than the interaction between CRM1 and its export substrates. Two NUP98 fusions, NUP98-HOXA9 and NUP98-DDX10, whose fusion partners are structurally and functionally unrelated, interacted with endogenous CRM1 in myeloid cells as shown by co-immunoprecipitation. These leukemogenic NUP98 fusion proteins interacted with CRM1, Ran, and the nucleoporin NUP214 in a manner fundamentally different from that of wild-type NUP98. NUP98-HOXA9 and NUP98-DDX10 formed characteristic aggregates within the nuclei of a myeloid cell line and primary human CD34+ cells and caused aberrant localization of CRM1 to these aggregates. These NUP98 fusions caused nuclear accumulation of two transcription factors, NFAT and NFkappaB, that are regulated by CRM1-mediated export. The nuclear entrapment of NFAT and NFkappaB correlated with enhanced transcription from promoters responsive to these transcription factors. Taken together, the results suggest a new mechanism by which NUP98 fusions dysregulate transcription and cause leukemia, namely, inhibition of CRM1-mediated nuclear export with aberrant nuclear retention of transcriptional regulators.

Characterization of a nuclear export signal within the human T cell leukemia virus type I transactivator protein Tax.

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Alefantis, Timothy; Barmak, Kate; Harhaj, Edward W; Grant, Christian; Wigdahl, Brian

2003-06-13

Human T cell leukemia virus type I (HTLV-I) is the etiologic agent of adult T cell leukemia and HTLV-I-associated myelopathy/tropical spastic paraparesis. The HTLV-I transactivator protein Tax plays an integral role in the etiology of adult T cell leukemia, as expression of Tax in T lymphocytes has been shown to result in immortalization. In addition, Tax is known to interface with numerous transcription factor families, including activating transcription factor/cAMP response element-binding protein and nuclear factor-kappaB, requiring Tax to localize to both the nucleus and cytoplasm. In this report, the nucleocytoplasmic localization of Tax was examined in Jurkat, HeLa, and U-87 MG cells. The results reported herein indicate that Tax contains a leucine-rich nuclear export signal (NES) that, when fused to green fluorescent protein (GFP), can direct nuclear export via the CRM-1 pathway, as determined by leptomycin B inhibition of nuclear export. However, cytoplasmic localization of full-length Tax was not altered by treatment with leptomycin B, suggesting that native Tax utilizes another nuclear export pathway. Additional support for the presence of a functional NES has also been shown because the NES mutant Tax(L200A)-GFP localized to the nuclear membrane in the majority of U-87 MG cells. Evidence has also been provided suggesting that the Tax NES likely exists as a conditionally masked signal because the truncation mutant TaxDelta214-GFP localized constitutively to the cytoplasm. These results suggest that Tax localization may be directed by specific changes in Tax conformation or by specific interactions with cellular proteins leading to changes in the availability of the Tax NES and nuclear localization signal.

Efficient nuclear export of p65-IkappaBalpha complexes requires 14-3-3 proteins.

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Aguilera, Cristina; Fernández-Majada, Vanessa; Inglés-Esteve, Julia; Rodilla, Verónica; Bigas, Anna; Espinosa, Lluís

2006-09-01

IkappaB are responsible for maintaining p65 in the cytoplasm under non-stimulating conditions and promoting the active export of p65 from the nucleus following NFkappaB activation to terminate the signal. We now show that 14-3-3 proteins regulate the NFkappaB signaling pathway by physically interacting with p65 and IkappaBalpha proteins. We identify two functional 14-3-3 binding domains in the p65 protein involving residues 38-44 and 278-283, and map the interaction region of IkappaBalpha in residues 60-65. Mutation of these 14-3-3 binding domains in p65 or IkappaBalpha results in a predominantly nuclear distribution of both proteins. TNFalpha treatment promotes recruitment of 14-3-3 and IkappaBalpha to NFkappaB-dependent promoters and enhances the binding of 14-3-3 to p65. Disrupting 14-3-3 activity by transfection with a dominant-negative 14-3-3 leads to the accumulation of nuclear p65-IkappaBalpha complexes and the constitutive association of p65 with the chromatin. In this situation, NFkappaB-dependent genes become unresponsive to TNFalpha stimulation. Together our results indicate that 14-3-3 proteins facilitate the nuclear export of IkappaBalpha-p65 complexes and are required for the appropriate regulation of NFkappaB signaling.

Influenza A Virus NS1 Protein Promotes Efficient Nuclear Export of Unspliced Viral M1 mRNA.

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Pereira, Carina F; Read, Eliot K C; Wise, Helen M; Amorim, Maria J; Digard, Paul

2017-08-01

Influenza A virus mRNAs are transcribed by the viral RNA-dependent RNA polymerase in the cell nucleus before being exported to the cytoplasm for translation. Segment 7 produces two major transcripts: an unspliced mRNA that encodes the M1 matrix protein and a spliced transcript that encodes the M2 ion channel. Export of both mRNAs is dependent on the cellular NXF1/TAP pathway, but it is unclear how they are recruited to the export machinery or how the intron-containing but unspliced M1 mRNA bypasses the normal quality-control checkpoints. Using fluorescent in situ hybridization to monitor segment 7 mRNA localization, we found that cytoplasmic accumulation of unspliced M1 mRNA was inefficient in the absence of NS1, both in the context of segment 7 RNPs reconstituted by plasmid transfection and in mutant virus-infected cells. This effect was independent of any major effect on steady-state levels of segment 7 mRNA or splicing but corresponded to a ∼5-fold reduction in the accumulation of M1. A similar defect in intronless hemagglutinin (HA) mRNA nuclear export was seen with an NS1 mutant virus. Efficient export of M1 mRNA required both an intact NS1 RNA-binding domain and effector domain. Furthermore, while wild-type NS1 interacted with cellular NXF1 and also increased the interaction of segment 7 mRNA with NXF1, mutant NS1 polypeptides unable to promote mRNA export did neither. Thus, we propose that NS1 facilitates late viral gene expression by acting as an adaptor between viral mRNAs and the cellular nuclear export machinery to promote their nuclear export. IMPORTANCE Influenza A virus is a major pathogen of a wide variety of mammalian and avian species that threatens public health and food security. A fuller understanding of the virus life cycle is important to aid control strategies. The virus has a small genome that encodes relatively few proteins that are often multifunctional. Here, we characterize a new function for the NS1 protein, showing that, as well as

Mechanism for G2 phase-specific nuclear export of the kinetochore protein CENP-F.

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Loftus, Kyle M; Cui, Heying; Coutavas, Elias; King, David S; Ceravolo, Amanda; Pereiras, Dylan; Solmaz, Sozanne R

2017-08-03

Centromere protein F (CENP-F) is a component of the kinetochore and a regulator of cell cycle progression. CENP-F recruits the dynein transport machinery and orchestrates several cell cycle-specific transport events, including transport of the nucleus, mitochondria and chromosomes. A key regulatory step for several of these functions is likely the G2 phase-specific export of CENP-F from the nucleus to the cytosol, where the cytoplasmic dynein transport machinery resides; however, the molecular mechanism of this process is elusive. Here, we have identified 3 phosphorylation sites within the bipartite classical nuclear localization signal (cNLS) of CENP-F. These sites are specific for cyclin-dependent kinase 1 (Cdk1), which is active in G2 phase. Phosphomimetic mutations of these residues strongly diminish the interaction of the CENP-F cNLS with its nuclear transport receptor karyopherin α. These mutations also diminish nuclear localization of the CENP-F cNLS in cells. Notably, the cNLS is phosphorylated in the -1 position, which is important to orient the adjacent major motif for binding into its pocket on karyopherin α. We propose that localization of CENP-F is regulated by a cNLS, and a nuclear export pathway, resulting in nuclear localization during most of interphase. In G2 phase, the cNLS is weakened by phosphorylation through Cdk1, likely resulting in nuclear export of CENP-F via the still active nuclear export pathway. Once CENP-F resides in the cytosol, it can engage in pathways that are important for cell cycle progression, kinetochore assembly and the faithful segregation of chromosomes into daughter cells.

Nuclear export of human hepatitis B virus core protein and pregenomic RNA depends on the cellular NXF1-p15 machinery.

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Yang, Ching-Chun; Huang, Er-Yi; Li, Hung-Cheng; Su, Pei-Yi; Shih, Chiaho

2014-01-01

Hepatitis B virus (HBV) core protein (HBc) can shuttle between nucleus and cytoplasm. Cytoplasm-predominant HBc is clinically associated with severe liver inflammation. Previously, we found that HBc arginine-rich domain (ARD) can associate with a host factor NXF1 (TAP) by coimmunoprecipitation. It is well known that NXF1-p15 heterodimer can serve as a major export receptor of nuclear mRNA as a ribonucleoprotein complex (RNP). In the NXF1-p15 pathway, TREX (transcription/export) complex plays an important role in coupling nuclear pre-mRNA processing with mRNA export in mammalian cells. Here, we tested the hypothesis whether HBc and HBV specific RNA can be exported via the TREX and NXF1-p15 mediated pathway. We demonstrated here that HBc can physically and specifically associate with TREX components, and the NXF1-p15 export receptor by coimmunoprecipitation. Accumulation of HBc protein in the nucleus can be induced by the interference with TREX and NXF1-p15 mediated RNA export machinery. HBV transcripts encodes a non-spliced 3.5 kb pregenomic RNA (pgRNA) which can serve as a template for reverse transcription. Cytoplasmic HBV pgRNA appeared to be reduced by siRNA treatment specific for the NXF1-p15 complex by quantitative RT-qPCR and Northern blot analyses. This result suggests that the pgRNA was also exported via the NXF1-p15 machinery. We entertain the hypothesis that HBc protein can be exported as an RNP cargo via the mRNA export pathway by hijacking the TREX and NXF1-p15 complex. In our current and previous studies, HBc is not required for pgRNA accumulation in the cytoplasm. Furthermore, HBc ARD can mediate nuclear export of a chimeric protein containing HBc ARD in a pgRNA-independent manner. Taken together, it suggests that while both pgRNA and HBc protein exports are dependent on NXF1-p15, they are using the same export machinery in a manner independent of each other.

Nucleocytoplasmic trafficking of Nipah virus W protein involves multiple discrete interactions with the nuclear import and export machinery

International Nuclear Information System (INIS)

Audsley, Michelle D.; Jans, David A.; Moseley, Gregory W.

2016-01-01

Paramyxoviruses replicate in the cytoplasm with no obvious requirement to interact with the nucleus. Nevertheless, the W protein of the highly lethal bat-borne paramyxovirus Nipah virus (NiV) is known to undergo specific targeting to the nucleus, mediated by a single nuclear localisation signal (NLS) within the C-terminal domain. Here, we report for the first time that additional sites modulate nucleocytoplasmic localisation of W. We show that the N-terminal domain interacts with importin α1 and contributes to nuclear accumulation of W, indicative of a novel N-terminal NLS. We also find that W undergoes exportin-1 mediated nuclear export, dependent on a leucine at position 174. Together, these data enable significant revision of the generally accepted model of W trafficking, with implications for understanding of the mechanisms of NiV immune evasion. - Highlights: • A new model for Nipah virus W protein nucleocytoplasmic trafficking is proposed. • Nipah W protein is shown to undergo active nuclear export via exportin-1. • Nipah W nuclear import is mediated by multiple nuclear localisation signals.

The function of the inner nuclear envelope protein SUN1 in mRNA export is regulated by phosphorylation.

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Li, Ping; Stumpf, Maria; Müller, Rolf; Eichinger, Ludwig; Glöckner, Gernot; Noegel, Angelika A

2017-08-22

SUN1, a component of the LINC (Linker of Nucleoskeleton and Cytoskeleton) complex, functions in mammalian mRNA export through the NXF1-dependent pathway. It associates with mRNP complexes by direct interaction with NXF1. It also binds to the NPC through association with the nuclear pore component Nup153, which is involved in mRNA export. The SUN1-NXF1 association is at least partly regulated by a protein kinase C (PKC) which phosphorylates serine 113 (S113) in the N-terminal domain leading to reduced interaction. The phosphorylation appears to be important for the SUN1 function in nuclear mRNA export since GFP-SUN1 carrying a S113A mutation was less efficient in restoring mRNA export after SUN1 knockdown as compared to the wild type protein. By contrast, GFP-SUN1-S113D resembling the phosphorylated state allowed very efficient export of poly(A)+RNA. Furthermore, probing a possible role of the LINC complex component Nesprin-2 in this process we observed impaired mRNA export in Nesprin-2 knockdown cells. This effect might be independent of SUN1 as expression of a GFP tagged SUN-domain deficient SUN1, which no longer can interact with Nesprin-2, did not affect mRNA export.

Analysis and prediction of leucine-rich nuclear export signals

DEFF Research Database (Denmark)

La Cour, T.; Kiemer, Lars; Mølgaard, Anne

2004-01-01

We present a thorough analysis of nuclear export signals and a prediction server, which we have made publicly available. The machine learning prediction method is a significant improvement over the generally used consensus patterns. Nuclear export signals (NESs) are extremely important regulators...... this analysis is that the most important properties of NESs are accessibility and flexibility allowing relevant proteins to interact with the signal. Furthermore, we show that not only the known hydrophobic residues are important in defining a nuclear export signals. We employ both neural networks and hidden...

Nuclear export controls

International Nuclear Information System (INIS)

Thorne, C.E.

1999-01-01

One approach to describing the multilateral nuclear export controls is to do it according to time. This led to an interesting discovery, i.e. multilateral export controls have been defined by four distinct periods, the forst two of abut five years each, the second two about twice as long. These time periods have another interesting property. The two suppliers groups, which we will discuss in detail, have alternated in dominance over nearly thirty years. After describing the historical developments, the status of the present situation in multilateral nuclear export controls is examined, with the strengths and weaknesses. The future of multilateral nuclear export controls and possible ways that might be taken are considered

Nuclear export of RNA: Different sizes, shapes and functions.

Science.gov (United States)

Williams, Tobias; Ngo, Linh H; Wickramasinghe, Vihandha O

2018-03-01

Export of protein-coding and non-coding RNA molecules from the nucleus to the cytoplasm is critical for gene expression. This necessitates the continuous transport of RNA species of different size, shape and function through nuclear pore complexes via export receptors and adaptor proteins. Here, we provide an overview of the major RNA export pathways in humans, highlighting the similarities and differences between each. Its importance is underscored by the growing appreciation that deregulation of RNA export pathways is associated with human diseases like cancer. Crown Copyright © 2017. Published by Elsevier Ltd. All rights reserved.

Promising SINEs for embargoing nuclear-cytoplasmic export as an anticancer strategy.

Science.gov (United States)

Tan, David S P; Bedard, Philippe L; Kuruvilla, John; Siu, Lillian L; Razak, Albiruni R Abdul

2014-05-01

In cancer cells, the nuclear-cytoplasmic transport machinery is frequently disrupted, resulting in mislocalization and loss of function for many key regulatory proteins. In this review, the mechanisms by which tumor cells co-opt the nuclear transport machinery to facilitate carcinogenesis, cell survival, drug resistance, and tumor progression will be elucidated, with a particular focus on the role of the nuclear-cytoplasmic export protein. The recent development of a new generation of selective inhibitors of nuclear export (XPO1 antagonists) and how these novel anticancer drugs may bring us closer to the implementation of this therapeutic strategy in the clinic will be discussed.

NESmapper: accurate prediction of leucine-rich nuclear export signals using activity-based profiles.

Directory of Open Access Journals (Sweden)

Shunichi Kosugi

2014-09-01

Full Text Available The nuclear export of proteins is regulated largely through the exportin/CRM1 pathway, which involves the specific recognition of leucine-rich nuclear export signals (NESs in the cargo proteins, and modulates nuclear-cytoplasmic protein shuttling by antagonizing the nuclear import activity mediated by importins and the nuclear import signal (NLS. Although the prediction of NESs can help to define proteins that undergo regulated nuclear export, current methods of predicting NESs, including computational tools and consensus-sequence-based searches, have limited accuracy, especially in terms of their specificity. We found that each residue within an NES largely contributes independently and additively to the entire nuclear export activity. We created activity-based profiles of all classes of NESs with a comprehensive mutational analysis in mammalian cells. The profiles highlight a number of specific activity-affecting residues not only at the conserved hydrophobic positions but also in the linker and flanking regions. We then developed a computational tool, NESmapper, to predict NESs by using profiles that had been further optimized by training and combining the amino acid properties of the NES-flanking regions. This tool successfully reduced the considerable number of false positives, and the overall prediction accuracy was higher than that of other methods, including NESsential and Wregex. This profile-based prediction strategy is a reliable way to identify functional protein motifs. NESmapper is available at http://sourceforge.net/projects/nesmapper.

Interaction of HTLV-1 Tax protein with calreticulin: implications for Tax nuclear export and secretion.

Science.gov (United States)

Alefantis, Timothy; Flaig, Katherine E; Wigdahl, Brian; Jain, Pooja

2007-05-01

Human T cell leukemia virus type 1 (HTLV-1) is the etiologic agent of adult T cell leukemia (ATL) and HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP). The HTLV-1 transcriptional transactivator protein Tax plays an integral role in virus replication and disease progression. Traditionally, Tax is described as a nuclear protein where it performs its primary role as a transcriptional transactivator. However, recent studies have clearly shown that Tax can also be localized to the cytoplasm where it has been shown to interact with a number of host transcription factors most notably NF-kappaB, constitutive expression of which is directly related to the T cell transforming properties of Tax in ATL patients. The presence of a functional nuclear export signal (NES) within Tax and the secretion of full-length Tax have also been demonstrated previously. Additionally, release of Tax from HTLV-1-infected cells and the presence of cell-free Tax was demonstrated in the CSF of HAM/TSP patients suggesting that the progression to HAM/TSP might be mediated by the ability of Tax to function as an extracellular cytokine. Therefore, in both ATL and HAM/TSP Tax nuclear export and nucleocytoplasmic shuttling may play a critical role, the mechanism of which remains unknown. In this study, we have demonstrated that the calcium binding protein calreticulin interacts with Tax by co-immunoprecipitation. This interaction was found to localize to a region at or near the nuclear membrane. In addition, differential expression of calreticulin was demonstrated in various cell types that correlated with their ability to retain cytoplasmic Tax, particularly in astrocytes. Finally, a comparison of a number of HTLV-1-infected T cell lines to non-infected T cells revealed higher expression of calreticulin in infected cells implicating a direct role for this protein in HTLV-1 infection.

Nuclear Factor 90, a cellular dsRNA binding protein inhibits the HIV Rev-export function

Directory of Open Access Journals (Sweden)

St-Laurent Georges

2006-11-01

Full Text Available Abstract Background The HIV Rev protein is known to facilitate export of incompletely spliced and unspliced viral transcripts to the cytoplasm, a necessary step in virus life cycle. The Rev-mediated nucleo-cytoplasmic transport of nascent viral transcripts, dependents on interaction of Rev with the RRE RNA structural element present in the target RNAs. The C-terminal variant of dsRNA-binding nuclear protein 90 (NF90ctv has been shown to markedly attenuate viral replication in stably transduced HIV-1 target cell line. Here we examined a mechanism of interference of viral life cycle involving Rev-NF90ctv interaction. Results Since Rev:RRE complex formations depend on protein:RNA and protein:protein interactions, we investigated whether the expression of NF90ctv might interfere with Rev-mediated export of RRE-containing transcripts. When HeLa cells expressed both NF90ctv and Rev protein, we observed that NF90ctv inhibited the Rev-mediated RNA transport. In particular, three regions of NF90ctv protein are involved in blocking Rev function. Moreover, interaction of NF90ctv with the RRE RNA resulted in the expression of a reporter protein coding sequences linked to the RRE structure. Moreover, Rev influenced the subcellular localization of NF90ctv, and this process is leptomycin B sensitive. Conclusion The dsRNA binding protein, NF90ctv competes with HIV Rev function at two levels, by competitive protein:protein interaction involving Rev binding to specific domains of NF90ctv, as well as by its binding to the RRE-RNA structure. Our results are consistent with a model of Rev-mediated HIV-1 RNA export that envisions Rev-multimerization, a process interrupted by NF90ctv.

Hierarchical protein export mechanism of the bacterial flagellar type III protein export apparatus.

Science.gov (United States)

Minamino, Tohru

2018-06-01

The bacterial flagellum is supramolecular motility machinery consisting of the basal body, the hook and the filament. Flagellar proteins are translocated across the cytoplasmic membrane via a type III protein export apparatus, diffuse down the central channel of the growing structure and assemble at the distal end. Flagellar assembly begins with the basal body, followed by the hook and finally the filament. The completion of hook assembly is the most important morphological checkpoint of the sequential flagellar assembly process. When the hook reaches its mature length of about 55 nm in Salmonella enterica, the type III protein export apparatus switches export specificity from proteins required for the structure and assembly of the hook to those responsible for filament assembly, thereby terminating hook assembly and initiating filament assembly. Three flagellar proteins, namely FliK, FlhB and FlhA, are responsible for this substrate specificity switching. Upon completion of the switching event, interactions among FlhA, the cytoplasmic ATPase complex and flagellar type III export chaperones establish the assembly order of the filament at the hook tip. Here, we describe our current understanding of a hierarchical protein export mechanism used in flagellar type III protein export.

Comparative analysis of seven viral nuclear export signals (NESs reveals the crucial role of nuclear export mediated by the third NES consensus sequence of nucleoprotein (NP in influenza A virus replication.

Directory of Open Access Journals (Sweden)

Nopporn Chutiwitoonchai

Full Text Available The assembly of influenza virus progeny virions requires machinery that exports viral genomic ribonucleoproteins from the cell nucleus. Currently, seven nuclear export signal (NES consensus sequences have been identified in different viral proteins, including NS1, NS2, M1, and NP. The present study examined the roles of viral NES consensus sequences and their significance in terms of viral replication and nuclear export. Mutation of the NP-NES3 consensus sequence resulted in a failure to rescue viruses using a reverse genetics approach, whereas mutation of the NS2-NES1 and NS2-NES2 sequences led to a strong reduction in viral replication kinetics compared with the wild-type sequence. While the viral replication kinetics for other NES mutant viruses were also lower than those of the wild-type, the difference was not so marked. Immunofluorescence analysis after transient expression of NP-NES3, NS2-NES1, or NS2-NES2 proteins in host cells showed that they accumulated in the cell nucleus. These results suggest that the NP-NES3 consensus sequence is mostly required for viral replication. Therefore, each of the hydrophobic (Φ residues within this NES consensus sequence (Φ1, Φ2, Φ3, or Φ4 was mutated, and its viral replication and nuclear export function were analyzed. No viruses harboring NP-NES3 Φ2 or Φ3 mutants could be rescued. Consistent with this, the NP-NES3 Φ2 and Φ3 mutants showed reduced binding affinity with CRM1 in a pull-down assay, and both accumulated in the cell nucleus. Indeed, a nuclear export assay revealed that these mutant proteins showed lower nuclear export activity than the wild-type protein. Moreover, the Φ2 and Φ3 residues (along with other Φ residues within the NP-NES3 consensus were highly conserved among different influenza A viruses, including human, avian, and swine. Taken together, these results suggest that the Φ2 and Φ3 residues within the NP-NES3 protein are important for its nuclear export function

Notice to exporters on products prohibited from export (nuclear material, equipment and large nuclear units)

International Nuclear Information System (INIS)

1988-01-01

In order to ensure that the policy to avoid the proliferation of nuclear weapons is complied with, the French Administration applies stricter controls over the export of certain sensitive products, materials and equipment. To this effect, lists of such products, materials and equipment are published in the form of Notices to exporters and periodically revised. This Notice repeals and replaces the previous Notice published in the Official Gazette of 21 January 1986. Annex I contains the list of materials whose export is subject to nuclear non-proliferation controls. Annex II lists the equipment whose export is subject to the same controls. Annex III includes the list of large nuclear units for which an application for prior approval of export must be submitted to the Administrations concerned. (NEA) [fr

Export markets for nuclear technology

International Nuclear Information System (INIS)

Huettl, A.J.

1985-01-01

By late 1984, nuclear power plants were in operation or under construction in 32 countries of the globe. An additional six countries had concrete plans for building nuclear power plants. Of these 38 countries, ten have shown that they posses the necessary know-how and the technical facilities to plan and build nuclear power plants practically on their own. Seven of these ten countries have already acted as exporters of nuclear power plants, albeit with very different degrees of market penetration. In addition, there have been a number of countries for quite some time whose industries have managed to manufacture many important nuclear power plant components. Their high level of technical development and the problems frequently encountered in export financing have made them very attractive partners of the true exporters of nuclear power plants. For the future, it must be expected that some of the countries which have so far limited their efforts to the construction of nuclear power plants at home will also develop into exporters of nuclear technology. The report contains a survey of the range of nuclear products available, a list of reactor vendors, reactor lines, and data on the economics of electricity generation in nuclear plants. It then goes on to offer detailed descriptions of the market and the demand situation. Interesting chapters are devoted to the selection criteria applied by importing countries, to financing problems, and to the influences exerted by the political environment. A realistic forecast is attempted in order to make a quantitative analysis of possible export contracts up until the year 2000. (orig.) [de

Inhibiting cancer cell hallmark features through nuclear export inhibition.

Science.gov (United States)

Sun, Qingxiang; Chen, Xueqin; Zhou, Qiao; Burstein, Ezra; Yang, Shengyong; Jia, Da

2016-01-01

Treating cancer through inhibition of nuclear export is one of the best examples of basic research translation into clinical application. Nuclear export factor chromosomal region maintenance 1 (CRM1; Xpo1 and exportin-1) controls cellular localization and function of numerous proteins that are critical for the development of many cancer hallmarks. The diverse actions of CRM1 are likely to explain the broad ranging anti-cancer potency of CRM1 inhibitors observed in pre-clinical studies and/or clinical trials (phase I-III) on both advanced-stage solid and hematological tumors. In this review, we compare and contrast the mechanisms of action of different CRM1 inhibitors, and discuss the potential benefit of unexplored non-covalent CRM1 inhibitors. This emerging field has uncovered that nuclear export inhibition is well poised as an attractive target towards low-toxicity broad-spectrum potent anti-cancer therapy.

RNA-binding proteins of the NXF (nuclear export factor) family and their connection with the cytoskeleton.

Science.gov (United States)

Mamon, L A; Ginanova, V R; Kliver, S F; Yakimova, A O; Atsapkina, A A; Golubkova, E V

2017-04-01

The mutual relationship between mRNA and the cytoskeleton can be seen from two points of view. On the one hand, the cytoskeleton is necessary for mRNA trafficking and anchoring to subcellular domains. On the other hand, cytoskeletal growth and rearrangement require the translation of mRNAs that are connected to the cytoskeleton. β-actin mRNA localization may influence dynamic changes in the actin cytoskeleton. In the cytoplasm, long-lived mRNAs exist in the form of RNP (ribonucleoprotein) complexes, where they interact with RNA-binding proteins, including NXF (Nuclear eXport Factor). Dm NXF1 is an evolutionarily conserved protein in Drosophila melanogaster that has orthologs in different animals. The universal function of nxf1 genes is the nuclear export of different mRNAs in various organisms. In this mini-review, we briefly discuss the evidence demonstrating that Dm NXF1 fulfils not only universal but also specialized cytoplasmic functions. This protein is detected not only in the nucleus but also in the cytoplasm. It is a component of neuronal granules. Dm NXF1 marks nuclear division spindles during early embryogenesis and the dense body on one side of the elongated spermatid nuclei. The characteristic features of sbr mutants (sbr 10 and sbr 5 ) are impairment of chromosome segregation and spindle formation anomalies during female meiosis. sbr 12 mutant sterile males with immobile spermatozoa exhibit disturbances in the axoneme, mitochondrial derivatives and cytokinesis. These data allow us to propose that the Dm NXF1 proteins transport certain mRNAs in neurites and interact with localized mRNAs that are necessary for dynamic changes of the cytoskeleton. © 2017 Wiley Periodicals, Inc.

Nuclear export controls and nuclear safeguards

International Nuclear Information System (INIS)

Sevini, F.

2013-01-01

The export control of dual use goods has developed since the early seventies to counter nuclear proliferation. The paper provides an overview of dual-use export control issues also in relation with the Additional Protocol to the Comprehensive Safeguards Agreement, which requires States to provide declarations of the export of the controlled items listed in its Annex II, derived from the Nuclear Suppliers Group Trigger list. Recommendations for improvement are proposed. On the EU level, the paper summarises the framework set by the European Council Regulation 428/2009, requiring Member States to impose control on exports, brokering and transit of dual use goods. The Regulation includes the so-called 'EU dual-use control list' integrating the lists of dual-use items defined by the international regimes and requires also the control on intangible technology transfers as foreseen by U.N. Security Council Resolution 1540. ESARDA has recently launched a new sub-Working Group on export control, which raised large interest and may evolve to a full-fledged working group. Export control may provide an opportunity of technical collaboration between ESARDA and INMM. The paper is followed by the slides of the presentation. (author)

Protein export through the bacterial flagellar type III export pathway.

Science.gov (United States)

Minamino, Tohru

2014-08-01

For construction of the bacterial flagellum, which is responsible for bacterial motility, the flagellar type III export apparatus utilizes both ATP and proton motive force across the cytoplasmic membrane and exports flagellar proteins from the cytoplasm to the distal end of the nascent structure. The export apparatus consists of a membrane-embedded export gate made of FlhA, FlhB, FliO, FliP, FliQ, and FliR and a water-soluble ATPase ring complex consisting of FliH, FliI, and FliJ. FlgN, FliS, and FliT act as substrate-specific chaperones that do not only protect their cognate substrates from degradation and aggregation in the cytoplasm but also efficiently transfer the substrates to the export apparatus. The ATPase ring complex facilitates the initial entry of the substrates into the narrow pore of the export gate. The export gate by itself is a proton-protein antiporter that uses the two components of proton motive force, the electric potential difference and the proton concentration difference, for different steps of the export process. A specific interaction of FlhA with FliJ located in the center of the ATPase ring complex allows the export gate to efficiently use proton motive force to drive protein export. The ATPase ring complex couples ATP binding and hydrolysis to its assembly-disassembly cycle for rapid and efficient protein export cycle. This article is part of a Special Issue entitled: Protein trafficking and secretion in bacteria. Guest Editors: Anastassios Economou and Ross Dalbey. © 2013 Elsevier B.V. All rights reserved.

Nuclear exports. Parliamentary control and confidentiality

International Nuclear Information System (INIS)

Feldmann, Ulrike

2015-01-01

With its decision taken on 21. October 2014 (Az.: 2 BvE 5/11) the Federal Constitutional Court (BVerfG) decided during court proceedings between administrative bodies on the scope and limits of the parliamentary right of information. Even though the proceeding did not deal with nuclear exports but arm exports, foreign trade law, however, does not only designate an export licence obligation for military weapons but also for so called dual-use goods meaning goods, which can be used both for friendly as well as for military purposes. The export of these goods requires according to the so-called Dual-Use Regulation (EG) 428/2009 a licence. Annex I category 0 of the regulation (EG) 428/2009 lists a variety of nuclear materials, plants and equipment items for which this licence applies. In the same manner as arm exports, also exports of nuclear dual-use goods are being discussed in a special cabinet committee, the Federal Security Council (BSR), which shall coordinate cross-departmentally the German security and defence policy under consideration of economic interests and which categorises its results, according to the rules of procedure, as confidential. Also legally not regulated but common ''preliminary enquiries'' at the responsible Federal Ministry or rather Federal Office of Economics and Export Control by companies which plan an export and want to affirm the general approval for their export business prior to conclusion of contract take not only place for arm exports but also for nuclear dual-use goods. The decision by the Federal Constitutional Court can be applied to consultations about the authorisation of nuclear dual-use goods.

Hormone-dependent nuclear export of estradiol receptor and DNA synthesis in breast cancer cells

Science.gov (United States)

Lombardi, Maria; Castoria, Gabriella; Migliaccio, Antimo; Barone, Maria Vittoria; Di Stasio, Rosina; Ciociola, Alessandra; Bottero, Daniela; Yamaguchi, Hiroshi; Appella, Ettore; Auricchio, Ferdinando

2008-01-01

In breast cancer cells, cytoplasmic localization of the estradiol receptor α (ERα) regulates estradiol-dependent S phase entry. We identified a nuclear export sequence (NES) in ERα and show that its export is dependent on both estradiol-mediated phosphatidylinositol-3-kinase (PI3K)/AKT activation and chromosome region maintenance 1 (CRM1). A Tat peptide containing the ERα NES disrupts ERα–CRM1 interaction and prevents nuclear export of ERα- and estradiol-induced DNA synthesis. NES-ERα mutants do not exit the nucleus and inhibit estradiol-induced S phase entry; ERα-dependent transcription is normal. ERα is associated with Forkhead proteins in the nucleus, and estradiol stimulates nuclear exit of both proteins. ERα knockdown or ERα NES mutations prevent ERα and Forkhead nuclear export. A mutant of forkhead in rhabdomyosarcoma (FKHR), which cannot be phosphorylated by estradiol-activated AKT, does not associate with ERα and is trapped in the nucleus, blocking S phase entry. In conclusion, estradiol-induced AKT-dependent phosphorylation of FKHR drives its association with ERα, thereby triggering complex export from the nucleus necessary for initiation of DNA synthesis and S phase entry. PMID:18644889

Morbillivirus nucleoprotein possesses a novel nuclear localization signal and a CRM1-independent nuclear export signal

International Nuclear Information System (INIS)

Sato, Hiroki; Masuda, Munemitsu; Miura, Ryuichi; Yoneda, Misako; Kai, Chieko

2006-01-01

Morbilliviruses, which belong to the Mononegavirales, replicate its RNA genome in the cytoplasm of the host cell. However, they also form characteristic intranuclear inclusion bodies, consisting of nucleoprotein (N), in infected cells. To analyze the mechanisms of nucleocytoplasmic transport of N protein, we characterized the nuclear localization (NLS) and nuclear export (NES) signals of canine distemper virus (CDV) N protein by deletion mutation and alanine substitution of the protein. The NLS has a novel leucine/isoleucine-rich motif (TGILISIL) at positions 70-77, whereas the NES is composed of a leucine-rich motif (LLRSLTLF) at positions 4-11. The NLS and NES of the N proteins of other morbilliviruses, that is, measles virus (MV) and rinderpest virus (RPV), were also analyzed. The NLS of CDV-N protein is conserved at the same position in MV-N protein, whereas the NES of MV-N protein is located in the C-terminal region. The NES of RPV-N protein is also located at the same position as CDV-N protein, whereas the NLS motif is present not only at the same locus as CDV-N protein but also at other sites. Interestingly, the nuclear export of all these N proteins appears to proceed via a CRM1-independent pathway

Identification of a functional nuclear export signal in the green fluorescent protein asFP499

International Nuclear Information System (INIS)

Mustafa, Huseyin; Strasser, Bernd; Rauth, Sabine; Irving, Robert A.; Wark, Kim L.

2006-01-01

The green fluorescent protein (GFP) asFP499 from Anemonia sulcata is a distant homologue of the GFP from Aequorea victoria. We cloned the asFP499 gene into a mammalian expression vector and showed that this protein was expressed in the human lymphoblast cell line Ramos RA1 and in the embryonic kidney 293T cell line (HEK 293T). In HEK 293T cells, asFP499 was localized mainly in the cytoplasm, suggesting that the protein was excluded from the nucleus. We identified 194 LRMEKLNI 201 as a candidate nuclear export signal in asFP499 and mutated the isoleucine at position 201 to an alanine. Unlike the wildtype form, the mutant protein was distributed throughout the cytoplasm and nucleus. This is First report of a GFP that contains a functional NES

Identification of a putative nuclear export signal motif in human NANOG homeobox domain

International Nuclear Information System (INIS)

Park, Sung-Won; Do, Hyun-Jin; Huh, Sun-Hyung; Sung, Boreum; Uhm, Sang-Jun; Song, Hyuk; Kim, Nam-Hyung; Kim, Jae-Hwan

2012-01-01

Highlights: ► We found the putative nuclear export signal motif within human NANOG homeodomain. ► Leucine-rich residues are important for human NANOG homeodomain nuclear export. ► CRM1-specific inhibitor LMB blocked the potent human NANOG NES-mediated nuclear export. -- Abstract: NANOG is a homeobox-containing transcription factor that plays an important role in pluripotent stem cells and tumorigenic cells. To understand how nuclear localization of human NANOG is regulated, the NANOG sequence was examined and a leucine-rich nuclear export signal (NES) motif ( 125 MQELSNILNL 134 ) was found in the homeodomain (HD). To functionally validate the putative NES motif, deletion and site-directed mutants were fused to an EGFP expression vector and transfected into COS-7 cells, and the localization of the proteins was examined. While hNANOG HD exclusively localized to the nucleus, a mutant with both NLSs deleted and only the putative NES motif contained (hNANOG HD-ΔNLSs) was predominantly cytoplasmic, as observed by nucleo/cytoplasmic fractionation and Western blot analysis as well as confocal microscopy. Furthermore, site-directed mutagenesis of the putative NES motif in a partial hNANOG HD only containing either one of the two NLS motifs led to localization in the nucleus, suggesting that the NES motif may play a functional role in nuclear export. Furthermore, CRM1-specific nuclear export inhibitor LMB blocked the hNANOG potent NES-mediated export, suggesting that the leucine-rich motif may function in CRM1-mediated nuclear export of hNANOG. Collectively, a NES motif is present in the hNANOG HD and may be functionally involved in CRM1-mediated nuclear export pathway.

The export of China nuclear power

International Nuclear Information System (INIS)

Zhang Jian

2012-01-01

The article first introduces the meaning of nuclear power export, and then analyses the advantages of China nuclear industry based on the status and development of this industry. At the same time. the collection of nuclear development for the next 30 years of several nations in south-east Asia, south Asia, Middle East, Africa and South America is compiled, which could be a valuable reference for foreseeing nuclear power export market. Finally, as the situation throughout the world is considered, some suggestions are made that what else could be done for future development and export. (author)

Selective nuclear export of specific classes of mRNA from mammalian nuclei is promoted by GANP

Science.gov (United States)

Wickramasinghe, Vihandha O.; Andrews, Robert; Ellis, Peter; Langford, Cordelia; Gurdon, John B.; Stewart, Murray; Venkitaraman, Ashok R.; Laskey, Ronald A.

2014-01-01

The nuclear phase of the gene expression pathway culminates in the export of mature messenger RNAs (mRNAs) to the cytoplasm through nuclear pore complexes. GANP (germinal- centre associated nuclear protein) promotes the transfer of mRNAs bound to the transport factor NXF1 to nuclear pore complexes. Here, we demonstrate that GANP, subunit of the TRanscription-EXport-2 (TREX-2) mRNA export complex, promotes selective nuclear export of a specific subset of mRNAs whose transport depends on NXF1. Genome-wide gene expression profiling showed that half of the transcripts whose nuclear export was impaired following NXF1 depletion also showed reduced export when GANP was depleted. GANP-dependent transcripts were highly expressed, yet short-lived, and were highly enriched in those encoding central components of the gene expression machinery such as RNA synthesis and processing factors. After injection into Xenopus oocyte nuclei, representative GANP-dependent transcripts showed faster nuclear export kinetics than representative transcripts that were not influenced by GANP depletion. We propose that GANP promotes the nuclear export of specific classes of mRNAs that may facilitate rapid changes in gene expression. PMID:24510098

The NPT and nuclear export controls

International Nuclear Information System (INIS)

Berkhout, F.

1992-01-01

Controls on the export of nuclear materials and technology were originally imposed in wartime and under the United States Atomic Energy Act of 1946 to restrict the supply of uranium. But there was no international agreement until the mid 1960s; before that the United States, Canada, France and the Soviet Union imposed export controls on a national basis. The Non-Proliferation Treaty, especially Articles I-IV, set out the first world wide controls on the nuclear trade. These articles are explained in the context of the relevant Committees (the Zangger Committee, the Committee on the Assurance of Supply, the National Export Committee and the Coordinating Committee for Multilateral Export Control) and Guidelines (the Nuclear Suppliers Guidelines and the International Nuclear Fuel Cycle Evaluation). Recent developments which have a bearing on nuclear trade, such as the single European market, the emergence of new supplies and the break-up of the Soviet Union, are considered. (UK)

Exporting nuclear engineering and the industry's viewpoint

International Nuclear Information System (INIS)

Barthelt, K.

1986-01-01

Nuclear energy offers all possibilities to reduce the energy problems in the world which arise with the world-wide increasing population and the energy demand connected with it. The Federal Republic of Germany lives on the exports of refined technical methods which also include nuclear engineering. The exports of nuclear engineering should lead to a technology transfer with guidance and training on an equal basis between the industrial and developing countries. The preconditions of exporting nuclear-technical systems are a well-functioning domestic market and a certain support by the government, especially with regard to giving guarantees for the special exports risks of these big projects. On the other hand, exports are also needed in order to be able to continue providing high-level technology for the domestic market. (UA) [de

Political implications of US nuclear-export-policy development

International Nuclear Information System (INIS)

Johnson-Freese, J.S.

1981-01-01

There has been a great deal of international debate regarding how effective strict export controls on nuclear-energy supplies are toward a non-proliferation goal. With the Carter Administration, the debate was heightened by a new, more-vigorous US nuclear-export policy, much of which was codified by the Nuclear Non-Proliferation Act of 1978 (NNPA). Because of the US position in both the international non-proliferation regime and nuclear export market, the NNPA has had far-reaching consequences. The thesis of this paper is that a nuclear-export policy that fails to consider its short-term ramifications, as the NNPA has been accused of, will be self-defeating. If the US wants a viable worldwide nuclear non-proliferation policy, it must first direct its efforts toward building a domestic non-proliferation consensus, and then worldwide, rather than first setting a highly controversial policy and expecting other nations to fall into line. This work provides a comprehensive case study of US nuclear-export policy between the years 1976 to 1980 in support of the thesis. Further, the behavior and impact of the interest groups which seem to shape US nuclear-export policies is examined, and recommendations made regarding the role of groups in nuclear policy-making and implementation. Finally, recommendations are made regarding non-proliferation policy for the future, as it relates to nuclear exports

NLSdb-major update for database of nuclear localization signals and nuclear export signals.

Science.gov (United States)

Bernhofer, Michael; Goldberg, Tatyana; Wolf, Silvana; Ahmed, Mohamed; Zaugg, Julian; Boden, Mikael; Rost, Burkhard

2018-01-04

NLSdb is a database collecting nuclear export signals (NES) and nuclear localization signals (NLS) along with experimentally annotated nuclear and non-nuclear proteins. NES and NLS are short sequence motifs related to protein transport out of and into the nucleus. The updated NLSdb now contains 2253 NLS and introduces 398 NES. The potential sets of novel NES and NLS have been generated by a simple 'in silico mutagenesis' protocol. We started with motifs annotated by experiments. In step 1, we increased specificity such that no known non-nuclear protein matched the refined motif. In step 2, we increased the sensitivity trying to match several different families with a motif. We then iterated over steps 1 and 2. The final set of 2253 NLS motifs matched 35% of 8421 experimentally verified nuclear proteins (up from 21% for the previous version) and none of 18 278 non-nuclear proteins. We updated the web interface providing multiple options to search protein sequences for NES and NLS motifs, and to evaluate your own signal sequences. NLSdb can be accessed via Rostlab services at: https://rostlab.org/services/nlsdb/. © The Author(s) 2017. Published by Oxford University Press on behalf of Nucleic Acids Research.

A Study on Improvement of Export Control law's understanding for nuclear control items' exporters in Rep. of Korea

International Nuclear Information System (INIS)

Lim, Dong Hyuk; Choi, Sun Do; Yang, Seung Hyo

2011-01-01

According to export of UAE commercial reactor and JRTR(Jordan Research and Training Reactor) in 2009, Korea's international prestige has enhanced and it has been more important for researcher in charge of export control to understand and carry out duties on export control by obeying Nuclear Suppliers Group(NSG) Guidelines. Currently, the NSG tries to prevent the proliferation of nuclear weapons by harmonising export control systems of participating countries in relation to trade with nuclear commodities and nuclear-related dual-use materials, equipment, software and technology. In addition, through the implementation of two sets of Guidelines for nuclear exports and nuclear-related exports, the NSG aims to ensure that nuclear trade for peaceful purposes does not contribute to the proliferation of nuclear weapons or other nuclear explosive devices, and that international trade and cooperation in the nuclear field is not hindered unjustly in the process. However, there is still not a little confusion of export businesses owing to lack of understanding of nuclear items in Korea. Therefore, by correctly understanding export control systems, permits and licenses, ITT and persistingly communicating with export businesses, Researchers in charge of export control are able to eliminate confusion of production businesses regarding export and establish a export control culture

High-Resolution Imaging Reveals New Features of Nuclear Export of mRNA through the Nuclear Pore Complexes

Directory of Open Access Journals (Sweden)

Joseph M. Kelich

2014-08-01

Full Text Available The nuclear envelope (NE of eukaryotic cells provides a physical barrier for messenger RNA (mRNA and the associated proteins (mRNPs traveling from sites of transcription in the nucleus to locations of translation processing in the cytoplasm. Nuclear pore complexes (NPCs embedded in the NE serve as a dominant gateway for nuclear export of mRNA. However, the fundamental characterization of export dynamics of mRNPs through the NPC has been hindered by several technical limits. First, the size of NPC that is barely below the diffraction limit of conventional light microscopy requires a super-resolution microscopy imaging approach. Next, the fast transit of mRNPs through the NPC further demands a high temporal resolution by the imaging approach. Finally, the inherent three-dimensional (3D movements of mRNPs through the NPC demand the method to provide a 3D mapping of both transport kinetics and transport pathways of mRNPs. This review will highlight the recently developed super-resolution imaging techniques advanced from 1D to 3D for nuclear export of mRNPs and summarize the new features in the dynamic nuclear export process of mRNPs revealed from these technical advances.

Exportin-5 mediates nuclear export of SRP RNA in vertebrates.

Science.gov (United States)

Takeiwa, Toshihiko; Taniguchi, Ichiro; Ohno, Mutsuhito

2015-04-01

The signal recognition particle is a ribonucleoprotein complex that is essential for the translocation of nascent proteins into the endoplasmic reticulum. It has been shown that the RNA component (SRP RNA) is exported from the nucleus by CRM1 in the budding yeast. However, how SRP RNA is exported in higher species has been elusive. Here, we show that SRP RNA does not use the CRM1 pathway in Xenopus oocytes. Instead, SRP RNA uses the same export pathway as pre-miRNA and tRNA as showed by cross-competition experiments. Consistently, the recombinant Exportin-5 protein specifically stimulated export of SRP RNA as well as of pre-miRNA and tRNA, whereas an antibody raised against Exportin-5 specifically inhibited export of the same RNA species. Moreover, biotinylated SRP RNA can pull down Exportin-5 but not CRM1 from HeLa cell nuclear extracts in a RanGTP-dependent manner. These results, taken together, strongly suggest that the principal export receptor for SRP RNA in vertebrates is Exportin-5 unlike in the budding yeast. © 2015 The Authors. Genes to Cells published by Molecular Biology Society of Japan and Wiley Publishing Asia Pty Ltd.

Nuclear export signal of PRRSV NSP1α is necessary for type I IFN inhibition

International Nuclear Information System (INIS)

Chen, Zhi; Liu, Shaoning; Sun, Wenbo; Chen, Lei; Yoo, Dongwan; Li, Feng; Ren, Sufang; Guo, Lihui; Cong, Xiaoyan; Li, Jun; Zhou, Shun; Wu, Jiaqiang

2016-01-01

The nonstructural protein 1α (NSP1α) of porcine reproductive and respiratory syndrome virus (PRRSV) is a nucleo-cytoplasmic protein that suppresses the production of type I interferon (IFN). In this study, we investigated the relationship between the subcellular distribution of NSP1α and its inhibition of type I IFN. NSP1α was found to contain the classical nuclear export signal (NES) and NSP1α nuclear export was CRM-1-mediated. NSP1α was shuttling between the nucleus and cytoplasm. We also showed that the nuclear export of NSP1α was necessary for its ability for type I IFN inhibition. NSP1α was also found to interact with CBP, which implies a possible mechanism of CBP degradation by NSP1α. Taken together, our results describe a novel mechanism of PRRSV NSP1α for type I IFN inhibition and suppression of the host innate antiviral response. - Highlights: •NSP1α contains the NES and NSP1α nuclear export was CRM-1-mediated. •NSP1α was shuttling between the nucleus and cytoplasm continuously. •The nuclear export of NSP1α was necessary for its ability for type I IFN inhibition. •NSP1α interacts with CBP, which implies the mechanism of CBP degradation by NSP1α.

Nuclear export signal of PRRSV NSP1α is necessary for type I IFN inhibition

Energy Technology Data Exchange (ETDEWEB)

Chen, Zhi [Shandong Key Laboratory of Animal Disease Control and Breeding, Institute of Animal Science and Veterinary Medicine, Shandong Academy of Agricultural Sciences, Sangyuan Road No. 8, Jinan 250100 (China); Liu, Shaoning [Shandong Key Laboratory of Animal Disease Control and Breeding, Institute of Animal Science and Veterinary Medicine, Shandong Academy of Agricultural Sciences, Sangyuan Road No. 8, Jinan 250100 (China); Shandong Institute of Veterinary Drug Quality Inspection, Shandong Key Laboratory for Quality Safety Monitoring and Risk Assessment of Animal Products, Huaicun Street No. 68, Jinan 250722, Shandong Province (China); Sun, Wenbo; Chen, Lei [Shandong Key Laboratory of Animal Disease Control and Breeding, Institute of Animal Science and Veterinary Medicine, Shandong Academy of Agricultural Sciences, Sangyuan Road No. 8, Jinan 250100 (China); Yoo, Dongwan [Department of Pathobiology, University of Illinois at Urbana-Champaign, 2001 South Lincoln Ave, Urbana, IL 61802 (United States); Li, Feng [Department of Biology and Microbiology, Department of Veterinary and Biomedical Sciences, South Dakota State University, Brookings, SD 57007 (United States); Ren, Sufang; Guo, Lihui; Cong, Xiaoyan; Li, Jun [Shandong Key Laboratory of Animal Disease Control and Breeding, Institute of Animal Science and Veterinary Medicine, Shandong Academy of Agricultural Sciences, Sangyuan Road No. 8, Jinan 250100 (China); Zhou, Shun [College of marine science and engineering, Qingdao Agricultural University, Changcheng Road No. 700, Qingdao 266109 (China); Wu, Jiaqiang, E-mail: wujiaqiang2000@sina.com [Shandong Key Laboratory of Animal Disease Control and Breeding, Institute of Animal Science and Veterinary Medicine, Shandong Academy of Agricultural Sciences, Sangyuan Road No. 8, Jinan 250100 (China); and others

2016-12-15

The nonstructural protein 1α (NSP1α) of porcine reproductive and respiratory syndrome virus (PRRSV) is a nucleo-cytoplasmic protein that suppresses the production of type I interferon (IFN). In this study, we investigated the relationship between the subcellular distribution of NSP1α and its inhibition of type I IFN. NSP1α was found to contain the classical nuclear export signal (NES) and NSP1α nuclear export was CRM-1-mediated. NSP1α was shuttling between the nucleus and cytoplasm. We also showed that the nuclear export of NSP1α was necessary for its ability for type I IFN inhibition. NSP1α was also found to interact with CBP, which implies a possible mechanism of CBP degradation by NSP1α. Taken together, our results describe a novel mechanism of PRRSV NSP1α for type I IFN inhibition and suppression of the host innate antiviral response. - Highlights: •NSP1α contains the NES and NSP1α nuclear export was CRM-1-mediated. •NSP1α was shuttling between the nucleus and cytoplasm continuously. •The nuclear export of NSP1α was necessary for its ability for type I IFN inhibition. •NSP1α interacts with CBP, which implies the mechanism of CBP degradation by NSP1α.

Canada's nuclear export policy

Energy Technology Data Exchange (ETDEWEB)

Morrison, R W; Wonder, E F [Carleton Univ., Ottawa, Ontario (Canada)

1978-01-01

The factors influencing the evolution of Canada's nuclear export policy are examined. Initially, nuclear technology was exported to establish an industry in Canada and to share the technology with other countries. After 1974 an increasingly broad range of political and social factors were taken into account and safeguards became the dominant factor. The indirect impacts of the new policy fall into two groups. One consists of the effects of Canada's leadership in taking a tough stand on safeguards. The second group of effects involve the concern of other countries about access to secure energy supplies and advanced technology.

Canada's nuclear export policy

International Nuclear Information System (INIS)

Morrison, R.W.; Wonder, E.F.

1978-01-01

The factors influencing the evolution of Canada's nuclear export policy are examined. Initially, nuclear technology was exported to establish an industry in Canada and to share the technology with other countries. After 1974 an increasingly broad range of political and social factors were taken into account and safeguards became the dominant factor. The indirect impacts of the new policy fall into two groups. One consists of the effects of Canada's leadership in taking a tough stand on safeguards. The second group of effects involve the concern of other countries about access to secure energy supplies and advanced technology. (O.T.)

Nuclear export criteria and controls in the United States

International Nuclear Information System (INIS)

Shapar, H.K.

1979-01-01

The paper describes the export licensing procedure and the modifications made to it under the 1978 Nuclear Non-Proliferation Act (NNPA) to achieve greater control over exports of nuclear material and facilities. Export licences from the Nuclear Regulatory Commission are now required for certain items connected with nuclear plant construction and the procedure for obtaining the views of the Executive Branch have been formalised. The President is enabled to override the denial of an export licence by the NRC. Amongst the new criteria on the export licensing procedure added to the 1954 Atomic Energy Act, the NNPA provides that the IAEA Safeguards under the Non-Proliferation Treaty are applicable to exported nuclear material or facilities, together with adequate physical protection measures. (NEA) [fr

A biochemical framework for eIF4E-dependent mRNA export and nuclear recycling of the export machinery.

Science.gov (United States)

Volpon, Laurent; Culjkovic-Kraljacic, Biljana; Sohn, Hye Seon; Blanchet-Cohen, Alexis; Osborne, Michael J; Borden, Katherine L B

2017-06-01

The eukaryotic translation initiation factor eIF4E acts in the nuclear export and translation of a subset of mRNAs. Both of these functions contribute to its oncogenic potential. While the biochemical mechanisms that underlie translation are relatively well understood, the molecular basis for eIF4E's role in mRNA export remains largely unexplored. To date, over 3000 transcripts, many encoding oncoproteins, were identified as potential nuclear eIF4E export targets. These target RNAs typically contain a ∼50-nucleotide eIF4E sensitivity element (4ESE) in the 3' UTR and a 7-methylguanosine cap on the 5' end. While eIF4E associates with the cap, an unknown factor recognizes the 4ESE element. We previously identified cofactors that functionally interacted with eIF4E in mammalian cell nuclei including the leucine-rich pentatricopeptide repeat protein LRPPRC and the export receptor CRM1/XPO1. LRPPRC simultaneously interacts with both eIF4E bound to the 5' mRNA cap and the 4ESE element in the 3' UTR. In this way, LRPPRC serves as a specificity factor to recruit 4ESE-containing RNAs within the nucleus. Further, we show that CRM1 directly binds LRPPRC likely acting as the export receptor for the LRPPRC-eIF4E-4ESE RNA complex. We also found that Importin 8, the nuclear importer for cap-free eIF4E, imports RNA-free LRPPRC, potentially providing both coordinated nuclear recycling of the export machinery and an important surveillance mechanism to prevent futile export cycles. Our studies provide the first biochemical framework for the eIF4E-dependent mRNA export pathway. © 2017 Volpon et al.; Published by Cold Spring Harbor Laboratory Press for the RNA Society.

A common high standard for nuclear power plant exports: overview and analysis of the Nuclear Power Plant Exporters' Principles of Conduct

International Nuclear Information System (INIS)

Perkovich, George; Radzinsky, Brian

2012-01-01

At this time, there is no overarching global framework to regulate the development of the nuclear power industry. Laws concerning the export of nuclear technology vary across jurisdictions, and politically-binding arrangements such as the Nuclear Suppliers Group (NSG) help ensure that weapons-usable or dual-use technologies are not exported, but no single international regime or agreement manages the gamut of potential risks that may arise from the export of civilian nuclear power plants. Accordingly in 2008, the Carnegie Endowment for International Peace convened internationally-recognised experts in nuclear energy to begin a dialogue with nuclear power plant vendors about defining common criteria for the socially responsible export of nuclear power plants. The goal was to articulate a comprehensive set of principles and best practices that would raise the overall standard of practice for exports of nuclear power plants while enjoying widespread support and adherence. The outcome of this process is the Nuclear Power Plant Exporters' Principles of Conduct - an export-oriented code of conduct for nuclear power plant vendors. The Principles of Conduct help ensure that the participating companies will proceed with the sale of a new nuclear power plant only after a careful assessment of the legal, political, and technical contexts surrounding potential customers. It comprises six 'principles' that each address a major area of concern involved in the export of a nuclear power plant: safety, physical security, environmental protection and spent fuel management, systems of compensation for nuclear damage, non-proliferation and safeguards, and business ethics. The Principles of Conduct entail vendor responsibilities to apply specific standards or engage in certain practices before signing contracts and during the marketing and construction phases of a nuclear power plant export project. Conformity with the Principles of Conduct is voluntary and not-legally binding, but the

Characterization of the ptr5+ gene involved in nuclear mRNA export in fission yeast

International Nuclear Information System (INIS)

Watanabe, Nobuyoshi; Ikeda, Terumasa; Mizuki, Fumitaka; Tani, Tokio

2012-01-01

Highlights: ► We cloned the ptr5 + gene involved in nuclear mRNA export in fission yeast. ► The ptr5 + gene was found to encode nucleoporin 85 (Nup85). ► Seh1p and Mlo3p are multi-copy suppressors for the ptr5 mutation. ► Ptr5p/Nup85p functions in nuclear mRNA export through the mRNA export factor Rae1p. ► Ptr5p/Nup85p interacts genetically with pre-mRNA splicing factors. -- Abstract: To analyze the mechanisms of mRNA export from the nucleus to the cytoplasm, we have isolated eleven mutants, ptr [poly(A) + RNA transport] 1 to 11, which accumulate poly(A) + RNA in the nucleus at a nonpermissive temperature in Schizosaccharomyces pombe. Of those, the ptr5–1 mutant shows dots- or a ring-like accumulation of poly(A) + RNA at the nuclear periphery after shifting to the nonpermissive temperature. We cloned the ptr5 + gene and found that it encodes a component of the nuclear pore complex (NPC), nucleoporin 85 (Nup85). The ptr5–1 mutant shows no defects in protein transport, suggesting the specific involvement of Ptr5p/Nup85p in nuclear mRNA export in S. pombe. We identified Seh1p, a nucleoporin interacting with Nup85p, an mRNA-binding protein Mlo3p, and Sac3p, a component of the TREX-2 complex involved in coupling of nuclear mRNA export with transcription, as multi-copy suppressors for the ptr5–1 mutation. In addition, we found that the ptr5–1 mutation is synthetically lethal with a mutation of the mRNA export factor Rae1p, and that the double mutant exaggerates defective nuclear mRNA export, suggesting that Ptr5p/Nup85p is involved in nuclear mRNA export through Rae1p. Interestingly, the ptr5–1 mutation also showed synthetic effects with several prp pre-mRNA splicing mutations, suggesting a functional linkage between the NPCs and the splicing apparatus in the yeast nucleus.

Nuclear exporters cartel

International Nuclear Information System (INIS)

Mandelbaum, M.

1977-01-01

Events that have transpired in the past few years that have caused renewed concern about the spread of nuclear weapons are reviewed. Many proposals have been made recently for keeping the bomb from spreading. The author feels that the most novel and intriguing of them is the one advanced by Senator Abraham Ribicoff and Steven J. Baker; in their proposal, the world market for nuclear reactors would be divided into precisely defined shares among the industrial nations that now manufacture them for export; each exporter would be guaranteed a certain number of sales annually; and each would pledge not to sell uranium enrichment or plutonium reprocessing technology, as Germany did to Brazil. This might not halt proliferation, but it would give the world a few more years to find a solution

Nuclear export of cutaneous HPV8 E7 oncoprotein is mediated by a leucine-rich nuclear export signal via a CRM1 pathway

Energy Technology Data Exchange (ETDEWEB)

Onder, Zeynep; Chang, Vivian; Moroianu, Junona, E-mail: moroianu@bc.edu

2015-01-01

We recently determined that the nuclear import of cutaneous beta genus HPV8 E7 oncoprotein it is mediated by its zinc-binding domain via direct hydrophobic interactions with the FG nucleoporins Nup62 and Nup153 (Onder and Moroianu, 2014). Here we investigated the nuclear export of HPV8 E7 oncoprotein using confocal microscopy after transfections of HeLa cells with EGFP–8cE7 and mutant plasmids and treatment with Ratjadone A nuclear export inhibitor. We determined that HPV8 E7 contains a leucine-rich nuclear export signal (NES), {sub 76}IRTFQELLF{sub 84}, within its zinc-binding domain that mediates its nuclear export via a CRM1 pathway. We found that HPV8 E7 interacts with CRM1 and that the hydrophobic amino acid residues I76, F79 and L82 of the NES are essential for this interaction and for nuclear export of HPV8 E7 oncoprotein. - Highlights: • HPV8 E7 has a leucine-rich NES within its zinc-binding domain that mediates its nuclear export. • CRM1 nuclear export receptor interacts with HPV8 E7 and mediates its export. • Identification of the critical hydrophobic amino acids of the NES of HPV8 E7.

KLF4 Nuclear Export Requires ERK Activation and Initiates Exit from Naive Pluripotency.

Science.gov (United States)

Dhaliwal, Navroop K; Miri, Kamelia; Davidson, Scott; Tamim El Jarkass, Hala; Mitchell, Jennifer A

2018-04-10

Cooperative action of a transcription factor complex containing OCT4, SOX2, NANOG, and KLF4 maintains the naive pluripotent state; however, less is known about the mechanisms that disrupt this complex, initiating exit from pluripotency. We show that, as embryonic stem cells (ESCs) exit pluripotency, KLF4 protein is exported from the nucleus causing rapid decline in Nanog and Klf4 transcription; as a result, KLF4 is the first pluripotency transcription factor removed from transcription-associated complexes during differentiation. KLF4 nuclear export requires ERK activation, and phosphorylation of KLF4 by ERK initiates interaction of KLF4 with nuclear export factor XPO1, leading to KLF4 export. Mutation of the ERK phosphorylation site in KLF4 (S132) blocks KLF4 nuclear export, the decline in Nanog, Klf4, and Sox2 mRNA, and differentiation. These findings demonstrate that relocalization of KLF4 to the cytoplasm is a critical first step in exit from the naive pluripotent state and initiation of ESC differentiation. Copyright © 2018 The Authors. Published by Elsevier Inc. All rights reserved.

Challenges to nuclear export controls today

International Nuclear Information System (INIS)

Chatelus, R.; Sevini, F.; Janssens, W.; Michel, Q.

2014-01-01

Nuclear energy and nuclear proliferation programs are potentially inter-twinned, which is a point to be taken into account when analysing the development of civil nuclear energy, both domestically and as foreign investment. International agreements ensure that the adhering countries fulfil their obligations and do not abuse civil nuclear programs for the production of nuclear weapons. Uranium enrichment is the process currently most focused on in this respect by recent news and recent technological and commercial developments. But also the so-called reactor-based pathway, with extraction of plutonium from spent nuclear fuel by reprocessing remains in the spotlight of inspectors. Two of the main and complementary pillars on which the prevention of such diversion relies, are Strategic Export Control and International Safeguards. Strategic export control is a key barrier against nuclear proliferation. In many countries including the EU, it is set by a legal framework, envisaging implementation, enforcement and prosecution. The goods that can exported only with authorisations are those identified by the international export control regimes; primarily the Nuclear Suppliers Group in the case of nuclear items. It is complemented by nuclear safeguards measures, and especially in the past few years, by the IAEA State Level concept, which looks at the overall country's potential, including its industrial structure to derive conclusions on the absence of undeclared activities. However, the strict control of goods and knowledge is a moving target, since technological developments, globalisation and the intensifying exchange of information via the worldwide web offer increasing opportunities to proliferators to acquire sensitive items and competencies, and create bigger challenges to enforcement, calling for new responses. Research and development programmes must be directed towards supporting the adaptation of current proliferation containment systems to these new

Nuclear exports and international cooperation

International Nuclear Information System (INIS)

McCardle, J.J.

1981-06-01

Canada's nuclear export policy together with its non-proliferation and safeguards policy embrace both the country's desire to promote international cooperation in the peaceful uses of nuclear energy and its effort to minimize the risk of further proliferation of nuclear weapons. This policy reflects the belief that only if Canadian parliamentary and public opinion can be convinced that Canada's nuclear exports will not contribute to nuclear proliferation will the long-term health of the country's nuclear industry be assured. Canada requires a political commitment to non-proliferation from its nuclear partners, and looks to the IAEA to administer safeguards on nuclear material of Canadian origin to guarantee that commitment. Agreements reached with its nuclear partners are in accordance with provisions of the non-proliferation treaty and include a contingency provision for fall-back safeguards if the other state should withdraw from the NPT. Provision is made for mutual agreement on reprocessing and enrichment of nuclear material. Agreements have been reached with some twenty nuclear partners, and efforts are continuing to come to new international understanding on reprocessing, enrichment, and plutonium storage

Nuclear exportation and importation - the Brazilian situation

International Nuclear Information System (INIS)

Lavos Coimbra, G.

1986-01-01

The author proposes to set up a working group which should be responsible for the compilation of laws, procedures, and national policies for the nuclear importation and exportation in the supplying and receiving countries. Shared international views would simplify the flow of imports and exports between the countries. The author describes the different phases of exportation and importation of nuclear material are processed in her country, Brazil. (CW) [de

The politics of fading dreams: Britain and the nuclear export business

International Nuclear Information System (INIS)

Boardman, R.; Grieve, M.

1983-01-01

The subject is discussed as follows: introduction to a chapter focused on the politics of Britain's foreign nuclear trade; export goals and the nuclear programme (discussion of Magnox, AGR, SGHWR and PWR); the pursuit of exports; nuclear exports and proliferation (reprocessing; fast reactors; plutonium; INFCE); public opinion, nuclear power and exports (interest groups); conclusions (Britain's nuclear exports and non-proliferation). (U.K.)

Russian nuclear industry exports

International Nuclear Information System (INIS)

Gorbatchev, A.

2016-01-01

Rosatom is the world leader for the export of nuclear technologies. 34 reactors of Russian technology are being built or planned worldwide. Most reactors proposed by Rosatom are third generation VVER-1200 units with an electric power output of 1200 MWe. Although the nuclear island is always built by Rosatom, the remain of the plant can be subcontracted to other enterprises and European companies are sought because they would bring a european quality touch to Russian works. One of the main assets of Rosatom is to propose an integrated offer from supplying nuclear fuel to managing nuclear waste via the turnkey building of nuclear power plants. Another important asset is the financial assistance of the Russian state through state credit or the support from Russian national banks that appears to be a decisive advantage in the international competition to win markets. We have to temper the Russian export perspectives by noting that most projects are set in countries that are prone to instabilities and that the economic crisis affecting Russia has a negative impact on its financial means. (A.C.)

Three-Dimensional Mapping of mRNA Export through the Nuclear Pore Complex

Directory of Open Access Journals (Sweden)

Steven J. Schnell

2014-11-01

Full Text Available The locations of transcription and translation of mRNA in eukaryotic cells are spatially separated by the nuclear envelope (NE. Plenty of nuclear pore complexes (NPCs embedded in the NE function as the major gateway for the export of transcribed mRNAs from the nucleus to the cytoplasm. Whereas the NPC, perhaps one of the largest protein complexes, provides a relatively large channel for macromolecules to selectively pass through it in inherently three-dimensional (3D movements, this channel is nonetheless below the diffraction limit of conventional light microscopy. A full understanding of the mRNA export mechanism urgently requires real-time mapping of the 3D dynamics of mRNA in the NPC of live cells with innovative imaging techniques breaking the diffraction limit of conventional light microscopy. Recently, super-resolution fluorescence microscopy and single-particle tracking (SPT techniques have been applied to the study of nuclear export of mRNA in live cells. In this review, we emphasize the necessity of 3D mapping techniques in the study of mRNA export, briefly summarize the feasibility of current 3D imaging approaches, and highlight the new features of mRNA nuclear export elucidated with a newly developed 3D imaging approach combining SPT-based super-resolution imaging and 2D-to-3D deconvolution algorithms.

Study on status of nuclear export/import implementation in KAERI

International Nuclear Information System (INIS)

Kim, H. J.; Lee, B. D.; Lee, S. H.; Park, H. J.; So, D. S.

2004-01-01

As Korea is the member of ZC(Zangger Committee) and NSG(Nuclear Suppliers Group), domestic legislation reflected their guideline of nuclear export. The paper investigate the status of implementation procedures of nuclear export and import in KAERI based on domestic and international law. In addition, the paper analyzes on problem of export/import implementation system and also extract the efficient implementation system of nuclear export and import

Characterization of the ptr5{sup +} gene involved in nuclear mRNA export in fission yeast

Energy Technology Data Exchange (ETDEWEB)

Watanabe, Nobuyoshi; Ikeda, Terumasa; Mizuki, Fumitaka [Department of Biological Sciences, Graduate School of Science and Technology, Kumamoto University, Kurokami, Kumamoto 860-8555 (Japan); Tani, Tokio, E-mail: ttani@sci.kumamoto-u.ac.jp [Department of Biological Sciences, Graduate School of Science and Technology, Kumamoto University, Kurokami, Kumamoto 860-8555 (Japan)

2012-02-03

Highlights: Black-Right-Pointing-Pointer We cloned the ptr5{sup +} gene involved in nuclear mRNA export in fission yeast. Black-Right-Pointing-Pointer The ptr5{sup +} gene was found to encode nucleoporin 85 (Nup85). Black-Right-Pointing-Pointer Seh1p and Mlo3p are multi-copy suppressors for the ptr5 mutation. Black-Right-Pointing-Pointer Ptr5p/Nup85p functions in nuclear mRNA export through the mRNA export factor Rae1p. Black-Right-Pointing-Pointer Ptr5p/Nup85p interacts genetically with pre-mRNA splicing factors. -- Abstract: To analyze the mechanisms of mRNA export from the nucleus to the cytoplasm, we have isolated eleven mutants, ptr [poly(A){sup +} RNA transport] 1 to 11, which accumulate poly(A){sup +} RNA in the nucleus at a nonpermissive temperature in Schizosaccharomyces pombe. Of those, the ptr5-1 mutant shows dots- or a ring-like accumulation of poly(A){sup +} RNA at the nuclear periphery after shifting to the nonpermissive temperature. We cloned the ptr5{sup +} gene and found that it encodes a component of the nuclear pore complex (NPC), nucleoporin 85 (Nup85). The ptr5-1 mutant shows no defects in protein transport, suggesting the specific involvement of Ptr5p/Nup85p in nuclear mRNA export in S. pombe. We identified Seh1p, a nucleoporin interacting with Nup85p, an mRNA-binding protein Mlo3p, and Sac3p, a component of the TREX-2 complex involved in coupling of nuclear mRNA export with transcription, as multi-copy suppressors for the ptr5-1 mutation. In addition, we found that the ptr5-1 mutation is synthetically lethal with a mutation of the mRNA export factor Rae1p, and that the double mutant exaggerates defective nuclear mRNA export, suggesting that Ptr5p/Nup85p is involved in nuclear mRNA export through Rae1p. Interestingly, the ptr5-1 mutation also showed synthetic effects with several prp pre-mRNA splicing mutations, suggesting a functional linkage between the NPCs and the splicing apparatus in the yeast nucleus.

SR proteins are NXF1 adaptors that link alternative RNA processing to mRNA export.

Science.gov (United States)

Müller-McNicoll, Michaela; Botti, Valentina; de Jesus Domingues, Antonio M; Brandl, Holger; Schwich, Oliver D; Steiner, Michaela C; Curk, Tomaz; Poser, Ina; Zarnack, Kathi; Neugebauer, Karla M

2016-03-01

Nuclear export factor 1 (NXF1) exports mRNA to the cytoplasm after recruitment to mRNA by specific adaptor proteins. How and why cells use numerous different export adaptors is poorly understood. Here we critically evaluate members of the SR protein family (SRSF1-7) for their potential to act as NXF1 adaptors that couple pre-mRNA processing to mRNA export. Consistent with this proposal, >1000 endogenous mRNAs required individual SR proteins for nuclear export in vivo. To address the mechanism, transcriptome-wide RNA-binding profiles of NXF1 and SRSF1-7 were determined in parallel by individual-nucleotide-resolution UV cross-linking and immunoprecipitation (iCLIP). Quantitative comparisons of RNA-binding sites showed that NXF1 and SR proteins bind mRNA targets at adjacent sites, indicative of cobinding. SRSF3 emerged as the most potent NXF1 adaptor, conferring sequence specificity to RNA binding by NXF1 in last exons. Interestingly, SRSF3 and SRSF7 were shown to bind different sites in last exons and regulate 3' untranslated region length in an opposing manner. Both SRSF3 and SRSF7 promoted NXF1 recruitment to mRNA. Thus, SRSF3 and SRSF7 couple alternative splicing and polyadenylation to NXF1-mediated mRNA export, thereby controlling the cytoplasmic abundance of transcripts with alternative 3' ends. © 2016 Müller-McNicoll et al.; Published by Cold Spring Harbor Laboratory Press.

Export financing of nuclear power plants - banks experience

International Nuclear Information System (INIS)

Loeber

1977-01-01

1) Dimension and volume of the export financing of a nuclear power plant: 1.1) export orders of a new dimension; 1.2) individual loans occurring in connection with the export of a nuclear power plant: a) financial loans for maturities falling due under the export portion of the project; b) financial loans for the settlement of down- and interim payments to be made in connection with the export portion of the project; c) financial loans for the payment of local costs; d) loans for the financing of fuel elements; 2) governmental export insurance; 3) export financing in the individual industrial countries: USA, France, Great Britain, Japan (EXIMBANK), FRG. (orig./HP) [de

IRAK2 directs stimulus-dependent nuclear export of inflammatory mRNAs.

Science.gov (United States)

Zhou, Hao; Bulek, Katarzyna; Li, Xiao; Herjan, Tomasz; Yu, Minjia; Qian, Wen; Wang, Han; Zhou, Gao; Chen, Xing; Yang, Hui; Hong, Lingzi; Zhao, Junjie; Qin, Luke; Fukuda, Koichi; Flotho, Annette; Gao, Ji; Dongre, Ashok; Carman, Julie A; Kang, Zizhen; Su, Bing; Kern, Timothy S; Smith, Jonathan D; Hamilton, Thomas A; Melchior, Frauke; Fox, Paul L; Li, Xiaoxia

2017-10-09

Expression of inflammatory genes is determined in part by post-transcriptional regulation of mRNA metabolism but how stimulus- and transcript-dependent nuclear export influence is poorly understood. Here, we report a novel pathway in which LPS/TLR4 engagement promotes nuclear localization of IRAK2 to facilitate nuclear export of a specific subset of inflammation-related mRNAs for translation in murine macrophages. IRAK2 kinase activity is required for LPS-induced RanBP2-mediated IRAK2 sumoylation and subsequent nuclear translocation. Array analysis showed that an SRSF1-binding motif is enriched in mRNAs dependent on IRAK2 for nuclear export. Nuclear IRAK2 phosphorylates SRSF1 to reduce its binding to target mRNAs, which promotes the RNA binding of the nuclear export adaptor ALYREF and nuclear export receptor Nxf1 loading for the export of the mRNAs. In summary, LPS activates a nuclear function of IRAK2 that facilitates the assembly of nuclear export machinery to export selected inflammatory mRNAs to the cytoplasm for translation.

US Nuclear Non-Proliferation Policy: impact on exports and nuclear industry could not be determined

International Nuclear Information System (INIS)

Staats, E.B.

1980-01-01

The Nuclear Non-Proliferation Act of 1978 established new measures to prevent the diversion to weapons use of peaceful nuclear exports. It also created a policy to confirm US reliability as a nuclear supplier. GAO did not identify any export sales lost as a result of the Act, but did find indications that nonprofileration policies can influence export sales. Based on avavailable data, GAO could not determine the impact of the Act on the competitiveness of US nuclear exports. However, US companies are at some disadvantage because importers perceive that implementation of the Act may result in delayed export licenses. The United States dominated the nuclear export market through the early 1970s. However, foreign competitors, some aided by US technology transfers, emerged to monopolize home markets and complete for third-country business. Further, the market has been depressed since 1974 and prospects for US nuclear power plant exports have dimmed greatly. However, US companies continue to view exports as important to sustain production capacity

Nuclear export controls - Closing the gaps

International Nuclear Information System (INIS)

Schmidt, Fritz W.

2005-01-01

Concerns over a nuclear 'black market' have focused international attention on the effectiveness of nuclear export controls. IAEA Director General Mohamed ElBaradei has stated that the emergence of a multinational illicit network demonstrated the inadequacy of the present export control system, that international cooperation on export controls lay on informal arrangements that were not only not binding but also limited in membership, and that export control information was not systematically shared with the IAEA. This criticism, often heard on the political level, does not really do justice to the work of export control groups. The emergence of a multinational illicit network does not necessarily prove failures in export control systems. Criminal activities, by definition, try to circumvent existing rules and regulations, or they exploit the absence of such rules on State level. To fight such individual cases is not so much a task of regular export control systems, whose function lies primarily in establishing standards and procedures for export controls on State level, but rather the task for intelligence services and their international cooperation. The basis of the export control regime is the Nuclear Non-Proliferation Treaty (NPT). Export controls can - and do - play an important role in fostering this universality goal by demanding the implementation of internationally agreed security standards in recipient countries before export licenses are granted. Drawn from the deliberations in the NPT conferences, the current standards to be demanded as conditions of supply are the following: Safeguards, Physical Protection, National export control provisions. According to the NPT system, export controls require IAEA verification in the recipient country. In addition, export controls enable States to provide information to the IAEA on exports and imports as required by the Additional Protocol. The 2005 NPT Review Conference will be an opportunity to review developments

Sharing the load: Mex67-Mtr2 cofunctions with Los1 in primary tRNA nuclear export.

Science.gov (United States)

Chatterjee, Kunal; Majumder, Shubhra; Wan, Yao; Shah, Vijay; Wu, Jingyan; Huang, Hsiao-Yun; Hopper, Anita K

2017-11-01

Eukaryotic transfer RNAs (tRNAs) are exported from the nucleus, their site of synthesis, to the cytoplasm, their site of function for protein synthesis. The evolutionarily conserved β-importin family member Los1 (Exportin-t) has been the only exporter known to execute nuclear export of newly transcribed intron-containing pre-tRNAs. Interestingly, LOS1 is unessential in all tested organisms. As tRNA nuclear export is essential, we previously interrogated the budding yeast proteome to identify candidates that function in tRNA nuclear export. Here, we provide molecular, genetic, cytological, and biochemical evidence that the Mex67-Mtr2 (TAP-p15) heterodimer, best characterized for its essential role in mRNA nuclear export, cofunctions with Los1 in tRNA nuclear export. Inactivation of Mex67 or Mtr2 leads to rapid accumulation of end-matured unspliced tRNAs in the nucleus. Remarkably, merely fivefold overexpression of Mex67-Mtr2 can substitute for Los1 in los1 Δ cells. Moreover, in vivo coimmunoprecipitation assays with tagged Mex67 document that the Mex67 binds tRNAs. Our data also show that tRNA exporters surprisingly exhibit differential tRNA substrate preferences. The existence of multiple tRNA exporters, each with different tRNA preferences, may indicate that the proteome can be regulated by tRNA nuclear export. Thus, our data show that Mex67-Mtr2 functions in primary nuclear export for a subset of yeast tRNAs. © 2017 Chatterjee et al.; Published by Cold Spring Harbor Laboratory Press.

Dual function of the nuclear export signal of the Borna disease virus nucleoprotein in nuclear export activity and binding to viral phosphoprotein.

Science.gov (United States)

Yanai, Mako; Sakai, Madoka; Makino, Akiko; Tomonaga, Keizo

2017-07-11

Borna disease virus (BoDV), which has a negative-sense, single-stranded RNA genome, causes persistent infection in the cell nucleus. The nuclear export signal (NES) of the viral nucleoprotein (N) consisting of leucine at positions 128 and 131 and isoleucine at positions 133 and 136 overlaps with one of two predicted binding sites for the viral phosphoprotein (P). A previous study demonstrated that higher expression of BoDV-P inhibits nuclear export of N; however, the function of N NES in the interaction with P remains unclear. We examined the subcellular localization, viral polymerase activity, and P-binding ability of BoDV-N NES mutants. We also characterized a recombinant BoDV (rBoDV) harboring an NES mutation of N. BoDV-N with four alanine-substitutions in the leucine and isoleucine residues of the NES impaired its cytoplasmic localization and abolished polymerase activity and P-binding ability. Although an alanine-substitution at position 131 markedly enhanced viral polymerase activity as determined by a minigenome assay, rBoDV harboring this mutation showed expression of viral RNAs and proteins relative to that of wild-type rBoDV. Our results demonstrate that BoDV-N NES has a dual function in BoDV replication, i.e., nuclear export of N and an interaction with P, affecting viral polymerase activity in the nucleus.

A Study on Improvement of Export Control law's understanding for nuclear control items' exporters in Rep. of Korea

Energy Technology Data Exchange (ETDEWEB)

Lim, Dong Hyuk; Choi, Sun Do; Yang, Seung Hyo [Korea Institute of Nuclear Nonproliferation and Control, Daejeon (Korea, Republic of)

2011-10-15

According to export of UAE commercial reactor and JRTR(Jordan Research and Training Reactor) in 2009, Korea's international prestige has enhanced and it has been more important for researcher in charge of export control to understand and carry out duties on export control by obeying Nuclear Suppliers Group(NSG) Guidelines. Currently, the NSG tries to prevent the proliferation of nuclear weapons by harmonising export control systems of participating countries in relation to trade with nuclear commodities and nuclear-related dual-use materials, equipment, software and technology. In addition, through the implementation of two sets of Guidelines for nuclear exports and nuclear-related exports, the NSG aims to ensure that nuclear trade for peaceful purposes does not contribute to the proliferation of nuclear weapons or other nuclear explosive devices, and that international trade and cooperation in the nuclear field is not hindered unjustly in the process. However, there is still not a little confusion of export businesses owing to lack of understanding of nuclear items in Korea. Therefore, by correctly understanding export control systems, permits and licenses, ITT and persistingly communicating with export businesses, Researchers in charge of export control are able to eliminate confusion of production businesses regarding export and establish a export control culture

Nuclear export of cutaneous HPV8 E7 oncoprotein is mediated by a leucine-rich nuclear export signal via a CRM1 pathway.

Science.gov (United States)

Onder, Zeynep; Chang, Vivian; Moroianu, Junona

2015-01-01

We recently determined that the nuclear import of cutaneous beta genus HPV8 E7 oncoprotein it is mediated by its zinc-binding domain via direct hydrophobic interactions with the FG nucleoporins Nup62 and Nup153 (Onder and Moroianu, 2014). Here we investigated the nuclear export of HPV8 E7 oncoprotein using confocal microscopy after transfections of HeLa cells with EGFP-8cE7 and mutant plasmids and treatment with Ratjadone A nuclear export inhibitor. We determined that HPV8 E7 contains a leucine-rich nuclear export signal (NES), 76IRTFQELLF84, within its zinc-binding domain that mediates its nuclear export via a CRM1 pathway. We found that HPV8 E7 interacts with CRM1 and that the hydrophobic amino acid residues I76, F79 and L82 of the NES are essential for this interaction and for nuclear export of HPV8 E7 oncoprotein. Copyright © 2014 Elsevier Inc. All rights reserved.

Characterization of nuclear localization and export signals of the major tegument protein VP8 of bovine herpesvirus-1

International Nuclear Information System (INIS)

Zheng Chunfu; Brownlie, Robert; Babiuk, Lorne A.; Hurk, Sylvia van Drunen Littel-van den

2004-01-01

Bovine herpesvirus-1 (BHV-1) VP8 is found in the nucleus immediately after infection. Transient expression of VP8 fused to yellow fluorescent protein (YFP) in COS-7 cells confirmed the nuclear localization of VP8 in the absence of other viral proteins. VP8 has four putative nuclear localization signals (NLS). Deletion of pat4 ( 51 RRPR 54 ) or pat7 ( 48 PRVRRPR 54 ) NLS2 abrogated nuclear accumulation, whereas deletion of 48 PRV 50 did not, so pat4 NLS2 is critical for nuclear localization of VP8. Furthermore, NLS1 ( 11 RRPRR 15 ), pat4 NLS2, and pat7 NLS2 were all capable of transporting the majority of YFP to the nucleus. Finally, a 12-amino-acid peptide with the sequence RRPRRPRVRRPR directed all of YFP into the nucleus, suggesting that reiteration of the RRPR motif makes the nuclear localization more efficient. Heterokaryon assays demonstrated that VP8 is also capable of shuttling between the nucleus and cytoplasm of the cell. Deletion mutant analysis revealed that this property is attributed to a leucine-rich nuclear export sequence (NES) consisting of amino acids 485 LSAYLTLFVAL 495 . This leucine-rich NES caused transport of YFP to the cytoplasm. These results demonstrate that VP8 shuttles between the nucleus and cytoplasm

CD151, a novel host factor of nuclear export signaling in influenza virus infection.

Science.gov (United States)

Qiao, Yongkang; Yan, Yan; Tan, Kai Sen; Tan, Sheryl S L; Seet, Ju Ee; Arumugam, Thiruma Valavan; Chow, Vincent T K; Wang, De Yun; Tran, Thai

2018-05-01

Despite advances in our understanding of the mechanisms of influenza A virus (IAV) infection, the crucial virus-host interactions during the viral replication cycle still remain incomplete. Tetraspanin CD151 is highly expressed in the human respiratory tract, but its pathological role in IAV infection is unknown. We sought to characterize the functional role and mechanisms of action of CD151 in IAV infection of the upper and lower respiratory tracts with H1N1 and H3N2 strains. We used CD151-null mice in an in vivo model of IAV infection and clinical donor samples of in vitro-differentiated human nasal epithelial cells cultured at air-liquid interface. As compared with wild-type infected mice, CD151-null infected mice exhibited a significant reduction in virus titer and improvement in survival that is associated with pronounced host antiviral response and inflammasome activation together with accelerated lung repair. Interestingly, we show that CD151 complexes newly synthesized viral proteins with host nuclear export proteins and stabilizes microtubule complexes, which are key processes necessary for the polarized trafficking of viral progeny to the host plasma membrane for assembly. Our results provide new mechanistic insights into our understanding of IAV infection. We show that CD151 is a critical novel host factor of nuclear export signaling whereby the IAV nuclear export uses it to complement its own nuclear export proteins (a site not targeted by current therapy), making this regulation unique, and holds promise for the development of novel alternative/complementary strategies to reduce IAV severity. Copyright © 2017 American Academy of Allergy, Asthma & Immunology. Published by Elsevier Inc. All rights reserved.

Nuclear transport of heat shock proteins in stressed cells

International Nuclear Information System (INIS)

Chughtai, Zahoor Saeed

2001-01-01

Nuclear import of proteins that are too large to passively enter the nucleus requires soluble factors, energy , and a nuclear localization signal (NLS). Nuclear protein transport can be regulated, and different forms of stress affect nucleocytoplasmic trafficking. As such, import of proteins containing a classical NLS is inhibited in starving yeast cells. In contrast, the heat shock protein hsp70 Ssa4p concentrates in nuclei upon starvation. Nuclear concentration of Ssa4p in starving cells is reversible, and transfer of nutrient-depleted cells to fresh medium induces Ssa4p nuclear export. This export reaction represents an active process that is sensitive to oxidative stress. Upon starvation, the N-terminal domain of Ssa4p mediates Ssa4p nuclear accumulation, and a short hydrophobic sequence, termed Star (for starvation), is sufficient to localize the reporter proteins green fluorescent protein or β-gaIactosidase to nuclei. To determine whether nuclear accumulation of Star-β-galactosidase depends on a specific nuclear carrier, I have analyzed its distribution in mutant yeast strains that carry a deletion of a single β-importin gene. With this assay I have identified Nmd5p as a β-importin required to concentrate Star-β-galactosidase in nuclei of stationary phase cells. (author)

Nuclear transport of heat shock proteins in stressed cells

Energy Technology Data Exchange (ETDEWEB)

Chughtai, Zahoor Saeed

2001-07-01

Nuclear import of proteins that are too large to passively enter the nucleus requires soluble factors, energy , and a nuclear localization signal (NLS). Nuclear protein transport can be regulated, and different forms of stress affect nucleocytoplasmic trafficking. As such, import of proteins containing a classical NLS is inhibited in starving yeast cells. In contrast, the heat shock protein hsp70 Ssa4p concentrates in nuclei upon starvation. Nuclear concentration of Ssa4p in starving cells is reversible, and transfer of nutrient-depleted cells to fresh medium induces Ssa4p nuclear export. This export reaction represents an active process that is sensitive to oxidative stress. Upon starvation, the N-terminal domain of Ssa4p mediates Ssa4p nuclear accumulation, and a short hydrophobic sequence, termed Star (for starvation), is sufficient to localize the reporter proteins green fluorescent protein or {beta}-gaIactosidase to nuclei. To determine whether nuclear accumulation of Star-{beta}-galactosidase depends on a specific nuclear carrier, I have analyzed its distribution in mutant yeast strains that carry a deletion of a single {beta}-importin gene. With this assay I have identified Nmd5p as a {beta}-importin required to concentrate Star-{beta}-galactosidase in nuclei of stationary phase cells. (author)

The nuclear importation and exportation - The Brazilian situation

International Nuclear Information System (INIS)

Coimbra, G.L.

1985-01-01

The panorama of Brazilian economy emphasizing the measurements adopted by Brazilian government referring to importation and exportation policy is presented. The Brazilian Nuclear Program knows the nuclear trade gives good economic perspective. In the context of importation and exportation policy the laws concerned to nuclear trade transactions, taxes, national organizations responsible by the external trade policy and their attributions are presented. (M.C.K.) [pt

The metalloid arsenite induces nuclear export of Id3 possibly via binding to the N-terminal cysteine residues

International Nuclear Information System (INIS)

Kurooka, Hisanori; Sugai, Manabu; Mori, Kentaro; Yokota, Yoshifumi

2013-01-01

Highlights: •Sodium arsenite induces cytoplasmic accumulation of Id3. •Arsenite binds to closely spaced N-terminal cysteine residues of Id3. •N-terminal cysteines are essential for arsenite-induced nuclear export of Id3. •Nuclear export of Id3 counteracts its transcriptional repression activity. -- Abstract: Ids are versatile transcriptional repressors that regulate cell proliferation and differentiation, and appropriate subcellular localization of the Id proteins is important for their functions. We previously identified distinct functional nuclear export signals (NESs) in Id1 and Id2, but no active NES has been reported in Id3. In this study, we found that treatment with the stress-inducing metalloid arsenite led to the accumulation of GFP-tagged Id3 in the cytoplasm. Cytoplasmic accumulation was impaired by a mutation in the Id3 NES-like sequence resembling the Id1 NES, located at the end of the HLH domain. It was also blocked by co-treatment with the CRM1-specific nuclear export inhibitor leptomycin B (LMB), but not with the inhibitors for mitogen-activated protein kinases (MAPKs). Importantly, we showed that the closely spaced N-terminal cysteine residues of Id3 interacted with the arsenic derivative phenylarsine oxide (PAO) and were essential for the arsenite-induced cytoplasmic accumulation, suggesting that arsenite induces the CRM1-dependent nuclear export of Id3 via binding to the N-terminal cysteines. Finally, we demonstrated that Id3 significantly repressed arsenite-stimulated transcription of the immediate-early gene Egr-1 and that this repression activity was inversely correlated with the arsenite-induced nuclear export. Our results imply that Id3 may be involved in the biological action of arsenite

Exporting nuclear engineering and the government's viewpoint

International Nuclear Information System (INIS)

Schill, H.

1986-01-01

The reasons for the government's positive attitude to nuclear engineering exports are explained, especially with regard to them being a compensation of the decreasing domestic demand. The federal government considers such exports to be necessary and correct for economical and energy-political reasons. Their contribution reaches from accompanying measures to the provision of state guarantees of export financing activities. (UA) [de

Export and import provisions for nuclear materials and power plants

International Nuclear Information System (INIS)

Malsch, M.G.

1976-01-01

The present paper deals with 1) statutory requirements for export and import licensing of nuclear reactors and fuels; 2) regulations and procedures to issuance of exportlicenses; 3) environmental impact of export licensing; 4) licensing of reactor equipment; 5) recent restrictions on imports and exports of nuclear fuels. (RW) [de

Information Interaction with IAEA on Nuclear Import and Export

International Nuclear Information System (INIS)

Osokina, A.; Snytnikov, A.

2015-01-01

This paper considers organizational aspects of nuclear import and export interaction between the Russian Federation and the Agency. Requirements of nuclear import and export in Russia, information submission procedure and forms are determined in RF Government Regulation No 973 from December 15th 2000. Particularly, according to these requirements Russian licenced organizations implementing nuclear import and export submit reports about appointed transfers to State Corporation 'Rosatom'. Regulations of State Corporation 'Rosatom' entrusted gathering and processing of reporting information and interaction with IAEA to FSUE 'SCC of Rosatom'. Regulations of reporting information interaction were developed by SCC and approved by State Corporation 'Rosatom'. Russian organizations send notifications to SCC using regulation electron or paper forms. Regulations determine information security measures in reporting process. Automated nuclear import and export accounting system developed by SCC provides data entering, keeping and processing, enables to choose and submit requested information in different formats. This system is integrated with State Nuclear Material Control and Accounting System. Also submitted information is regularly compared with customs declarations data to improve reliability and consistency of information. Generalized nuclear import and export data is using by Departments of State Corporation 'Rosatom' and transmitting to Federal Environmental, Industrial and Nuclear Supervision Service of Russia in agreed forms. Summary information about international nuclear transfers is sending to IAEA according to INFCIRC/207. Reporting information is coordinating. Messaging with IAEA is realized by email using enciphering program. (author)

Export of nuclear equipment and materials and the non-proliferation of nuclear weapons

International Nuclear Information System (INIS)

Courteix, Simone.

1977-01-01

The problem of the non-proliferation of nuclear weapons is one of great concern today despite the entry into force in the early '70s of the NPT. To master civilian nuclear technology implies the ability to develop nuclear explosive devices; therefore in recent years contacts have strengthened between countries exporting nuclear equipment, specially in the frame of the 'London Club' so as to ensure that their exports will not result in disseminating nuclear weapons. (NEA) [fr

New U.S. nuclear export legislation

International Nuclear Information System (INIS)

Patermann, C.

1978-01-01

The new 1978 Export Control Act of the United States of America introduces a comprehensive arrangement of the criteria, responsibilities and procedures associated with nuclear exports, especially under the nonproliferation aspect. After a detailed analysis of the multitude of provisions it must be feared that, merely as a result of the high degree of formalization, bureaucratization and politicalization of these procedures, the U.S. can henceforth no longer be regarded as a reliable source of nuclear materials and facilities. An aspect received abroad with particular anguish is the fact that this unilateral aggravation of export controls was initiated after the start of the two-year INFCE program for international fuel cycle evaluation and that the new legislation forces the American government to renegotiate existing agreements on cooperation with the receiver countries under the threat of a delivery stop. (orig.) [de

Assessing mRNA nuclear export in mammalian cells by microinjection.

Science.gov (United States)

Lee, Eliza S; Palazzo, Alexander F

2017-08-15

The nuclear export of mRNAs is an important yet little understood part of eukaryotic gene expression. One of the easiest methods for monitoring mRNA export in mammalian tissue culture cells is through the microinjection of DNA plasmids into the nucleus and monitoring the distribution of the transcribed product over time. Here we describe how to setup a microscope equipped with a micromanipulator used in cell microinjections, and we explain how to perform a nuclear mRNA export assay and obtain the nuclear export rate for any given mRNA. Copyright © 2017 Elsevier Inc. All rights reserved.

Oil exporting countries need nuclear power

International Nuclear Information System (INIS)

Stauffer, T.R.

1982-01-01

The economic rationale for nuclear power in the oil exporting countries is analysed, with the collateral objective of defining the size of the potential market in terms of the exporting countries' economic opportunities and energy needs. The need for appropriate new institutions for licensing reactors, training personnel, and starting up plants follows directly from the size of the market and the economic incentives for the oil exporters to husband gas and oil. Gas and oil resources of the Middle Eastern countries are discussed, and future electricity needs estimated. (author)

Study on the establishment of effective nuclear export system

International Nuclear Information System (INIS)

Kim, Byung Koo; So, Dong Sup; Baik, Dae Hyun; Kwack, Eun Ho; Shin, Jang Soo; Yoon, Wan Ki; Park, Wan Soo; Kim, Hyun Tae.

1997-02-01

To improve Korean nuclear export control system, the modification of the present export license procedure for the nuclear equipment and materials and the classification of control items and their related technologies are required. And it is also necessary to make a database of the original countries who have the right of prior consent. For the efficient export control of LWR items to DPRK, it is desirable to manage the export license scheme of nuclear reactor facility as a total package, and to prepare a control regime for the retransfer of nuclear reactor component such as reactor coolant pump and nuclear fuel whose technologies are not self-reliant. It is especially essential to prepare a systematic procedure for the supply of nuclear equipment and materials to DPRK in order to meet international guidelines of NSG and others through an accord on the nuclear cooperation between Republic of Korea (ROK) and DPRK. The principal elements to be included in the accord are the range of cooperation, the restriction within the peaceful uses, prior consent right in case of retransfer of important nuclear reactor components and of storage, transfer and changes of nuclear fuels, application of safeguards to the supplied Trigger list items, physical protection of nuclear material, requirement of the return of nuclear equipment and materials, and restriction right for the suspension or termination of the agreement. (author). 40 refs., 5 tabs., 8 figs

Introduction to Technology Export License of Nuclear Facility

Energy Technology Data Exchange (ETDEWEB)

Seo, Hana; Lee, Chansuh; Shin, Donghoon [Korea Institute of Nuclear Nonproliferation and Control, Daejeon (Korea, Republic of)

2014-05-15

In this regime, the Nuclear Safety and Security Commission (NSSC) has authority on final decision making. And the Korea Institute of Nuclear nonproliferation and Control (KINAC) has missions to review the classification and export licensing technically. In principle, classification and export licensing are applied and reviewed individually. However, the number of application for classification and licensing has increased geometrically in the last three years. This is largely a due to the contract that the Republic of Korea (ROK) has finalized to build the UAE Barakah Nuclear Power Plant (BNPP) and Jordan Research and Training Reactor (JRTR). This circumstance brought an administrative burden for the government and related institutes as well as stakeholders. This article introduces the law related to the 'Technology Export License of Nuclear Facility' which was developed and legislated to improve the efficiency and effectiveness of commodities classification and export licensing. This system could significantly reduce the licensing burden for transferring the technologies. However, the classification and license on this system are still requested when transferring the goods. Therefore, KINAC will continue to figure out the needs for the stakeholders and keep searching for solutions to problems inherent in the industry.

Introduction to Technology Export License of Nuclear Facility

International Nuclear Information System (INIS)

Seo, Hana; Lee, Chansuh; Shin, Donghoon

2014-01-01

In this regime, the Nuclear Safety and Security Commission (NSSC) has authority on final decision making. And the Korea Institute of Nuclear nonproliferation and Control (KINAC) has missions to review the classification and export licensing technically. In principle, classification and export licensing are applied and reviewed individually. However, the number of application for classification and licensing has increased geometrically in the last three years. This is largely a due to the contract that the Republic of Korea (ROK) has finalized to build the UAE Barakah Nuclear Power Plant (BNPP) and Jordan Research and Training Reactor (JRTR). This circumstance brought an administrative burden for the government and related institutes as well as stakeholders. This article introduces the law related to the 'Technology Export License of Nuclear Facility' which was developed and legislated to improve the efficiency and effectiveness of commodities classification and export licensing. This system could significantly reduce the licensing burden for transferring the technologies. However, the classification and license on this system are still requested when transferring the goods. Therefore, KINAC will continue to figure out the needs for the stakeholders and keep searching for solutions to problems inherent in the industry

Implementation of the Nuclear Export Control at KAERI

International Nuclear Information System (INIS)

Kim, Hyun-Jo; Lee, Byung-Doo; Lee, Sung-Ho

2006-01-01

Korea has joined multilateral export control regimes which include Wassenaar Arrangement(WA), Nuclear Suppliers Group(NSG), Missile Technology Control Regime(MTCR) and Australian Group(AG), and their guideline and control lists are reflected in domestic legislation. Also, Catch-all control entered into force on 1 January 2003 in Korea. The frequency of the exports of product as a result of R and D and cooperation with other countries has been increased at Korea Atomic Energy Research Institute (KAERI). Therefore, this report describes the implementation status of a nuclear export control at KAERI and points out the practical issues

Korea nuclear exports: Why did the Koreans win the UAE tender? Will Korea achieve its goal of exporting 80 nuclear reactors by 2030?

International Nuclear Information System (INIS)

Berthelemy, Michel; Leveque, Francois

2011-01-01

The success of Korea in winning, in December 2009, a USD 18.6 billion nuclear tender in the United Arab Emirates (UAE) has led to a growing interest in the organization and strengths of the Korean nuclear industry. In this paper, we present the main economic and political factors that explain the success of the Korean consortium. In particular, thanks to an active national program of Nuclear Power Plant (NPP) construction, Korea has developed distinct competitive advantages in terms of low cost, high credibility and high performance. At the same time, due to the important barriers to enter into the nuclear export market in the UAE, Korea has had to sacrifice its profit margin and has benefited from a strong political support from its government through export financing. More importantly, Korea's success is also due to its alliance with Westinghouse and the support of the US diplomacy. Subsequently, we show that while Korea has recently experienced setbacks in nuclear tenders, it will most certainly try to win in the short run a second nuclear tender with another aggressive price. In the longer run, Korea could take a growing share of the international market for NPPs. However, the extent to which Korea can achieve its long term export target will depend upon its capacity to finance nuclear export through export credits and upon the development of its alliance with Westinghouse. It is important to note that this paper was written before the Fukushima nuclear disaster. The scale of the human and environmental consequences of this accident are still unknown, and will undoubtedly have short and long term consequences on nuclear safety requirements and public attitude toward nuclear energy, which will most certainly impact the outlooks for nuclear new-builds. (authors)

Study on international publicity and export strategy establishment of nuclear technology

Energy Technology Data Exchange (ETDEWEB)

Lee, Ji Bok; Choi, C.O.; Park, K. B.; Chang, M. H.; Kim, K. K.; Yang, M. S.; Jung, I. H.; Kim, K. P.; Wu, J. S.; Jang, C. I.; Han, B. O.; Sim, J. H.; Chung, M.; Chung, J.K

1999-05-01

The objective of this study is to devise a proper measure for international publicity and technology export strategy. Analysed and summaries in detail are other countries nuclear policy trend and the current technology development status of Korea Standard Nuclear Plant that we developed on our own technology, design and construction technology for research reactor, System-integrated Modular Advanced Reactor of which design is in progress, Direct use of Spent PWR Fuel in CANDU Reactors, and Radioisotopes. Based on that, the measures are proposed for the export industrialization of nuclear technology and establishment of the export basis. Also the international nuclear cooperation and publicity strategy are suggested to support the technology export basis. By surveying the world nuclear status, the direction for the international cooperation and publicity is settled and the specific publicity strategy is proposed for the cooperation with IAEA and multi-countries and the establishment of the nuclear technology export basis. As part of this project, the panel on major technologies such as Korea Standard Nuclear Plant, HANARO, and System-integrated Modular Advanced Reactor was displayed successfully at the IAEA meeting, which contribute much to the publicity of our nuclear technology to the international nuclear society. (author)

Deciphering mechanisms of drug sensitivity and resistance to Selective Inhibitor of Nuclear Export (SINE) compounds

International Nuclear Information System (INIS)

Crochiere, Marsha; Kashyap, Trinayan; Kalid, Ori; Shechter, Sharon; Klebanov, Boris; Senapedis, William; Saint-Martin, Jean-Richard; Landesman, Yosef

2015-01-01

Exportin 1 (XPO1) is a well-characterized nuclear export protein whose expression is up-regulated in many types of cancers and functions to transport key tumor suppressor proteins (TSPs) from the nucleus. Karyopharm Therapeutics has developed a series of small-molecule Selective Inhibitor of Nuclear Export (SINE) compounds, which have been shown to block XPO1 function both in vitro and in vivo. The drug candidate, selinexor (KPT-330), is currently in Phase-II/IIb clinical trials for treatment of both hematologic and solid tumors. The present study sought to decipher the mechanisms that render cells either sensitive or resistant to treatment with SINE compounds, represented by KPT-185, an early analogue of KPT-330. Using the human fibrosarcoma HT1080 cell line, resistance to SINE was acquired over a period of 10 months of constant incubation with increasing concentration of KPT-185. Cell viability was assayed by MTT. Immunofluorescence was used to compare nuclear export of TSPs. Fluorescence activated cell sorting (FACS), quantitative polymerase chain reaction (qPCR), and immunoblots were used to measure effects on cell cycle, gene expression, and cell death. RNA from naïve and drug treated parental and resistant cells was analyzed by Affymetrix microarrays. Treatment of HT1080 cells with gradually increasing concentrations of SINE resulted in > 100 fold decrease in sensitivity to SINE cytotoxicity. Resistant cells displayed prolonged cell cycle, reduced nuclear accumulation of TSPs, and similar changes in protein expression compared to parental cells, however the magnitude of the protein expression changes were more significant in parental cells. Microarray analyses comparing parental to resistant cells indicate that a number of key signaling pathways were altered in resistant cells including expression changes in genes involved in adhesion, apoptosis, and inflammation. While the patterns of changes in transcription following drug treatment are similar in parental

CRM1-dependent nuclear export and dimerization with hMSH5 contribute to the regulation of hMSH4 subcellular localization

International Nuclear Information System (INIS)

Neyton, Sophie; Lespinasse, Francoise; Lahaye, Francois; Staccini, Pascal; Paquis-Flucklinger, Veronique; Santucci-Darmanin, Sabine

2007-01-01

MSH4 and MSH5 are members of the MutS homolog family, a conserved group of proteins involved in DNA mismatch correction and homologous recombination. Although several studies have provided compelling evidences suggesting that MSH4 and MSH5 could act together in early and late stages of meiotic recombination, their precise roles are poorly understood and recent findings suggest that the human MSH4 protein may also exert a cytoplasmic function. Here we show that MSH4 is present in the cytoplasm and the nucleus of both testicular cells and transfected somatic cells. Confocal studies on transfected cells provide the first evidence that the subcellular localization of MSH4 is regulated, at least in part, by an active nuclear export pathway dependent on the exportin CRM1. We used deletion mapping and mutagenesis to define two functional nuclear export sequences within the C-terminal part of hMSH4 that mediate nuclear export through the CRM1 pathway. Our results suggest that CRM1 is also involved in MSH5 nuclear export. In addition, we demonstrate that dimerization of MSH4 and MSH5 facilitates their nuclear localization suggesting that dimerization may regulate the intracellular trafficking of these proteins. Our findings suggest that nucleocytoplasmic traffic may constitute a regulatory mechanism for MSH4 and MSH5 functions

An evaluation of Kazakhstan nuclear export control system

International Nuclear Information System (INIS)

Yeligbayeva, G.; Masenov, Ch.

2002-01-01

A system to control the export nuclear materials and technologies is a natural part of creating a self-sustaining government. The government of Kazakhstan has made a great deal of progress in building such a system. Control of export and import of nuclear materials and technologies and dual-use materials, related to nuclear activity, became one of the important part of mechanism of Non-Proliferation conditions realization in Kazakhstan. The system of export control has developed well over the 10 years. Kazakhstan is in the midst of a long process of building a functional export control system consistent with World standards. The state system of export control currently exists in Kazakhstan on the legislative base, and is based on efficient cooperation of the KAEC with a number of competent state bodies (Ministry of Economy, Ministry of Foreign Affairs, State Customs Committee) each of them has its own specific functions, duties and rights. The export is carried out using licenses, issued by the Ministry of Economy of the RK, according to applications of certain standard which are previously agreed with the KAEC under decision of the RK Government. The KAEC, acting on the base of export control principles and observance of international obligations on non-proliferation matter, makes decisions, only after thorough evaluation of ways of export and reliability of an end-user of the commodity, to agree the application for a license. The most fully developed aspect is the licensing process. General politics of export regulation in Kazakhstan are based on normative acts and rules, which are wholly appropriate (complementary) to the managing principles of nuclear export. There exists a full legal basis for the licensing system. But the process is going, some provisions is changing: in 2000 Kazakhstan corrected the export control law and approved the national control list very similar with EU control list, in 2002 the rules of the process of licensing the export and import

Integration of mRNP formation and export.

Science.gov (United States)

Björk, Petra; Wieslander, Lars

2017-08-01

Expression of protein-coding genes in eukaryotes relies on the coordinated action of many sophisticated molecular machineries. Transcription produces precursor mRNAs (pre-mRNAs) and the active gene provides an environment in which the pre-mRNAs are processed, folded, and assembled into RNA-protein (RNP) complexes. The dynamic pre-mRNPs incorporate the growing transcript, proteins, and the processing machineries, as well as the specific protein marks left after processing that are essential for export and the cytoplasmic fate of the mRNPs. After release from the gene, the mRNPs move by diffusion within the interchromatin compartment, making up pools of mRNPs. Here, splicing and polyadenylation can be completed and the mRNPs recruit the major export receptor NXF1. Export competent mRNPs interact with the nuclear pore complex, leading to export, concomitant with compositional and conformational changes of the mRNPs. We summarize the integrated nuclear processes involved in the formation and export of mRNPs.

Functional analysis of the interaction of the human immunodeficiency virus type 1 Rev nuclear export signal with its cofactors

International Nuclear Information System (INIS)

Kiss, A.; Li, L.; Gettemeier, T.; Venkatesh, L.K.

2003-01-01

Human immunodeficiency virus type 1 (HIV-1) Rev-mediated nuclear export of viral RNAs involves the interaction of its leucine-rich nuclear export sequence (NES) with nuclear cofactors. In yeast two-hybrid screens of a human lymph node derived cDNA expression library, we identified the human nucleoporin Nup98 as a highly specific and potent interactor of the Rev NES. Using an extensive panel of nuclear export positive and negative mutants of the functionally homologous NESs of the HIV-1 Rev, human T cell leukemia virus type 1 (HTLV-1) Rex, and equine infectious anemia virus (EIAV) Rev proteins, physiologically significant interaction of hNup98 with the various NESs was demonstrated. Missense mutations in the yeast nuclear export factor Crm1p that abrogated Rev NES interaction with the XXFG repeat-containing nucleoporin, Rab/hRIP, had minimal effects on the interaction of GLFG repeat-containing hNup98. Functional analysis of Nup98 domains required for nuclear localization demonstrated that the entire ORF was required for efficient incorporation into the nuclear envelope. A putative nuclear localization signal was identified downstream of the GLFG repeat region. Whereas overexpression of both full-length Nup98 and the amino-terminal GLFG repeat region, but not the unique carboxy-terminal region, induced significant suppression of HIV unspliced RNA export, lower levels of exogenous Nup98 expression resulted in a relatively modest increase in unspliced RNA export. These results suggest a physiological role for hNup98 in modulating Rev-dependent RNA export during HIV infection

The RNA Exosome Adaptor ZFC3H1 Functionally Competes with Nuclear Export Activity to Retain Target Transcripts

DEFF Research Database (Denmark)

Silla, Toomas; Karadoulama, Evdoxia; Mąkosa, Dawid

2018-01-01

, containing polyadenylated (pA+) RNA secluded from nucleocytoplasmic export. We asked whether exosome co-factors could serve such nuclear retention. Co-localization studies revealed the enrichment of pA+ RNA foci with "pA-tail exosome targeting (PAXT) connection" components MTR4, ZFC3H1, and PABPN1......Mammalian genomes are promiscuously transcribed, yielding protein-coding and non-coding products. Many transcripts are short lived due to their nuclear degradation by the ribonucleolytic RNA exosome. Here, we show that abolished nuclear exosome function causes the formation of distinct nuclear foci...... but no overlap with known nuclear structures such as Cajal bodies, speckles, paraspeckles, or nucleoli. Interestingly, ZFC3H1 is required for foci formation, and in its absence, selected pA+ RNAs, including coding and non-coding transcripts, are exported to the cytoplasm in a process dependent on the mRNA export...

Exporting apocalypse: CANDU reactors and nuclear proliferation

International Nuclear Information System (INIS)

McKay, Paul.

The author believes that the peaceful use of nuclear technology leads inevitably to the production of nuclear weapons, and that CANDU reactors are being bought by countries that are likely to build bombs. He states that exports of reactors and nuclear materials cannot be defended and must be stopped

Legal problems concerning the export of nuclear power plants

International Nuclear Information System (INIS)

Pierer, Heinrich von.

1977-01-01

The legal problems raised by the export of nuclear power plants may be divided into three main categories: nuclear operator's liability for nuclear damage, the consequences for the supplier of the licensing requirements in the national laws of the buyer country and finally, the constraints of applying non-proliferation safeguards on export of nuclear equipment. As regards the third party liability regime in particular, the difficulties lie essentially in the insufficiency of the definition of the nuclear operator and the lack of harmonization in, or even the absence of national laws in this field. (NEA) [fr

Protein export in bacillus subtilis and escherichia coli

NARCIS (Netherlands)

Dijl, Jan Maarten van

1990-01-01

The export of heterologous proteins in Bacillus subtilis and Escherichia coli is often inefficient. Frequently observed problems are: 1) accumulation of the precursor form of the exported protein in the cytoplasm or in the membrane; 2), inefficient or incorrect processing of the precursor; 3),

Analysis of nuclear export control system and implementing international nonproliferation regime in China

International Nuclear Information System (INIS)

Kim, J. S.; Lee, J. S.; Ahn, J. S.; Kim, B. G.; Min, K. S.

2000-01-01

China's exporting behaviour of nuclear items had been disconnected from the international non-proliferation regime such as IAEA safeguards and export control related with peaceful use of nuclear energy since 1970s. Especially, China had been one of principle suppliers of nuclear facility and technologies to Pakistan and Iran which had developed nuclear weapon programs. On the other hand, according to the rapid growth of economic scale after China began to open to the world, an active program for nuclear power plant as an electricity source had established. This means that China have surfaced as a big market to Korean nuclear industries. Regarding this, the paper dealt with the nuclear export control matters, i.e. the history of nuclear export control system and analyzed on background of enforcement of U.S.-China Nuclear Cooperation Agreement that had been apolitical issue between U.S. and China. Prospects toward conforming its nuclear export policies, laws and regulations to international standards also analyzed in results

Overview of nuclear export policies of major foreign supplier nations

International Nuclear Information System (INIS)

1977-01-01

The United States faces increased competition from foreign nuclear suppliers, including West Germany, France, the United Kingdom, Canada, and possibly, in the near future, Japan. This general overview shows the differences and similarities in foreign nuclear supplier export requirements. It is based on summaries furnished by the Department of State covering the nuclear export policies and procedures of the major foreign supplier nations

Analysis of nuclear export using photoactivatable GFP fusion proteins and interspecies heterokaryons.

Science.gov (United States)

Nakrieko, Kerry-Ann; Ivanova, Iordanka A; Dagnino, Lina

2010-01-01

In this chapter, we review protocols for the analysis of nucleocytoplasmic shuttling of transcription factors and nuclear proteins, using two different approaches. The first involves the use of photoactivatable forms of the protein of interest by fusion to photoactivatable green fluorescent protein to follow its movement out of the nucleus by live-cell confocal microscopy. This methodology allows for the kinetic characterization of protein movements as well as measurement of steady-state levels. In a second procedure to assess the ability of a nuclear protein to move into and out of the nucleus, we describe the use of interspecies heterokaryon assays, which provide a measurement of steady-state distribution. These technologies are directly applicable to the analysis of nucleocytoplasmic movements not only of transcription factors, but also other nuclear proteins.

The Cellular Distribution of RanGAP1 Is Regulated by CRM1-Mediated Nuclear Export in Mammalian Cells.

Directory of Open Access Journals (Sweden)

Keith Cha

Full Text Available The Ran GTPase activating protein RanGAP1 plays an essential role in nuclear transport by stimulating RanGTP hydrolysis in the cytoplasmic compartment. In mammalian cells, unmodified RanGAP1 is predominantly cytoplasmic, whereas modification by small ubiquitin-related modifier protein (SUMO targets RanGAP1 to the cytoplasmic filaments of nuclear pore complex (NPC. Although RanGAP1 contains nine putative nuclear export signals and a nuclear localization signal, little is known if RanGAP1 shuttles between the nuclear and cytoplasmic compartments and how its primary localization in the cytoplasm and at the NPC is regulated. Here we show that inhibition of CRM1-mediated nuclear export using RNAi-knockdown of CRM1 and inactivation of CRM1 by leptomycin B (LMB results in nuclear accumulation of RanGAP1. LMB treatment induced a more robust redistribution of RanGAP1 from the cytoplasm to the nucleoplasm compared to CRM1 RNAi and also uniquely triggered a decrease or loss of RanGAP1 localization at the NPC, suggesting that LMB treatment is more effective in inhibiting CRM1-mediated nuclear export of RanGAP1. Our time-course analysis of LMB treatment reveals that the NPC-associated RanGAP1 is much more slowly redistributed to the nucleoplasm than the cytoplasmic RanGAP1. Furthermore, LMB-induced nuclear accumulation of RanGAP1 is positively correlated with an increase in levels of SUMO-modified RanGAP1, suggesting that SUMOylation of RanGAP1 may mainly take place in the nucleoplasm. Lastly, we demonstrate that the nuclear localization signal at the C-terminus of RanGAP1 is required for its nuclear accumulation in cells treated with LMB. Taken together, our results elucidate that RanGAP1 is actively transported between the nuclear and cytoplasmic compartments, and that the cytoplasmic and NPC localization of RanGAP1 is dependent on CRM1-mediated nuclear export.

Nuclear Non-Proliferation and Export Control in the Republic of Croatia

International Nuclear Information System (INIS)

Valcic, I.; Prah, M.; Mikec, N.

2006-01-01

In accordance with its internationally accepted obligations, the Republic of Croatia is actively implementing principles of non-proliferation and export control of nuclear materials and/or equipment. The article deals with treaties, conventions, agreements and other international arrangements that are creating certain obligation for Republic of Croatia related to nuclear non-proliferation. The most important are the Treaty on the Non-proliferation of Nuclear Weapons, the Convention on the Physical Protection of Nuclear Material, the Agreement between the Republic of Croatia and the International Atomic Energy Agency for the Application of Safeguards with Protocol, the Protocol Additional to the Agreement Between the Republic of Croatia and the International Atomic Energy Agency for the Application of Safeguards, the Comprehensive Nuclear Test-Ban Treaty, the NSG Guidelines for the Export of Nuclear Material, Equipment and Technology and NSG Guidelines for Transfers of Nuclear-Related Dual-Use Equipment, Materials, Software and Related Technology. In addition the article describes a national regulative framework, the basis for conducting activities in nuclear material control, export control of dual-use items as well as non-proliferation of the weapons of mass destruction. Details are given about the Nuclear Safety Act, the Act on Liability for Nuclear Damage, the Act on Export of Dual-Use Items, the Decree on the List of Dual-Use Items, the Law on Production, Repair and Trade in Arms and Military Equipment and the Decree specifying goods subject to export and import licenses. (author)

Nuclear Trafficking of Retroviral RNAs and Gag Proteins during Late Steps of Replication

Directory of Open Access Journals (Sweden)

Matthew S. Stake

2013-11-01

Full Text Available Retroviruses exploit nuclear trafficking machinery at several distinct stages in their replication cycles. In this review, we will focus primarily on nucleocytoplasmic trafficking events that occur after the completion of reverse transcription and proviral integration. First, we will discuss nuclear export of unspliced viral RNA transcripts, which serves two essential roles: as the mRNA template for the translation of viral structural proteins and as the genome for encapsidation into virions. These full-length viral RNAs must overcome the cell’s quality control measures to leave the nucleus by co-opting host factors or encoding viral proteins to mediate nuclear export of unspliced viral RNAs. Next, we will summarize the most recent findings on the mechanisms of Gag nuclear trafficking and discuss potential roles for nuclear localization of Gag proteins in retrovirus replication.

NPT, export controls and nuclear trade

International Nuclear Information System (INIS)

Pande, Savita

1997-01-01

Nuclear trade has by and large remained unhampered vis-a-vis both the NPT as well as export control regulations. The NPT rules are regarded as insufficient, the guidelines appear to contravene the spirit of cooperation in trade and development between suppliers and recipients and there is no agreement among leading suppliers themselves on what constitutes the proper conduct of trade. Export control regimes are more or less too informal to be able to be implemented. The supplier states have to invariably depend on national legislations which again vary from country to country. The only common formal basis on which action can be taken is, therefore, the NPT, its loopholes notwithstanding. The idea of transparency, and supplier-recipient dialogue continues to be a myth and will continue to be so long as these regimes remain discriminatory, so long as some nations are more powerful than others by virtue of retaining nuclear weapons and superiority in nuclear technology and trade

U.S. nuclear non-proliferation policy: impact on exports and nuclear industry could not be determined. Report to the Congress

International Nuclear Information System (INIS)

1980-01-01

The Nuclear Non-Proliferation Act of 1978 established new measures to prevent the diversion to weapons use of peaceful nuclear exports. It also created a policy to confirm U.S. reliability as a nuclear supplier. GAO did not identify any export sales lost as a result of the Act, but did find indications that nonproliferation policies can influence export sales. Based on available data, GAO could not determine the impact of the Act on the competitiveness of U.S. nuclear exports. However, U.S. companies are at some disadvantage because importers perceive that implementation of the Act may result in delayed export licenses. The United States dominated the nuclear export market through the early 1970s. However, foreign competitors, some aided by U.S. technology transfers, emerged to monopolize home markets and compete for third-country business. Further, the market has been depressed since 1974 and prospects for U.S. nuclear power plant exports have dimmed greatly. However, U.S. companies continue to view exports as important to sustain production capacity

Influenza polymerase encoding mRNAs utilize atypical mRNA nuclear export.

Science.gov (United States)

Larsen, Sean; Bui, Steven; Perez, Veronica; Mohammad, Adeba; Medina-Ramirez, Hilario; Newcomb, Laura L

2014-08-28

Influenza is a segmented negative strand RNA virus. Each RNA segment is encapsulated by influenza nucleoprotein and bound by the viral RNA dependent RNA polymerase (RdRP) to form viral ribonucleoproteins responsible for RNA synthesis in the nucleus of the host cell. Influenza transcription results in spliced mRNAs (M2 and NS2), intron-containing mRNAs (M1 and NS1), and intron-less mRNAs (HA, NA, NP, PB1, PB2, and PA), all of which undergo nuclear export into the cytoplasm for translation. Most cellular mRNA nuclear export is Nxf1-mediated, while select mRNAs utilize Crm1. Here we inhibited Nxf1 and Crm1 nuclear export prior to infection with influenza A/Udorn/307/1972(H3N2) virus and analyzed influenza intron-less mRNAs using cellular fractionation and reverse transcription-quantitative polymerase chain reaction (RT-qPCR). We examined direct interaction between Nxf1 and influenza intron-less mRNAs using immuno purification of Nxf1 and RT-PCR of associated RNA. Inhibition of Nxf1 resulted in less influenza intron-less mRNA export into the cytoplasm for HA and NA influenza mRNAs in both human embryonic kidney cell line (293 T) and human lung adenocarcinoma epithelial cell line (A549). However, in 293 T cells no change was observed for mRNAs encoding the components of the viral ribonucleoproteins; NP, PA, PB1, and PB2, while in A549 cells, only PA, PB1, and PB2 mRNAs, encoding the RdRP, remained unaffected; NP mRNA was reduced in the cytoplasm. In A549 cells NP, NA, HA, mRNAs were found associated with Nxf1 but PA, PB1, and PB2 mRNAs were not. Crm1 inhibition also resulted in no significant difference in PA, PB1, and PB2 mRNA nuclear export. These results further confirm Nxf1-mediated nuclear export is functional during the influenza life cycle and hijacked for select influenza mRNA nuclear export. We reveal a cell type difference for Nxf1-mediated nuclear export of influenza NP mRNA, a reminder that cell type can influence molecular mechanisms. Importantly, we

Nuclear technology and the export control laws

International Nuclear Information System (INIS)

Munroe, J.L.; Pankratz, M.C.; Hogsett, V.H.; Lundy, A.S.

1988-01-01

Three basic US laws regulate the export of commodities, services, and technical data. People working in nuclear fields need to know of these laws and their impact on professional endeavors. Export of technical data means the communication of any information by oral, written, or any other means to foreign nationals within or outside the US. The medium for the communication may be a model, blueprint, sketch, or any other device that can convey information. If the data relates to items on one of the control lists, a license must be sought from the appropriated federal agency. The Militarily Critical Technologies List (MCTL), though not itself a control list, plays a major role in determining what technical data will require a validated license. The US Department of Energy (DOE), through Technical Working Gorup (TWG) 11, is responsible for the Nuclear Technology chapter of the MCTL. TWG 11 also prepares the Nuclear Technology Reference Book (NTRB), a classified guide to sensitive nuclear technology

Role of regulatory subunits and protein kinase inhibitor (PKI) in determining nuclear localization and activity of the catalytic subunit of protein kinase A.

Science.gov (United States)

Wiley, J C; Wailes, L A; Idzerda, R L; McKnight, G S

1999-03-05

Regulation of protein kinase A by subcellular localization may be critical to target catalytic subunits to specific substrates. We employed epitope-tagged catalytic subunit to correlate subcellular localization and gene-inducing activity in the presence of regulatory subunit or protein kinase inhibitor (PKI). Transiently expressed catalytic subunit distributed throughout the cell and induced gene expression. Co-expression of regulatory subunit or PKI blocked gene induction and prevented nuclear accumulation. A mutant PKI lacking the nuclear export signal blocked gene induction but not nuclear accumulation, demonstrating that nuclear export is not essential to inhibit gene induction. When the catalytic subunit was targeted to the nucleus with a nuclear localization signal, it was not sequestered in the cytoplasm by regulatory subunit, although its activity was completely inhibited. PKI redistributed the nuclear catalytic subunit to the cytoplasm and blocked gene induction, demonstrating that the nuclear export signal of PKI can override a strong nuclear localization signal. With increasing PKI, the export process appeared to saturate, resulting in the return of catalytic subunit to the nucleus. These results demonstrate that both the regulatory subunit and PKI are able to completely inhibit the gene-inducing activity of the catalytic subunit even when the catalytic subunit is forced to concentrate in the nuclear compartment.

[Polyadenylated RNA and mRNA export factors in extrachromosomal nuclear domains of vitellogenic oocytes of the insect Tenebrio molitor].

Science.gov (United States)

Bogoliubov, D S; Kiselev, A M; Shabel'nikov, S V; Parfenov, V N

2012-01-01

The nucleus ofvitellogenic oocytes of the yellow mealworm, Tenebrio molitor, contains a karyosphere that consists of the condensed chromatin embedded in an extrachromosomal fibrogranular material. Numerous nuclear bodies located freely in the nucleoplasm are also observed. Amongst these bodies, counterparts of nuclear speckles (= interchromatin granule clusters, IGCs) can be identified by the presence of the marker protein SC35. Microinjections of fluorescently tagged methyloligoribonucleotide probes 2'-O-Me(U)22, complementary to poly(A) tails of RNAs, revealed poly(A)+ RNA in the vast majority of IGCs. We found that all T. molitor oocyte IGCs contain heterogeneous ribonucleoprotein (hnRNP) core protein Al that localizes to IGCs in an RNA-dependent manner. The extrachromosomal material of the karyosphere and a part of nucleoplasmic IGCs also contain the adapter protein Aly that is known to provide a link between pre-mRNA splicing and mRNA export. The essential mRNA export factor/receptor NXF1 was observed to colocalize with Aly. In nucleoplasmic IGCs, NXF1 was found to localize in an RNA-dependent manner whereas it is RNA-independently located in the extrachromosomal material of the karyosphere. We believe our data suggest on a role of the nucleoplasmic IGCs in mRNA biogenesis and retention in a road to nuclear export.

Korean system of export control to support the commercial nuclear transfer to UAE

International Nuclear Information System (INIS)

Cho, Young Ho

2011-01-01

In December 2009, the Republic of Korea won the contract to build 4 1,400 MW nuclear power reactors worth USD 20 billion in the UAE. The states-owned KEPCO will complete the turnkey project to the UAE including design, engineering, construction, nuclear fuel, operations, maintenance and technical support. Since sensitive nuclear technologies convertible to military purpose can be spread by the transfer of commercial nuclear power plant, it is essential prerequisite to implement nuclear export control tenaciously and effectively. About twenty years have passed since the Republic of Korea introduced export control system in domestic laws and regulations. Marking a major historical milestone in 2009 by ranking among global nuclear suppliers, the Korean government made a major step forward in export control framework to support its next nuclear export goal. (orig.)

A comparative study on export control systems of nuclear technology in ROK and USA

Energy Technology Data Exchange (ETDEWEB)

Tae, Jae Woong; Shin, Dong Hoon [Korea Institute of Nuclear Nonproliferation and Control, Daejeon (Korea, Republic of)

2013-10-15

Perfect removal of transferred technology is impossible because it is impossible to find all copies of technologies such as files and documents. International community concerns about Terrorists' acquirement of nuclear technologies related to nuclear reactors, enrichment and reprocessing Facilities and heavy water production facilities, which can be used for production of nuclear weapons. Non-state actors as well as concerning countries have tried to possess nuclear technology for developing nuclear weapons. Non-state actors' activities threaten global nuclear security. Korea exported four nuclear power plants to UAE and a research reactor to Jordan. Non-state actors may try to procure nuclear equipment and technology from Korean nuclear industries. Therefore, the export control system should be enhanced for national nuclear security and safety. In this study, the export control system of Korea and the United States were compared concerning to nuclear technology. In summary, controlled activities related to nuclear technology are treated more variously and more diverse activities are controlled in the United States than In Korea. Catch-all control will lose its effectiveness without this. Related to the control of ITT (Intangible Technology Transfer), Korea and the United States are trying to amend the export control regulation. Both of them are trying to control intangible technology transfers effectively. Revised Foreign Trade Act in Korea is expected to introduce a more rigorous system of nuclear technology controls. It focuses on nationality rather than residence. The revised law may face into other problems such as dual nationals like as the United States. However, this satisfies legislative requirements for control of a deemed export. The revised law will enter into force in 2014. Accurate meanings of technology and export will be defined soon in the enforcement decree and the public notice before 2014. However, it is hard to revise the definition

A comparative study on export control systems of nuclear technology in ROK and USA

International Nuclear Information System (INIS)

Tae, Jae Woong; Shin, Dong Hoon

2013-01-01

Perfect removal of transferred technology is impossible because it is impossible to find all copies of technologies such as files and documents. International community concerns about Terrorists' acquirement of nuclear technologies related to nuclear reactors, enrichment and reprocessing Facilities and heavy water production facilities, which can be used for production of nuclear weapons. Non-state actors as well as concerning countries have tried to possess nuclear technology for developing nuclear weapons. Non-state actors' activities threaten global nuclear security. Korea exported four nuclear power plants to UAE and a research reactor to Jordan. Non-state actors may try to procure nuclear equipment and technology from Korean nuclear industries. Therefore, the export control system should be enhanced for national nuclear security and safety. In this study, the export control system of Korea and the United States were compared concerning to nuclear technology. In summary, controlled activities related to nuclear technology are treated more variously and more diverse activities are controlled in the United States than In Korea. Catch-all control will lose its effectiveness without this. Related to the control of ITT (Intangible Technology Transfer), Korea and the United States are trying to amend the export control regulation. Both of them are trying to control intangible technology transfers effectively. Revised Foreign Trade Act in Korea is expected to introduce a more rigorous system of nuclear technology controls. It focuses on nationality rather than residence. The revised law may face into other problems such as dual nationals like as the United States. However, this satisfies legislative requirements for control of a deemed export. The revised law will enter into force in 2014. Accurate meanings of technology and export will be defined soon in the enforcement decree and the public notice before 2014. However, it is hard to revise the definition of export

Murine Leukemia Virus Uses TREX Components for Efficient Nuclear Export of Unspliced Viral Transcripts

Directory of Open Access Journals (Sweden)

Toshie Sakuma

2014-03-01

Full Text Available Previously we reported that nuclear export of both unspliced and spliced murine leukemia virus (MLV transcripts depends on the nuclear export factor (NXF1 pathway. Although the mRNA export complex TREX, which contains Aly/REF, UAP56, and the THO complex, is involved in the NXF1-mediated nuclear export of cellular mRNAs, its contribution to the export of MLV mRNA transcripts remains poorly understood. Here, we studied the involvement of TREX components in the export of MLV transcripts. Depletion of UAP56, but not Aly/REF, reduced the level of both unspliced and spliced viral transcripts in the cytoplasm. Interestingly, depletion of THO components, including THOC5 and THOC7, affected only unspliced viral transcripts in the cytoplasm. Moreover, the RNA immunoprecipitation assay showed that only the unspliced viral transcript interacted with THOC5. These results imply that MLV requires UAP56, THOC5 and THOC7, in addition to NXF1, for nuclear export of viral transcripts. Given that naturally intronless mRNAs, but not bulk mRNAs, require THOC5 for nuclear export, it is plausible that THOC5 plays a key role in the export of unspliced MLV transcripts.

Mapping the nuclear localization signal in the matrix protein of potato yellow dwarf virus.

Science.gov (United States)

Anderson, Gavin; Jang, Chanyong; Wang, Renyuan; Goodin, Michael

2018-05-01

The ability of the matrix (M) protein of potato yellow dwarf virus (PYDV) to remodel nuclear membranes is controlled by a di-leucine motif located at residues 223 and 224 of its primary structure. This function can be uncoupled from that of its nuclear localization signal (NLS), which is controlled primarily by lysine and arginine residues immediately downstream of the LL motif. In planta localization of green fluorescent protein fusions, bimolecular fluorescence complementation assays with nuclear import receptor importin-α1 and yeast-based nuclear import assays provided three independent experimental approaches to validate the authenticity of the M-NLS. The carboxy terminus of M is predicted to contain a nuclear export signal, which is belived to be functional, given the ability of M to bind the Arabidopsis nuclear export receptor 1 (XPO1). The nuclear shuttle activity of M has implications for the cell-to-cell movement of PYDV nucleocapsids, based upon its interaction with the N and Y proteins.

Leukemia-Associated Nup214 Fusion Proteins Disturb the XPO1-Mediated Nuclear-Cytoplasmic Transport Pathway and Thereby the NF-κB Signaling Pathway.

Science.gov (United States)

Saito, Shoko; Cigdem, Sadik; Okuwaki, Mitsuru; Nagata, Kyosuke

2016-07-01

Nuclear-cytoplasmic transport through nuclear pore complexes is mediated by nuclear transport receptors. Previous reports have suggested that aberrant nuclear-cytoplasmic transport due to mutations or overexpression of nuclear pore complexes and nuclear transport receptors is closely linked to diseases. Nup214, a component of nuclear pore complexes, has been found as chimeric fusion proteins in leukemia. Among various Nup214 fusion proteins, SET-Nup214 and DEK-Nup214 have been shown to be engaged in tumorigenesis, but their oncogenic mechanisms remain unclear. In this study, we examined the functions of the Nup214 fusion proteins by focusing on their effects on nuclear-cytoplasmic transport. We found that SET-Nup214 and DEK-Nup214 interact with exportin-1 (XPO1)/CRM1 and nuclear RNA export factor 1 (NXF1)/TAP, which mediate leucine-rich nuclear export signal (NES)-dependent protein export and mRNA export, respectively. SET-Nup214 and DEK-Nup214 decreased the XPO1-mediated nuclear export of NES proteins such as cyclin B and proteins involved in the NF-κB signaling pathway by tethering XPO1 onto nuclear dots where Nup214 fusion proteins are localized. We also demonstrated that SET-Nup214 and DEK-Nup214 expression inhibited NF-κB-mediated transcription by abnormal tethering of the complex containing p65 and its inhibitor, IκB, in the nucleus. These results suggest that SET-Nup214 and DEK-Nup214 perturb the regulation of gene expression through alteration of the nuclear-cytoplasmic transport system. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

A study on the revision of nuclear safety act to build the foundation of nuclear export and import control system in Korea

International Nuclear Information System (INIS)

Yang, Seung Hyo; Choi, Sun Do

2012-01-01

Nuclear related items require export and import control beyond the multilateral export control system according to Safeguard Agreement, Additional Protocol and bilateral agreements. Besides Korea as a nuclear supplier is needed to actively cope with its export control system, which is being reinforced internationally. In regard to this trend, this study drew the revision plan of present Nuclear Safety Act to found the nuclear export and import control system in Korea by examining the related legislations and analyzing the implementation status of nuclear export and import control

A study on the revision of nuclear safety act to build the foundation of nuclear export and import control system in Korea

Energy Technology Data Exchange (ETDEWEB)

Yang, Seung Hyo; Choi, Sun Do [Korea Institute of Nuclear Nonproliferation and Control, Daejeon (Korea, Republic of)

2012-10-15

Nuclear related items require export and import control beyond the multilateral export control system according to Safeguard Agreement, Additional Protocol and bilateral agreements. Besides Korea as a nuclear supplier is needed to actively cope with its export control system, which is being reinforced internationally. In regard to this trend, this study drew the revision plan of present Nuclear Safety Act to found the nuclear export and import control system in Korea by examining the related legislations and analyzing the implementation status of nuclear export and import control.

A study on establishing export system of nuclear related equipments to the IAEA

Energy Technology Data Exchange (ETDEWEB)

Song, Ki Dong; Lee, Man Ki; Moon, Ki Hwan; Kim, Seung Soo; Lim, Chae Young; Kim, Hwa Sup; Min, Tae Sik [Korea Atomic Energy Research Institute, Taejeon (Korea)

2002-04-01

In spite of the advanced status in the international nuclear society, exports of domestic nuclear industries to procurement market of the international organizations has been negligible. This study briefly explained the role and the structure of the IAEA. Then, this study surveyed the size of procurement market, major procurement items, and procurement process. This study also gave an export example to the IAEA from Korea Atomic Energy Research Institute for the ease of understanding the procurement process. Based on these surveys and analysis, this study established the goal and strategy for exports of nuclear equipments to the IAEA. Besides, this study surveyed domestic nuclear industries that have potential to export their products to the IAEA. Then, Korea Atomic Energy Research Institute, by a cooperation with Korea Atomic Industrial Forum Inc., held workshop on 'export of nuclear equipments to IAEA' in May 2001 for them. 4 refs., 1 fig., 10 tabs. (Author)

An Interaction between KSHV ORF57 and UIF Provides mRNA-Adaptor Redundancy in Herpesvirus Intronless mRNA Export

Science.gov (United States)

Jackson, Brian R.; Boyne, James R.; Noerenberg, Marko; Taylor, Adam; Hautbergue, Guillaume M.; Walsh, Matthew J.; Wheat, Rachel; Blackbourn, David J.; Wilson, Stuart A.; Whitehouse, Adrian

2011-01-01

The hTREX complex mediates cellular bulk mRNA nuclear export by recruiting the nuclear export factor, TAP, via a direct interaction with the export adaptor, Aly. Intriguingly however, depletion of Aly only leads to a modest reduction in cellular mRNA nuclear export, suggesting the existence of additional mRNA nuclear export adaptor proteins. In order to efficiently export Kaposi's sarcoma-associated herpesvirus (KSHV) intronless mRNAs from the nucleus, the KSHV ORF57 protein recruits hTREX onto viral intronless mRNAs allowing access to the TAP-mediated export pathway. Similarly however, depletion of Aly only leads to a modest reduction in the nuclear export of KSHV intronless mRNAs. Herein, we identify a novel interaction between ORF57 and the cellular protein, UIF. We provide the first evidence that the ORF57-UIF interaction enables the recruitment of hTREX and TAP to KSHV intronless mRNAs in Aly-depleted cells. Strikingly, depletion of both Aly and UIF inhibits the formation of an ORF57-mediated nuclear export competent ribonucleoprotein particle and consequently prevents ORF57-mediated mRNA nuclear export and KSHV protein production. Importantly, these findings highlight that redundancy exists in the eukaryotic system for certain hTREX components involved in the mRNA nuclear export of intronless KSHV mRNAs. PMID:21814512

Regulation of p53 tetramerization and nuclear export by ARC.

Science.gov (United States)

Foo, Roger S-Y; Nam, Young-Jae; Ostreicher, Marc Jason; Metzl, Mark D; Whelan, Russell S; Peng, Chang-Fu; Ashton, Anthony W; Fu, Weimin; Mani, Kartik; Chin, Suet-Feung; Provenzano, Elena; Ellis, Ian; Figg, Nichola; Pinder, Sarah; Bennett, Martin R; Caldas, Carlos; Kitsis, Richard N

2007-12-26

Inactivation of the transcription factor p53 is central to carcinogenesis. Yet only approximately one-half of cancers have p53 loss-of-function mutations. Here, we demonstrate a mechanism for p53 inactivation by apoptosis repressor with caspase recruitment domain (ARC), a protein induced in multiple cancer cells. The direct binding in the nucleus of ARC to the p53 tetramerization domain inhibits p53 tetramerization. This exposes a nuclear export signal in p53, triggering Crm1-dependent relocation of p53 to the cytoplasm. Knockdown of endogenous ARC in breast cancer cells results in spontaneous tetramerization of endogenous p53, accumulation of p53 in the nucleus, and activation of endogenous p53 target genes. In primary human breast cancers with nuclear ARC, p53 is almost always WT. Conversely, nearly all breast cancers with mutant p53 lack nuclear ARC. We conclude that nuclear ARC is induced in cancer cells and negatively regulates p53.

Know-how and nuclear exports

International Nuclear Information System (INIS)

Luxo, A.

1978-01-01

The concrete content of nuclear know-how is defined, and the present position as to the exchange of know-how is discussed. The new forms which may be taken by this know-how are considered and the results which may be expected from a know-how transfer (both for the exporting and the importing countries) are related [fr

A study on establishing export system of nuclear related equipments to the IAEA

Energy Technology Data Exchange (ETDEWEB)

Song, Ki Dong; Lee, Man Ki; Moon, Ki Hwan; Kim, Seung Soo; Lim, Chae Young; Kim, Hwa Sup; Min, Tae Sik [Korea Atomic Energy Research Institute, Taejeon (Korea)

2002-04-01

In spite of the advanced status in the international nuclear society, exports of domestic nuclear industries to procurement market of the international organizations has been negligible. This study briefly explained the role and the structure of the IAEA. Then, this study surveyed the size of procurement market, major procurement items, and procurement process. This study also gave an export example to the IAEA from Korea Atomic Energy Research Institute for the ease of understanding the procurement process. Based on these surveys and analysis, this study established the goal and strategy for exports of nuclear equipments to the IAEA. Besides, this study surveyed domestic nuclear industries that have potential to export their products to the IAEA. Then, Korea Atomic Energy Research Institute, by a cooperation with Korea Atomic Industrial Forum Inc., held workshop on 'export of nuclear equipments to IAEA' in May 2001 for them. 4 refs., 1 fig., 10 tabs. (Author)

Nuclear export policy of the Reagan Administration

Energy Technology Data Exchange (ETDEWEB)

Pilat, J F; Donnelly, W H [Library of Congress, Washington, DC (USA)

1983-06-01

The Reagan Administration maintains the Carter Administration's objective of non-proliferation of nuclear weapons as being fundamental to US nuclear export policy. However, it sees the USA as having another important role to play in influencing the use of nuclear power and the trading of related goods and technologies in other countries. While the Administration believes its policies will prove beneficial to the USA, there is concern that trade considerations are being given priority over preventing the proliferation of nuclear weapons.

Conditional Depletion of Nuclear Proteins by the Anchor Away System (ms# CP-10-0125)

Science.gov (United States)

Fan, Xiaochun; Geisberg, Joseph V.; Wong, Koon Ho; Jin, Yi

2011-01-01

Nuclear proteins play key roles in the regulation of many important cellular processes. In Saccharomyces cerevisiae, many genes encoding nuclear proteins are essential. Here we describe a method termed Anchor Away that can be used to conditionally and rapidly deplete nuclear proteins of interest. It involves conditional export of the protein of interest out of the nucleus and its subsequent sequestration in the cytoplasm. This method can be used to simultaneously deplete multiple proteins from nucleus. PMID:21225637

How the Eximbank helps US nuclear exporters

International Nuclear Information System (INIS)

Moore, J.L. Jr.

1981-01-01

The way in which the Export-Import Bank operates in support of the United States nuclear industry noting particularly its flexibility in responding to changing needs and budget constraints is described. (author)

German nuclear fuel exports and imports 1991

International Nuclear Information System (INIS)

Anon.

1993-01-01

The statistics compiled by the German Federal Office for Trade and Industry (Bundesamt fuer Wirtschaft) for the Federal Ministry for the Environment, Conservation of Nature, and Reactor Safety of imports and exports of nuclear fuels and source materials in 1991 show a major drop by 33.8% in imports and a pronounced rise by 191.5% in exports, compared to the levels in the previous year. Source material for the purposes of these statistics refers only to uranium concentrate. Quantitatively, the biggest import items are source materials, depleted uranium, and uranium enriched up to 3%. Exports of unirradiated material quantitatively comprise mainly depleted uranium, source material, and uranium enriched up to 10%. (orig.) [de

Multiple Export Mechanisms for mRNAs

Science.gov (United States)

Delaleau, Mildred; Borden, Katherine L. B.

2015-01-01

Nuclear mRNA export plays an important role in gene expression. We describe the mechanisms of mRNA export including the importance of mRNP assembly, docking with the nuclear basket of the nuclear pore complex (NPC), transit through the central channel of the NPC and cytoplasmic release. We describe multiple mechanisms of mRNA export including NXF1 and CRM1 mediated pathways. Selective groups of mRNAs can be preferentially transported in order to respond to cellular stimuli. RNAs can be selected based on the presence of specific cis-acting RNA elements and binding of specific adaptor proteins. The role that dysregulation of this process plays in human disease is also discussed. PMID:26343730

Development of Export Control Comprehensive Management Model for Nuclear Power Plants and Others Projects

Energy Technology Data Exchange (ETDEWEB)

Lee, Chansuh; Seo, Hana; Choi, Sundo [Korea Institute of Nuclear Nonproliferation And Control, Daejeon (Korea, Republic of)

2014-05-15

It is required that there are lots of managements of care and concern if the project contains strategic items such as NPPs. The Korean nuclear industry and its related companies, such as the Korea Hydro and Nuclear Power (KHNP), are promoting greater exports of NPPs. It is likely that Korea will export more this technology to newcomer states in the future. As a result, the ROK has been improving its export control management system for NPPs. In keeping with this national effort, Korea Institute of Nuclear Nonproliferation And Control (KINAC) developed comprehensive export control management model for NPPs and other projects, in preparation for this projected growth in the industry. This model also applies to the nuclear export case of the UAE, aims to manage the project from bidding to the end of the contract. The recent Export Licensing of Nuclear Facility Technology was reflected in the Notice on Export and Import of Strategic Items in January 2014. Through this license, the large-scale project legislation framework was established. It can also minimize nonproliferation concerns of the international community through strict management. It is expected that the Korea will be able to enhance transparency and secure the nuclear use, while meeting nonproliferation purpose.

Development of Export Control Comprehensive Management Model for Nuclear Power Plants and Others Projects

International Nuclear Information System (INIS)

Lee, Chansuh; Seo, Hana; Choi, Sundo

2014-01-01

It is required that there are lots of managements of care and concern if the project contains strategic items such as NPPs. The Korean nuclear industry and its related companies, such as the Korea Hydro and Nuclear Power (KHNP), are promoting greater exports of NPPs. It is likely that Korea will export more this technology to newcomer states in the future. As a result, the ROK has been improving its export control management system for NPPs. In keeping with this national effort, Korea Institute of Nuclear Nonproliferation And Control (KINAC) developed comprehensive export control management model for NPPs and other projects, in preparation for this projected growth in the industry. This model also applies to the nuclear export case of the UAE, aims to manage the project from bidding to the end of the contract. The recent Export Licensing of Nuclear Facility Technology was reflected in the Notice on Export and Import of Strategic Items in January 2014. Through this license, the large-scale project legislation framework was established. It can also minimize nonproliferation concerns of the international community through strict management. It is expected that the Korea will be able to enhance transparency and secure the nuclear use, while meeting nonproliferation purpose

AKT3 controls mitochondrial biogenesis and autophagy via regulation of the major nuclear export protein CRM-1.

Science.gov (United States)

Corum, Daniel G; Tsichlis, Philip N; Muise-Helmericks, Robin C

2014-01-01

Our previous work has shown that Akt3 is required for mitochondrial biogenesis in primary human endothelial cells (ECs) and in Akt3-null mice; Akt3 affects subcellular localization of peroxisome proliferator-activated receptor γ coactivator-1 (PGC-1α), the master regulator of mitochondrial biogenesis. The purpose of this study is to determine the mechanism by which Akt3 controls the subcellular distribution of PGC-1α and to explore the effect on mitochondrial biogenesis and turnover during angiogenesis. Here we use standard biochemical analyses and Akt3-knockdown strategies to show that Akt3 controls the stabilization of chromosome maintenance region-1 (CRM-1), the major nuclear export receptor. Site-directed mutagenesis and association analyses show that PGC-1α nuclear export is CRM-1 dependent. Akt3 knockdown and CRM-1 overexpression cause 3-fold reductions in PGC-1α target gene expression, compared to control levels. Akt3 inhibition causes autophagy, as measured by autophagosome formation, in a CRM-1-dependent, Akt1/mTOR-independent pathway. In vivo, Akt3-null and heterozygous mice show dose-dependent decreases in angiogenesis compared to wild-type littermates (~5- and 2.5-fold decreases, respectively), as assessed by Matrigel plug assays. This correlates with an ~1.5-fold decrease in mitochondrial Cox IV expression. Our studies suggest that Akt3 is a regulator of mitochondrial dynamics in the vasculature via regulation of CRM-1-dependent nuclear export.

Nuclear Export of Pre-Ribosomal Subunits Requires Dbp5, but Not as an RNA-Helicase as for mRNA Export.

Science.gov (United States)

Neumann, Bettina; Wu, Haijia; Hackmann, Alexandra; Krebber, Heike

2016-01-01

The DEAD-box RNA-helicase Dbp5/Rat8 is known for its function in nuclear mRNA export, where it displaces the export receptor Mex67 from the mRNA at the cytoplasmic side of the nuclear pore complex (NPC). Here we show that Dbp5 is also required for the nuclear export of both pre-ribosomal subunits. Yeast temperature-sensitive dbp5 mutants accumulate both ribosomal particles in their nuclei. Furthermore, Dbp5 genetically and physically interacts with known ribosomal transport factors such as Nmd3. Similar to mRNA export we show that also for ribosomal transport Dbp5 is required at the cytoplasmic side of the NPC. However, unlike its role in mRNA export, Dbp5 does not seem to undergo its ATPase cycle for this function, as ATPase-deficient dbp5 mutants that selectively inhibit mRNA export do not affect ribosomal transport. Furthermore, mutants of GLE1, the ATPase stimulating factor of Dbp5, show no major ribosomal export defects. Consequently, while Dbp5 uses its ATPase cycle to displace the export receptor Mex67 from the translocated mRNAs, Mex67 remains bound to ribosomal subunits upon transit to the cytoplasm, where it is detectable on translating ribosomes. Therefore, we propose a model, in which Dbp5 supports ribosomal transport by capturing ribosomal subunits upon their cytoplasmic appearance at the NPC, possibly by binding export factors such as Mex67. Thus, our findings reveal that although different ribonucleoparticles, mRNAs and pre-ribosomal subunits, use shared export factors, they utilize different transport mechanisms.

French nuclear industry exportations: companies and organisations, achievements and projects

International Nuclear Information System (INIS)

Faudon, V.; Pailler, S.; Miniere, D.; Pouget-Abadie, X.; Journes, F.; Ouali, F.; Brochard, D.; Choho, T.; Lagarde, D.; Anglaret, P.; Kottman, G.; Mockly, D.; Ouzounian, G.; Cordier, P.Y.; Prenez, J.C.; Arpino, J.M.; Jaouen, C.; Jolly, B.

2013-01-01

This document gathers a series of short articles in which the following players: French Nuclear Safety Authority (ASN), Electricity of France (EdF), French Alternative Energies and Atomic Energy Commission (CEA), AREVA, ALSTOM, the Association of French Nuclear Industry Exporters (AIFEN), the National Radioactive Waste Management Agency (ANDRA) and the French Society of Nuclear Energy (SFEN) present their competencies in their respective fields and their strategies and commercial offers for exports. 2 articles are dedicated to the achievements of the French nuclear industry in China and another details the cooperation between SFEN and its foreign counterparts. Another article briefly presents the EPR and ATMEA reactors. (A.C.)

RNA Export through the NPC in Eukaryotes.

Science.gov (United States)

Okamura, Masumi; Inose, Haruko; Masuda, Seiji

2015-03-20

In eukaryotic cells, RNAs are transcribed in the nucleus and exported to the cytoplasm through the nuclear pore complex. The RNA molecules that are exported from the nucleus into the cytoplasm include messenger RNAs (mRNAs), ribosomal RNAs (rRNAs), transfer RNAs (tRNAs), small nuclear RNAs (snRNAs), micro RNAs (miRNAs), and viral mRNAs. Each RNA is transported by a specific nuclear export receptor. It is believed that most of the mRNAs are exported by Nxf1 (Mex67 in yeast), whereas rRNAs, snRNAs, and a certain subset of mRNAs are exported in a Crm1/Xpo1-dependent manner. tRNAs and miRNAs are exported by Xpot and Xpo5. However, multiple export receptors are involved in the export of some RNAs, such as 60S ribosomal subunit. In addition to these export receptors, some adapter proteins are required to export RNAs. The RNA export system of eukaryotic cells is also used by several types of RNA virus that depend on the machineries of the host cell in the nucleus for replication of their genome, therefore this review describes the RNA export system of two representative viruses. We also discuss the NPC anchoring-dependent mRNA export factors that directly recruit specific genes to the NPC.

Export financing of nuclear power plants - banks experience

International Nuclear Information System (INIS)

Loeber

1976-01-01

Export financing of a nuclear power plant to be exported from Germany, is, in principle, provided by German commercial banks and KfW (Kreditanstalt fuer Wiederaufbau). As a rule, 50 per cent of the financing of maturities falling due under the export portion of the loan will be taken over by a banking syndicate of approximately 25 member banks, and the remaining 50 per cent would be provided by KfW. KfW and the commercial banks must grant their loans at the respective money market conditions. The banks' and KfW's loans will normally be disbursed pro rata delivery. (HP) [de

Nuclear Import and Export of the Thyroid Hormone Receptor.

Science.gov (United States)

Zhang, Jibo; Roggero, Vincent R; Allison, Lizabeth A

2018-01-01

The thyroid hormone receptors, TRα1 and TRβ1, are members of the nuclear receptor superfamily that forms one of the most abundant classes of transcription factors in multicellular organisms. Although primarily localized to the nucleus, TRα1 and TRβ1 shuttle rapidly between the nucleus and cytoplasm. The fine balance between nuclear import and export of TRs has emerged as a critical control point for modulating thyroid hormone-responsive gene expression. Mutagenesis studies have defined two nuclear localization signal (NLS) motifs that direct nuclear import of TRα1: NLS-1 in the hinge domain and NLS-2 in the N-terminal A/B domain. Three nuclear export signal (NES) motifs reside in the ligand-binding domain. A combined approach of shRNA-mediated knockdown and coimmunoprecipitation assays revealed that nuclear entry of TRα1 is facilitated by importin 7, likely through interactions with NLS-2, and importin β1 and the adapter importin α1 interacting with both NLS-1 and NLS-2. Interestingly, TRβ1 lacks NLS-2 and nuclear import depends solely on the importin α1/β1 heterodimer. Heterokaryon and fluorescence recovery after photobleaching shuttling assays identified multiple exportins that play a role in nuclear export of TRα1, including CRM1 (exportin 1), and exportins 4, 5, and 7. Even single amino acid changes in TRs dramatically alter their intracellular distribution patterns. We conclude that mutations within NLS and NES motifs affect nuclear shuttling activity, and propose that TR mislocalization contributes to the development of some types of cancer and Resistance to Thyroid Hormone syndrome. © 2018 Elsevier Inc. All rights reserved.

The National Implementation of Nuclear Export Controls: Developing a Best Practices Model

Energy Technology Data Exchange (ETDEWEB)

Viski, Andrea [European University Institute, Department of Law, Badia Fiesolana, S.Domenico di Fiesole, Firenze (Italy)

2011-12-15

The nuclear renaissance promises significant benefits to the international community, but also raises security challenges, particularly relating to the trade of nuclear materials and equipment. The objective of this paper is to examine how supply-side non-proliferation efforts can be strengthened by developing a best practices model for national nuclear export control implementation. In order to achieve this goal, nuclear export control measures identified by the 1540 Committee will be used as a framework from which a best practices model can be formed. Such a model concentrates specifically on national legislation and enforcement measures delineated by the Committee in order to bring countries in accordance with international law. Developing a best practices model seeks to deliver an ideal process for national export control law actualization in order to encourage the peaceful development of nuclear energy and develop the infrastructure and framework for precluding nuclear proliferation.

Examining the intersection between splicing, nuclear export and small RNA pathways.

Science.gov (United States)

Nabih, Amena; Sobotka, Julia A; Wu, Monica Z; Wedeles, Christopher J; Claycomb, Julie M

2017-11-01

Nuclear Argonaute/small RNA pathways in a variety of eukaryotic species are generally known to regulate gene expression via chromatin modulation and transcription attenuation in a process known as transcriptional gene silencing (TGS). However, recent data, including genetic screens, phylogenetic profiling, and molecular mechanistic studies, also point to a novel and emerging intersection between the splicing and nuclear export machinery with nuclear Argonaute/small RNA pathways in many organisms. In this review, we summarize the field's current understanding regarding the relationship between splicing, export and small RNA pathways, and consider the biological implications for coordinated regulation of transcripts by these pathways. We also address the importance and available approaches for understanding the RNA regulatory logic generated by the intersection of these particular pathways in the context of synthetic biology. The interactions between various eukaryotic RNA regulatory pathways, particularly splicing, nuclear export and small RNA pathways provide a type of combinatorial code that informs the identity ("self" versus "non-self") and dictates the fate of each transcript in a cell. Although the molecular mechanisms for how splicing and nuclear export impact small RNA pathways are not entirely clear at this early stage, the links between these pathways are widespread across eukaryotic phyla. The link between splicing, nuclear export, and small RNA pathways is emerging and establishes a new frontier for understanding the combinatorial logic of gene regulation across species that could someday be harnessed for therapeutic, biotechnology and agricultural applications. This article is part of a Special Issue entitled "Biochemistry of Synthetic Biology - Recent Developments" Guest Editor: Dr. Ilka Heinemann and Dr. Patrick O'Donoghue. Copyright © 2017 Elsevier B.V. All rights reserved.

Upgrading the safety assessment of exported nuclear power plants

International Nuclear Information System (INIS)

Rosen, M.

1978-01-01

An examination of the safety aspects of exported nuclear power plants demonstrates that additional and somewhat special considerations exist for these plants, and thus that some new approaches may be required to insure their safety. In view of the generally small regulatory staffs of importing countries, suggestions are given for measures which should be taken by the various organizations involved in the export and import of nuclear power facilities to raise the level of the very essential safety assessment. These include the upgrading of the 'export edition' of the traditionally supplied safety documentation by use of a Supplementary Information Report, written specifically for the needs of a smaller and/or less technically qualified staff, which highlights the differences that exist between the facility to be constructed and the supposedly similar reference plant of the supplier country; by improvement of supporting safety documentation to allow for adequate understanding of significant safety parameters; and by attention to the needs of smaller countries in the critical Operating Regulations (Technical Specifications for Operation). Consideration is also given to upgrading the regulatory effort and to the obligations of principal organizations involved with exported nuclear plants, including national and international, for insuring the importing countries' technical readiness and the adequacy of the regulatory effort. Special attention is directed towards the project contract as a means of implementing programmes to achieve these goals. (author)

Decision support for selecting exportable nuclear technology using the analytic hierarchy process: A Korean case

International Nuclear Information System (INIS)

Lee, Deok Joo; Hwang, Jooho

2010-01-01

The Korean government plans to increase strategically focused R and D investment in some promising nuclear technology areas to create export opportunities of technology in a global nuclear market. The purpose of this paper is to present a decision support process for selecting promising nuclear technology with the perspective of exportability by using the AHP based on extensive data gathered from nuclear experts in Korea. In this study, the decision criteria for evaluating the export competitiveness of nuclear technologies were determined, and a hierarchical structure for the decision-making process was systematically developed. Subsequently relative weights of decision criteria were derived using AHP methodology and the export competitiveness of nuclear technology alternatives was quantified to prioritize them. We discuss the implications of our results with a viewpoint toward national nuclear technology policy.

Nuclear export policy and regulation for non-proliferation: Federal Republic of Germany

International Nuclear Information System (INIS)

Boulanger, Werner.

1978-01-01

The nuclear export policy of the Federal Republic of Germany complies with the principle of non-proliferation of nuclear weapons. Already in 1967 the Federal Government stated in a Peace Note that no export was authorised to countries (outside Euratom) which did not comply with the IAEA Safeguards. In the bilateral agreement the Federal Republic signed with Brasil in 1975, emphasis was put on international safeguards and the control exercised on exported materials to avoid any diversion for military purposes. (NEA) [fr

The Bacterial Flagellar Type III Export Gate Complex Is a Dual Fuel Engine That Can Use Both H+ and Na+ for Flagellar Protein Export.

Directory of Open Access Journals (Sweden)

Tohru Minamino

2016-03-01

Full Text Available The bacterial flagellar type III export apparatus utilizes ATP and proton motive force (PMF to transport flagellar proteins to the distal end of the growing flagellar structure for self-assembly. The transmembrane export gate complex is a H+-protein antiporter, of which activity is greatly augmented by an associated cytoplasmic ATPase complex. Here, we report that the export gate complex can use sodium motive force (SMF in addition to PMF across the cytoplasmic membrane to drive protein export. Protein export was considerably reduced in the absence of the ATPase complex and a pH gradient across the membrane, but Na+ increased it dramatically. Phenamil, a blocker of Na+ translocation, inhibited protein export. Overexpression of FlhA increased the intracellular Na+ concentration in the presence of 100 mM NaCl but not in its absence, suggesting that FlhA acts as a Na+ channel. In wild-type cells, however, neither Na+ nor phenamil affected protein export, indicating that the Na+ channel activity of FlhA is suppressed by the ATPase complex. We propose that the export gate by itself is a dual fuel engine that uses both PMF and SMF for protein export and that the ATPase complex switches this dual fuel engine into a PMF-driven export machinery to become much more robust against environmental changes in external pH and Na+ concentration.

The Bacterial Flagellar Type III Export Gate Complex Is a Dual Fuel Engine That Can Use Both H+ and Na+ for Flagellar Protein Export.

Science.gov (United States)

Minamino, Tohru; Morimoto, Yusuke V; Hara, Noritaka; Aldridge, Phillip D; Namba, Keiichi

2016-03-01

The bacterial flagellar type III export apparatus utilizes ATP and proton motive force (PMF) to transport flagellar proteins to the distal end of the growing flagellar structure for self-assembly. The transmembrane export gate complex is a H+-protein antiporter, of which activity is greatly augmented by an associated cytoplasmic ATPase complex. Here, we report that the export gate complex can use sodium motive force (SMF) in addition to PMF across the cytoplasmic membrane to drive protein export. Protein export was considerably reduced in the absence of the ATPase complex and a pH gradient across the membrane, but Na+ increased it dramatically. Phenamil, a blocker of Na+ translocation, inhibited protein export. Overexpression of FlhA increased the intracellular Na+ concentration in the presence of 100 mM NaCl but not in its absence, suggesting that FlhA acts as a Na+ channel. In wild-type cells, however, neither Na+ nor phenamil affected protein export, indicating that the Na+ channel activity of FlhA is suppressed by the ATPase complex. We propose that the export gate by itself is a dual fuel engine that uses both PMF and SMF for protein export and that the ATPase complex switches this dual fuel engine into a PMF-driven export machinery to become much more robust against environmental changes in external pH and Na+ concentration.

Nuclear safety aspects of exported replicate nuclear power plants and associated problems

International Nuclear Information System (INIS)

Kern, H.G.

1978-01-01

The standardization of the export nuclear power plant is being pursued with the concept of replication. This concept entails using another exported Nuclear Power Plant (NPP) as the base design and adapting it to a new site. The general ground rule applied to this concept is upgrading the design where necessary and duplicating the design where it is superior. Such continuous improvement will result in a standard export NPP that incorporates design features which will make it essentially acceptable for any suitable site. The advantages of replication are, therefore, boundless. However, the replication mode requires superior design control by the engineer to assure that only improvements alter the base design. With this concept, the replicating engineer is essentially assigned the responsiblity of safeguarding the standard export plant design. He is delegated the task of filtering the design such that only the conservative aspects prevail. Tight control of design changes via properly administered procedures is necessary to assure that no unforeseen compromises are made in designs which have already achieved optimization. Techniques to accomplish successful replication include, among others, the use of PCNs, system cognizant engineers, design verfication review, and the participation of all engineering disciplines in the development of the project schedule. (author)

The nuclear export policy of the Reagan administration

International Nuclear Information System (INIS)

Pilat, J.F.; Donnelly, W.H.

1983-01-01

tThe Reagan Administration maintains the Carter Administration's objective of non-proliferation of nuclear weapons as being fundamental to US nuclear export policy. However, it sees the USA as having another important role to play in influencing the use of nuclear power and the trading of related goods and technologies in other countries. While the Administration believes its policies will prove beneficial to the USA, there is concern that trade considerations are being given priority over preventing the proliferation of nuclear weapons. (author)

O. Nuclear energy in a food exporting country

International Nuclear Information System (INIS)

1976-01-01

This report attempts to estimate the affect on agricultural exports from New Zealand which might result from the operation of nuclear power. By far the most serious of these would result from an accidental release of radioactive material, and the likely affects of such releases are considered both in the first year after an accident and in the future. Previous assessments of this type have concentrated attention on property damage and on the health hazards which might result to consumers of contaminated food in the first year or two after a release. In this report the emphasis is on exported foods to which different criteria might apply, and some very approximate estimates are made of long-term implications. To a large extent these can be described only as speculations, but they have some value as a guide. No analgous report has been found in the open literature from other countries, and this particularly includes Denmark which has much in common with New Zealand in this regard. The possible effect of routine operation of nuclear power on food exports is also briefly considered

10 CFR 110.26 - General license for the export of nuclear reactor components.

Science.gov (United States)

2010-01-01

... 10 Energy 2 2010-01-01 2010-01-01 false General license for the export of nuclear reactor components. 110.26 Section 110.26 Energy NUCLEAR REGULATORY COMMISSION (CONTINUED) EXPORT AND IMPORT OF... Denmark Finland France Germany Greece Indonesia Ireland Italy Japan Latvia Lithuania Luxembourg...

Ubiquitination of HTLV-I Tax in response to DNA damage regulates nuclear complex formation and nuclear export

Directory of Open Access Journals (Sweden)

Marriott Susan J

2007-12-01

Full Text Available Abstract Background The HTLV-I oncoprotein, Tax, is a pleiotropic protein whose activity is partially regulated by its ability to interact with, and perturb the functions of, numerous cellular proteins. Tax is predominantly a nuclear protein that localizes to nuclear foci known as Tax Speckled Structures (TSS. We recently reported that the localization of Tax and its interactions with cellular proteins are altered in response to various forms of genotoxic and cellular stress. The level of cytoplasmic Tax increases in response to stress and this relocalization depends upon the interaction of Tax with CRM1. Cellular pathways and signals that regulate the subcellular localization of Tax remain to be determined. However, post-translational modifications including sumoylation and ubiquitination are known to influence the subcellular localization of Tax and its interactions with cellular proteins. The sumoylated form of Tax exists predominantly in the nucleus while ubiquitinated Tax exists predominantly in the cytoplasm. Therefore, we hypothesized that post-translational modifications of Tax that occur in response to DNA damage regulate the localization of Tax and its interactions with cellular proteins. Results We found a significant increase in mono-ubiquitination of Tax in response to UV irradiation. Mutation of specific lysine residues (K280 and K284 within Tax inhibited DNA damage-induced ubiquitination. In contrast to wild-type Tax, which undergoes transient nucleocytoplasmic shuttling in response to DNA damage, the K280 and K284 mutants were retained in nuclear foci following UV irradiation and remained co-localized with the cellular TSS protein, sc35. Conclusion This study demonstrates that the localization of Tax, and its interactions with cellular proteins, are dynamic following DNA damage and depend on the post-translational modification status of Tax. Specifically, DNA damage induces the ubiquitination of Tax at K280 and K284

Role of Non-Government Organizations in strengthening Kazakstan nuclear export control

International Nuclear Information System (INIS)

Tazhibaeva, L.; Prokhodtseva, T.

2002-01-01

Non-governmental organizations (NGO) are the structures that were born by the time, the time when deep changes in our society led us to new trends in the all spheres of society development, to new decisions and, as a consequence, to new structural findings that where able to govern, to support and put into reality the new ideas the could not be inserted in the structure assemblies of the former society. All non-governmental organizations in Kazakhstan are younger than ten years old, but they already could be considered highly experienced, for intensity of their activity is rather high. The main advantages of NGOs are flexibility and independent source of ideas, basic data and policy assessment. There are several non-government organizations that are working in the field of non-proliferation and export control. Kazakhstan Nuclear Technology Safety Center (NTSC) is among them. Non-proliferation and export control is only a small part of activity that NTSC is involved in. Non-governmental organizations could be of several types: NGOs that are affiliated with university or institute, independent associations, quasi-governmental structures and various foundations. NTSC complementing efforts of Kazakhstan Atomic Energy Committee (KAEC) in the field of non-proliferation and export control. The activity of NTSC in the field of non-proliferation includes: Holding conferences, seminars and workshops; Creating databases and reports; Develop proposal for legislation; Provide specialized training; Analyze data. NTSC is involved in a number of projects devoted to non-proliferation and export control. The following projects are supported by the US Department of Energy cooperation program on nuclear export controls for Russia and the Newly Independent States: System to review Kazakhstan exports (STROKE); Computerization of historical licensing data; Export control reference materials for Kazakhstan organizations; Additional Protocol. STROKE is a technical analysis database for

Germany's imports and exports of nuclear fuels in 1981

International Nuclear Information System (INIS)

Anon.

1982-01-01

The statistics of imports and exports of nuclear fuels and basic materials which is set up by the Federal Authority for trade and industry for the Ministry of the Interior shows for 1981 (without taking the basic materials into account) a slight increase by 5% on the imports' side and also a slight increase by 10,5% on the exports' side. (orig./UA) [de

Cdc25A localisation and shuttling: characterisation of sequences mediating nuclear export and import

International Nuclear Information System (INIS)

Kaellstroem, Helena; Lindqvist, Arne; Pospisil, Vitek; Lundgren, Andreas; Karlsson Rosenthal, Christina

2005-01-01

The Cdc25 phosphatases play crucial roles in cell cycle progression by removing inhibitory phosphates from tyrosine and threonine residues of cyclin-dependent kinases. Cdc25A is an important regulator of the G1/S transition but functions also in the mitotic phase of the human cell cycle. In this paper, we investigate the sub-cellular localisation of exogenously expressed Cdc25A. We show that YFP-Cdc25A is localised both in the nucleus and the cytoplasm of HeLa cells and untransformed fibroblasts. Cell fusion assays and fluorescence loss in photobleaching (FLIP) assays reveal that the localisation is dynamic and the protein shuttles between the nucleus and the cytoplasm. We demonstrate that nuclear export of Cdc25A is partly mediated by an N-terminal nuclear export sequence (NES), in a manner not sensitive to the Exportin 1-inhibitor leptomycin B. A nuclear localisation signal (NLS) is also characterised, mutation of which leads to cytoplasmic localisation of Cdc25A. Our results imply that the Cdc25A phosphatase may interact with substrates and regulators both in the nucleus and the cytoplasm

Crystal structure of the Xpo1p nuclear export complex bound to the SxFG/PxFG repeats of the nucleoporin Nup42p.

Science.gov (United States)

Koyama, Masako; Hirano, Hidemi; Shirai, Natsuki; Matsuura, Yoshiyuki

2017-10-01

Xpo1p (yeast CRM1) is the major nuclear export receptor that carries a plethora of proteins and ribonucleoproteins from the nucleus to cytoplasm. The passage of the Xpo1p nuclear export complex through nuclear pore complexes (NPCs) is facilitated by interactions with nucleoporins (Nups) containing extensive repeats of phenylalanine-glycine (so-called FG repeats), although the precise role of each Nup in the nuclear export reaction remains incompletely understood. Here we report structural and biochemical characterization of the interactions between the Xpo1p nuclear export complex and the FG repeats of Nup42p, a nucleoporin localized at the cytoplasmic face of yeast NPCs and has characteristic SxFG/PxFG sequence repeat motif. The crystal structure of Xpo1p-PKI-Nup42p-Gsp1p-GTP complex identified three binding sites for the SxFG/PxFG repeats on HEAT repeats 14-20 of Xpo1p. Mutational analyses of Nup42p showed that the conserved serines and prolines in the SxFG/PxFG repeats contribute to Xpo1p-Nup42p binding. Our structural and biochemical data suggest that SxFG/PxFG-Nups such as Nup42p and Nup159p at the cytoplasmic face of NPCs provide high-affinity docking sites for the Xpo1p nuclear export complex in the terminal stage of NPC passage and that subsequent disassembly of the nuclear export complex facilitates recycling of free Xpo1p back to the nucleus. © 2017 Molecular Biology Society of Japan and John Wiley & Sons Australia, Ltd.

Nuclear Trafficking of the Rabies Virus Interferon Antagonist P-Protein Is Regulated by an Importin-Binding Nuclear Localization Sequence in the C-Terminal Domain.

Directory of Open Access Journals (Sweden)

Caitlin L Rowe

Full Text Available Rabies virus P-protein is expressed as five isoforms (P1-P5 which undergo nucleocytoplasmic trafficking important to roles in immune evasion. Although nuclear import of P3 is known to be mediated by an importin (IMP-recognised nuclear localization sequence in the N-terminal region (N-NLS, the mechanisms underlying nuclear import of other P isoforms in which the N-NLS is inactive or has been deleted have remained unresolved. Based on the previous observation that mutation of basic residues K214/R260 of the P-protein C-terminal domain (P-CTD can result in nuclear exclusion of P3, we used live cell imaging, protein interaction analysis and in vitro nuclear transport assays to examine in detail the nuclear trafficking properties of this domain. We find that the effect of mutation of K214/R260 on P3 is largely dependent on nuclear export, suggesting that nuclear exclusion of mutated P3 involves the P-CTD-localized nuclear export sequence (C-NES. However, assays using cells in which nuclear export is pharmacologically inhibited indicate that these mutations significantly inhibit P3 nuclear accumulation and, importantly, prevent nuclear accumulation of P1, suggestive of effects on NLS-mediated import activity in these isoforms. Consistent with this, molecular binding and transport assays indicate that the P-CTD mediates IMPα2/IMPβ1-dependent nuclear import by conferring direct binding to the IMPα2/IMPβ1 heterodimer, as well as to a truncated form of IMPα2 lacking the IMPβ-binding autoinhibitory domain (ΔIBB-IMPα2, and IMPβ1 alone. These properties are all dependent on K214 and R260. This provides the first evidence that P-CTD contains a genuine IMP-binding NLS, and establishes the mechanism by which P-protein isoforms other than P3 can be imported to the nucleus. These data underpin a refined model for P-protein trafficking that involves the concerted action of multiple NESs and IMP-binding NLSs, and highlight the intricate regulation of P-protein

In Vitro Reconstitution of Functional Type III Protein Export and Insights into Flagellar Assembly.

Science.gov (United States)

Terashima, Hiroyuki; Kawamoto, Akihiro; Tatsumi, Chinatsu; Namba, Keiichi; Minamino, Tohru; Imada, Katsumi

2018-06-26

The type III secretion system (T3SS) forms the functional core of injectisomes, protein transporters that allow bacteria to deliver virulence factors into their hosts for infection, and flagella, which are critical for many pathogens to reach the site of infection. In spite of intensive genetic and biochemical studies, the T3SS protein export mechanism remains unclear due to the difficulty of accurate measurement of protein export in vivo Here, we developed an in vitro flagellar T3S protein transport assay system using an inverted cytoplasmic membrane vesicle (IMV) for accurate and controlled measurements of flagellar protein export. We show that the flagellar T3SS in the IMV fully retains export activity. The flagellar hook was constructed inside the lumen of the IMV by adding purified component proteins externally to the IMV solution. We reproduced the hook length control and export specificity switch in the IMV consistent with that seen in the native cell. Previous in vivo analyses showed that flagellar protein export is driven by proton motive force (PMF) and facilitated by ATP hydrolysis by FliI, a T3SS-specific ATPase. Our in vitro assay recapitulated these previous in vivo observations but furthermore clearly demonstrated that even ATP hydrolysis by FliI alone can drive flagellar protein export. Moreover, this assay showed that addition of the FliH 2 /FliI complex to the assay solution at a concentration similar to that in the cell dramatically enhanced protein export, confirming that the FliH 2 /FliI complex in the cytoplasm is important for effective protein transport. IMPORTANCE The type III secretion system (T3SS) is the functional core of the injectisome, a bacterial protein transporter used to deliver virulence proteins into host cells, and bacterial flagella, critical for many pathogens. The molecular mechanism of protein transport is still unclear due to difficulties in accurate measurements of protein transport under well-controlled conditions in

Subcellular sites for bacterial protein export

NARCIS (Netherlands)

Campo, Nathalie; Tjalsma, Harold; Buist, Girbe; Stepniak, Dariusz; Meijer, Michel; Veenhuis, Marten; Westermann, Martin; Müller, Jörg P.; Bron, Sierd; Kok, Jan; Kuipers, Oscar P.; Jongbloed, Jan D.H.

2004-01-01

Most bacterial proteins destined to leave the cytoplasm are exported to extracellular compartments or imported into the cytoplasmic membrane via the highly conserved SecA-YEG pathway. In the present studies, the subcellular distributions of core components of this pathway, SecA and SecY, and of the

Subcellular sites for bacterial protein export.

NARCIS (Netherlands)

Campo, N.; Tjalsma, H.; Buist, G.; Stepniak, D.; Meijer, M.; Veenhuis, M.; Westermann, M.; Muller, J.P.; Bron, S.; Kok, J.; Kuipers, O.P.; Jongbloed, J.D.

2004-01-01

Most bacterial proteins destined to leave the cytoplasm are exported to extracellular compartments or imported into the cytoplasmic membrane via the highly conserved SecA-YEG pathway. In the present studies, the subcellular distributions of core components of this pathway, SecA and SecY, and of the

One recommendation of nuclear power export. GDP model application to the countries which expressed nuclear power introduction and consideration

International Nuclear Information System (INIS)

Iida, Tekehiko

2010-01-01

South Korea has been excited in nuclear business after the success in the contract to build nuclear power plants in UAE. Since more than 60 countries expressed nuclear power introduction and new countries were on the rise with exporting reactor technology accumulated, new era over nuclear renaissance seems to begin. This article at first classified countries, which expressed nuclear power introduction, with an economic level of GDP per capita. Then each classified country's requirements of nuclear power introduction were taken into consideration such as economic development, consumption pattern and technology attitude. As a result recommendation of nuclear power export was proposed. Different approach to each country targeted was suggested as shown in 'nuclear power GDP model'. (T. Tanaka)

Effect of the unfolded protein response on ER protein export: a potential new mechanism to relieve ER stress.

Science.gov (United States)

Shaheen, Alaa

2018-05-05

The unfolded protein response (UPR) is an adaptive cellular response that aims to relieve endoplasmic reticulum (ER) stress via several mechanisms, including inhibition of protein synthesis and enhancement of protein folding and degradation. There is a controversy over the effect of the UPR on ER protein export. While some investigators suggested that ER export is inhibited during ER stress, others suggested the opposite. In this article, their conflicting studies are analyzed and compared in attempt to solve this controversy. The UPR appears indeed to enhance ER export, possibly via multiple mechanisms. However, another factor, which is the integrity of the folding machinery/environment inside ER, determines whether ER export will appear increased or decreased during experimentation. Also, different methods of stress induction appear to have different effects on ER export. Thus, improvement of ER export may represent a new mechanism by which the UPR alleviates ER stress. This may help researchers to understand how the UPR works inside cells and how to manipulate it to alter cell fate during stress, either to promote cell survival or death. This may open up new approaches for the treatment of ER stress-related diseases.

RNA helicase MOV10 functions as a co-factor of HIV-1 Rev to facilitate Rev/RRE-dependent nuclear export of viral mRNAs

International Nuclear Information System (INIS)

Huang, Feng; Zhang, Junsong; Zhang, Yijun; Geng, Guannan; Liang, Juanran; Li, Yingniang; Chen, Jingliang; Liu, Chao; Zhang, Hui

2015-01-01

Human immunodeficiency virus type 1 (HIV-1) exploits multiple host factors during its replication. The REV/RRE-dependent nuclear export of unspliced/partially spliced viral transcripts needs the assistance of host proteins. Recent studies have shown that MOV10 overexpression inhibited HIV-1 replication at various steps. However, the endogenous MOV10 was required in certain step(s) of HIV-1 replication. In this report, we found that MOV10 potently enhances the nuclear export of viral mRNAs and subsequently increases the expression of Gag protein and other late products through affecting the Rev/RRE axis. The co-immunoprecipitation analysis indicated that MOV10 interacts with Rev in an RNA-independent manner. The DEAG-box of MOV10 was required for the enhancement of Rev/RRE-dependent nuclear export and the DEAG-box mutant showed a dominant-negative activity. Our data propose that HIV-1 utilizes the anti-viral factor MOV10 to function as a co-factor of Rev and demonstrate the complicated effects of MOV10 on HIV-1 life cycle. - Highlights: • MOV10 can function as a co-factor of HIV-1 Rev. • MOV10 facilitates Rev/RRE-dependent transport of viral mRNAs. • MOV10 interacts with Rev in an RNA-independent manner. • The DEAG-box of MOV10 is required for the enhancement of Rev/RRE-dependent export.

RNA helicase MOV10 functions as a co-factor of HIV-1 Rev to facilitate Rev/RRE-dependent nuclear export of viral mRNAs

Energy Technology Data Exchange (ETDEWEB)

Huang, Feng; Zhang, Junsong; Zhang, Yijun; Geng, Guannan; Liang, Juanran; Li, Yingniang; Chen, Jingliang [Institute of Human Virology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou 510080 (China); Key Laboratory of Tropical Disease Control of Ministry of Education, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou 510080 (China); Liu, Chao, E-mail: liuchao9@mail.sysu.edu.cn [Institute of Human Virology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou 510080 (China); Key Laboratory of Tropical Disease Control of Ministry of Education, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou 510080 (China); Zhang, Hui [Institute of Human Virology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou 510080 (China); Key Laboratory of Tropical Disease Control of Ministry of Education, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou 510080 (China)

2015-12-15

Human immunodeficiency virus type 1 (HIV-1) exploits multiple host factors during its replication. The REV/RRE-dependent nuclear export of unspliced/partially spliced viral transcripts needs the assistance of host proteins. Recent studies have shown that MOV10 overexpression inhibited HIV-1 replication at various steps. However, the endogenous MOV10 was required in certain step(s) of HIV-1 replication. In this report, we found that MOV10 potently enhances the nuclear export of viral mRNAs and subsequently increases the expression of Gag protein and other late products through affecting the Rev/RRE axis. The co-immunoprecipitation analysis indicated that MOV10 interacts with Rev in an RNA-independent manner. The DEAG-box of MOV10 was required for the enhancement of Rev/RRE-dependent nuclear export and the DEAG-box mutant showed a dominant-negative activity. Our data propose that HIV-1 utilizes the anti-viral factor MOV10 to function as a co-factor of Rev and demonstrate the complicated effects of MOV10 on HIV-1 life cycle. - Highlights: • MOV10 can function as a co-factor of HIV-1 Rev. • MOV10 facilitates Rev/RRE-dependent transport of viral mRNAs. • MOV10 interacts with Rev in an RNA-independent manner. • The DEAG-box of MOV10 is required for the enhancement of Rev/RRE-dependent export.

77 FR 51581 - Request for a License To Export Nuclear Grade Graphite

Science.gov (United States)

2012-08-24

... NUCLEAR REGULATORY COMMISSION Request for a License To Export Nuclear Grade Graphite Pursuant to... 27, 2012, graphite for of nuclear grade graphite to the XMAT424, 11006032. nuclear end use. graphite. Shanghai Institute of Applied Physics in China to test various types of nuclear grade graphite material in...

A study on improvement of export control system for the nuclear facility

International Nuclear Information System (INIS)

Kim, Ok Joo; Shin, Dong Hoon; Yang, Seung Hyo

2012-01-01

The Republic of Korea joined Nuclear Suppliers Group(NSG) in 1995 and became a major nuclear supplier both in name and reality by contracting the Project of UAE Braka Nuclear Power Plant(BNPP) in 2009 and the Project of Jordan Research and Training Reactor(JRTR) in 2010. And ROK is currently negotiating with several countries such as Finland and Vietnam for more projects, so it is expected to obtain more orders of commercial and research reactor. At this point of time, we found that it is difficult to apply individual export licensing system as it is for the big nuclear project such as BNPP and JRTR Project. Because the nuclear project in foreign country contains transfer of thousands of items and technical documents, including a considerable number of strategic items, issuing individual licenses for all items and documents can cause the inefficiency of the project. So, an appropriate export control system which can support such a project is necessary. In this study, we focused on how to improve the export control system to guarantee not only time efficiency but careful management of strategic goods

Analysis of World Nuclear Market and Strategy of Korean NPP's Competitiveness Improvement for Exportation

International Nuclear Information System (INIS)

Choi, Jae Young; Jeong, Yong Hoon; Roh, Seungkook; Chang, Soon Heung

2016-01-01

China, India and USA (nuclear adopted countries) are planning tremendous number of NPPs to meet their increasing electricity demand and Saudi Arabia, Vietnam (nuclear adopting countries) are also planning to include nuclear power in their energy mix as a long-term plan. Korea has exported 4 units of APR1400 to the UAE in December, 2009. Korea became sixth NPP supplier country and our economic feasibility and safety features were started to evaluate worldwide. Nuclear industries became a new driver of Korea’s export and nuclear industries in Korea are now expecting another NPP export to Middle-eastern countries, including UAE and Saudi Arabia, based on the first-mover’s advantage at the UAE. In 2000s, five countries (Japan, USA, France, Russia and Korea), which are able to build NPP, focused on NPP export more than domestic construction. Global trend of world nuclear market changed rapidly, especially after NPP export to the UAE. By the global trend, hegemony of nuclear market migrated from supplier country to buyer country. Nuclear companies started cooperating rather than competing. Financing to developing countries become more important. In general, one of the considerable combinations is Korea-Japan-USA alliance. Korea is in charge of EPC, Japan supports financing and deficient technology (with USA partner), and Japan-USA handles fuel supply and back-end fuel cycle based on new agreed terms of ROK-US Nuclear Cooperation Agreement. This combination was judged to best way to collaborate with global companies. Paying attention to many delayed (or potentially delayed) constructions from Russia, intercepting the construction work will be available in case of contracted countries. Korea can emphasize the short construction time, high responsiveness and mild/equal diplomatic position to the target countries

Conditionally controlling nuclear trafficking in yeast by chemical-induced protein dimerization.

Science.gov (United States)

Xu, Tao; Johnson, Cole A; Gestwicki, Jason E; Kumar, Anuj

2010-11-01

We present here a protocol to conditionally control the nuclear trafficking of target proteins in yeast. In this system, rapamycin is used to heterodimerize two chimeric proteins. One chimera consists of a FK506-binding protein (FKBP12) fused to a cellular 'address' (nuclear localization signal or nuclear export sequence). The second chimera consists of a target protein fused to a fluorescent protein and the FKBP12-rapamycin-binding (FRB) domain from FKBP-12-rapamycin associated protein 1 (FRAP1, also known as mTor). Rapamycin induces dimerization of the FKBP12- and FRB-containing chimeras; these interactions selectively place the target protein under control of the cell address, thereby directing the protein into or out of the nucleus. By chemical-induced dimerization, protein mislocalization is reversible and enables the identification of conditional loss-of-function and gain-of-function phenotypes, in contrast to other systems that require permanent modification of the targeted protein. Yeast strains for this analysis can be constructed in 1 week, and the technique allows protein mislocalization within 15 min after drug treatment.

SRSF3 represses the expression of PDCD4 protein by coordinated regulation of alternative splicing, export and translation

Energy Technology Data Exchange (ETDEWEB)

Park, Seung Kuk; Jeong, Sunjoo, E-mail: sjsj@dankook.ac.kr

2016-02-05

Gene expression is regulated at multiple steps, such as transcription, splicing, export, degradation and translation. Considering diverse roles of SR proteins, we determined whether the tumor-related splicing factor SRSF3 regulates the expression of the tumor-suppressor protein, PDCD4, at multiple steps. As we have reported previously, knockdown of SRSF3 increased the PDCD4 protein level in SW480 colon cancer cells. More interestingly, here we showed that the alternative splicing and the nuclear export of minor isoforms of pdcd4 mRNA were repressed by SRSF3, but the translation step was unaffected. In contrast, only the translation step of the major isoform of pdcd4 mRNA was repressed by SRSF3. Therefore, overexpression of SRSF3 might be relevant to the repression of all isoforms of PDCD4 protein levels in most types of cancer cell. We propose that SRSF3 could act as a coordinator of the expression of PDCD4 protein via two mechanisms on two alternatively spliced mRNA isoforms.

Tap and Dbp5, but not Gag, are involved in DR-mediated nuclear export of unspliced Rous sarcoma virus RNA

International Nuclear Information System (INIS)

LeBlanc, Jason J.; Uddowla, Sabena; Abraham, Benjamin; Clatterbuck, Sarah; Beemon, Karen L.

2007-01-01

All retroviruses must circumvent cellular restrictions on the export of unspliced RNAs from the nucleus. While the unspliced RNA export pathways for HIV and Mason-Pfizer monkey virus are well characterized, that of Rous sarcoma virus (RSV) is not. We have previously reported that the RSV direct repeat (DR) elements are involved in the cytoplasmic accumulation of unspliced viral RNA. Here, using fluorescent in situ hybridization (FISH), we demonstrate that unspliced viral RNAs bearing a single point mutation (G8863C) in the DR exhibit a restricted cellular localization in and around the nucleus. In contrast, wild type unspliced viral RNA had a diffuse localization throughout the nucleus and cytoplasm. Since the RSV Gag protein has a transient localization in the nucleus, we examined the effect of Gag over-expression on a DR-mediated reporter construct. While Gag did not enhance DR-mediated nuclear export, the dominant-negative expression of two cellular export factors, Tap and Dbp5, inhibited expression of the same reporter construct. Furthermore, FISH studies using the dominant-negative Dbp5 demonstrated that unspliced wild type RSV RNA was retained within the nucleus. Taken together, these results further implicate the DR in nuclear RNA export through interactions with Tap and Dbp5

Nuclear safeguards and export controls

International Nuclear Information System (INIS)

Mueller, H.

1994-01-01

Precisely from the perspective of the two most important nonnuclear weapons states, Japan and Germany, the safeguards and arms control agendas have not been finally dealt with. Because of their central position in the nonproliferation regime as nuclear suppliers and states with large nuclear energy industries, both countries are compelled to take a leading role in pursuing future reforms. In the dialogue with the nonaligned, this leadership position is helped by their nonnuclear status. In fact, Japan and Germany have some interests in common with the nonaligned states, such as the expansion of safeguards in the nuclear weapons states. To be sure, both Japan and Germany will pursue such interests with due regard to the interests of their friends and allies. For Japan, maintaining a close relationship with the United States is as important as shaping viable relations with China. Initiatives and controversies on nuclear policy must be weighed against this interest. By the same token, Germany must take into account the dense network of relations with its allies and with Russia, in addition to the German-French friendship. This will always set limits to Germany's readiness to confront the nuclear weapons states on nuclear issues. This, however, does not mean that both countries must shut up when the P 5 speak. The nuclear weapons register and the extension of the ''erga omnes'' rule in export controls, for example, should not be relegated to the dustbin of history, just because some friendly nuclear powers don't like these ideas. (orig.)

Government experience in nuclear power plant export financing

International Nuclear Information System (INIS)

Kalbitz, K.

1976-01-01

Because the long-term funds at the disposal of the commercial banks were insufficient to make available the amounts required for the exportation of nuclear power plants, it was necessary to make available long-term funds of the mortgage banks. On account of the strict regulations governing the lending operations of such banks, it was, however, necessary to introduce a Federal guarantee which covers 100% of the contract value in each case. On balance, however, the Federal Government does not take over any additional risks, because recourse may be taken to the commercial banks, which are liable for all additional payments under the credit arrangement having arisen from the improvement of the guarantee in favour of the mortgage banks. This has resulted in a considerable improvement of the export financing system which, of course, is for benefit of other major export projects too. (HP) [de

Late Maturation Steps Preceding Selective Nuclear Export and Egress of Progeny Parvovirus.

Science.gov (United States)

Wolfisberg, Raphael; Kempf, Christoph; Ros, Carlos

2016-06-01

Although the mechanism is not well understood, growing evidence indicates that the nonenveloped parvovirus minute virus of mice (MVM) may actively egress before passive release through cell lysis. We have dissected the late maturation steps of the intranuclear progeny with the aims of confirming the existence of active prelytic egress and identifying critical capsid rearrangements required to initiate the process. By performing anion-exchange chromatography (AEX), we separated intranuclear progeny particles by their net surface charges. Apart from empty capsids (EC), two distinct populations of full capsids (FC) arose in the nuclei of infected cells. The earliest population of FC to appear was infectious but, like EC, could not be actively exported from the nucleus. Further maturation of this early population, involving the phosphorylation of surface residues, gave rise to a second, late population with nuclear export potential. While capsid surface phosphorylation was strictly associated with nuclear export capacity, mutational analysis revealed that the phosphoserine-rich N terminus of VP2 (N-VP2) was dispensable, although it contributed to passive release. The reverse situation was observed for the incoming particles, which were dephosphorylated in the endosomes. Our results confirm the existence of active prelytic egress and reveal a late phosphorylation event occurring in the nucleus as a selective factor for initiating the process. In general, the process of egress of enveloped viruses is active and involves host cell membranes. However, the release of nonenveloped viruses seems to rely more on cell lysis. At least for some nonenveloped viruses, an active process before passive release by cell lysis has been reported, although the underlying mechanism remains poorly understood. By using the nonenveloped model parvovirus minute virus of mice, we could confirm the existence of an active process of nuclear export and further characterize the associated capsid

CRM1-mediated nuclear export is required for 26 S proteasome-dependent degradation of the TRIP-Br2 proto-oncoprotein.

Science.gov (United States)

Cheong, Jit Kong; Gunaratnam, Lakshman; Hsu, Stephen I-Hong

2008-04-25

Overexpression of the proto-oncogene TRIP-Br2 (SERTAD2) has been shown to induce E2F activity and promote tumorigenesis, whereas ablation of TRIP-Br2 arrests cell proliferation. Timely degradation of many cell cycle regulators is fundamental to the maintenance of proper cell cycle progression. Here we report novel mechanism(s) that govern the tight regulation of TRIP-Br2 levels during cell cycle progression. TRIP-Br2 was observed to be a short-lived protein in which the expression level peaks at the G(1)/S boundary. TRIP-Br2 accumulated in cells treated with 26 S proteasome inhibitors. Co-immunoprecipitation studies revealed that TRIP-Br2 forms ubiquitin conjugates. In silico analysis identified a putative leucine-rich nuclear export signal (NES) motif that overlaps with the PHD-Bromo interaction domain in the acidic C-terminal transactivation domain (TAD) of TRIP-Br2. This NES motif is highly conserved in widely divergent species and in all TRIP-Br family members. TRIP-Br2 was shown to be stabilized in G(2)/M phase cells through nuclear entrapment, either by deletion of the acidic C-terminal TAD, which includes the NES motif, or by leptomycin B-mediated inhibition of the CRM1-dependent nuclear export machinery. Mutation of leucine residue 238 of this NES motif abolished the interaction between CRM1 and TRIP-Br2, as well as the nuclear export of TRIP-Br2 and its subsequent 26 S proteasome-dependent degradation. These data suggest that CRM1-mediated nuclear export may be required for the proper execution of ubiquitin-proteasome-dependent degradation of TRIP-Br2.

Export and import provisions for nuclear materials and power plants, from the legal point of view

International Nuclear Information System (INIS)

Shapar, H.K.

1975-01-01

This paper provides a general review of the legal bases for and the administrative procedures involved in the export and import licensing of nuclear power reactors, fuels, and other nuclear materials by the United States. The basic statutory provisions and requirements are briefly described, and the requirement of an agreement for cooperation reviewed. The regulations of the Nuclear Regulatory Commission are covered in greater detail as they apply to the export and import of power reactors, nuclear fuels, source materials and byproduct materials. The intra-governmental procedures for review of an application for an export license are described in detail. Problems encountered in the administration of the law and regulations are described and the methods of resolving them are noted. The paper concludes with a brief account of three current topics, 1) the preparation of an environmental impact statement for export programs, 2) the situation with respect to the export licensing of component parts of reactors by the U.S. Department of Commerce, and 3) the shipment of plutonium by air. (orig.) [de

Biologic activity of the novel orally bioavailable selective inhibitor of nuclear export (SINE) KPT-335 against canine melanoma cell lines

Science.gov (United States)

2014-01-01

Background Exportin 1 (XPO1, also known as CRM1), is a chaperone protein responsible for the export of over 200 target proteins out of the nucleus. The expression and activity of XPO1 is upregulated in several human cancers and its expression is also linked to the development of chemotherapy resistance. Recent studies using both human and murine cancer cell lines have demonstrated that XPO1 is a relevant target for therapeutic intervention. The present study sought to characterize the biologic activity of an orally bioavailable selective inhibitor of nuclear export (SINE), KPT-335, against canine melanoma cell lines as a prelude to future clinical trials in dogs with melanoma. Results We evaluated the effects of KPT-335 on 4 canine malignant melanoma cell lines and found that KPT-335 inhibited proliferation, blocked colony formation, and induced apoptosis of treated cells at biologically relevant concentrations of drug. Additionally, KPT-335 downregulated XPO1 protein while inducing a concomitant increase in XPO1 messenger RNA. Lastly, KPT-335 treatment of cell lines upregulated the expression of both protein and mRNA for the tumor suppressor proteins p53 and p21, and promoted their nuclear localization. Conclusions KPT-335 demonstrates biologic activity against canine melanoma cell lines at physiologically relevant doses, suggesting that KPT-335 may represent a viable treatment option for dogs with malignant melanoma. PMID:25022346

Nuclear Export Control Policy in Korea - Present and future

International Nuclear Information System (INIS)

Kim, Jongsook

2008-01-01

The International community has been facing with the continued challenges for possession and proliferation of WMD over the past years. In addition, it is known that the terrorist groups are interested in acquiring WMD. The black market of WMD related materials and technologies show also the one of seriousness of our challenges. A number of international treaties, agreements and initiatives to control the proliferation of weapons of N, B, C and their delivery system have been existed to deal with these challenges, but their missions are challenged greatly in recent a series of nuclear issues by Iran and North Korea. The paper reviews the current international export control status and Korea export control system and policy. It also addresses some agenda to be done as future export control policy in Korea

Cell biological characterization of the malaria vaccine candidate trophozoite exported protein 1.

Directory of Open Access Journals (Sweden)

Caroline Kulangara

Full Text Available In a genome-wide screen for alpha-helical coiled coil motifs aiming at structurally defined vaccine candidates we identified PFF0165c. This protein is exported in the trophozoite stage and was named accordingly Trophozoite exported protein 1 (Tex1. In an extensive preclinical evaluation of its coiled coil peptides Tex1 was identified as promising novel malaria vaccine candidate providing the rational for a comprehensive cell biological characterization of Tex1. Antibodies generated against an intrinsically unstructured N-terminal region of Tex1 and against a coiled coil domain were used to investigate cytological localization, solubility and expression profile. Co-localization experiments revealed that Tex1 is exported across the parasitophorous vacuole membrane and located to Maurer's clefts. Change in location is accompanied by a change in solubility: from a soluble state within the parasite to a membrane-associated state after export to Maurer's clefts. No classical export motifs such as PEXEL, signal sequence/anchor or transmembrane domain was identified for Tex1.

RITA, a novel modulator of Notch signalling, acts via nuclear export of RBP-J.

Science.gov (United States)

Wacker, Stephan Armin; Alvarado, Cristobal; von Wichert, Götz; Knippschild, Uwe; Wiedenmann, Jörg; Clauss, Karen; Nienhaus, Gerd Ulrich; Hameister, Horst; Baumann, Bernd; Borggrefe, Tilman; Knöchel, Walter; Oswald, Franz

2011-01-05

The evolutionarily conserved Notch signal transduction pathway regulates fundamental cellular processes during embryonic development and in the adult. Ligand binding induces presenilin-dependent cleavage of the receptor and a subsequent nuclear translocation of the Notch intracellular domain (NICD). In the nucleus, NICD binds to the recombination signal sequence-binding protein J (RBP-J)/CBF-1 transcription factor to induce expression of Notch target genes. Here, we report the identification and functional characterization of RBP-J interacting and tubulin associated (RITA) (C12ORF52) as a novel RBP-J/CBF-1-interacting protein. RITA is a highly conserved 36 kDa protein that, most interestingly, binds to tubulin in the cytoplasm and shuttles rapidly between cytoplasm and nucleus. This shuttling RITA exports RBP-J/CBF-1 from the nucleus. Functionally, we show that RITA can reverse a Notch-induced loss of primary neurogenesis in Xenopus laevis. Furthermore, RITA is able to downregulate Notch-mediated transcription. Thus, we propose that RITA acts as a negative modulator of the Notch signalling pathway, controlling the level of nuclear RBP-J/CBF-1, where its amounts are limiting.

Technical modifications and management innovations in exporting nuclear reactor projects

International Nuclear Information System (INIS)

Mao Xiaoming; Qin Xijiu; Ding Hu; Xue Zhaoqun; Wen Shengjun

2009-01-01

As a main channel for the foreign economic cooperation of China nuclear industry, China Zhongyuan Engineering Corporation (CZEC) has been constantly engaged in technical modifications and management innovations in its exporting nuclear reactor projects. In the implementation of heavy water research reactor contract in Algeria, CZEC had established a complete and adequate design standards system in compliance with the international standards, and made significant modifications to the reference reactor in the aspects of reactor power and reactor safety, solved quite some technical issues which-affected the reactor technical performance. The modifications and improvements enabled the technical parameters, safety features, reactor multipurpose application to attain to the advanced level in the world. In the 300 MWe PWR NPPs in Pakistan, safety features had been updated in line with upgrading regulatory requisites. The design philosophy and technology application demonstrated CZEC' s creation and innovation on basis of constant safety enhancement of nuclear power projects. Efforts had also been made by CZEC' s creation and innovation on basis of constant safety enhancement of nuclear power projects. Efforts had also been made by CZEC in promoting China made equipment items and components exportation. (authors)

hnRNP A2/B1 interacts with influenza A viral protein NS1 and inhibits virus replication potentially through suppressing NS1 RNA/protein levels and NS1 mRNA nuclear export

Energy Technology Data Exchange (ETDEWEB)

Wang, Yimeng; Zhou, Jianhong; Du, Yuchun, E-mail: ydu@uark.edu

2014-01-20

The NS1 protein of influenza viruses is a major virulence factor and exerts its function through interacting with viral/cellular RNAs and proteins. In this study, we identified heterogeneous nuclear ribonucleoprotein A2/B1 (hnRNP A2/B1) as an interacting partner of NS1 proteins by a proteomic method. Knockdown of hnRNP A2/B1 by small interfering RNA (siRNA) resulted in higher levels of NS vRNA, NS1 mRNA, and NS1 protein in the virus-infected cells. In addition, we demonstrated that hnRNP A2/B1 proteins are associated with NS1 and NS2 mRNAs and that knockdown of hnRNP A2/B1 promotes transport of NS1 mRNA from the nucleus to the cytoplasm in the infected cells. Lastly, we showed that knockdown of hnRNP A2/B1 leads to enhanced virus replication. Our results suggest that hnRNP A2/B1 plays an inhibitory role in the replication of influenza A virus in host cells potentially through suppressing NS1 RNA/protein levels and NS1 mRNA nucleocytoplasmic translocation. - Highlights: • Cellular protein hnRNP A2/B1 interacts with influenza viral protein NS1. • hnRNP A2/B1 suppresses the levels of NS1 protein, vRNA and mRNA in infected cells. • hnRNP A2/B1 protein is associated with NS1 and NS2 mRNAs. • hnRNP A2/B1 inhibits the nuclear export of NS1 mRNAs. • hnRNP A2/B1 inhibits influenza virus replication.

Protein Export by the Mycobacterial SecA2 System Is Determined by the Preprotein Mature Domain

Science.gov (United States)

Feltcher, Meghan E.; Gibbons, Henry S.; Ligon, Lauren S.

2013-01-01

At the core of the bacterial general secretion (Sec) pathway is the SecA ATPase, which powers translocation of unfolded preproteins containing Sec signal sequences through the SecYEG membrane channel. Mycobacteria have two nonredundant SecA homologs: SecA1 and SecA2. While the essential SecA1 handles “housekeeping” export, the nonessential SecA2 exports a subset of proteins and is required for Mycobacterium tuberculosis virulence. Currently, it is not understood how SecA2 contributes to Sec export in mycobacteria. In this study, we focused on identifying the features of two SecA2 substrates that target them to SecA2 for export, the Ms1704 and Ms1712 lipoproteins of the model organism Mycobacterium smegmatis. We found that the mature domains of Ms1704 and Ms1712, not the N-terminal signal sequences, confer SecA2-dependent export. We also demonstrated that the lipid modification and the extreme N terminus of the mature protein do not impart the requirement for SecA2 in export. We further showed that the Ms1704 mature domain can be efficiently exported by the twin-arginine translocation (Tat) pathway. Because the Tat system exports only folded proteins, this result implies that SecA2 substrates can fold in the cytoplasm and suggests a putative role of SecA2 in enabling export of such proteins. Thus, the mycobacterial SecA2 system may represent another way that bacteria solve the problem of exporting proteins that can fold in the cytoplasm. PMID:23204463

Physical protection of export/import and transportation of nuclear material in the Slovak Republic

International Nuclear Information System (INIS)

Vaclav, J

2002-01-01

Full text: The paper contains short overview about average amount of nuclear materials transported on the territory of the Slovak Republic in a year, and the physical protection of these nuclear materials. There are several types of transportation and export/import of nuclear materials in the SR: fresh fuel import; import of other unirradiated nuclear materials (e.g. depleted uranium, natural uranium); export of unirradiated nuclear materials (e.g. natural uranium); internal transportation of fresh fuel; internal transportation of other unirradiated nuclear materials; internal transportation of spent fuel. The main objective of the nuclear regulatory authority SR is to supervise observation of the national legislation as follows: the act no. 130 / 1998 on peaceful use of nuclear energy; UJD SR's regulation no. 186/1999 which details the physical protection of the nuclear facilities, nuclear materials, and radioactive waste (following requirements of INFCIRC 225 / Rev. 4); UJD SR's regulation no. 284 / 1999 which details conditions of nuclear material and radioactive wastes transportation. (author)

Final report of the 2. committee of investigation of the 11. legislative period. Nuclear exports

International Nuclear Information System (INIS)

1990-01-01

On the subject of 'nuclear exports' the Committee dealt with political and legal principles of the Federal Government's nuclear export policy, particularly questions concerning the Non-Proliferation Treaty, and scientific-technical cooperation of the FRG with other countries, especially Argentina, Brazil, India, and Pakistan. Individual export transactions were then investigated, followed by a general assessment of the FRG's nuclear policy. - Concerning non-proliferation policy there have been certain administrative weaknesses in converting control measures into practice. Remedy is expected from the duty of terms to report deliveries punctually and completely and subsequent supervision. - The illegal transactions with India and Pakistan require improvements in the legal instruments, in the execution of administrative measures, and in border controls. Decisive steps have been introduced. (HSCH) [de

Nuclear power, nuclear exports and the non-proliferation of nuclear weapons

International Nuclear Information System (INIS)

Hildenbrand, G.

1977-01-01

Developed and developing countries alike unfortunately have no other options in replacing oil in electricity generation than to use coal or nuclear energy. As far as the supplier countries are concerned, there is no doubt that nobody is interested in adding to the proliferation of nuclear weapons. On the other hand, the future electricity requirement in the developing countries, especially the need for nuclear power plants, represents a considerable market in the medium and long term which the supplier countries cannot simply ignore because they must seek to secure their export shares in order to protect jobs at home. For the receiver countries it is a matter of principle to achieve the highest possible degree of independence in energy generation so as to be able to guarantee continuity of supply. The interest in building up national fuel cycle activities is also closely linked with the creation of jobs in the receiver countries and with the efforts of these countries to straighten out their balance of payments situation. (orig.) [de

Analysis of World Nuclear Market and Strategy of Korean NPP's Competitiveness Improvement for Exportation

Energy Technology Data Exchange (ETDEWEB)

Choi, Jae Young; Jeong, Yong Hoon [KAIST, Daejeon (Korea, Republic of); Roh, Seungkook [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of); Chang, Soon Heung [Handong Global University, Pohang (Korea, Republic of)

2016-10-15

China, India and USA (nuclear adopted countries) are planning tremendous number of NPPs to meet their increasing electricity demand and Saudi Arabia, Vietnam (nuclear adopting countries) are also planning to include nuclear power in their energy mix as a long-term plan. Korea has exported 4 units of APR1400 to the UAE in December, 2009. Korea became sixth NPP supplier country and our economic feasibility and safety features were started to evaluate worldwide. Nuclear industries became a new driver of Korea’s export and nuclear industries in Korea are now expecting another NPP export to Middle-eastern countries, including UAE and Saudi Arabia, based on the first-mover’s advantage at the UAE. In 2000s, five countries (Japan, USA, France, Russia and Korea), which are able to build NPP, focused on NPP export more than domestic construction. Global trend of world nuclear market changed rapidly, especially after NPP export to the UAE. By the global trend, hegemony of nuclear market migrated from supplier country to buyer country. Nuclear companies started cooperating rather than competing. Financing to developing countries become more important. In general, one of the considerable combinations is Korea-Japan-USA alliance. Korea is in charge of EPC, Japan supports financing and deficient technology (with USA partner), and Japan-USA handles fuel supply and back-end fuel cycle based on new agreed terms of ROK-US Nuclear Cooperation Agreement. This combination was judged to best way to collaborate with global companies. Paying attention to many delayed (or potentially delayed) constructions from Russia, intercepting the construction work will be available in case of contracted countries. Korea can emphasize the short construction time, high responsiveness and mild/equal diplomatic position to the target countries.

Nuclear export and armament. New threats and peace perspectives

International Nuclear Information System (INIS)

Kubbig, B.W.; Mueller, H.

1993-02-01

The authors give a condensed analysis of safety and politico-economic dimensions regarding the further proliferation of nuclear weapons and carrier systems with which nuclear blasting charges can be transported. From the content: - Proliferation and non-proliferation: technology, economy and (international) law in a political historic survey. - Missile defense: appropriate technological answer to the political proliferation problem? -export strategies: USA and FRG in comparison, interest and policy of the European Community. - Components for an extensive proliferation strategy. (orig./HP) [de

Intersectin goes nuclear: secret life of an endocytic protein.

Science.gov (United States)

Alvisi, Gualtiero; Paolini, Lucia; Contarini, Andrea; Zambarda, Chiara; Di Antonio, Veronica; Colosini, Antonella; Mercandelli, Nicole; Timmoneri, Martina; Palù, Giorgio; Caimi, Luigi; Ricotta, Doris; Radeghieri, Annalisa

2018-04-27

Intersectin 1-short (ITSN1-s) is a 1220 amino acid ubiquitously expressed scaffold protein presenting a multidomain structure that allows to spatiotemporally regulate the functional interaction of a plethora of proteins. Besides its well-established role in endocytosis, ITSN1-s is involved in the regulation of cell signaling and is implicated in tumorigenesis processes, although the signaling pathways involved are still poorly understood. Here, we identify ITSN1-s as a nucleocytoplasmic trafficking protein. We show that, by binding to importin (IMP)α, a small fraction of ITSN1-s localizes in the cell nucleus at the steady state, where it preferentially associates with the nuclear envelope and interacts with lamin A/C. However, upon pharmacological ablation of chromosome region maintenance 1 (CRM-1)-dependent nuclear export pathway, the protein accumulates into the nucleus, thus revealing its moonlighting nature. Analysis of deletion mutants revealed that the coiled coil (CC) and Src homology (SH3) regions play the major role in its nucleocytoplasmic shuttling. While no evidence of nuclear localization signal (NLS) was detected in the CC region, a functional bipartite NLS was identified within the SH3D region of ITSN1-s (RKKNPGGWWEGELQARGKKRQIGW-1127), capable of conferring energy-dependent nuclear accumulation to reporter proteins and whose mutational ablation affects nuclear import of the whole SH3 region. Thus, ITSN1-s is an endocytic protein, which shuttles between the nucleus and the cytoplasm in a CRM-1- and IMPα-dependent fashion. © 2018 The Author(s). Published by Portland Press Limited on behalf of the Biochemical Society.

Inhibition of the Nuclear Export Receptor XPO1 as a Therapeutic Target for Platinum-Resistant Ovarian Cancer

DEFF Research Database (Denmark)

Chen, Ying; Camacho, Sandra Catalina; Silvers, Thomas R

2017-01-01

Purpose: The high fatality-to-case ratio of ovarian cancer is directly related to platinum resistance. Exportin-1 (XPO1) is a nuclear exporter that mediates nuclear export of multiple tumor suppressors. We investigated possible clinicopathologic correlations of XPO1 expression levels and evaluate...

Nuclear export controls and the CTBT: Where we`ve been and challenges ahead -- Views of an engineer

Energy Technology Data Exchange (ETDEWEB)

Lundy, A.S.

1998-09-01

The paper discusses the following topics: the importance of export controls; the uniqueness of nuclear weapons and their export control requirements; ``dual-use`` controls; and recent developments in nonproliferation beyond export control. Also discussed are some non-obvious challenges which include computer modeling and visualization, and fissile material availability and instant nukes. The author concludes by asking the Nuclear Suppliers Group to consider whether there are ways to make its controls more effective.

Nuclear export controls and the CTBT: Where we've been and challenges ahead - Views of an engineer

International Nuclear Information System (INIS)

Lundy, A.S.

1998-01-01

The paper discusses the following topics: the importance of export controls; the uniqueness of nuclear weapons and their export control requirements; ''dual-use'' controls; and recent developments in nonproliferation beyond export control. Also discussed are some non-obvious challenges which include computer modeling and visualization, and fissile material availability and instant nukes. The author concludes by asking the Nuclear Suppliers Group to consider whether there are ways to make its controls more effective

Variant Exported Blood-Stage Proteins Encoded by Plasmodium Multigene Families Are Expressed in Liver Stages Where They Are Exported into the Parasitophorous Vacuole.

Directory of Open Access Journals (Sweden)

Aurélie Fougère

2016-11-01

Full Text Available Many variant proteins encoded by Plasmodium-specific multigene families are exported into red blood cells (RBC. P. falciparum-specific variant proteins encoded by the var, stevor and rifin multigene families are exported onto the surface of infected red blood cells (iRBC and mediate interactions between iRBC and host cells resulting in tissue sequestration and rosetting. However, the precise function of most other Plasmodium multigene families encoding exported proteins is unknown. To understand the role of RBC-exported proteins of rodent malaria parasites (RMP we analysed the expression and cellular location by fluorescent-tagging of members of the pir, fam-a and fam-b multigene families. Furthermore, we performed phylogenetic analyses of the fam-a and fam-b multigene families, which indicate that both families have a history of functional differentiation unique to RMP. We demonstrate for all three families that expression of family members in iRBC is not mutually exclusive. Most tagged proteins were transported into the iRBC cytoplasm but not onto the iRBC plasma membrane, indicating that they are unlikely to play a direct role in iRBC-host cell interactions. Unexpectedly, most family members are also expressed during the liver stage, where they are transported into the parasitophorous vacuole. This suggests that these protein families promote parasite development in both the liver and blood, either by supporting parasite development within hepatocytes and erythrocytes and/or by manipulating the host immune response. Indeed, in the case of Fam-A, which have a steroidogenic acute regulatory-related lipid transfer (START domain, we found that several family members can transfer phosphatidylcholine in vitro. These observations indicate that these proteins may transport (host phosphatidylcholine for membrane synthesis. This is the first demonstration of a biological function of any exported variant protein family of rodent malaria parasites.

Define rules for the exporter and importer of minerals or ores containing nuclear elements

International Nuclear Information System (INIS)

1969-01-01

The present resolution establishes regulations for the exporter of minerals or ores containing associated nuclear elements, and for the importer of chemical compounds of technical purity grade, containing a quantity of fissile of fertile materials equal to the existent in the exported material

Simplification of the Provisions of the Nuclear Energy Act on Imports and Exports; A Working Group Report

International Nuclear Information System (INIS)

2001-01-01

The Ministry of Trade and Industry appointed a working group to map out possibilities of simplifying the provisions on imports and exports of nuclear products and to submit a proposal for the amendment of the Nuclear Energy Act in this respect. The working group should especially map out relevant international and EU norms and consider to what extent it would be possible to replace the present licensing procedure with obligations imposed on operators and/or a notification procedure. The working group should further study the possibility of combining the provisions on the control of nuclear materials, the safety of transports of nuclear and other radioactive material nuclear liability and physical protection of nuclear materials with the provisions on imports and exports. The working group did not discuss the provisions on the imports and exports of nuclear waste. The Council Regulation concerning the control of exports of dual-use items and technology, which entered into force in September 2000, and the amendment of the Regulation with a view to nuclear material adopted in January 2001 call for an amendment of the provisions of the Nuclear Energy Act concerning exports. The working group proposes that a direct reference to the EU Regulation should be included in the Nuclear Energy Decree. The definition of exports is proposed to be changed so that it corresponds to the definition in the EU Regulation. The Nuclear Energy Decree should, however, comprise provisions on applying for an authorization, on a licensing authority and on the possibility of applying for a global authorisation. The global authorisation shall replace the Intra-Community trade licence, which is proposed to be abolished. It is proposed that the Ministry of Trade and Industry should be the licensing authority. It is further proposed that provisions should be issued on a notification procedure for products falling under the scope of the Nuclear Energy Act for which no export authorisation is

A Novel Nuclear Trafficking Module Regulates the Nucleocytoplasmic Localization of the Rabies Virus Interferon Antagonist, P Protein*

Science.gov (United States)

Oksayan, Sibil; Wiltzer, Linda; Rowe, Caitlin L.; Blondel, Danielle; Jans, David A.; Moseley, Gregory W.

2012-01-01

Regulated nucleocytoplasmic transport of proteins is central to cellular function and dysfunction during processes such as viral infection. Active protein trafficking into and out of the nucleus is dependent on the presence within cargo proteins of intrinsic specific modular signals for nuclear import (nuclear localization signals, NLSs) and export (nuclear export signals, NESs). Rabies virus (RabV) phospho (P) protein, which is largely responsible for antagonising the host anti-viral response, is expressed as five isoforms (P1–P5). The subcellular trafficking of these isoforms is thought to depend on a balance between the activities of a dominant N-terminal NES (N-NES) and a distinct C-terminal NLS (C-NLS). Specifically, the N-NES-containing isoforms P1 and P2 are cytoplasmic, whereas the shorter P3–P5 isoforms, which lack the N-NES, are believed to be nuclear through the activity of the C-NLS. Here, we show for the first time that RabV P contains an additional strong NLS in the N-terminal region (N-NLS), which, intriguingly, overlaps with the N-NES. This arrangement represents a novel nuclear trafficking module where the N-NLS is inactive in P1 but becomes activated in P3, concomitant with truncation of the N-NES, to become the principal targeting signal conferring nuclear accumulation. Understanding this unique switch arrangement of overlapping, co-regulated NES/NLS sequences is vital to delineating the critical role of RabV P protein in viral infection. PMID:22700958

Ketamine produces antidepressant-like effects through phosphorylation-dependent nuclear export of histone deacetylase 5 (HDAC5) in rats

Science.gov (United States)

Choi, Miyeon; Lee, Seung Hoon; Wang, Sung Eun; Ko, Seung Yeon; Song, Mihee; Choi, June-Seek; Duman, Ronald S.; Son, Hyeon

2015-01-01

Ketamine produces rapid antidepressant-like effects in animal assays for depression, although the molecular mechanisms underlying these behavioral actions remain incomplete. Here, we demonstrate that ketamine rapidly stimulates histone deacetylase 5 (HDAC5) phosphorylation and nuclear export in rat hippocampal neurons through calcium/calmodulin kinase II- and protein kinase D-dependent pathways. Consequently, ketamine enhanced the transcriptional activity of myocyte enhancer factor 2 (MEF2), which leads to regulation of MEF2 target genes. Transfection of a HDAC5 phosphorylation-defective mutant (Ser259/Ser498 replaced by Ala259/Ala498, HDAC5-S/A), resulted in resistance to ketamine-induced nuclear export, suppression of ketamine-mediated MEF2 transcriptional activity, and decreased expression of MEF2 target genes. Behaviorally, viral-mediated hippocampal knockdown of HDAC5 blocked or occluded the antidepressant effects of ketamine both in unstressed and stressed animals. Taken together, our results reveal a novel role of HDAC5 in the actions of ketamine and suggest that HDAC5 could be a potential mechanism contributing to the therapeutic actions of ketamine. PMID:26647181

Export Control Guide: Loose Parts Monitoring Systems for Nuclear Power Plants

Energy Technology Data Exchange (ETDEWEB)

Langenberg, Donald W. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

2012-12-01

This report describes a typical LPMS, emphasizing its application to the RCS of a modern NPP. The report also examines the versatility of AE monitoring technology by describing several nuclear applications other than loose parts monitoring, as well as some non-nuclear applications. In addition, LPMS implementation requirements are outlined, and LPMS suppliers are identified. Finally, U.S. export controls applicable to LPMSs are discussed.

Nuclear exports. Parliamentary control and confidentiality; Parlamentarische Kontrolle und Geheimhaltungsbeduerftigkeit bei Nuklearexporten. Zum Urteil des Bundesverfassungsgerichts vom 21. Oktober 2014

Energy Technology Data Exchange (ETDEWEB)

Feldmann, Ulrike

2015-03-15

With its decision taken on 21. October 2014 (Az.: 2 BvE 5/11) the Federal Constitutional Court (BVerfG) decided during court proceedings between administrative bodies on the scope and limits of the parliamentary right of information. Even though the proceeding did not deal with nuclear exports but arm exports, foreign trade law, however, does not only designate an export licence obligation for military weapons but also for so called dual-use goods meaning goods, which can be used both for friendly as well as for military purposes. The export of these goods requires according to the so-called Dual-Use Regulation (EG) 428/2009 a licence. Annex I category 0 of the regulation (EG) 428/2009 lists a variety of nuclear materials, plants and equipment items for which this licence applies. In the same manner as arm exports, also exports of nuclear dual-use goods are being discussed in a special cabinet committee, the Federal Security Council (BSR), which shall coordinate cross-departmentally the German security and defence policy under consideration of economic interests and which categorises its results, according to the rules of procedure, as confidential. Also legally not regulated but common ''preliminary enquiries'' at the responsible Federal Ministry or rather Federal Office of Economics and Export Control by companies which plan an export and want to affirm the general approval for their export business prior to conclusion of contract take not only place for arm exports but also for nuclear dual-use goods. The decision by the Federal Constitutional Court can be applied to consultations about the authorisation of nuclear dual-use goods.

The new US nuclear non-proliferation and export policy

International Nuclear Information System (INIS)

Welck, S. von.

1981-01-01

The future American nuclear non-proliferation and export policy will be determined chiefly by three elements: (1) Adherence to the former objective of nuclear non-proliferation. (2) A large and varied assortment of old and new tools for implementing this goal. (3) Much more differentiation in applying these tools in the light of the reliability, with respect to non-proliferation policy, of the respective partner. Consequently, it would make little sense for the new Administration to force upon allied industrialized countries, whose nuclear technologies are at the same level as that of the United States, restrictive rules on reprocessing and breeder technology. The new measures designed to curb proliferation are especially meant to destroy motivations that could cause states to own nuclear explosives. This also applies to the removal of economic motivations. (orig.) [de

A novel mechanism of E2F1 regulation via nucleocytoplasmic shuttling: determinants of nuclear import and export.

Science.gov (United States)

Ivanova, Iordanka A; Vespa, Alisa; Dagnino, Lina

2007-09-01

E2F1 is a transcription factor central for cell survival, proliferation, and repair following genomic insult. Depending on the cell type and conditions, E2F1 can induce apoptosis in transformed cells, behaving as a tumour suppressor, or impart growth advantages favouring tumour formation. The pleiotropic functions of E2F1 are a likely consequence of its ability to transcriptionally control a wide variety of target genes, and require tight regulation of its activity at multiple levels. Although sequestration of proteins to particular cellular compartments is a well-established regulatory mechanism, virtually nothing is known about its contribution to modulation of E2F1 target gene expression. We have examined the subcellular trafficking of E2F1 and, contrary to the widely held notion that this factor is constitutively nuclear, we now demonstrate that it is subjected to continuous nucleocytoplasmic shuttling. We have also defined two nuclear localization domains and a nuclear export region, which mediates CRM1-dependent transit out of the nucleus. The predominant subcellular location of E2F1 is likely determined by the balance between the activity of nuclear import and export domains, and can be modulated by differentiation stimuli in epidermal cells. Thus, we have identified a hitherto unrecognized mechanism to control E2F1 function through modulation of its subcellular localization.

Communications received from certain Member States regarding guidelines for the export of nuclear material, equipment and technology

International Nuclear Information System (INIS)

1994-04-01

The Director General has received notes verbales dated 27 August 1993 and 28 October 1993 from the Permanent Missions of Finland and Spain to the International Atomic Energy relating to the export of nuclear material, equipment and technology. The purpose of these notes verbales is to provide further information on those Governments' nuclear export policies and practices

Ubiquitin-regulated nuclear-cytoplasmic trafficking of the Nipah virus matrix protein is important for viral budding.

Directory of Open Access Journals (Sweden)

Yao E Wang

2010-11-01

Full Text Available Paramyxoviruses are known to replicate in the cytoplasm and bud from the plasma membrane. Matrix is the major structural protein in paramyxoviruses that mediates viral assembly and budding. Curiously, the matrix proteins of a few paramyxoviruses have been found in the nucleus, although the biological function associated with this nuclear localization remains obscure. We report here that the nuclear-cytoplasmic trafficking of the Nipah virus matrix (NiV-M protein and associated post-translational modification play a critical role in matrix-mediated virus budding. Nipah virus (NiV is a highly pathogenic emerging paramyxovirus that causes fatal encephalitis in humans, and is classified as a Biosafety Level 4 (BSL4 pathogen. During live NiV infection, NiV-M was first detected in the nucleus at early stages of infection before subsequent localization to the cytoplasm and the plasma membrane. Mutations in the putative bipartite nuclear localization signal (NLS and the leucine-rich nuclear export signal (NES found in NiV-M impaired its nuclear-cytoplasmic trafficking and also abolished NiV-M budding. A highly conserved lysine residue in the NLS served dual functions: its positive charge was important for mediating nuclear import, and it was also a potential site for monoubiquitination which regulates nuclear export of the protein. Concordantly, overexpression of ubiquitin enhanced NiV-M budding whereas depletion of free ubiquitin in the cell (via proteasome inhibitors resulted in nuclear retention of NiV-M and blocked viral budding. Live Nipah virus budding was exquisitely sensitive to proteasome inhibitors: bortezomib, an FDA-approved proteasome inhibitor for treating multiple myeloma, reduced viral titers with an IC(50 of 2.7 nM, which is 100-fold less than the peak plasma concentration that can be achieved in humans. This opens up the possibility of using an "off-the-shelf" therapeutic against acute NiV infection.

Nuclear fuels imports and exports of the Federal Republic of Germany 1989

International Nuclear Information System (INIS)

Anon.

1990-01-01

The statistics compiled by the Federal Office for the Economy (Bundesamt fuer Wirtschaft) on behalf of the German Federal Ministry for the Environment, Nature Conservation and Reactor Safety of the imports and exports of nuclear fuels and source material in 1989 show a drop in imports by 29.5% and a considerable increase in exports by 104%. For comparison, the relevant figures of the preceding year are given in brackets throughout this statistical survey. (orig.) [de

1987 nuclear fuel imports and exports of the Federal Republic of Germany

International Nuclear Information System (INIS)

Anon.

1988-01-01

The statistics of imports and exports of nuclear fuels and source materials compiled by the German Federal Office for Industry (Bundesamt fuer Wirtschaft) and the Federal Ministry for the Environment, Protection of Nature, and Reactor Safety (Bundesministerium fuer Umwelt, Naturschutz und Reaktorsicherheit) shows a 29.1% increase in imports and a 16.9% decrease of exports in 1987 compared to the previous year. A major rise was experienced in imports of natural uranium, uranium enriched up to 3% and to 3-10%, and plutonium, while there was a decline in imports of depleted uranium, source materials, and more highly enriched uranium. Uranium enriched 3-10%, highly enriched uranium, and plutonium were exported in larger quantities, while only smaller quantities of depleted uranium, source materials, natural uranium, uranium enriched up to 3%, and uranium enriched 10-85% were exported. (orig.) [de

Problems associated with the export of nuclear power plants

International Nuclear Information System (INIS)

1978-01-01

Full text: Recent forecasts indicate that by the year 2000 there will be more than 1000 nuclear power plants operating in 50 countries and with several countries expecting to derive one-half or more of their electric generation from nuclear power plants At present only six countries are exporters of nuclear power systems, three more currently supply their own domestic markets, while the remainder are importers. It is expected that most of the importers will continue to depend to varying degrees on foreign supply, at least in the near future. If nuclear power is to offer an important benefit to the world, the achievement of this benefit will require co-operation between the supplying and receiving nations in overcoming problems which might inhibit the full development of this energy source. In addition to ensuring safety and reliability, special problem areas include financing, skilled manpower needs, adequate local industrial and engineering infrastructure, access to advanced technology, and an assured supply of nuclear fuel. The symposium had special emphasis on the problems facing many of the developing countries in the initial stages of nuclear power programmes, and was divided into three major topics nuclear safety, domestic contributions, and international aspects In the safety area, emphasis was given to the special considerations that may exist for countries that import nuclear plants. These special considerations can be due to some non-standard features of the exported reactor such as lower power ratings, dissimilar site characteristics that can effect the design, and the evolution and changes in design and safety requirements during construction. This can be complicated by differences in safety philosophy and codified standards of the various suppliers and unique construction problems in the less developed countries. Thus, the ability of the importing country to carry out the regulatory and safety function is obviously important. A number of presentations

A Human Nuclear Shuttling Protein That Interacts with Human Immunodeficiency Virus Type 1 Matrix Is Packaged into Virions

Science.gov (United States)

Gupta, Kalpana; Ott, David; Hope, Thomas J.; Siliciano, Robert F.; Boeke, Jef D.

2000-01-01

Active nuclear import of the human immunodeficiency virus type 1 (HIV-1) preintegration complex (PIC) is essential for the productive infection of nondividing cells. Nuclear import of the PIC is mediated by the HIV-1 matrix protein, which also plays several critical roles during viral entry and possibly during virion production facilitating the export of Pr55Gag and genomic RNA. Using a yeast two-hybrid screen, we identified a novel human virion-associated matrix-interacting protein (VAN) that is highly conserved in vertebrates and expressed in most human tissues. Its expression is upregulated upon activation of CD4+ T cells. VAN is efficiently incorporated into HIV-1 virions and, like matrix, shuttles between the nucleus and cytoplasm. Furthermore, overexpression of VAN significantly inhibits HIV-1 replication in tissue culture. We propose that VAN regulates matrix nuclear localization and, by extension, both nuclear import of the PIC and export of Pr55Gag and viral genomic RNA during virion production. Our data suggest that this regulatory mechanism reflects a more global process for regulation of nucleocytoplasmic transport. PMID:11090181

Canada's reactor exports

International Nuclear Information System (INIS)

Morrison, R.W.

1981-01-01

A brief sketch of the development of Canada's nuclear exports is presented and some of the factors which influence the ability to export reactors have been identified. The potential market for CANDUs is small and will develop slowly. The competition will be tough. There are few good prospects for immediate export orders in the next two or three years. Nonetheless there are reasonable opportunities for CANDU exports, especially in the mid-to-late 1980s. Such sales could be of great benefit to Canada and could do much to sustain the domestic nuclear industry. Apart from its excellent economic and technical performance, the main attraction of the CANDU seems to be the autonomy it confers on purchasing countries, the effectiveness with which the associated technology can be transferred, and the diversification it offers to countries which wish to reduce their dependence on the major industrial suppliers. Each sales opportunity is unique, and marketing strategy will have to be tailored to the customer's needs. Over the next decade, the factors susceptible to Canadian government action which are most likely to influence CANDU exports will be the political commitment of the government to those reactor exports, the performance established by the four 600 MWe CANDUs now nearing completion, the continuing successful operation of the nuclear program in Ontario, and the co-ordination of the different components of Canada's nuclear program (AECL, nuclear industry, utilities, and government) in putting forth a coherent marketing effort and following through with effective project management

Host cell subversion by Toxoplasma GRA16, an exported dense granule protein that targets the host cell nucleus and alters gene expression.

Science.gov (United States)

Bougdour, Alexandre; Durandau, Eric; Brenier-Pinchart, Marie-Pierre; Ortet, Philippe; Barakat, Mohamed; Kieffer, Sylvie; Curt-Varesano, Aurélie; Curt-Bertini, Rose-Laurence; Bastien, Olivier; Coute, Yohann; Pelloux, Hervé; Hakimi, Mohamed-Ali

2013-04-17

After invading host cells, Toxoplasma gondii multiplies within a parasitophorous vacuole (PV) that is maintained by parasite proteins secreted from organelles called dense granules. Most dense granule proteins remain within the PV, and few are known to access the host cell cytosol. We identify GRA16 as a dense granule protein that is exported through the PV membrane and reaches the host cell nucleus, where it positively modulates genes involved in cell-cycle progression and the p53 tumor suppressor pathway. GRA16 binds two host enzymes, the deubiquitinase HAUSP and PP2A phosphatase, which exert several functions, including regulation of p53 and the cell cycle. GRA16 alters p53 levels in a HAUSP-dependent manner and induces nuclear translocation of the PP2A holoenzyme. Additionally, certain GRA16-deficient strains exhibit attenuated virulence, indicating the importance of these host alterations in pathogenesis. Therefore, GRA16 represents a potentially emerging subfamily of exported dense granule proteins that modulate host function. Copyright © 2013 Elsevier Inc. All rights reserved.

Function of Nup98 subtypes and their fusion proteins, Nup98-TopIIβ and Nup98-SETBP1 in nuclear-cytoplasmic transport.

Science.gov (United States)

Saito, Shoko; Yokokawa, Takafumi; Iizuka, Gemmei; Cigdem, Sadik; Okuwaki, Mitsuru; Nagata, Kyosuke

2017-05-20

Nup98 is a component of the nuclear pore complex. The nup98-fusion genes derived by chromosome translocations are involved in hematopoietic malignancies. Here, we investigated the functions of Nup98 isoforms and two unexamined Nup98-fusion proteins, Nup98-TopIIβ and Nup98-SETBP1. We first demonstrated that two Nup98 isoforms are expressed in various mouse tissues and similarly localized in the nucleus and the nuclear envelope. We also showed that Nup98-TopIIβ and Nup98-SETBP1 are localized in the nucleus and partially co-localized with full-length Nup98 and a nuclear export receptor XPO1. We demonstrated that Nup98-TopIIβ and Nup98-SETBP1 negatively regulate the XPO1-mediated protein export. Our results will contribute to the understanding of the molecular mechanism by which the Nup98-fusion proteins induce tumorigenesis. Copyright © 2017 Elsevier Inc. All rights reserved.

Import and export of small quantities of nuclear materials

International Nuclear Information System (INIS)

Grenier, M.

1986-06-01

Administrative procedures for import export of nuclear materials are specific for each country. In France regulations are reviewed for small quantities, lower threshold, in some cases, allows a simplified procedure, however thresholds are not the same in the different texts (and for one of them, concerning proliferation, is zero). It is obvious that regulations are necessary even for small quantities but national and international threshold should be harmonized [fr

A prototype system dynamic model of nuclear and radiological export controls in Central Asia and the Caucasus; enhancing the effectiveness of preventing illicit nuclear material trafficking

International Nuclear Information System (INIS)

Ferguston, C.D.; Ouagrham, S.B.

2002-01-01

An urgent need calls out for improved border security and export control systems in the Central Asian and Caucasus regions to prevent illicit nuclear and radioactive materials trafficking. Effective nuclear and radiological exports controls are essential because these regions contain numerous nuclear facilities and radioactive materials as well as lie at the crossroads between seekers and suppliers of technologies that could be employed in nuclear and radiological weapons. Porous and unprotected borders compound these concerns. Moreover, the states within these regions are struggling with forming new regulations and laws, obtaining sufficient portal monitoring equipment, training customs and border security personnel, and coordinating these activities with neighboring states. Building this infrastructure all at once can severely task any government. Thus, unsurprisingly, most of these states have inadequate export control and border security systems. To enable each state in these regions determine how to better prevent illicit nuclear and radiological materials trafficking, the authors have developed a prototype system dynamics model focused on evaluating and improving of effectiveness of export controls. System dynamics modeling, a management tool that grew out of the field of system engineering and nonlinear dynamics, uses two structures: causal loop diagrams and stock and flow diagrams. The former shows how endogenous systematic factors interact with each other to produce feedback mechanisms that results in either balancing or reinforcing loops. A classic example is a arms race, modeled as a vicious cycle or reinforcing loop. In addition to interacting with each other, causal loops influence the flow of stock, which is material concern. In the export control system dynamics model, the stock represents nuclear and radioactive materials. System dynamics modelling is an iterative process that is continually modified by user input. Therefore, export control

Four decades of living with the genie: United States nuclear export policy

International Nuclear Information System (INIS)

Kramish, A.

1983-01-01

The subject is discussed as follows: general introduction (examples of complex nature of nuclear trade); non-proliferation policy - the beginnings (early US action to control dealings with other countries); the Nuclear Non-Proliferation Act of 1978 (formulation of US policy on nuclear trade; INFCE (International Nuclear Fuel Cycle Evaluation)); the Symington and Glenn Amendments (US legislation to control trade with other countries); the Export-Import Bank Act (US legislation for the same purpose as above); the Non-Proliferation Treaty; the Reagan Policy (US present policy to support IAEA safeguards and Non-Proliferation Treaty); future prospects. (U.K.)

Identification of an exported heat shock protein 70 in Plasmodium falciparum

Directory of Open Access Journals (Sweden)

Grover Manish

2013-01-01

Full Text Available Host cell remodelling is a hallmark of malaria pathogenesis. It involves protein folding, unfolding and trafficking events and thus participation of chaperones such as Hsp70s and Hsp40s is well speculated. Until recently, only Hsp40s were thought to be the sole representative of the parasite chaperones in the exportome. However, based on the re-annotated Plasmodium falciparum genome sequence, a putative candidate for exported Hsp70 has been reported, which otherwise was known to be a pseudogene. We raised a specific antiserum against a C-terminal peptide uniquely present in PfHsp70-x. Immunoblotting and immunofluorescence-based approaches in combination with sub-cellular fractionation by saponin and streptolysin-O have been taken to determine the expression and localization of PfHsp70-x in infected erythrocyte. The re-annotated sequence of PfHsp70-x reveals it to be a functional protein with an endoplasmic reticulum signal peptide. It gets maximally expressed at the schizont stage of intra-erythrocytic life cycle. Majority of the protein localizes to the parasitophorous vacuole and some of it gets exported to the erythrocyte compartment where it associates with Maurer’s clefts. The identification of an exported parasite Hsp70 chaperone presents us with the fact that the parasite has evolved customized chaperones which might be playing crucial roles in aspects of trafficking and host cell remodelling.

The Gpn3 Q279* cancer-associated mutant inhibits Gpn1 nuclear export and is deficient in RNA polymerase II nuclear targeting.

Science.gov (United States)

Barbosa-Camacho, Angel A; Méndez-Hernández, Lucía E; Lara-Chacón, Bárbara; Peña-Gómez, Sonia G; Romero, Violeta; González-González, Rogelio; Guerra-Moreno, José A; Robledo-Rivera, Angélica Y; Sánchez-Olea, Roberto; Calera, Mónica R

2017-11-01

Gpn3 is required for RNA polymerase II (RNAPII) nuclear targeting. Here, we investigated the effect of a cancer-associated Q279* nonsense mutation in Gpn3 cellular function. Employing RNAi, we replaced endogenous Gpn3 by wt or Q279* RNAi-resistant Gpn3R in epithelial model cells. RNAPII nuclear accumulation and transcriptional activity were markedly decreased in cells expressing only Gpn3R Q279*. Wild-type Gpn3R localized to the cytoplasm but a fraction of Gpn3R Q279* entered the cell nucleus and inhibited Gpn1-EYFP nuclear export. This property and the transcriptional deficit in Gpn3R Q279*-expressing cells required a PDZ-binding motif generated by the Q279* mutation. We conclude that an acquired PDZ-binding motif in Gpn3 Q279* caused Gpn3 nuclear entry, and inhibited Gpn1 nuclear export and Gpn3-mediated RNAPII nuclear targeting. © 2017 Federation of European Biochemical Societies.

Nuclear imprisonment of host cellular mRNA by nsp1β protein of porcine reproductive and respiratory syndrome virus

International Nuclear Information System (INIS)

Han, Mingyuan; Ke, Hanzhong; Zhang, Qingzhan; Yoo, Dongwan

2017-01-01

Positive-strand RNA genomes function as mRNA for viral protein synthesis which is fully reliant on host cell translation machinery. Competing with cellular protein translation apparatus needs to ensure the production of viral proteins, but this also stifles host innate defense. In the present study, we showed that porcine reproductive and respiratory syndrome virus (PRRSV), whose replication takes place in the cytoplasm, imprisoned host cell mRNA in the nucleus, which suggests a novel mechanism to enhance translation of PRRSV genome. PRRSV nonstructural protein (nsp) 1β was identified as the nuclear protein playing the role for host mRNA nuclear retention and subversion of host protein synthesis. A SAP (SAF-A/B, Acinus, and PIAS) motif was identified in nsp1β with the consensus sequence of 126 -LQxxLxxxGL- 135 . In situ hybridization unveiled that SAP mutants were unable to cause nuclear retention of host cell mRNAs and did not suppress host protein synthesis. In addition, these SAP mutants reverted PRRSV-nsp1β-mediated suppression of interferon (IFN) production, IFN signaling, and TNF-α production pathway. Using reverse genetics, a series of SAP mutant PRRS viruses, vK124A, vL126A, vG134A, and vL135A were generated. No mRNA nuclear retention was observed during vL126A and vL135A infections. Importantly, vL126A and vL135A did not suppress IFN production. For other arteriviruses, mRNA nuclear accumulation was also observed for LDV-nsp1β and SHFV-nsp1β. EAV-nsp1 was exceptional and did not block the host mRNA nuclear export. - Highlights: •PRRS virus blocks host mRNA nuclear export to the cytoplasm. •PRRSV nsp1β is the viral protein responsible for host mRNA nuclear retention. •SAP domain in nsp1β is essential for host mRNA nuclear retention and type I interferon suppression. •Mutation in the SAP domain of nsp1β causes the loss of function. •Host mRNA nuclear retention by nsp1β is common in the family Arteriviridae, except equine arteritis virus.

Nuclear imprisonment of host cellular mRNA by nsp1β protein of porcine reproductive and respiratory syndrome virus

Energy Technology Data Exchange (ETDEWEB)

Han, Mingyuan, E-mail: hanming@umich.edu; Ke, Hanzhong; Zhang, Qingzhan; Yoo, Dongwan, E-mail: dyoo@illinois.edu

2017-05-15

Positive-strand RNA genomes function as mRNA for viral protein synthesis which is fully reliant on host cell translation machinery. Competing with cellular protein translation apparatus needs to ensure the production of viral proteins, but this also stifles host innate defense. In the present study, we showed that porcine reproductive and respiratory syndrome virus (PRRSV), whose replication takes place in the cytoplasm, imprisoned host cell mRNA in the nucleus, which suggests a novel mechanism to enhance translation of PRRSV genome. PRRSV nonstructural protein (nsp) 1β was identified as the nuclear protein playing the role for host mRNA nuclear retention and subversion of host protein synthesis. A SAP (SAF-A/B, Acinus, and PIAS) motif was identified in nsp1β with the consensus sequence of {sub 126}-LQxxLxxxGL-{sub 135}. In situ hybridization unveiled that SAP mutants were unable to cause nuclear retention of host cell mRNAs and did not suppress host protein synthesis. In addition, these SAP mutants reverted PRRSV-nsp1β-mediated suppression of interferon (IFN) production, IFN signaling, and TNF-α production pathway. Using reverse genetics, a series of SAP mutant PRRS viruses, vK124A, vL126A, vG134A, and vL135A were generated. No mRNA nuclear retention was observed during vL126A and vL135A infections. Importantly, vL126A and vL135A did not suppress IFN production. For other arteriviruses, mRNA nuclear accumulation was also observed for LDV-nsp1β and SHFV-nsp1β. EAV-nsp1 was exceptional and did not block the host mRNA nuclear export. - Highlights: •PRRS virus blocks host mRNA nuclear export to the cytoplasm. •PRRSV nsp1β is the viral protein responsible for host mRNA nuclear retention. •SAP domain in nsp1β is essential for host mRNA nuclear retention and type I interferon suppression. •Mutation in the SAP domain of nsp1β causes the loss of function. •Host mRNA nuclear retention by nsp1β is common in the family Arteriviridae, except equine

Nuclear Successor States of the Soviet Union, Nuclear Weapon and Sensitive Export Status Report

Science.gov (United States)

1994-05-01

international advisory group composed of: Valentin Alexandrov Ministry of Foreign Affairs, Minsk Alexander Bolsunovsky Institute of Biophysics, Krasnoyarsk Oleg...Center for Nonproliferation and Export Control, Minsk Alexander Pikayev Inst. of World Economy and Intl. Relations, Moscow Anatoly Scherba Ministry of...Bulletin of the Atomic Scientists, March/April 1994; A. Pikayev and A. Savelyev , "The USSR’s Nuclear Might: On Land, At Sea, At Air," Nezavisimaya Gazeta

Control of nuclear β-dystroglycan content is crucial for the maintenance of nuclear envelope integrity and function.

Science.gov (United States)

Vélez-Aguilera, Griselda; de Dios Gómez-López, Juan; Jiménez-Gutiérrez, Guadalupe E; Vásquez-Limeta, Alejandra; Laredo-Cisneros, Marco S; Gómez, Pablo; Winder, Steve J; Cisneros, Bulmaro

2018-02-01

β-Dystroglycan (β-DG) is a plasma membrane protein that has ability to target to the nuclear envelope (NE) to maintain nuclear architecture. Nevertheless, mechanisms controlling β-DG nuclear localization and the physiological consequences of a failure of trafficking are largely unknown. We show that β-DG has a nuclear export pathway in myoblasts that depends on the recognition of a nuclear export signal located in its transmembrane domain, by CRM1. Remarkably, NES mutations forced β-DG nuclear accumulation resulting in mislocalization and decreased levels of emerin and lamin B1 and disruption of various nuclear processes in which emerin (centrosome-nucleus linkage and β-catenin transcriptional activity) and lamin B1 (cell cycle progression and nucleoli structure) are critically involved. In addition to nuclear export, the lifespan of nuclear β-DG is restricted by its nuclear proteasomal degradation. Collectively our data show that control of nuclear β-DG content by the combination of CRM1 nuclear export and nuclear proteasome pathways is physiologically relevant to preserve proper NE structure and activity. Copyright © 2017 Elsevier B.V. All rights reserved.

A quasi-lentiviral green fluorescent protein reporter exhibits nuclear export features of late human immunodeficiency virus type 1 transcripts

International Nuclear Information System (INIS)

Graf, Marcus; Ludwig, Christine; Kehlenbeck, Sylvia; Jungert, Kerstin; Wagner, Ralf

2006-01-01

We have previously shown that Rev-dependent expression of HIV-1 Gag from CMV immediate early promoter critically depends on the AU-rich codon bias of the gag gene. Here, we demonstrate that adaptation of the green fluorescent protein (GFP) reporter gene to HIV codon bias is sufficient to turn this hivGFP RNA into a quasi-lentiviral message following the rules of late lentiviral gene expression. Accordingly, GFP expression was significantly decreased in transfected cells strictly correlating with reduced RNA levels. In the presence of the HIV 5' major splice donor, the hivGFP RNAs were stabilized in the nucleus and efficiently exported to the cytoplasm following fusion of the 3' Rev-responsive element (RRE) and coexpression of HIV-1 Rev. This Rev-dependent translocation was specifically inhibited by leptomycin B suggesting export via the CRM1-dependent pathway used by late lentiviral transcripts. In conclusion, this quasi-lentiviral reporter system may provide a new platform for developing sensitive Rev screening assays

Export control guide: Spent nuclear fuel reprocessing and preparation of plutonium metal

International Nuclear Information System (INIS)

1993-10-01

The international Treaty on the Non-Proliferation of Nuclear Weapons, also referred to as the Non-Proliferation Treaty (NPT), states in Article III, paragraph 2(b) that open-quotes Each State Party to the Treaty undertakes not to provide . . . equipment or material especially designed or prepared for the processing, use or production of special fissionable material to any non-nuclear-weapon State for peaceful purposes, unless the source or special fissionable material shall be subject to the safeguards required by this Article.close quotes This guide was prepared to assist export control officials in the interpretation, understanding, and implementation of export laws and controls relating to the international Trigger List for irradiated nuclear fuel reprocessing equipment, components, and materials. The guide also contains information related to the production of plutonium metal. Reprocessing and its place in the nuclear fuel cycle are described briefly; the standard procedure to prepare metallic plutonium is discussed; steps used to prepare Trigger List controls are cited; descriptions of controlled items are given; and special materials of construction are noted. This is followed by a comprehensive description of especially designed or prepared equipment, materials, and components of reprocessing and plutonium metal processes and includes photographs and/or pictorial representations. The nomenclature of the Trigger List has been retained in the numbered sections of this document for clarity

Competitiveness, export control and export promotion of dual-use goods. European and German balancing exercises

International Nuclear Information System (INIS)

Feldmann, Ulrike

2014-01-01

The EU Commission Communication of 24 April 2014 to the Council and the European Parliament ''The review of export control policy: Ensuring Security and Competitiveness in a changing world'' as well as the increasingly number of inquiries and applications to the German Federal Government (e.g. the rejection of Hermes guarantees and state funding of nuclear export and termination of bilateral cooperation in the field of nuclear technologies) once again reason to discuss the current tension between the principle of free movement of goods, competitiveness and export promotion on the one hand and the export control on the other.

Intermolecular masking of the HIV-1 Rev NLS by the cellular protein HIC: novel insights into the regulation of Rev nuclear import.

LENUS (Irish Health Repository)

Gu, Lili

2011-01-01

The HIV-1 regulatory protein Rev, which is essential for viral replication, mediates the nuclear export of unspliced viral transcripts. Rev nuclear function requires active nucleocytoplasmic shuttling, and Rev nuclear import is mediated by the recognition of its Nuclear Localisation Signal (NLS) by multiple import factors, which include transportin and importin β. However, it remains unclear which nuclear import pathway(s) predominate in vivo, and the cellular environment that modulates Rev nucleocytoplasmic shuttling remains to be characterised.

Uncoupling of the hnRNP Npl3p from mRNAs during the stress-induced block in mRNA export.

Science.gov (United States)

Krebber, H; Taura, T; Lee, M S; Silver, P A

1999-08-01

Npl3p, the major mRNA-binding protein of the yeast Saccharomyces cerevisiae shuttles between the nucleus and the cytoplasm. A single amino acid change in the carboxyl terminus of Npl3p (E409 --> K) renders the mutant protein largely cytoplasmic because of a delay in its import into the nucleus. This import defect can be reversed by increasing the intracellular concentration of Mtr10p, the nuclear import receptor for Npl3p. Conversely, using this mutant, we show that Npl3p and mRNA export out of the nucleus is significantly slowed in cells bearing mutations in XPO1/CRM1, which encodes the export receptor for NES-containing proteins and in RAT7, which encodes an essential nucleoporin. Interestingly, following induction of stress by heat shock, high salt, or ethanol, conditions under which most mRNA export is blocked, Npl3p is still exported from the nucleus. The stress-induced export of Npl3p is independent of both the activity of Xpo1p and the continued selective export of heat-shock mRNAs that occurs following stress. UV-cross-linking experiments show that Npl3p is bound to mRNA under normal conditions, but is no longer RNA associated in stressed cells. Taken together, we suggest that the uncoupling of Npl3p and possibly other mRNA-binding proteins from mRNAs in the nucleus provides a general switch that regulates mRNA export. By this model, under normal conditions Npl3p is a major component of an export-competent RNP complex. However, under conditions of stress, Npl3p no longer associates with the export complex, rendering it export incompetent and thus nuclear.

The directionality of the nuclear transport of the influenza A genome is driven by selective exposure of nuclear localization sequences on nucleoprotein

Directory of Open Access Journals (Sweden)

Panté Nelly

2009-06-01

Full Text Available Abstract Background Early in infection, the genome of the influenza A virus, consisting of eight complexes of RNA and proteins (termed viral ribonucleoproteins; vRNPs, enters the nucleus of infected cells for replication. Incoming vRNPs are imported into the nucleus of infected cells using at least two nuclear localization sequences on nucleoprotein (NP; NLS1 at the N terminus, and NLS2 in the middle of the protein. Progeny vRNP assembly occurs in the nucleus, and later in infection, these are exported from the nucleus to the cytoplasm. Nuclear-exported vRNPs are different from incoming vRNPs in that they are prevented from re-entering the nucleus. Why nuclear-exported vRNPs do not re-enter the nucleus is unknown. Results To test our hypothesis that the exposure of NLSs on the vRNP regulates the directionality of the nuclear transport of the influenza vRNPs, we immunolabeled the two NLSs of NP (NLS1 and NLS2 and analyzed their surface accessibility in cells infected with the influenza A virus. We found that the NLS1 epitope on NP was exposed throughout the infected cells, but the NLS2 epitope on NP was only exposed in the nucleus of the infected cells. Addition of the nuclear export inhibitor leptomycin B further revealed that NLS1 is no longer exposed in cytoplasmic NP and vRNPs that have already undergone nuclear export. Similar immunolabeling studies in the presence of leptomycin B and with cells transfected with the cDNA of NP revealed that the NLS1 on NP is hidden in nuclear exported-NP. Conclusion NLS1 mediates the nuclear import of newly-synthesized NP and incoming vRNPs. This NLS becomes hidden on nuclear-exported NP and nuclear-exported vRNPs. Thus the selective exposure of the NLS1 constitutes a critical mechanism to regulate the directionality of the nuclear transport of vRNPs during the influenza A viral life cycle.

Actin, actin-binding proteins, and actin-related proteins in the nucleus.

Science.gov (United States)

Kristó, Ildikó; Bajusz, Izabella; Bajusz, Csaba; Borkúti, Péter; Vilmos, Péter

2016-04-01

Extensive research in the past decade has significantly broadened our view about the role actin plays in the life of the cell and added novel aspects to actin research. One of these new aspects is the discovery of the existence of nuclear actin which became evident only recently. Nuclear activities including transcriptional activation in the case of all three RNA polymerases, editing and nuclear export of mRNAs, and chromatin remodeling all depend on actin. It also became clear that there is a fine-tuned equilibrium between cytoplasmic and nuclear actin pools and that this balance is ensured by an export-import system dedicated to actin. After over half a century of research on conventional actin and its organizing partners in the cytoplasm, it was also an unexpected finding that the nucleus contains more than 30 actin-binding proteins and new classes of actin-related proteins which are not able to form filaments but had evolved nuclear-specific functions. The actin-binding and actin-related proteins in the nucleus have been linked to RNA transcription and processing, nuclear transport, and chromatin remodeling. In this paper, we attempt to provide an overview of the wide range of information that is now available about actin, actin-binding, and actin-related proteins in the nucleus.

Communications received from Member States regarding guidelines for the export of nuclear material, equipment and technology

International Nuclear Information System (INIS)

1994-04-01

The Director General has received notes verbales to the export of nuclear material, equipment and technology from the following Permanent Missions to the International Atomic Energy Agency: notes verbales dated 1 March 1994 from the Permanent Missions of Australia, Austria, Belgium, Bulgaria, Canada, the Czech Republic, Denmark, Finland, France, Germany, Hungary, Italy, Japan, the Netherlands, Poland, Portugal, Spain, Sweden, Switzerland, the United Kingdom of Great Britain and Northern Ireland, the United States of America; and a note verbale dated 12 March 1994 from the Permanent Mission of Romania. The purpose of these notes verbales is to provide further information on these Governments' nuclear export policies and practices

HuR and GRSF1 modulate the nuclear export and mitochondrial localization of the lncRNA RMRP

Science.gov (United States)

Noh, Ji Heon; Kim, Kyoung Mi; Abdelmohsen, Kotb; Yoon, Je-Hyun; Panda, Amaresh C.; Munk, Rachel; Kim, Jiyoung; Curtis, Jessica; Moad, Christopher A.; Wohler, Christina M.; Indig, Fred E.; de Paula, Wilson; Dudekula, Dawood B.; De, Supriyo; Piao, Yulan; Yang, Xiaoling; Martindale, Jennifer L.; de Cabo, Rafael; Gorospe, Myriam

2016-01-01

Some mitochondrial long noncoding RNAs (lncRNAs) are encoded by nuclear DNA, but the mechanisms that mediate their transport to mitochondria are poorly characterized. Using affinity RNA pull-down followed by mass spectrometry analysis, we found two RNA-binding proteins (RBPs), HuR (human antigen R) and GRSF1 (G-rich RNA sequence-binding factor 1), that associated with the nuclear DNA-encoded lncRNA RMRP and mobilized it to mitochondria. In cultured human cells, HuR bound RMRP in the nucleus and mediated its CRM1 (chromosome region maintenance 1)-dependent export to the cytosol. After RMRP was imported into mitochondria, GRSF1 bound RMRP and increased its abundance in the matrix. Loss of GRSF1 lowered the mitochondrial levels of RMRP, in turn suppressing oxygen consumption rates and modestly reducing mitochondrial DNA replication priming. Our findings indicate that RBPs HuR and GRSF1 govern the cytoplasmic and mitochondrial localization of the lncRNA RMRP, which is encoded by nuclear DNA but has key functions in mitochondria. PMID:27198227

Unprecedented NES non-antagonistic inhibitor for nuclear export of Rev from Sida cordifolia.

Science.gov (United States)

Tamura, Satoru; Kaneko, Masafumi; Shiomi, Atsushi; Yang, Guang-Ming; Yamaura, Toshiaki; Murakami, Nobutoshi

2010-03-15

Bioassay-guided separation from the MeOH extract of the South American medicinal plant Sida cordifolia resulted in isolation of (10E,12Z)-9-hydroxyoctadeca-10,12-dienoic acid (1) as an unprecedented NES non-antagonistic inhibitor for nuclear export of Rev. This mechanism of action was established by competitive experiment by the biotinylated probe derived from leptomycin B, the known NES antagonistic inhibitor. Additionally, structure-activity relationship analysis by use of the synthesized analogs clarified cooperation of several functionalities in the Rev-export inhibitory activity of 1. Copyright 2010 Elsevier Ltd. All rights reserved.

Notification to the Agency of exports and imports of nuclear material

International Nuclear Information System (INIS)

1991-12-01

The document reproduces the letter dated 15 November 1991 received by the Director General of the IAEA from the Resident Representative to the Agency of the People's Republic of China, informing him that, in the interest of assisting the Agency in its safeguards activities, the Government of the People's Republic of China had decided to provide it henceforth with information on exports and imports of nuclear material

Efficient and dynamic nuclear localization of green fluorescent protein via RNA binding

Energy Technology Data Exchange (ETDEWEB)

Kitamura, Akira; Nakayama, Yusaku; Kinjo, Masataka, E-mail: kinjo@sci.hokudai.ac.jp

2015-07-31

Classical nuclear localization signal (NLS) sequences have been used for artificial localization of green fluorescent protein (GFP) in the nucleus as a positioning marker or for measurement of the nuclear-cytoplasmic shuttling rate in living cells. However, the detailed mechanism of nuclear retention of GFP-NLS remains unclear. Here, we show that a candidate mechanism for the strong nuclear retention of GFP-NLS is via the RNA-binding ability of the NLS sequence. GFP tagged with a classical NLS derived from Simian virus 40 (GFP-NLS{sup SV40}) localized not only in the nucleoplasm, but also to the nucleolus, the nuclear subdomain in which ribosome biogenesis takes place. GFP-NLS{sup SV40} in the nucleolus was mobile, and intriguingly, the diffusion coefficient, which indicates the speed of diffusing molecules, was 1.5-fold slower than in the nucleoplasm. Fluorescence correlation spectroscopy (FCS) analysis showed that GFP-NLS{sup SV40} formed oligomers via RNA binding, the estimated molecular weight of which was larger than the limit for passive nuclear export into the cytoplasm. These findings suggest that the nuclear localization of GFP-NLS{sup SV40} likely results from oligomerization mediated via RNA binding. The analytical technique used here can be applied for elucidating the details of other nuclear localization mechanisms, including those of several types of nuclear proteins. In addition, GFP-NLS{sup SV40} can be used as an excellent marker for studying both the nucleoplasm and nucleolus in living cells. - Highlights: • Nuclear localization signal-tagged GFP (GFP-NLS) showed clear nuclear localization. • The GFP-NLS dynamically localized not only in the nucleoplasm, but also to the nucleolus. • The nuclear localization of GFP-NLS results from transient oligomerization mediated via RNA binding. • Our NLS-tagging procedure is ideal for use in artificial sequestration of proteins in the nucleus.

Efficient and dynamic nuclear localization of green fluorescent protein via RNA binding

International Nuclear Information System (INIS)

Kitamura, Akira; Nakayama, Yusaku; Kinjo, Masataka

2015-01-01

Classical nuclear localization signal (NLS) sequences have been used for artificial localization of green fluorescent protein (GFP) in the nucleus as a positioning marker or for measurement of the nuclear-cytoplasmic shuttling rate in living cells. However, the detailed mechanism of nuclear retention of GFP-NLS remains unclear. Here, we show that a candidate mechanism for the strong nuclear retention of GFP-NLS is via the RNA-binding ability of the NLS sequence. GFP tagged with a classical NLS derived from Simian virus 40 (GFP-NLS SV40 ) localized not only in the nucleoplasm, but also to the nucleolus, the nuclear subdomain in which ribosome biogenesis takes place. GFP-NLS SV40 in the nucleolus was mobile, and intriguingly, the diffusion coefficient, which indicates the speed of diffusing molecules, was 1.5-fold slower than in the nucleoplasm. Fluorescence correlation spectroscopy (FCS) analysis showed that GFP-NLS SV40 formed oligomers via RNA binding, the estimated molecular weight of which was larger than the limit for passive nuclear export into the cytoplasm. These findings suggest that the nuclear localization of GFP-NLS SV40 likely results from oligomerization mediated via RNA binding. The analytical technique used here can be applied for elucidating the details of other nuclear localization mechanisms, including those of several types of nuclear proteins. In addition, GFP-NLS SV40 can be used as an excellent marker for studying both the nucleoplasm and nucleolus in living cells. - Highlights: • Nuclear localization signal-tagged GFP (GFP-NLS) showed clear nuclear localization. • The GFP-NLS dynamically localized not only in the nucleoplasm, but also to the nucleolus. • The nuclear localization of GFP-NLS results from transient oligomerization mediated via RNA binding. • Our NLS-tagging procedure is ideal for use in artificial sequestration of proteins in the nucleus

Communication Received from Canada Regarding its New Nuclear Export Policy

International Nuclear Information System (INIS)

1977-01-01

On 29 December 1976 the Director General received a letter dated 28 December from the Resident Representative of Canada to the Agency, informing him of a change in Canada's nuclear export policy and attaching a statement made in the Canadian House of Commons on this subject. In accordance with the request made by the Resident Representative of Canada the texts of his letter and of its attachment are reproduced below for the information of all Members.

1988 nuclear fuel imports and exports of the Federal Republic of Germany

International Nuclear Information System (INIS)

Anon.

1989-01-01

The statistic of imports and exports of nuclear fuels and source materials compiled by the Federal Office for Industry on behalf of the Federal Ministry for the Environment, Nature Conservation, and Reactor Safety show a 32.3% decrease in imports and a 17.6% increase in exports in 1988 compared to the previous year. Most of the imports are made up of source materials, natural uranium, and uranium enriched up to 10%. The term 'source material' as used in these statistics refers only to uranium concentrate. A considerable increase is reported in imports of uranium enriched 3 to 10% and of plutonium. All other products have suffered major or minor decreases. (orig.)

Export regulation

International Nuclear Information System (INIS)

Gates, D.J.

1978-01-01

Australia is a major uranium supplier. Uranium is exported under conditions laid down to avoid any nuclear proliferation. On 24 May 1977 the Prime Minister had stated the main elements of Australian policy: the strengthening of the system of international safeguards and the selection of importing countries. (Non-nuclear weapon states must be Contracting Parties to the NPT. Nuclear weapon states must undertake not to use Australian uranium for this purpose). Australia retains property of the uranium up to the UF 6 stage (uranium hexafluoride) in the fuel cycle; it reserves the right to stop any export if the importing country no longer complies with AIEA Safeguards. Any transfer to a third country, any irradiated fuel reprocessing, requires Australia's prior agreement. Finally, importing countries must satisfy physical protection conditions. (NEA) [fr

Role of the mRNA export factor Sus1 in oxidative stress tolerance in Candida albicans.

Science.gov (United States)

Xiao, Chenpeng; Yu, Qilin; Zhang, Bing; Li, Jianrong; Zhang, Dan; Li, Mingchun

2018-02-05

In eukaryotes, the nuclear export of mRNAs is essential for gene expression. However, little is known about the role of mRNA nuclear export in the important fungal pathogen, Candida albicans. In this study, we identified C. albicans Sus1, a nucleus-localized protein that is required for mRNA export. Interestingly, the sus1Δ/Δ displayed hyper-sensitivity to extracellular oxidative stress, enhanced ROS accumulation and severe oxidative stress-related cell death. More strikingly, although the mutant exhibited normal activation of the expression of oxidative stress response (OSR) genes, it had attenuated activity of ROS scavenging system, which may be attributed to the defect in OSR mRNA export in this mutant. In addition, the virulence of the sus1Δ/Δ was seriously attenuated. Taken together, our findings provide evidence that the mRNA export factor Sus1 plays an important role in oxidative stress tolerance and pathogenesis. Copyright © 2018 Elsevier Inc. All rights reserved.

Interaction of HTLV-1 Tax protein with the calreticulin: Implications for Tax nuclear export and secretion

OpenAIRE

Alefantis, Timothy; Flaig, Katherine E.; Wigdahl, Brian; Jain, Pooja

2007-01-01

Human T cell leukemia virus type 1 (HTLV-1) is the etiologic agent of adult T cell leukemia (ATL) and HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP). The HTLV-1 transcriptional transactivator protein Tax plays an integral role in virus replication and disease progression. Traditionally, Tax is described as a nuclear protein where it performs its primary role as a transcriptional transactivator. However, recent studies have clearly shown that Tax can also be localized to t...

A study on the establishment of national nuclear foreign policy with reference to nuclear export control system, strategy toward IAEA, and NPT review conferences

International Nuclear Information System (INIS)

Choi, Young Myung; Nam, Jang Soo; Lee, Han Myung

1990-02-01

The objectives of this study are follows: suggestion for i) our future nuclear development directions, ii) establishment of national export control system, iii) establishment of strategy toward IAEA, and suggestion of our standpoints toward the 4th NPT review conference. This study proposes the following; 1) It is desirable that nuclear power generation strategy is propelled under the premise of economics and proven technology. And international cooperation in connection with the nuclear fuel cycle should be reinforced. 2) It is recommened that nuclear export control system should be government-led. 3) Our country needs to make efforts in increasing the number of Korean staff in the IAEA, and to establish permanent mission which is wholly responsible for the IAEA affairs, and to construct a system which deals with nuclear foregin activities. 4) It is desirable that the basic position of our country toward the 4th NPT review conference should be : i) to urge parties to the NPT to conclude safeguards agreement with IAEA as early as possible, ii) to request nuclear suppliers to mitigate their nuclear technology for peaceful uses to nuclear developing countries, and iii) to urge nuclear weapon states to make further efforts for nuclear disarmament. (author)

Integrating complex functions: coordination of nuclear pore complex assembly and membrane expansion of the nuclear envelope requires a family of integral membrane proteins.

Science.gov (United States)

Schneiter, Roger; Cole, Charles N

2010-01-01

The nuclear envelope harbors numerous large proteinaceous channels, the nuclear pore complexes (NPCs), through which macromolecular exchange between the cytosol and the nucleoplasm occurs. This double-membrane nuclear envelope is continuous with the endoplasmic reticulum and thus functionally connected to such diverse processes as vesicular transport, protein maturation and lipid synthesis. Recent results obtained from studies in Saccharomyces cerevisiae indicate that assembly of the nuclear pore complex is functionally dependent upon maintenance of lipid homeostasis of the ER membrane. Previous work from one of our laboratories has revealed that an integral membrane protein Apq12 is important for the assembly of functional nuclear pores. Cells lacking APQ12 are viable but cannot grow at low temperatures, have aberrant NPCs and a defect in mRNA export. Remarkably, these defects in NPC assembly can be overcome by supplementing cells with a membrane fluidizing agent, benzyl alcohol, suggesting that Apq12 impacts the flexibility of the nuclear membrane, possibly by adjusting its lipid composition when cells are shifted to a reduced temperature. Our new study now expands these findings and reveals that an essential membrane protein, Brr6, shares at least partially overlapping functions with Apq12 and is also required for assembly of functional NPCs. A third nuclear envelope membrane protein, Brl1, is related to Brr6, and is also required for NPC assembly. Because maintenance of membrane homeostasis is essential for cellular survival, the fact that these three proteins are conserved in fungi that undergo closed mitoses, but are not found in metazoans or plants, may indicate that their functions are performed by proteins unrelated at the primary sequence level to Brr6, Brl1 and Apq12 in cells that disassemble their nuclear envelopes during mitosis.

Nuclear Sanctions: Section 102(b) of the Arms Export Control Act and its Application to India and Pakistan

National Research Council Canada - National Science Library

Grimmett, Jeanne J

2001-01-01

Section 102(b) of the Arms Export Control Act (AECA) requires the President to impose sanctions on any country that he has determined is a "non-nuclear-weapon state" and has received or detonated a "nuclear explosive device...

Serotype-specific Differences in Dengue Virus Non-structural Protein 5 Nuclear Localization*

Science.gov (United States)

Hannemann, Holger; Sung, Po-Yu; Chiu, Han-Chen; Yousuf, Amjad; Bird, Jim; Lim, Siew Pheng; Davidson, Andrew D.

2013-01-01

The four serotypes of dengue virus (DENV-1 to -4) cause the most important arthropod-borne viral disease of humans. DENV non-structural protein 5 (NS5) contains enzymatic activities required for capping and replication of the viral RNA genome that occurs in the host cytoplasm. However, previous studies have shown that DENV-2 NS5 accumulates in the nucleus during infection. In this study, we examined the nuclear localization of NS5 for all four DENV serotypes. We demonstrate for the first time that there are serotypic differences in NS5 nuclear localization. Whereas the DENV-2 and -3 proteins accumulate in the nucleus, DENV-1 and -4 NS5 are predominantly if not exclusively localized to the cytoplasm. Comparative studies on the DENV-2 and -4 NS5 proteins revealed that the difference in DENV-4 NS5 nuclear localization was not due to rapid nuclear export but rather the lack of a functional nuclear localization sequence. Interaction studies using DENV-2 and -4 NS5 and human importin-α isoforms failed to identify an interaction that supported the differential nuclear localization of NS5. siRNA knockdown of the human importin-α isoform KPNA2, corresponding to the murine importin-α isoform previously shown to bind to DENV-2 NS5, did not substantially affect DENV-2 NS5 nuclear localization, whereas knockdown of importin-β did. The serotypic differences in NS5 nuclear localization did not correlate with differences in IL-8 gene expression. The results show that NS5 nuclear localization is not strictly required for virus replication but is more likely to have an auxiliary function in the life cycle of specific DENV serotypes. PMID:23770669

Serotype-specific differences in dengue virus non-structural protein 5 nuclear localization.

Science.gov (United States)

Hannemann, Holger; Sung, Po-Yu; Chiu, Han-Chen; Yousuf, Amjad; Bird, Jim; Lim, Siew Pheng; Davidson, Andrew D

2013-08-02

The four serotypes of dengue virus (DENV-1 to -4) cause the most important arthropod-borne viral disease of humans. DENV non-structural protein 5 (NS5) contains enzymatic activities required for capping and replication of the viral RNA genome that occurs in the host cytoplasm. However, previous studies have shown that DENV-2 NS5 accumulates in the nucleus during infection. In this study, we examined the nuclear localization of NS5 for all four DENV serotypes. We demonstrate for the first time that there are serotypic differences in NS5 nuclear localization. Whereas the DENV-2 and -3 proteins accumulate in the nucleus, DENV-1 and -4 NS5 are predominantly if not exclusively localized to the cytoplasm. Comparative studies on the DENV-2 and -4 NS5 proteins revealed that the difference in DENV-4 NS5 nuclear localization was not due to rapid nuclear export but rather the lack of a functional nuclear localization sequence. Interaction studies using DENV-2 and -4 NS5 and human importin-α isoforms failed to identify an interaction that supported the differential nuclear localization of NS5. siRNA knockdown of the human importin-α isoform KPNA2, corresponding to the murine importin-α isoform previously shown to bind to DENV-2 NS5, did not substantially affect DENV-2 NS5 nuclear localization, whereas knockdown of importin-β did. The serotypic differences in NS5 nuclear localization did not correlate with differences in IL-8 gene expression. The results show that NS5 nuclear localization is not strictly required for virus replication but is more likely to have an auxiliary function in the life cycle of specific DENV serotypes.

Notification to the Agency of Exports and Imports of Nuclear Material

International Nuclear Information System (INIS)

1984-03-01

On 16 February 1984 the Director General received a letter dated 7 February 1984 from the Governor from France on the Agency's Board of Governors informing him that, in the interest of assisting the Agency in its safeguards activities, the Government of France had decided to provide it henceforth with information on exports and imports of nuclear material. In the light of the request made in this letter, its text is reproduced

A study on strengthening measures of non-proliferation regime through the export control system of sensitive materials, equipment and technology related to nuclear activities

International Nuclear Information System (INIS)

Kikuchi, Masahiro; Kurosawa, Mitsuru; Komizo, Yasuyoshi

2004-01-01

The strengthened safeguards caused from safeguards experiences to Iraq and DPRK leads to the expansion of the IAEA's activities for verification of all nuclear activities as well as verification of nuclear material in the States. The purpose of the activities, of course, includes detection of undeclared exports and imports of specified equipment and non-nuclear material. The Additional Protocol to the agreements between States and the IAEA for the application of safeguards requires to the States to declare the exports and imports information regarding specified equipment and non-nuclear material corresponding to the export control list that is established by the nuclear suppliers group. The Additional Protocol also insists the IAEA's right to access to the location identified by the State to resolve a question related to the declarations. Recently, the IAEA detected the black market group of the sensitive materials, equipment and technologies relevant to the nuclear proliferation through the safeguards activities to Iran and Libya. International community stated deeply concerns to the indecent facts. This paper would discuss and propose the supplemental strengthening measures of non-proliferation regime by effective combination of the safeguards activities under additional protocol and the export control regime. (author)

Export of radiopharmaceuticals and establishment of export base of cyclotron

International Nuclear Information System (INIS)

Jung, Kyungil; Kim, Youngsik

2006-01-01

Sam young Unit ech has seized an opportunity to advance into the radiopharmaceuticals market through successful transfer of radiopharmaceuticals manufacturing technology and medical cyclotron, an original technology in nuclear medicine that is the core of less developed areas in nuclear-related fields. The company has continued to push for research development and establishment of market base through industry-academia-research center cooperation with an aim to complement relatively less developed domestic technology and market than in advanced countries, and is making efforts to establish export base in the overseas market based on stabilized supply in the domestic market. As for radiopharmaceuticals, the company is exporting Tc-99m generator to Vietnam, Thailand and the Philippines and preparing itself to export manufacture facilities for Tc-99m generator to Syria and Kazakhstan. In addition, it plans to export 13Mev Cyclotron that has been commercialized after being developed in the domestic market to the U. S. The company plans to grow up to play a pivotal role in the domestic RT area by conducting proactive business activities with an aim to revitalize the domestic market and further domestic original technologies and products in the global market

Should Australia mine and export uranium?

International Nuclear Information System (INIS)

Cobb, M.; Broadbent, Steve.

1989-01-01

In this chapter, the case for and against the mining and export of Australian uranium is discussed. For those in favour of uranium export, the nuclear energy, a source of energy which could bring a much needed boost to Australian export and employment, is being stifled by specious 'scare tactics' about the danger and misuse of uranium. It is also shown that uranium is the only feasible energy source, being cheaper, safer and cleaner when compared with other energy sources. Meanwhile, the opponents of nuclear energy, argue that uranium mining is environmentally destructive, is a danger to workers and residents health, it is bad for economy and it provides raw materials for nuclear weapons. 2 tabs

Notification to the Agency of Exports and Imports of Nuclear Material

International Nuclear Information System (INIS)

1974-01-01

On 11 July 1974 the Director General received letters dated 10 July from the Resident Representatives to the Agency of the Union of Soviet Socialist Republics, the United Kingdom of Great Britain and Northern Ireland and the United States of America informing him that in the interest of assisting the Agency in its safeguards activities, the Governments of these three Members had decided to provide it henceforth with information on exports and imports of nuclear material

Identification of the nuclear export signals that regulate the intracellular localization of the mouse CMP-sialic acid synthetase

International Nuclear Information System (INIS)

Fujita, Akiko; Sato, Chihiro; Kitajima, Ken.

2007-01-01

The CMP-sialic acid synthetase (CSS) catalyzes the activation of sialic acid (Sia) to CMP-Sia which is a donor substrate of sialyltransferases. The vertebrate CSSs are usually localized in nucleus due to the nuclear localization signal (NLS) on the molecule. In this study, we first point out that a small, but significant population of the mouse CMP-sialic acid synthetase (mCSS) is also present in cytoplasm, though mostly in nucleus. As a mechanism for the localization in cytoplasm, we first identified two nuclear export signals (NESs) in mCSS, based on the localization studies of the potential NES-deleted mCSS mutants as well as the potential NES-tagged eGFP proteins. These two NESs are conserved among mammalian and fish CSSs, but not present in the bacterial or insect CSS. These results suggest that the intracellular localization of vertebrate CSSs is regulated by not only the NLS, but also the NES sequences

Communications received from certain member states regarding guidelines for the export of nuclear material, equipment and technology

International Nuclear Information System (INIS)

1993-04-01

The document reproduces the Note Verbale dated 8 February 1993 received by the Director General from the Permanent Mission of the Russian Federation to the International Organizations in Vienna, relating to the export of nuclear material, equipment or technology, in order to provide information on that Government's Guidelines for Nuclear Transfer

Export policy and non-proliferation

International Nuclear Information System (INIS)

Fischer, D.A.V.

1978-01-01

Developing countries with a nuclear programme are about a dozen according to information obtained by IAEA. They are a group hostile to any restriction imposed on nuclear technology export and consider that such restriction is contrary to the global concept of North/South co-operation which provides for transfer of advanced technology. In particular, they object to the fact that nuclear weapon states make use of Article 4 of the NPT. Industrialised countries are required to keep a balance between a regular and stable supply system and the assurance that exported nuclear installations and materials are placed under international control according to the IAEA Safeguards. (NEA) [fr

Studies with GFP-Vpr fusion proteins: induction of apoptosis but ablation of cell-cycle arrest despite nuclear membrane or nuclear localization

International Nuclear Information System (INIS)

Waldhuber, Megan G.; Bateson, Michael; Tan, Judith; Greenway, Alison L.; McPhee, Dale A.

2003-01-01

The human immunodeficiency virus type 1 (HIV-1) Vpr protein is known to arrest the cell cycle in G 2 /M and induce apoptosis following arrest. The functions of Vpr relative to its location in the cell remain unresolved. We now demonstrate that the location and function of Vpr are dependent on the makeup of fusion proteins and that the functions of G 2 /M arrest and apoptosis are separable. Using green fluorescence protein mutants (EGFP or EYFP), we found that fusion at either the N- or C-terminus compromised the ability of Vpr to arrest cell cycling, relative to that of His-Vpr or wild-type protein. Additionally, utilizing the ability to specifically identify cells expressing the fusion proteins, we confirm that Vpr can induce apoptosis, but appears to be independent of cell-cycle arrest in G 2 /M. Both N- and C-terminal Vpr/EYFP fusion proteins induced apoptosis but caused minimal G 2 /M arrest. These studies with Vpr fusion proteins indicate that the functions of Vpr leading to G 2 /M arrest and apoptosis are separable and that fusion of Vpr to EGFP or EYFP affected the localization of the protein. Our findings suggest that nuclear membrane localization and nuclear import and export are strongly governed by modification of the N-terminus of Vpr

Spastin subcellular localization is regulated through usage of different translation start sites and active export from the nucleus

International Nuclear Information System (INIS)

Claudiani, Pamela; Riano, Elena; Errico, Alessia; Andolfi, Gennaro; Rugarli, Elena I.

2005-01-01

Most cases of autosomal-dominant hereditary spastic paraplegia are linked to mutations in SPG4 encoding spastin, a protein involved in microtubule dynamics and membrane trafficking. In pyramidal neurons of the motor cortex and in immortalized motor neurons, spastin is localized to the synaptic terminals and growth cones. However, in other neurons and in proliferating cells spastin is prevalently nuclear. The mechanisms that determine targeting of spastin to the nucleus or the cytoplasm are unknown. We show here that the SPG4 mRNA is able to direct synthesis of two spastin isoforms, 68 and 60 kDa, respectively, through usage of two different translational start sites. Both isoforms are imported into the nucleus, but the 68-kDa isoform contains two nuclear export signals that efficiently drive export to the cytoplasm. Nuclear export is leptomycin-B sensitive. The cytoplasmic 68-kDa spastin isoform is more abundant in the brain and the spinal cord than in other tissues. Our data indicate that spastin function is modulated through usage of alternative translational start sites and active nuclear import and export, and open new perspectives for the pathogenesis of hereditary spastic paraplegia

Postage for the messenger: Designating routes for Nuclear mRNA Export

Science.gov (United States)

Natalizio, Barbara J.; Wente, Susan R.

2013-01-01

Transcription of messenger(m) RNA occurs in the nucleus, making the translocation of mRNA across the nuclear envelope (NE) boundary a critical determinant of proper gene expression and cell survival. A major mRNA export route occurs via the NXF1-dependent pathway through the nuclear pore complexes (NPCs) embedded in the NE. However, recent findings have discovered new evidence supporting the existence of multiple mechanisms for crossing the NE, including both NPC-mediated and NE budding-mediated pathways. An analysis of the trans-acting factors and cis components that define these pathways reveals shared elements as well as mechanistic differences. We review here the current understanding of the mechanisms that characterize each pathway and highlight the determinants that influence mRNA transport fate. PMID:23583578

A novel, mouse mammary tumor virus encoded protein with Rev-like properties

International Nuclear Information System (INIS)

Indik, Stanislav; Guenzburg, Walter H.; Salmons, Brian; Rouault, Francoise

2005-01-01

We have identified a novel, multiple spliced, subgenomic mRNA species in MMTV producing cells of different origin containing an open reading frame encoding a 39-kDa Rev-like protein, Rem (regulator of expression of MMTV). An EGFP-Rem fusion protein is shown to be predominantly in the nucleolus. Further leptomycin B inhibits the nuclear export of nonspliced MMTV transcripts, implicating Rem in nuclear export by the Crm1 pathway in MMTV. Rem is thus reminiscent of the Rec protein from the related endogenous human retrovirus, HERV-K

Communications received from certain Member States regarding guidelines for the export of nuclear material, equipment and technology

International Nuclear Information System (INIS)

1993-01-01

The document reproduces the Note Verbale dated 2 December 1992 received by the Director General from the Resident Representative of Argentina to the Agency relating to the export of nuclear material, equipment and technology in order to clarify parts of the Trigger List which is incorporated in Annex A to the Guidelines for Nuclear Transfers

Communications received from certain Member States regarding guidelines for the export of nuclear material, equipment and technology

International Nuclear Information System (INIS)

1993-01-01

The document reproduces the Note Verbale dated 2 December 1992 received by the Director General from the Resident Representative of Argentina to the Agency relating to the export of nuclear material, equipment or technology, in order to provide information on that Government's Guidelines for Transfers of Nuclear-related Dual-use Equipment, Material and related Technology

Nuclear pore complex protein mediated nuclear localization of dicer protein in human cells.

Directory of Open Access Journals (Sweden)

Yoshinari Ando

Full Text Available Human DICER1 protein cleaves double-stranded RNA into small sizes, a crucial step in production of single-stranded RNAs which are mediating factors of cytoplasmic RNA interference. Here, we clearly demonstrate that human DICER1 protein localizes not only to the cytoplasm but also to the nucleoplasm. We also find that human DICER1 protein associates with the NUP153 protein, one component of the nuclear pore complex. This association is detected predominantly in the cytoplasm but is also clearly distinguishable at the nuclear periphery. Additional characterization of the NUP153-DICER1 association suggests NUP153 plays a crucial role in the nuclear localization of the DICER1 protein.

Communication received from the permanent mission of the Argentine Republic regarding guidelines for the export of nuclear material, equipment and technology

International Nuclear Information System (INIS)

1994-11-01

On 11 May 1994, the Director General received a note verbale from the Permanent Mission of Argentina to the International Atomic Energy Agency relating to the export of nuclear material, equipment and technology. The purpose of this note verbale is to provide further information on the nuclear export policies and practices of the Government of the Argentine Republic. In the light of the wish expressed at the end of the note verbale, the text of the note verbale is annexed hereto

Communication received from the permanent mission of the Argentine Republic regarding guidelines for the export of nuclear material, equipment and technology

International Nuclear Information System (INIS)

1994-11-01

On 11 May 1994, the Director General received a note verbale from the Permanent Mission of Argentina to the International Atomic Energy Agency relating to the export of nuclear material, equipment and technology. The purpose of this note verbale is to provide further information on nuclear export policies and practices of the Government of the Argentine Republic. In the light of the wish expressed at the end of the note verbale, the text of the note verbale is annexed hereto

Communications received from Member States regarding guidelines for the export of nuclear material, equipment and technology

International Nuclear Information System (INIS)

1994-11-01

The Director General has received notes verbales relating to the export of nuclear material, equipment and technology from the following Permanent Missions to the International Atomic Energy Agency: notes verbales dated 15 June 1994 from the Permanent Missions of Argentina, Australia, Austria, Belgium, Bulgaria, Canada, the Czech Republic, Denmark, Finland, France, Germany, Greece, Hungary, Ireland, Italy, Japan, Luxembourg, Netherlands, Norway, Poland, Portugal, Romania, the Slovak Republic, Spain, Sweden, Switzerland, the United Kingdom of Great Britain and Northern Ireland and the United States of America; and a note verbale dated 10 November 1994 from the Permanent Mission of the Russian Federation. The purpose of these notes verbales is to provide further information on these Governments' nuclear export policies and practices. In the light of the wish expressed at the end of each note verbale, the analogous text of the notes verbales is attached hereto. The enclosure of these notes verbales with the amendments to the ''Guidelines for Nuclear Transfers'' contained in INFCIRC/254/Rev.1/Part 1/Mod.1 is reproduced in the Annex

Safety and exportation of nuclear power stations

International Nuclear Information System (INIS)

Coudray, M.; Perrais, J.P.

1976-01-01

Safety problems arising from exportation are especially handled through the French exportation of PWR stations. Regulations differ widely from one country to another. However, very large use of American regulations is made and frequently there is a tendency to harden such or such clause in the quotation. Industry must be ready to give satisfaction to such demands of customers. Sometimes also, it is a mere duplication of French stations which is above all looked for. In that case, it is the problem of using French regulations abroad which arises. Desirable changes in examination proceedings are analyzed together with a French regulation effort aiming to make easier the promotion of their use abroad. Finally, safety may be a factor of success for exportation attempts. It is shown how useless some outbiddings may be, but also how, on the contrary, speeding up of research and development effort towards specific safety problems in case of exportation, is to be promoted [fr

Application of U.S. export controls to DOE technical exchanges: New guidelines on export control and nonproliferation

International Nuclear Information System (INIS)

Lisann, E.G.; Hollander, Z.; Rudolph, R.R.

1995-01-01

As the Department of Energy's nuclear weapon's complex shrinks, concern regarding the proliferation of nuclear weapons technology through the release of export-controlled equipment, materials and information has come to the fore. In November, 1994 Under Secretary Charles Curtis issued new guidelines on export control and nonproliferation. The new policies and procedures are designed to help Department of Energy Headquarters Offices, Operations Offices, Area Offices, laboratories and contractors implement a consistent and technologically sound policy regarding DOE transfers of unclassified equipment, materials and information that could adversely affect US nuclear nonproliferation objectives or national security. The DOE Export Control Division has developed a multi-faceted program of guidelines and training materials to sensitize DOE and DOE-contractors to their responsibilities and to teach them how to evaluate the proliferation risks of their activities

A peptide export-import control circuit modulating bacterial development regulates protein phosphatases of the phosphorelay.

Science.gov (United States)

Perego, M

1997-08-05

The phosphorelay signal transduction system activates developmental transcription in sporulation of Bacillus subtilis by phosphorylation of aspartyl residues of the Spo0F and Spo0A response regulators. The phosphorylation level of these response regulators is determined by the opposing activities of protein kinases and protein aspartate phosphatases that interpret positive and negative signals for development in a signal integration circuit. The RapA protein aspartate phosphatase of the phosphorelay is regulated by a peptide that directly inhibits its activity. This peptide is proteolytically processed from an inactive pre-inhibitor protein encoded in the phrA gene. The pre-inhibitor is cleaved by the protein export apparatus to a putative pro-inhibitor that is further processed to the active inhibitor peptide and internalized by the oligopeptide permease. This export-import circuit is postulated to be a mechanism for timing phosphatase activity where the processing enzymes regulate the rate of formation of the active inhibitor. The processing events may, in turn, be controlled by a regulatory hierarchy. Chromosome sequencing has revealed several other phosphatase-prepeptide gene pairs in B. subtilis, suggesting that the use of this mechanism may be widespread in signal transduction.

Strategic plan for the development of core technologies for the Korean advanced nuclear power reactor for export

International Nuclear Information System (INIS)

Moon, Joo Hyun; Cho, Young Ho

2010-01-01

With the soaring oil price and worsening global warming, nuclear power has attracted considerable attention on a global scale and a new large market of nuclear power plants (NPPs) is expected. The Korean government aims to export up to 10 NPPs by 2012, based on the successful export of 2 NPPs to the UAE in 2009. It is also going to develop a follow-up model of the Advanced Power Reactor (APR) 1400, and join the world's NPP market under the banner of Korea's original reactor type. For this, it promulgated the strategic plan, NuTech 2012, a technology development plan intended for the early acquisition of core technologies for the Korean advanced NPP design and domestic production of the main components in NPP. This paper introduces the strategic plan of NuTech 2012. (orig.)

The role of the USNRC in power reactor exports. Legal and procedural aspects

International Nuclear Information System (INIS)

Shapar, H.K.; Stoiber, C.R.

1978-01-01

I. Background on the role of NRC in nuclear export activities. The United States Nuclear Regulatory Commission, created in January 1975 to assume the licensing and regulatory responsibilities of the former Atomic Energy Commission, has final licensing authority over US nuclear reactor exports. Independent of direct Presidential control, the Commission gives great weight to Executive Branch views on national security and foreign policy issues. II. The nuclear export review process. Procedures for NRC review of nuclear export licence applications include referral to the Executive Branch for a co-ordinated expression of agency views; analysis of the record by the NRC staff; and final Commission licensing decision based on consideration of safeguards, agreements and understandings to assure that US exports will be used only for their intended peaceful purposes. III. NRC's proposed export/import licensing regulations. NRC has recently proposed to consolidate and simplify all of its export and import licensing provisions into a new Part 110 for the convenience of the public - both US and foreign. IV. Public participation in nuclear reactor export licensing. In the past two years, after formal requests by domestic and foreign interest groups, the NRC has developed procedures for direct public participation in its export licensing proceedings. V. Statutory licensing requirements. During the past two years, the NRC has refined and particularized the extremely general 'common defence and security' standard for export licences set forth in the 1954 Atomic Energy Act. Eight questions routinely posed to the Executive Branch in reviewing licence applications has given content to Commission export decisions. Recently enacted non-proliferation legislation gives congressional recognition to even more specific, mandatory nuclear export licensing criteria

Communications received from certain Member States regarding guidelines for the export of nuclear material, equipment or technology

International Nuclear Information System (INIS)

1988-11-01

The document reproduces the text of a Note Verbale dated 20 October 1988 received by the IAEA Director General from the Permanent Mission of Spain relating to the export of nuclear material, equipment or technology

Export and import. Conformity with regulations

International Nuclear Information System (INIS)

Shapar, M.

1976-01-01

Since the division of the former US Atomic Energy Commission's tasks, the regulation and control of import and export of nuclear materials and equipment has become the responsability of the Nuclear Regulatory Commission (NRC). The import and export of nuclear fuels, equipment and reactors are therefore subject to prior licensing by the Commission. This requirement aims to guarantee that such activities will not create serious hazards for defense and national safety, and that the exported products will not be diverted from their peaceful uses. The relevant applicable legal provisions are based on the Atomic Energy Act of 1954 and on the detailed regulations issued by the Commission. Under the pressure of public opinion, there is a current tendency to restrict these activities because of the hazards they present, in particular during transport, until the Commission has completed all the necessary studies. (NEA) [fr

RRE-dependent HIV-1 Env RNA effects on Gag protein expression, assembly and release

International Nuclear Information System (INIS)

López, Claudia S.; Sloan, Rachel; Cylinder, Isabel; Kozak, Susan L.; Kabat, David; Barklis, Eric

2014-01-01

The HIV-1 Gag proteins are translated from the full-length HIV-1 viral RNA (vRNA), whereas the envelope (Env) protein is translated from incompletely spliced Env mRNAs. Nuclear export of vRNAs and Env mRNAs is mediated by the Rev accessory protein which binds to the rev-responsive element (RRE) present on these RNAs. Evidence has shown there is a direct or indirect interaction between the Gag protein, and the cytoplasmic tail (CT) of the Env protein. Our current work shows that env gene expression impacts HIV-1 Gag expression and function in two ways. At the protein level, full-length Env expression altered Gag protein expression, while Env CT-deletion proteins did not. At the RNA level, RRE-containing Env mRNA expression reduced Gag expression, processing, and virus particle release from cells. Our results support models in which Gag is influenced by the Env CT, and Env mRNAs compete with vRNAs for nuclear export. - Highlights: • At the protein level, full-length HIV-1 Env alters Gag protein expression. • HIV-1 Env RNA expression reduces Gag levels and virus release. • Env RNA effects on Gag are dependent on the RRE. • RRE-containing Env RNAs compete with vRNAs for nuclear export

A novel chromosome region maintenance 1-independent nuclear export signal of the large form of hepatitis delta antigen that is required for the viral assembly.

Science.gov (United States)

Lee, C H; Chang, S C; Wu, C H; Chang, M F

2001-03-16

Hepatitis delta virus (HDV) is a satellite virus of hepatitis B virus, as it requires hepatitis B virus for virion production and transmission. We have previously demonstrated that sequences within the C-terminal 19-amino acid domain flanking the isoprenylation motif of the large hepatitis delta antigen (HDAg-L) are important for virion assembly. In this study, site-directed mutagenesis and immunofluorescence staining demonstrated that in the absence of hepatitis B virus surface antigen (HBsAg), the wild-type HDAg-L was localized in the nuclei of transfected COS7 cells. Nevertheless, in the presence of HBsAg, the HDAg-L became both nuclei- and cytoplasm-distributed in about half of the cells. An HDAg-L mutant with a substitution of Pro-205 to alanine could neither form HDV-like particles nor shift the subcellular localization in the presence of HBsAg. In addition, nuclear trafficking of HDAg-L in heterokaryons indicated that HDAg-L is a nucleocytoplasmic shuttling protein. A proline-rich HDAg peptide spanning amino acid residues 198 to 210, designated NES(HDAg-L), can function as a nuclear export signal (NES) in Xenopus oocytes. Pro-205 is critical for the NES function. Furthermore, assembly of HDV is insensitive to leptomycin B, indicating that the NES(HDAg-L) directs nuclear export of HDAg-L to the cytoplasm via a chromosome region maintenance 1-independent pathway.

Communications received from certain Member States regarding guidelines for the export of nuclear material, equipment or technology

International Nuclear Information System (INIS)

1990-08-01

The document reproduces the text of the Note Verbale dated 1 August 1990 received by the Director General of the IAEA from the Permanent Mission of Romania and relating to the export of nuclear material, equipment and technology

Communications received from certain Member States regarding guidelines for the export of nuclear material, equipment and technology

International Nuclear Information System (INIS)

1992-01-01

The document reproduces the text of the Note Verbale dated 18 December 1991 received by the Director General of the IAEA from the Permanent Mission of Austria and relating to the export of nuclear material, equipment and technology

Interactions between mRNA export commitment, 3'-end quality control, and nuclear degradation

DEFF Research Database (Denmark)

Libri, Domenico; Dower, Ken; Boulay, Jocelyne

2002-01-01

Several aspects of eukaryotic mRNA processing are linked to transcription. In Saccharomyces cerevisiae, overexpression of the mRNA export factor Sub2p suppresses the growth defect of hpr1 null cells, yet the protein Hpr1p and the associated THO protein complex are implicated in transcriptional el...... results show that several classes of defective RNPs are subject to a quality control step that impedes release from transcription site foci and suggest that suboptimal messenger ribonucleoprotein assembly leads to RNA degradation by Rrp6p....

The implications of uranium export

International Nuclear Information System (INIS)

Anon.

1975-01-01

It is argued that Australia should not enter the business of uranium mining enrichment and export because of the hazards of nuclear power and because there are practical alternatives to the development of nuclear power. (R.L.)

mRNA export in the apicomplexan parasite Toxoplasma gondii: emerging divergent components of a crucial pathway.

Science.gov (United States)

Ávila, Andréa Rodrigues; Cabezas-Cruz, Alexjandro; Gissot, Mathieu

2018-01-25

Control of gene expression is crucial for parasite survival and is the result of a series of processes that are regulated to permit fine-tuning of gene expression in response to biological changes during the life-cycle of apicomplexan parasites. Control of mRNA nuclear export is a key process in eukaryotic cells but is poorly understood in apicomplexan parasites. Here, we review recent knowledge regarding this process with an emphasis on T. gondii. We describe the presence of divergent orthologs and discuss structural and functional differences in export factors between apicomplexans and other eukaryotic lineages. Undoubtedly, the use of the CRISPR/Cas9 system in high throughput screenings associated with the discovery of mRNA nuclear export complexes by proteomic analysis will contribute to identify these divergent factors. Ligand-based or structure-based strategies may be applied to investigate the potential use of these proteins as targets for new antiprotozoal agents.

A Study on the Export Control System at KAERI

International Nuclear Information System (INIS)

Kim, I. C.; Lee, B. D.; Kim, H. J.; Kim, H. S.; Jung, J. A.

2015-01-01

The current non-proliferation regime requires strengthening the export control from Korea to foreign countries. This means that the ministries related to export control deeply emphasize the prohibition of the illegal proliferation in the domestic society as well as international society. The principle of export control for non-proliferation of WMD is to control the transfer of the strategic items/technology to the countries which intend to develop the WMD in accordance with the multilateral agreements of the Nuclear Supply Group (NSG), Wassenaar Agreement (WA), Austrian Group (AG) and Missile Technology Control Regime (MTCR). Among them, export controls at KAERI are deeply related to the guidelines of the NSG, an international nuclear export control regime. Since the new concept of an export system was launched in Jan. 2014, KAERI needs to consider new approaches to meet the requirement of the revised domestic law and regulation. To cope with this environmental change, this paper suggests new approaches to effectively conduct the export control at KAERI

A Study on the cooperation policy in multilateral nuclear control regimes and the advancing of national export control system

International Nuclear Information System (INIS)

Lee, Byung Wook; Oh, K. B.; Yang, M. H.; Lee, H. M.; Lee, K. S.; Ko, H. S.; Ryu, J. S.; Kim, J. S.

2004-08-01

This study carried out the analysis of trends of the multilateral nuclear control in four aspects. First, this study analyzes the past trends of the international nuclear non-proliferation regime, which includes the NPT, the IAEA safeguards system, the international nuclear export control regime and the physical protection of nuclear materials. Second, this study establishes the multilateral cooperation strategies for the effective cooperation in the process of strengthening the nuclear control regimes. Third, this study reviews the major agenda of nuclear control regimes and establishes national positions on each agenda. Fourth, this study also analyzes outstanding issues in nuclear control regimes and derives some factors to reflect national nuclear control system

Design and construction of nuclear power plants for export. Adaptation of a reference plant from a series in a national power generating program

International Nuclear Information System (INIS)

Marcaillou, J.; Haond, H.

1977-01-01

The recent evolution of primary energy supplies places those countries having a nuclear industry in an exporting role. Exporting countries have generally developed a limited number of national reactor types and attempt to extend their manufacture with as few changes as possible. The E.D.F. in France is implementing an important PWR 900 MW program based on FRAMATOME nuclear reactors, initially conceived by WESTINGHOUSE. Such standardization poses certain problems for the importing countries. These problems and ways in which they can be solved are discussed [fr

A set of enhanced green fluorescent protein concatemers for quantitative determination of nuclear localization signal strength.

Science.gov (United States)

Böhm, Jennifer; Thavaraja, Ramya; Giehler, Susanne; Nalaskowski, Marcus M

2017-09-15

Regulated transport of proteins between nucleus and cytoplasm is an important process in the eukaryotic cell. In most cases, active nucleo-cytoplasmic protein transport is mediated by nuclear localization signal (NLS) and/or nuclear export signal (NES) motifs. In this study, we developed a set of vectors expressing enhanced GFP (EGFP) concatemers ranging from 2 to 12 subunits (2xEGFP to 12xEGFP) for analysis of NLS strength. As shown by in gel GFP fluorescence analysis and αGFP Western blotting, EGFP concatemers are expressed as fluorescent full-length proteins in eukaryotic cells. As expected, nuclear localization of concatemeric EGFPs decreases with increasing molecular weight. By oligonucleotide ligation this set of EGFP concatemers can be easily fused to NLS motifs. After determination of intracellular localization of EGFP concatemers alone and fused to different NLS motifs we calculated the size of a hypothetic EGFP concatemer showing a defined distribution of EGFP fluorescence between nucleus and cytoplasm (n/c ratio = 2). Clear differences of the size of the hypothetic EGFP concatemer depending on the fused NLS motif were observed. Therefore, we propose to use the size of this hypothetic concatemer as quantitative indicator for comparing strength of different NLS motifs. Copyright © 2017 Elsevier Inc. All rights reserved.

Export Control in the AREVA Group

International Nuclear Information System (INIS)

Zero, S.

2013-01-01

After the Second World War the nuclear technology was mostly considered inappropriate for the export. It remains strictly regulated today, but the development of the civil applications urged states to facilitate the peaceful uses while establishing a strict control in the domains of the internal security and the nuclear proliferation. AREVA decided to set up an Export Control program applied to all the products and in all the countries where the group operates. AREVA can export products or make transfer of technology considered as sensitive for the non-proliferation and the risks linked to the terrorism. This sensitiveness results from the nature of the products or from the country of destination and in certain cases both of them. AREVA has set up an Export Control program and an interactive e-learning training within the Group to make exports of sensitive products, raw materials and technologies more secure. The subject is rather complex, the regulations are constantly evolving, and becoming familiar with them is necessarily a gradual process, but it must be made in-depth, hence the idea of regular training sessions. The implementation of the Export Control in the AREVA Group declines in four fundamental stages: -) Policy and procedure; -) Appointment of Export Control Officers (ECO); -) Training; and -) Audit and Self Assessment. The training program is composed by the following elements: Ethics (Value Charter) of the Group, Non-proliferation, international regulations and more particularly those that are applicable in Europe (Germany and France) and in the United States. Particular attention is devoted to the Export Control practice in China, Japan and India. (A.C.)

Evaluating the role of CRM1-mediated export for adenovirus gene expression

International Nuclear Information System (INIS)

Carter, Christoph C.; Izadpanah, Reza; Bridge, Eileen

2003-01-01

A complex of the Adenovirus (Ad) early region 1b 55-kDa (E1b-55kDa) and early region 4 ORF6 34-kDa (E4-34kDa) proteins promotes viral late gene expression. E1b-55kDa and E4-34kDa have leucine-rich nuclear export signals (NESs) similar to that of HIV Rev. It was proposed that E1b-55kDa and/or E4-34kDa might promote the export of Ad late mRNA via their Rev-like NESs, and the transport receptor CRM1. We treated infected cells with the cytotoxin leptomycin B to inhibit CRM1-mediated export; treatment initially delays the onset of late gene expression, but this activity completely recovers as the late phase progresses. We find that the E1b-55kDa NES is not required to promote late gene expression. Previous results showed that E4-34kDa-mediated late gene expression does not require an intact NES (J. Virol. 74 (2000), 6684-6688). Our results indicate that these Ad regulatory proteins promote late gene expression without intact NESs or active CRM1

Effect of Appropriate Marketing Mix Strategies on Iranian Protein Products Export Performance

OpenAIRE

Hossein Rezaie Dolatabadi; Mohammad Hossein Forghani; Seyed Mehdi Tabatabaee; Fatemeh Faghani

2013-01-01

The purpose of the present paper is to examine effect of effect of appropriate marketing mix strategies on Iranian protein products export performance. 4P (Price, Product, Place, Promotion) were selected as marketing strategies. The data used to test the hypotheses were collected through an online standard questionnaire. The respondents were asked to rate on the scale between strongly agree and strongly Disagree. Reliability of questionnaire was measured using Cronbach Coefficient Alpha. The ...

A model for the dynamic nuclear/nucleolar/cytoplasmic trafficking of the porcine reproductive and respiratory syndrome virus (PRRSV) nucleocapsid protein based on live cell imaging

International Nuclear Information System (INIS)

You, Jae-Hwan; Howell, Gareth; Pattnaik, Asit K.; Osorio, Fernando A.; Hiscox, Julian A.

2008-01-01

Porcine reproductive and respiratory syndrome virus (PRRSV), an arterivirus, in common with many other positive strand RNA viruses, encodes a nucleocapsid (N) protein which can localise not only to the cytoplasm but also to the nucleolus in virus-infected cells and cells over-expressing N protein. The dynamic trafficking of positive strand RNA virus nucleocapsid proteins and PRRSV N protein in particular between the cytoplasm and nucleolus is unknown. In this study live imaging of permissive and non-permissive cell lines, in conjunction with photo-bleaching (FRAP and FLIP), was used to investigate the trafficking of fluorescent labeled (EGFP) PRRSV-N protein. The data indicated that EGFP-PRRSV-N protein was not permanently sequestered to the nucleolus and had equivalent mobility to cellular nucleolar proteins. Further the nuclear import of N protein appeared to occur faster than nuclear export, which may account for the observed relative distribution of N protein between the cytoplasm and the nucleolus

Nuclear import and export signals are essential for proper cellular trafficking and function of ZIC3.

Science.gov (United States)

Bedard, James E J; Purnell, Jennifer D; Ware, Stephanie M

2007-01-15

Missense, frameshift and nonsense mutations in the zinc finger transcription factor ZIC3 cause heterotaxy as well as isolated congenital heart disease. Previously, we developed transactivation and subcellular localization assays to test the function of ZIC3 point mutations. Aberrant cytoplasmic localization suggested that the pathogenesis of ZIC3 mutations results, at least in part, from failure of appropriate cellular trafficking. To further investigate this hypothesis, the nucleocytoplasmic shuttling properties of ZIC3 have been examined. Subcellular localization assays designed to span the entire open-reading frame of wild-type and mutant ZIC3 proteins identified the presence of nucleocytoplasmic transport signals. ZIC3 domain mapping indicates that a relatively large region containing the zinc finger binding sites and a known GLI interacting domain is required for transport to the nucleus. Site-directed mutagenesis of critical residues within two putative nuclear localization signals (NLSs) leads to loss of nuclear localization. No further decrease was observed when both NLS sites were mutated, suggesting that mutation of either NLS site is sufficient for loss of importin-mediated nuclear localization. Additionally, we identify a cryptic CRM-1-dependent nuclear export signal (NES) within ZIC3, and identify a mutation within this region in a patient with heterotaxy. These results provide the first evidence that control of cellular trafficking of ZIC3 is critical for function and suggest a possible mechanism for transcriptional control during left-right patterning. Identification of mutations in mapped NLS or NES domains in heterotaxy patients demonstrates the functional importance of these domains in cardiac morphogenesis and allows for integration of structural analysis with developmental function.

Communication from the Permanent Mission of Australia to the International Atomic Energy Agency regarding guidelines for the export of nuclear material, equipment and technology

International Nuclear Information System (INIS)

2000-01-01

The document reproduces the text of the Note Verbale received by the Director General of the IAEA from the Permanent Mission of Australia providing information on the export policies and practices of the Government of Australia with respect to the export of nuclear material, equipment and technology

Communication from the Permanent Mission of Finland to the International Atomic Energy Agency regarding guidelines for the export of nuclear material, equipment and technology

International Nuclear Information System (INIS)

2000-01-01

The document reproduces the text of the Note Verbale received by the Director General of the IAEA from the Permanent Mission of Finland providing information on the export policies and practices of the Government of Finland with respect to the export of nuclear material, equipment and technology

Communications received from members regarding the export of nuclear material and of certain categories of equipment and other material

International Nuclear Information System (INIS)

1993-05-01

The document reproduces the letter dated 11 February 1993 from the Resident Representative of the Russian Federation to the Agency concerning the export of nuclear material and of certain categories of equipment and other material

Uranium enrichment export control guide: Gaseous diffusion

Energy Technology Data Exchange (ETDEWEB)

1989-09-01

This document was prepared to serve as a guide for export control officials in their interpretation, understanding, and implementation of export laws that relate to the Zangger International Trigger List for gaseous diffusion uranium enrichment process components, equipment, and materials. Particular emphasis is focused on items that are especially designed or prepared since export controls are required for these by States that are party to the International Nuclear Nonproliferation Treaty.

Communication Received from Argentina regarding the Export of Nuclear Material and of Certain Categories of Equipment and Other Material

International Nuclear Information System (INIS)

1993-10-01

The Director General has received letters dated 27 May 1993 from the Resident Representatives of Portugal and Spain to the Agency concerning the export of nuclear material and of certain categories of equipment and other material [ru

Communications received from Members regarding the Export of Nuclear Material and of Certain Categories of Equipment and Other Material

International Nuclear Information System (INIS)

1993-10-01

The Director General has received letters dated 27 May 1993 from the Resident Representatives of Portugal and Spain to the Agency concerning the export of nuclear material and of certain categories of equipment and other material [es

A long HBV transcript encoding pX is inefficiently exported from the nucleus

International Nuclear Information System (INIS)

Doitsh, Gilad; Shaul, Yosef

2003-01-01

The longest hepatitis B virus transcript is a 3.9-kb mRNA whose function remained unclear. In this study, we wished to identify the translation products and physiological role of this viral transcript. This transcript initiates from the X promoter region ignoring the inefficient and noncanonical viral polyadenylation signal at the first round of transcription. However, an HBV mutant with canonical polyadenylation signal continues, though with lower efficiency, to program the synthesis of this long transcript, indicating that the deviated HBV polyadenylation signal is important but not essential to enable transcription of the 3.9-kb species. The 3.9-kb RNA contains two times the X open reading frame (ORF). The X ORF at the 5'-end is positioned upstream of the CORE gene. By generating an HBV DNA mutant in which the X and Core ORFs are fused, we demonstrated the production of a 40-kDa X-Core fusion protein that must be encoded by the 3.9-kb transcript. Mutagenesis studies revealed that the production of this protein depends on the 5' X ORF ATG, suggesting that the 3.9-kb RNA is active in translation of the X ORF. Based on these features, the 3.9-kb transcript was designated lxRNA for long X RNA. Unlike other HBV transcripts, lxRNA harbors two copies of PRE, the posttranscriptional regulatory element that controls the nuclear export of HBV mRNAs. Unexpectedly, despite the presence of PRE sequences, RNA fractionation analysis revealed that lxRNA barely accumulates in the cytoplasm, suggesting that nuclear export of lxRNA is poor. Collectively, our data suggest that two distinct HBV mRNA species encode pX and that the HBV transcripts are differentially regulated at the level of nuclear export

Soluble components of the flagellar export apparatus, FliI, FliJ, and FliH, do not deliver flagellin, the major filament protein, from the cytosol to the export gate.

Science.gov (United States)

Sajó, Ráchel; Liliom, Károly; Muskotál, Adél; Klein, Agnes; Závodszky, Péter; Vonderviszt, Ferenc; Dobó, József

2014-11-01

Flagella, the locomotion organelles of bacteria, extend from the cytoplasm to the cell exterior. External flagellar proteins are synthesized in the cytoplasm and exported by the flagellar type III secretion system. Soluble components of the flagellar export apparatus, FliI, FliH, and FliJ, have been implicated to carry late export substrates in complex with their cognate chaperones from the cytoplasm to the export gate. The importance of the soluble components in the delivery of the three minor late substrates FlgK, FlgL (hook-filament junction) and FliD (filament-cap) has been convincingly demonstrated, but their role in the transport of the major filament component flagellin (FliC) is still unclear. We have used continuous ATPase activity measurements and quartz crystal microbalance (QCM) studies to characterize interactions between the soluble export components and flagellin or the FliC:FliS substrate-chaperone complex. As controls, interactions between soluble export component pairs were characterized providing Kd values. FliC or FliC:FliS did not influence the ATPase activity of FliI alone or in complex with FliH and/or FliJ suggesting lack of interaction in solution. Immobilized FliI, FliH, or FliJ did not interact with FliC or FliC:FliS detected by QCM. The lack of interaction in the fluid phase between FliC or FliC:FliS and the soluble export components, in particular with the ATPase FliI, suggests that cells use different mechanisms for the export of late minor substrates, and the major substrate, FliC. It seems that the abundantly produced flagellin does not require the assistance of the soluble export components to efficiently reach the export gate. Copyright © 2014 Elsevier B.V. All rights reserved.

Rev and Rex proteins of human complex retroviruses function with the MMTV Rem-responsive element

Directory of Open Access Journals (Sweden)

Dudley Jaquelin P

2009-02-01

Full Text Available Abstract Background Mouse mammary tumor virus (MMTV encodes the Rem protein, an HIV Rev-like protein that enhances nuclear export of unspliced viral RNA in rodent cells. We have shown that Rem is expressed from a doubly spliced RNA, typical of complex retroviruses. Several recent reports indicate that MMTV can infect human cells, suggesting that MMTV might interact with human retroviruses, such as human immunodeficiency virus (HIV, human T-cell leukemia virus (HTLV, and human endogenous retrovirus type K (HERV-K. In this report, we test whether the export/regulatory proteins of human complex retroviruses will increase expression from vectors containing the Rem-responsive element (RmRE. Results MMTV Rem, HIV Rev, and HTLV Rex proteins, but not HERV-K Rec, enhanced expression from an MMTV-based reporter plasmid in human T cells, and this activity was dependent on the RmRE. No RmRE-dependent reporter gene expression was detectable using Rev, Rex, or Rec in HC11 mouse mammary cells. Cell fractionation and RNA quantitation experiments suggested that the regulatory proteins did not affect RNA stability or nuclear export in the MMTV reporter system. Rem had no demonstrable activity on export elements from HIV, HTLV, or HERV-K. Similar to the Rem-specific activity in rodent cells, the RmRE-dependent functions of Rem, Rev, or Rex in human cells were inhibited by a dominant-negative truncated nucleoporin that acts in the Crm1 pathway of RNA and protein export. Conclusion These data argue that many retroviral regulatory proteins recognize similar complex RNA structures, which may depend on the presence of cell-type specific proteins. Retroviral protein activity on the RmRE appears to affect a post-export function of the reporter RNA. Our results provide additional evidence that MMTV is a complex retrovirus with the potential for viral interactions in human cells.

NESbase version 1.0: a database of nuclear export signals

DEFF Research Database (Denmark)

la Cour, T.; Gupta, Ramneek; Rapacki, Krzysztof

2003-01-01

information of whether NES was shown to be necessary and/or sufficient for export, and whether the export was shown to be mediated by the export receptor CRM1. The compiled information was used to make a sequence logo of the Leucine-rich NESs, displaying the conservation of amino acids within a window of 25...

Amendment of the Ordinance on the export and transit of goods

International Nuclear Information System (INIS)

1989-12-01

This Ordinance amends the Annex of the Ordinance of 7 March 1983 on the export and transit of dangerous goods which lists the nuclear items, ie nuclear reactors, equipment and materials subject to export restrictions. The Ordinance came into force on 1 January 1990 (NEA) [fr

Erythropoietin and carbamylated erythropoietin promote histone deacetylase 5 phosphorylation and nuclear export in rat hippocampal neurons

International Nuclear Information System (INIS)

Jo, Hye-Ryeong; Kim, Yong-Seok; Son, Hyeon

2016-01-01

Erythropoietin (EPO) produces neurotrophic effects in animal model of neurodegeneration. However, clinical use of EPO is limited due to thrombotic risk. Carbamylated EPO (cEPO), devoid of thrombotic risk, has been proposed as a novel neuroprotective and neurotrophic agent although the molecular mechanisms of cEPO remain incomplete. Here, we show a previously unidentified role of histone deacetylase 5 (HDAC5) in the actions of EPO and cEPO. EPO and cEPO regulate the HDAC5 phosphorylation at two critical sites, Ser259 and Ser498 through a protein kinase D (PKD) dependent pathway. In addition, EPO and cEPO rapidly stimulates nuclear export of HDAC5 in rat hippocampal neurons which expressing HDAC5-GFP. Consequently, EPO and cEPO enhanced the myocyte enhancer factor-2 (MEF2) target gene expression. Taken together, our results reveal that EPO and cEPO mediate MEF2 target gene expression via the regulation of HDAC5 phosphorylation at Ser259/498, and suggest that HDAC5 could be a potential mechanism contributing to the therapeutic actions of EPO and cEPO.

Erythropoietin and carbamylated erythropoietin promote histone deacetylase 5 phosphorylation and nuclear export in rat hippocampal neurons

Energy Technology Data Exchange (ETDEWEB)

Jo, Hye-Ryeong [Department of Biomedical Sciences, Graduate School of Biomedical Science and Engineering (Korea, Republic of); Kim, Yong-Seok [Department of Biomedical Sciences, Graduate School of Biomedical Science and Engineering (Korea, Republic of); Department of Biochemistry and Molecular Biology, College of Medicine, Hanyang University, 17 Haengdang-dong, Sungdong-gu, Seoul 133-791 (Korea, Republic of); Son, Hyeon, E-mail: hyeonson@hanyang.ac.kr [Department of Biomedical Sciences, Graduate School of Biomedical Science and Engineering (Korea, Republic of); Department of Biochemistry and Molecular Biology, College of Medicine, Hanyang University, 17 Haengdang-dong, Sungdong-gu, Seoul 133-791 (Korea, Republic of)

2016-01-29

Erythropoietin (EPO) produces neurotrophic effects in animal model of neurodegeneration. However, clinical use of EPO is limited due to thrombotic risk. Carbamylated EPO (cEPO), devoid of thrombotic risk, has been proposed as a novel neuroprotective and neurotrophic agent although the molecular mechanisms of cEPO remain incomplete. Here, we show a previously unidentified role of histone deacetylase 5 (HDAC5) in the actions of EPO and cEPO. EPO and cEPO regulate the HDAC5 phosphorylation at two critical sites, Ser259 and Ser498 through a protein kinase D (PKD) dependent pathway. In addition, EPO and cEPO rapidly stimulates nuclear export of HDAC5 in rat hippocampal neurons which expressing HDAC5-GFP. Consequently, EPO and cEPO enhanced the myocyte enhancer factor-2 (MEF2) target gene expression. Taken together, our results reveal that EPO and cEPO mediate MEF2 target gene expression via the regulation of HDAC5 phosphorylation at Ser259/498, and suggest that HDAC5 could be a potential mechanism contributing to the therapeutic actions of EPO and cEPO.

Competitiveness, export control and export promotion of dual-use goods. European and German balancing exercises; Wettbewerbsfaehigkeit, Exportkontrolle und Exportfoerderung von Dual-Use-Guetern. Europaeische und deutsche Spagatuebungen

Energy Technology Data Exchange (ETDEWEB)

Feldmann, Ulrike

2014-08-15

The EU Commission Communication of 24 April 2014 to the Council and the European Parliament ''The review of export control policy: Ensuring Security and Competitiveness in a changing world'' as well as the increasingly number of inquiries and applications to the German Federal Government (e.g. the rejection of Hermes guarantees and state funding of nuclear export and termination of bilateral cooperation in the field of nuclear technologies) once again reason to discuss the current tension between the principle of free movement of goods, competitiveness and export promotion on the one hand and the export control on the other.

NES consensus redefined by structures of PKI-type and Rev-type nuclear export signals bound to CRM1.

Science.gov (United States)

Güttler, Thomas; Madl, Tobias; Neumann, Piotr; Deichsel, Danilo; Corsini, Lorenzo; Monecke, Thomas; Ficner, Ralf; Sattler, Michael; Görlich, Dirk

2010-11-01

Classic nuclear export signals (NESs) confer CRM1-dependent nuclear export. Here we present crystal structures of the RanGTP-CRM1 complex alone and bound to the prototypic PKI or HIV-1 Rev NESs. These NESs differ markedly in the spacing of their key hydrophobic (Φ) residues, yet CRM1 recognizes them with the same rigid set of five Φ pockets. The different Φ spacings are compensated for by different conformations of the bound NESs: in the case of PKI, an α-helical conformation, and in the case of Rev, an extended conformation with a critical proline docking into a Φ pocket. NMR analyses of CRM1-bound and CRM1-free PKI NES suggest that CRM1 selects NES conformers that pre-exist in solution. Our data lead to a new structure-based NES consensus, and explain why NESs differ in their affinities for CRM1 and why supraphysiological NESs bind the exportin so tightly.

Communication received from certain Member States regarding guidelines for the export of nuclear material, equipment and technology. Nuclear transfers

International Nuclear Information System (INIS)

1995-10-01

The Director General has received notes verbales dated 30 June 1995 from the Resident Representatives to the Agency of Argentina, Australia, Austria, Belgium, Bulgaria, Canada, the Czech Republic, Denmark, Finland, France, Germany, Greece, Hungary, Ireland, Italy, Japan, Luxembourg, the Netherlands, New Zealand, Norway, Poland, Portugal, Romania, the Slovak Republic, South Africa, Spain, Sweden, Switzerland, the United Kingdom of Great Britain and Northern Ireland, and the United States of America relating to the export of nuclear material, equipment and technology. The purpose of the notes verbales is to provide further information on those Governments' Guidelines for Nuclear Transfers. In the light of the wish expressed at the end of each note verbale, the text of the notes verbales is annexed hereto. The enclosure to these notes verbales is also reproduced in full in the Annex

Communication received from certain Member States regarding guidelines for the export of nuclear material, equipment and technology. Nuclear transfers

Energy Technology Data Exchange (ETDEWEB)

NONE

1995-10-01

The Director General has received notes verbales dated 30 June 1995 from the Resident Representatives to the Agency of Argentina, Australia, Austria, Belgium, Bulgaria, Canada, the Czech Republic, Denmark, Finland, France, Germany, Greece, Hungary, Ireland, Italy, Japan, Luxembourg, the Netherlands, New Zealand, Norway, Poland, Portugal, Romania, the Slovak Republic, South Africa, Spain, Sweden, Switzerland, the United Kingdom of Great Britain and Northern Ireland, and the United States of America relating to the export of nuclear material, equipment and technology. The purpose of the notes verbales is to provide further information on those Governments` Guidelines for Nuclear Transfers. In the light of the wish expressed at the end of each note verbale, the text of the notes verbales is annexed hereto. The enclosure to these notes verbales is also reproduced in full in the Annex.

Ddx19 links mRNA nuclear export with progression of transcription and replication and suppresses genomic instability upon DNA damage in proliferating cells.

Science.gov (United States)

Hodroj, Dana; Serhal, Kamar; Maiorano, Domenico

2017-09-03

The DEAD-box Helicase 19 (Ddx19) gene codes for an RNA helicase involved in both mRNA (mRNA) export from the nucleus into the cytoplasm and in mRNA translation. In unperturbed cells, Ddx19 localizes in the cytoplasm and at the cytoplasmic face of the nuclear pore. Here we review recent findings related to an additional Ddx19 function in the nucleus in resolving RNA:DNA hybrids (R-loops) generated during collision between transcription and replication, and upon DNA damage. Activation of a DNA damage response pathway dependent upon the ATR kinase, a major regulator of replication fork progression, stimulates translocation of the Ddx19 protein from the cytoplasm into the nucleus. Only nuclear Ddx19 is competent to resolve R-loops, and down regulation of Ddx19 expression induces DNA double strand breaks only in proliferating cells. Overall these observations put forward Ddx19 as an important novel mediator of the crosstalk between transcription and replication.

Communication from the Permanent Mission of Israel to the International Atomic Energy Agency regarding nuclear export controls

International Nuclear Information System (INIS)

2004-01-01

The Director General of the International Atomic Energy Agency has received a letter dated 13 July 2004 from the Permanent Mission of Israel providing information on Israel's nuclear export policies and practices. As requested by the Permanent Mission, the letter and document attached to it are reproduced herein for the information of Member States

The human nuclear poly(a-binding protein promotes RNA hyperadenylation and decay.

Directory of Open Access Journals (Sweden)

Stefan M Bresson

Full Text Available Control of nuclear RNA stability is essential for proper gene expression, but the mechanisms governing RNA degradation in mammalian nuclei are poorly defined. In this study, we uncover a mammalian RNA decay pathway that depends on the nuclear poly(A-binding protein (PABPN1, the poly(A polymerases (PAPs, PAPα and PAPγ, and the exosome subunits RRP6 and DIS3. Using a targeted knockdown approach and nuclear RNA reporters, we show that PABPN1 and PAPα, redundantly with PAPγ, generate hyperadenylated decay substrates that are recognized by the exosome and degraded. Poly(A tail extension appears to be necessary for decay, as cordycepin treatment or point mutations in the PAP-stimulating domain of PABPN1 leads to the accumulation of stable transcripts with shorter poly(A tails than controls. Mechanistically, these data suggest that PABPN1-dependent promotion of PAP activity can stimulate nuclear RNA decay. Importantly, efficiently exported RNAs are unaffected by this decay pathway, supporting an mRNA quality control function for this pathway. Finally, analyses of both bulk poly(A tails and specific endogenous transcripts reveals that a subset of nuclear RNAs are hyperadenylated in a PABPN1-dependent fashion, and this hyperadenylation can be either uncoupled or coupled with decay. Our results highlight a complex relationship between PABPN1, PAPα/γ, and nuclear RNA decay, and we suggest that these activities may play broader roles in the regulation of human gene expression.

France's Efforts to Promote NPP Exports and the Implications on the Role of Nuclear Regulatory Body

International Nuclear Information System (INIS)

Oh, Chae-Woon; Chang, Hyun-Sop; Choi, Young-Sung

2008-01-01

The global society facing sky-rocketing oil prices, global warming effects, and increased demand for electricity recognizes the comparative advantages of nuclear energy in terms of environmental impact and economic efficiency over the other energy sources of current use. Approximately 300 nuclear power plants (NPPs) expect to be constructed until 2030 worldwide. Accordingly, the global market size of nuclear power industry becomes scaled up to the extent of U$75 billion on the assumption that the construction of one reactor costs around U$2.5 billion. The nations in possession of advanced nuclear technology such as the U.S., France, Japan, etc not only recognized an abounding profitability in nuclear industry and anticipated nuclear renaissance but also prepared long before whatever necessary to expand their nuclear programs beyond their domestic boundaries. Amongst those nations, it seems to be France that has unfolded a remarkable array of government-led activities to export Evolutionary Pressurized Reactors (EPRs) under the cooperation of President, relevant government administration, utilities even a regulatory body. The omni-directional activities of France and its implications are presented in this paper

Management of a 600 MW CANDU project to facilitate electricity export

International Nuclear Information System (INIS)

Gunter, G.E.

1983-06-01

The export of electricity from 600-MW CANDU nuclear power plants built in Canada remains feasible providing certain requirements continue to be met. The principal objective in developing nuclear power resources for export is that they must produce economically attractive electricity. A review of the experience of construction and operation of Point Lepreau Unit 1 suggests an inherent ability to reduce construction costs and shorten construction schedules so as to make electrical power output from these stations even more attractive to export customers

Importance of dimer formation of myocardin family members in the regulation of their nuclear export.

Science.gov (United States)

Hayashi, Ken'ichiro; Morita, Tsuyoshi

2013-01-01

Myocardin (Mycd) family members function as a transcriptional cofactor for serum response factor (SRF). Dimer formation is necessary to exhibit their function, and the coiled-coil domain (CC) plays a critical role in their dimerization. We have recently revealed a detailed molecular mechanism for their Crm1 (exportin1)-mediated nuclear export. Here, we found other unique significances of the dimerization of Mycd family members. Introduction of mutations in the CC of myocardin-related transcription factor A (MRTF-A) and truncated Mycd resulted in significant decreases in their cytoplasmic localization and increases in their nuclear localization. In accordance with such subcellular localization changes, their binding to Crm1 were reduced. These results indicate that the dimerization of Mycd family members is necessary for their Crm1-mediated nuclear export. We have recently found that the N-terminal region of Mycd consisting of 128 amino acids (Mycd N128) self-associates to Mycd via the central basic domain (CB), resulting in masking the Crm1-binding site. Such self-association of MRTF-A would be unlikely. In this study, we also revealed that the dimerization of Mycd was also necessary for this self-association. Wild-type Mycd activated SRF-mediated transcription more potently than Mycd lacking the Mycd N128 (Mycd ΔN128) did. These results suggest two possible functions of the Mycd N128: 1) stabilization of Mycd dimer to enhance SRF-mediated transcription and 2) positive regulation of the transactivation ability of Mycd. These findings provide a new insight into the functional regulation of Mycd family members.

Nuclear trade between developing countries

International Nuclear Information System (INIS)

Stahl, K.

1990-01-01

The analysis of nuclear south-south cooperation is based on the evaluation of official documents (the texts of laws, of contracts for nuclear cooperation treaties, safeguard treaties, official government policy speeches etc.). These data were supplemented by numerous interviews with representatives of atomic energy authorities, foreign ministries, nuclear industries, members of parliament, representatives of the nuclear energy opposition movement and military representatives in the three states and by interviews with representatives of the IAEO and OPANAL in Mexico. The study deals with each country in turn: Chapter 2 gives an overview of the Indian nuclear energy programme and India's nuclear export activity and export policy. Chapter 3 analyzes Brazil's nuclear energy policy and Brazilian export capacities, exports and export policy in the nuclear sector. Chapter 4 looks at the development of the Argentinian nuclear energy programme and the crisis in it, at Argentina's nuclear export activities and its export policy and technology transfer policy in this field. Chapter 5 analyzes separately relations between Argentina and Brazil on nuclear cooperation, since they differ considerably from the two countries' relations with other Third World countries on this topic. The appendix documents the most important contractual agreements and government policy declarations on nuclear cooperation between the two states. (orig.) [de

Communications received from certain Member States regarding guidelines for the export of nuclear material, equipment and technology

International Nuclear Information System (INIS)

1992-07-01

The document reproduces the text of the notes verbales dated 15 May 1992, received by the Director General from the Resident Representatives to the Agency of Australia, Austria, Belgium, Bulgaria, Canada, Czech and Slovak Federal Republic, Denmark, Finland, France, Germany, Greece, Hungary, Ireland, Italy, Japan, Luxembourg, Netherlands, Norway, Poland, Portugal, Romania, Russia Federation, Spain, Sweden, Switzerland, the United Kingdom of Great Britain and Northern Ireland, and the United States of America relating to the export of nuclear material, equipment and technology and the Guidelines for Transfer of Nuclear-Related Dual-Use Equipment, Material and Related Technology. An Annex to these Guidelines contains the list of Nuclear-Related Dual-Use Equipment and Materials and Related Technology

Nuclear variants of bone morphogenetic proteins

Directory of Open Access Journals (Sweden)

Meinhart Christopher A

2010-03-01

Full Text Available Abstract Background Bone morphogenetic proteins (BMPs contribute to many different aspects of development including mesoderm formation, heart development, neurogenesis, skeletal development, and axis formation. They have previously been recognized only as secreted growth factors, but the present study detected Bmp2, Bmp4, and Gdf5/CDMP1 in the nuclei of cultured cells using immunocytochemistry and immunoblotting of nuclear extracts. Results In all three proteins, a bipartite nuclear localization signal (NLS was found to overlap the site at which the proproteins are cleaved to release the mature growth factors from the propeptides. Mutational analyses indicated that the nuclear variants of these three proteins are produced by initiating translation from downstream alternative start codons. The resulting proteins lack N-terminal signal peptides and are therefore translated in the cytoplasm rather than the endoplasmic reticulum, thus avoiding proteolytic processing in the secretory pathway. Instead, the uncleaved proteins (designated nBmp2, nBmp4, and nGdf5 containing the intact NLSs are translocated to the nucleus. Immunostaining of endogenous nBmp2 in cultured cells demonstrated that the amount of nBmp2 as well as its nuclear/cytoplasmic distribution differs between cells that are in M-phase versus other phases of the cell cycle. Conclusions The observation that nBmp2 localization varies throughout the cell cycle, as well as the conservation of a nuclear localization mechanism among three different BMP family members, suggests that these novel nuclear variants of BMP family proteins play an important functional role in the cell.

Quantification of the physiochemical constraints on the export of spider silk proteins by Salmonella type III secretion

Directory of Open Access Journals (Sweden)

Voigt Christopher A

2010-10-01

Full Text Available Abstract Background The type III secretion system (T3SS is a molecular machine in gram negative bacteria that exports proteins through both membranes to the extracellular environment. It has been previously demonstrated that the T3SS encoded in Salmonella Pathogenicity Island 1 (SPI-1 can be harnessed to export recombinant proteins. Here, we demonstrate the secretion of a variety of unfolded spider silk proteins and use these data to quantify the constraints of this system with respect to the export of recombinant protein. Results To test how the timing and level of protein expression affects secretion, we designed a hybrid promoter that combines an IPTG-inducible system with a natural genetic circuit that controls effector expression in Salmonella (psicA. LacO operators are placed in various locations in the psicA promoter and the optimal induction occurs when a single operator is placed at the +5nt (234-fold and a lower basal level of expression is achieved when a second operator is placed at -63nt to take advantage of DNA looping. Using this tool, we find that the secretion efficiency (protein secreted divided by total expressed is constant as a function of total expressed. We also demonstrate that the secretion flux peaks at 8 hours. We then use whole gene DNA synthesis to construct codon optimized spider silk genes for full-length (3129 amino acids Latrodectus hesperus dragline silk, Bombyx mori cocoon silk, and Nephila clavipes flagelliform silk and PCR is used to create eight truncations of these genes. These proteins are all unfolded polypeptides and they encompass a variety of length, charge, and amino acid compositions. We find those proteins fewer than 550 amino acids reliably secrete and the probability declines significantly after ~700 amino acids. There also is a charge optimum at -2.4, and secretion efficiency declines for very positively or negatively charged proteins. There is no significant correlation with hydrophobicity

Nucleocytoplasmic Shuttling of Cytoskeletal Proteins: Molecular Mechanism and Biological Significance

Directory of Open Access Journals (Sweden)

Masahiro Kumeta

2012-01-01

Full Text Available Various nuclear functional complexes contain cytoskeletal proteins as regulatory subunits; for example, nuclear actin participates in transcriptional complexes, and actin-related proteins are integral to chromatin remodeling complexes. Nuclear complexes such as these are involved in both basal and adaptive nuclear functions. In addition to nuclear import via classical nuclear transport pathways or passive diffusion, some large cytoskeletal proteins spontaneously migrate into the nucleus in a karyopherin-independent manner. The balance of nucleocytoplasmic distribution of such proteins can be altered by several factors, such as import versus export, or capture and release by complexes. The resulting accumulation or depletion of the nuclear populations thereby enhances or attenuates their nuclear functions. We propose that such molecular dynamics constitute a form of cytoskeleton-modulated regulation of nuclear functions which is mediated by the translocation of cytoskeletal components in and out of the nucleus.

International legal and political issues associated with the export/import of nuclear power plants

International Nuclear Information System (INIS)

Manning Muntzing, L.

1978-01-01

The benefits of nuclear power can be achieved by most nations only through international commerce that has been shaped by political considerations and implemented through legal instruments. The end product is a structure of legal agreements designed to implement the basic political and commercial decisions that are required for any nation to enter the nuclear power arena. The IAEA Statute, the Non-Proliferation Treaty and regional nuclear agreements have reflected the international political consensus concerning nuclear power. In recent years, however, events have occurred that in all probability will result in additional international arrangements. It is expected that the increase in terrorist activities will result in greater physical protection commitments, that concern for weapons proliferation will result in further definition of sanctions, and that such troublesome issues as double labelling of materials will be discussed by the international community. In areas such as bilateral agreements between nations, commercial arrangements and export licences, this is a period of rethinking, renegotiating, and readjusting. The result is a degree of uncertainty and lack of stability that could so jeopardize the potential for nuclear transfers that the nuclear energy option may not vest. While there always will be questions and issues, it is essential to settle some of the key problems without delay so that nuclear benefits can be realized. (author)

Intermolecular masking of the HIV-1 Rev NLS by the cellular protein HIC: Novel insights into the regulation of Rev nuclear import.

LENUS (Irish Health Repository)

Gu, Lili

2011-03-14

Abstract Background The HIV-1 regulatory protein Rev, which is essential for viral replication, mediates the nuclear export of unspliced viral transcripts. Rev nuclear function requires active nucleocytoplasmic shuttling, and Rev nuclear import is mediated by the recognition of its Nuclear Localisation Signal (NLS) by multiple import factors, which include transportin and importin β. However, it remains unclear which nuclear import pathway(s) predominate in vivo, and the cellular environment that modulates Rev nucleocytoplasmic shuttling remains to be characterised. Results In our study, we have identified the cellular protein HIC (Human I-mfa domain-Containing protein) as a novel interactor of HIV-1 Rev. We demonstrate that HIC selectively interferes with Rev NLS interaction with importin β and impedes its nuclear import and function, but does not affect Rev nuclear import mediated by transportin. Hence, the molecular determinants mediating Rev-NLS recognition by importin β and transportin appear to be distinct. Furthermore, we have employed HIC and M9 M, a peptide specifically designed to inhibit the transportin-mediated nuclear import pathway, to characterise Rev nuclear import pathways within different cellular environments. Remarkably, we could show that in 293T, HeLa, COS7, Jurkat, U937, THP-1 and CEM cells, Rev nuclear import is cell type specific and alternatively mediated by transportin or importin β, in a mutually exclusive fashion. Conclusions Rev cytoplasmic sequestration by HIC may represent a novel mechanism for the control of Rev function. These studies highlight that the multivalent nature of the Rev NLS for different import receptors enables Rev to adapt its nuclear trafficking strategy.

Analysis of Developed Country's Export Contract and Contract Risk and Development of Sample Contract and Guide

International Nuclear Information System (INIS)

Lee, D. S.; Oh, K. B.; Chung, W. S.; Lee, K. S.; Yun, S. W.; Lee, J. H.; Lee, B. W.; Kim, H. J.; Yang, M. H.

2008-10-01

This paper aimed at developing legal support for the non nuclear power plant industry's export. This study aids establishing government policy and promoting export of non nuclear power plant industry. This paper treated analysis of contractual risk and caution before entering into contract. To promote continuing export result, governmental and legal aids and guide will be required continuously. This study showed risks related with export contract and explained export control acts and procedures

An analysis on the export license criteria for NSG control items in the US and Japan

International Nuclear Information System (INIS)

Choi, Young Rok

1995-06-01

Korea has taken steps to join the Nuclear Suppliers Group (NSG) which is a major part of the international nuclear export control regime. In this connection, it is an urgent task to build a new Korean nuclear export control system that includes NSG guidelines and control items. In addition, it is necessary to review the developed supplier countries' experience in the field of export control. The main purpose of this study is to analyze how the US and Japan have controlled the items listed in NSG part 1 and 2 guidelines. To this end, various relevant regulations of the US and Japan were studied. Among those regulations, the US Export Administration Regulation, US 10 CFR 110 and 810, and the Japan's Export Administration Order are included. Through the review process, this study identified NSG items which are controlled in the export control systems of the US and Japan. Furthermore, this study summarized and compared the export license criteria that must be satisfied before exporting each NSG item in the two countries. The export license criteria consist of permitted destinations, document requirements, and types of license. The results of this study are expected to contribute to establishing an appropriate Korean nuclear export control system and could be used as references to the practical export licensing policies of the US and Japan. 6 tabs., 13 refs., (Author) .new

An analysis on the export license criteria for NSG control items in the US and Japan

Energy Technology Data Exchange (ETDEWEB)

Choi, Young Rok [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)

1995-06-01

Korea has taken steps to join the Nuclear Suppliers Group (NSG) which is a major part of the international nuclear export control regime. In this connection, it is an urgent task to build a new Korean nuclear export control system that includes NSG guidelines and control items. In addition, it is necessary to review the developed supplier countries` experience in the field of export control. The main purpose of this study is to analyze how the US and Japan have controlled the items listed in NSG part 1 and 2 guidelines. To this end, various relevant regulations of the US and Japan were studied. Among those regulations, the US Export Administration Regulation, US 10 CFR 110 and 810, and the Japan`s Export Administration Order are included. Through the review process, this study identified NSG items which are controlled in the export control systems of the US and Japan. Furthermore, this study summarized and compared the export license criteria that must be satisfied before exporting each NSG item in the two countries. The export license criteria consist of permitted destinations, document requirements, and types of license. The results of this study are expected to contribute to establishing an appropriate Korean nuclear export control system and could be used as references to the practical export licensing policies of the US and Japan. 6 tabs., 13 refs., (Author) .new.

Nuclear transport factor directs localization of protein synthesis during mitosis

NARCIS (Netherlands)

Bogaart, Geert van den; Meinema, Anne C.; Krasnikov, Viktor; Veenhoff, Liesbeth M.; Poolman, Bert

Export of messenger RNA from the transcription site in the nucleus and mRNA targeting to the translation site in the cytoplasm are key regulatory processes in protein synthesis. In yeast, the mRNA-binding proteins Nab2p and Nab4p/Hrp1p accompany transcripts to their translation site, where the

Communication received from the Permanent Mission of New Zealand regarding guidelines for the export of nuclear material, equipment and technology

International Nuclear Information System (INIS)

1995-01-01

The Director General has received a note verbale dated 22 December 1994 from the Permanent Mission of New Zealand to the International Atomic Energy Agency providing information on the nuclear export policies and practices of the Government of New Zealand

Exports and experts:proliferation risks from the new Commonwealth

International Nuclear Information System (INIS)

Potter, W.C.

1992-01-01

Ironically, given the Cold War history and Western stereotypes about Soviet misbehavior, the long-standing experience of US-Soviet cooperation on nonproliferation may have made US policy-makers less attentive to, and less concerned about, signs of change in Soviet nuclear export policy. The breakup of the Soviet Union and the nuclear inheritance of its successor states belatedly focused Western attention on the proliferation risks posed by the disintegration of central authority. Most concern to date, however, has continued to emphasize the problems of nuclear command and control. But the nonproliferation threats associated with the unregulated export of sensitive nuclear material, technology, and equipment may be equally great, and present problems that are already real. At the same time, the new nation-building process in the Soviet successor states presents opportunities for expanding the NPT and international safeguards, containing the nuclear brain drain, promoting the cleanup of hazardous nuclear waste, enhancing international capabilities for monitoring proliferation, and building new communities of nonproliferation specialists. A rare occasion now exists for Western policy-makers to have a direct impact on the long-term nuclear export and non-proliferation behavior of the successor states to the Soviet Union. The speed and seriousness with which the West undertakes this task will largely determine how much ground, if any, will be lost from its decades-long effort to stop the proliferation of nuclear weapons

Nuclear protein import is reduced in cells expressing nuclear envelopathy-causing lamin A mutants

International Nuclear Information System (INIS)

Busch, Albert; Kiel, Tilman; Heupel, Wolfgang-M.; Wehnert, Manfred; Huebner, Stefan

2009-01-01

Lamins, which form the nuclear lamina, not only constitute an important determinant of nuclear architecture, but additionally play essential roles in many nuclear functions. Mutations in A-type lamins cause a wide range of human genetic disorders (laminopathies). The importance of lamin A (LaA) in the spatial arrangement of nuclear pore complexes (NPCs) prompted us to study the role of LaA mutants in nuclear protein transport. Two mutants, causing prenatal skin disease restrictive dermopathy (RD) and the premature aging disease Hutchinson Gilford progeria syndrome, were used for expression in HeLa cells to investigate their impact on the subcellular localization of NPC-associated proteins and nuclear protein import. Furthermore, dynamics of the LaA mutants within the nuclear lamina were studied. We observed affected localization of NPC-associated proteins, diminished lamina dynamics for both LaA mutants and reduced nuclear import of representative cargo molecules. Intriguingly, both LaA mutants displayed similar effects on nuclear morphology and functions, despite their differences in disease severity. Reduced nuclear protein import was also seen in RD fibroblasts and impaired lamina dynamics for the nucleoporin Nup153. Our data thus represent the first study of a direct link between LaA mutant expression and reduced nuclear protein import.

Cooperation of nuclear manpower development between Viet Nam and Korea in order to enhance establishment of infrastructure in exporting nuclear technology to Viet Nam

International Nuclear Information System (INIS)

Lee, E. J.; Han, K. W.; Park, J. K.; Kim, Y. T.; Nam, Y. M.; Jang, Y. H.; Yang, M. H.

2003-08-01

Through this project, KAERI provided OJT Programme to 3 nuclear experts of Viet Nam at the KAERI for 3 months as a cooperation of human resource development in the field of nuclear policy, nuclear safety analysis and thermo hydraulic. We could have publicity activities of S/W and H/W then achieve an advantage position of economical and technical in exporting nuclear technology to Viet Nam. Also we have provided a training course and seminar for a high-level delegation of nuclear policy decision makers, which is consisted of 5 deputy ministers and general directors of Viet Nam in Korea. Thus we could have Vietnamese who are favoring Korea. The KAERI will also prepare a data base of trained Vietnamese in Korea for the maximum utilization of them in cooperating with Viet Nam. We accomplished the cooperation of human resource development and providing program and curriculum of the nuclear education and training in Viet Nam. Furthermore, it is expected that the enhancement of nuclear technical cooperation between Viet Nam and Korea and the nuclear human resource development

Cooperation of nuclear manpower development between Viet Nam and Korea in order to enhance establishment of infrastructure in exporting nuclear technology to Viet Nam

Energy Technology Data Exchange (ETDEWEB)

Lee, E. J.; Han, K. W.; Park, J. K.; Kim, Y. T.; Nam, Y. M.; Jang, Y. H.; Yang, M. H

2003-08-15

Through this project, KAERI provided OJT Programme to 3 nuclear experts of Viet Nam at the KAERI for 3 months as a cooperation of human resource development in the field of nuclear policy, nuclear safety analysis and thermo hydraulic. We could have publicity activities of S/W and H/W then achieve an advantage position of economical and technical in exporting nuclear technology to Viet Nam. Also we have provided a training course and seminar for a high-level delegation of nuclear policy decision makers, which is consisted of 5 deputy ministers and general directors of Viet Nam in Korea. Thus we could have Vietnamese who are favoring Korea. The KAERI will also prepare a data base of trained Vietnamese in Korea for the maximum utilization of them in cooperating with Viet Nam. We accomplished the cooperation of human resource development and providing program and curriculum of the nuclear education and training in Viet Nam. Furthermore, it is expected that the enhancement of nuclear technical cooperation between Viet Nam and Korea and the nuclear human resource development.

The nuclear import of the human T lymphotropic virus type I (HTLV-1) tax protein is carrier- and energy-independent.

Science.gov (United States)

Tsuji, Takahiro; Sheehy, Noreen; Gautier, Virginie W; Hayakawa, Hitoshi; Sawa, Hirofumi; Hall, William W

2007-05-04

HTLV-1 is the etiologic agent of the adult T cell leukemialymphoma (ATLL). The viral regulatory protein Tax plays a central role in leukemogenesis as a transcriptional transactivator of both viral and cellular gene expression, and this requires Tax activity in both the cytoplasm and the nucleus. In the present study, we have investigated the mechanisms involved in the nuclear localization of Tax. Employing a GFP fusion expression system and a range of Tax mutants, we could confirm that the N-terminal 60 amino acids, and specifically residues within the zinc finger motif in this region, are important for nuclear localization. Using an in vitro nuclear import assay, it could be demonstrated that the transportation of Tax to the nucleus required neither energy nor carrier proteins. Specific and direct binding between Tax and p62, a nucleoporin with which the importin beta family of proteins have been known to interact was also observed. The nuclear import activity of wild type Tax and its mutants and their binding affinity for p62 were also clearly correlated, suggesting that the entry of Tax into the nucleus involves a direct interaction with nucleoporins within the nuclear pore complex (NPC). The nuclear export of Tax was also shown to be carrier independent. It could be also demonstrated that Tax it self may have a carrier function and that the NF-kappaB subunit p65 could be imported into the nucleus by Tax. These studies suggest that Tax could alter the nucleocytoplasmic distribution of cellular proteins, and this could contribute to the deregulation of cellular processes observed in HTLV-1 infection.

The formation of nuclear export control in Azerbaijan

International Nuclear Information System (INIS)

Garibov, A.A.

2003-01-01

Full text: The controlling process of exporting and importing on Azerbaijan borders is being carried out by two state organizations. 1.Border Guard Department; 2.Azerbaijan State Customs Committee. The officers of these organizations have no enough necessary experience and knowledge dealing with the legal and illegal trafficking. There were not special educational institutions in order to train personals for both of these organizations made newly. So there's difference between the professions of the majority of the employees, that's why some of the employees follow the instructions linking to the normative documents while passing the border. When trafficking nuclear and dual-use items officially the controller and other employees should look through the list of all and know them how to behave and to make official, the characteristic parameters of the materials, and the instruction of monitoring. In order to realize all works pointed, the employees of Border Guard Department and Customs Control Check Points have to attend special courses. The employees of both organizations are frequently changed that's why studying courses are to be organized. The analysis of studying considered that will be realized shows mainly there may be two student groups. Mainly, the Institute of Radiation Problems of ANAS (Azerbaijan National Academy of Sciences) as the expert laboratory takes part in. On the borders of Azerbaijan Republic the dual-use items and equipment having the type of isotope sources being utilized in the technological process are mainly being transported. In the materials presented the results and the solution of the problems dealing with realizing the controlling expert system of nuclear materials in the existing control checkpoints due to the international standards have been given

Nuclear import and export signals of human cohesins SA1/STAG1 and SA2/STAG2 expressed in Saccharomyces cerevisiae.

Directory of Open Access Journals (Sweden)

Leszek J Tarnowski

Full Text Available BACKGROUND: Human SA/STAG proteins, homologues of the yeast Irr1/Scc3 cohesin, are the least studied constituents of the sister chromatid cohesion complex crucial for proper chromosome segregation. The two SA paralogues, SA1 and SA2, show some specificity towards the chromosome region they stabilize, and SA2, but not SA1, has been shown to participate in transcriptional regulation as well. The molecular basis of this functional divergence is unknown. METHODOLOGY/PRINCIPAL FINDINGS: In silico analysis indicates numerous putative nuclear localization (NLS and export (NES signals in the SA proteins, suggesting the possibility of their nucleocytoplasmic shuttling. We studied the functionality of those putative signals by expressing fluorescently tagged SA1 and SA2 in the yeast Saccharomyces cerevisiae. Only the N-terminal NLS turned out to be functional in SA1. In contrast, the SA2 protein has at least two functional NLS and also two functional NES. Depending on the balance between these opposing signals, SA2 resides in the nucleus or is distributed throughout the cell. Validation of the above conclusions in HeLa cells confirmed that the same N-terminal NLS of SA1 is functional in those cells. In contrast, in SA2 the principal NLS functioning in HeLa cells is different from that identified in yeast and is localized to the C-terminus. CONCLUSIONS/SIGNIFICANCE: This is the first demonstration of the possibility of non-nuclear localization of an SA protein. The reported difference in the organization between the two SA homologues may also be relevant to their partially divergent functions. The mechanisms determining subcellular localization of cohesins are only partially conserved between yeast and human cells.

p35 regulates the CRM1-dependent nucleocytoplasmic shuttling of nuclear hormone receptor coregulator-interacting factor 1 (NIF-1.

Directory of Open Access Journals (Sweden)

Xiao-Su Zhao

Full Text Available Cyclin-dependent kinase 5 (Cdk5 is a proline-directed serine/threonine kinase, which plays critical roles in a wide spectrum of neuronal functions including neuronal survival, neurite outgrowth, and synapse development and plasticity. Cdk5 activity is controlled by its specific activators: p35 or p39. While knockout studies reveal that Cdk5/p35 is critical for neuronal migration during early brain development, functions of Cdk5/p35 have been unraveled through the identification of the interacting proteins of p35, most of which are Cdk5/p35 substrates. However, it remains unclear whether p35 can regulate neuronal functions independent of Cdk5 activity. Here, we report that a nuclear protein, nuclear hormone receptor coregulator (NRC-interacting factor 1 (NIF-1, is a new interacting partner of p35. Interestingly, p35 regulates the functions of NIF-1 independent of Cdk5 activity. NIF-1 was initially discovered as a transcriptional regulator that enhances the transcriptional activity of nuclear hormone receptors. Our results show that p35 interacts with NIF-1 and regulates its nucleocytoplasmic trafficking via the nuclear export pathway. Furthermore, we identified a nuclear export signal on p35; mutation of this site or blockade of the CRM1/exportin-dependent nuclear export pathway resulted in the nuclear accumulation of p35. Intriguingly, blocking the nuclear export of p35 attenuated the nuclear accumulation of NIF-1. These findings reveal a new p35-dependent mechanism in transcriptional regulation that involves the nucleocytoplasmic shuttling of transcription regulators.

p35 regulates the CRM1-dependent nucleocytoplasmic shuttling of nuclear hormone receptor coregulator-interacting factor 1 (NIF-1).

Science.gov (United States)

Zhao, Xiao-Su; Fu, Wing-Yu; Chien, Winnie W Y; Li, Zhen; Fu, Amy K Y; Ip, Nancy Y

2014-01-01

Cyclin-dependent kinase 5 (Cdk5) is a proline-directed serine/threonine kinase, which plays critical roles in a wide spectrum of neuronal functions including neuronal survival, neurite outgrowth, and synapse development and plasticity. Cdk5 activity is controlled by its specific activators: p35 or p39. While knockout studies reveal that Cdk5/p35 is critical for neuronal migration during early brain development, functions of Cdk5/p35 have been unraveled through the identification of the interacting proteins of p35, most of which are Cdk5/p35 substrates. However, it remains unclear whether p35 can regulate neuronal functions independent of Cdk5 activity. Here, we report that a nuclear protein, nuclear hormone receptor coregulator (NRC)-interacting factor 1 (NIF-1), is a new interacting partner of p35. Interestingly, p35 regulates the functions of NIF-1 independent of Cdk5 activity. NIF-1 was initially discovered as a transcriptional regulator that enhances the transcriptional activity of nuclear hormone receptors. Our results show that p35 interacts with NIF-1 and regulates its nucleocytoplasmic trafficking via the nuclear export pathway. Furthermore, we identified a nuclear export signal on p35; mutation of this site or blockade of the CRM1/exportin-dependent nuclear export pathway resulted in the nuclear accumulation of p35. Intriguingly, blocking the nuclear export of p35 attenuated the nuclear accumulation of NIF-1. These findings reveal a new p35-dependent mechanism in transcriptional regulation that involves the nucleocytoplasmic shuttling of transcription regulators.

Intermolecular masking of the HIV-1 Rev NLS by the cellular protein HIC: Novel insights into the regulation of Rev nuclear import

Directory of Open Access Journals (Sweden)

Sheehy Noreen

2011-03-01

Full Text Available Abstract Background The HIV-1 regulatory protein Rev, which is essential for viral replication, mediates the nuclear export of unspliced viral transcripts. Rev nuclear function requires active nucleocytoplasmic shuttling, and Rev nuclear import is mediated by the recognition of its Nuclear Localisation Signal (NLS by multiple import factors, which include transportin and importin β. However, it remains unclear which nuclear import pathway(s predominate in vivo, and the cellular environment that modulates Rev nucleocytoplasmic shuttling remains to be characterised. Results In our study, we have identified the cellular protein HIC (Human I-mfa domain-Containing protein as a novel interactor of HIV-1 Rev. We demonstrate that HIC selectively interferes with Rev NLS interaction with importin β and impedes its nuclear import and function, but does not affect Rev nuclear import mediated by transportin. Hence, the molecular determinants mediating Rev-NLS recognition by importin β and transportin appear to be distinct. Furthermore, we have employed HIC and M9 M, a peptide specifically designed to inhibit the transportin-mediated nuclear import pathway, to characterise Rev nuclear import pathways within different cellular environments. Remarkably, we could show that in 293T, HeLa, COS7, Jurkat, U937, THP-1 and CEM cells, Rev nuclear import is cell type specific and alternatively mediated by transportin or importin β, in a mutually exclusive fashion. Conclusions Rev cytoplasmic sequestration by HIC may represent a novel mechanism for the control of Rev function. These studies highlight that the multivalent nature of the Rev NLS for different import receptors enables Rev to adapt its nuclear trafficking strategy.