• Journal of fish pathology
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• v.34 no.1
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• pp.17-22
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• 2021

Eukaryotic translation is initiated by either cap-dependent or cap-independent way, and the cap-independent translation can be initiated by the internal ribosomal entry site (IRES). In this study, to know whether the 5'UTR leader sequence of marine birnavirus (MABV) segment A and segment B can act as IRES, bicistronic vectors harboring a CMV promoter-driven red fluorescent gene (mCherry) and poliovirus IRES- or MABV's leader sequence-driven green fluorescent gene (eGFP) were constructed, then, transfected into a mammalian cell line (BHK-21 cells) and a fish cell line (CHSE-214 cells). The results showed that the poliovirus IRES worked well in BHK-21 cells, but did not work in CHSE-214 cells. In the evaluation of MABV's leader sequences, the reporter eGFP gene under the 5'UTR leader sequence of MABV's segment A was well-translated in CHSE-214 cells, indicating 5'UTR of MABV's segment A initiates translation in the cap-independent way and can be used as a fish-specific IRES system. However, the 5'UTR leader sequence of MABV's segment B did not initiate translation in CHSE-214 cells. As the precise mechanism of birnavirid IRES-mediated translation is not known, more elaborate investigations are needed to uncover why the leader sequence of segment B could not initiate translation in the present study. In addition, further studies on the host species range of MABV's segment A IRES and on the screening of other fish-specific IRESs are needed.

• Journal of the Korean Magnetic Resonance Society
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• v.7 no.2
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• pp.89-97
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• 2003

Foot-and-mouth disease virus (FMDV) belongs to the aphthovirus genus within the picornavirus which has a single copy of a positive sense RNA. The translation initiation process of FMDV occurs by a cap-independent mechanism directed by a highly structured element (∼435 nt) termed an internal ribosome entry site (IRES). We have designed and prepared FMDV 4-2 RNA (28nt) by in vitro transcription. The 2D NMR data revealed that FMDV 4-2 IRES domain RNA has a flexible loop and bulge conformation. In further study, we need to make an isotope labeled RNA sample and conduct 3D NMR experiments to completely determine the 3D structure. This study may establish a new drug design strategy to treat foot-and mouth disease.

• Toxicological Research
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• v.21 no.4
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• pp.347-353
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• 2005

Eukaryotic initiation factor 4E (elF4E) is a key element for cap-dependent protein translation controlled by affinity between elF4E and 4E-binding protein 1 (4E-BP1). Rapamycin can also affect protein translation by regulating 4E-BP1 phosphorylation. Tobacco-specific nitrosamine, 4(N-methyl-N-nitrosamino )-1-(3-pyridyl)-1-butanone (NNK) is a strong lung carcinogen, but its precise lung cancer induction mechanism remains unknown. Relative roles of cap-dependent and -independent protein translation in terms of NNK-induced lung carcinogenesis were elucidated using normal human bronchial epithelial cells. NNK concentrations applied in this study did not decrease cell viability. Addition of NNK restored rapamycin-induced decrease of protein synthesis and rapamycin-induced phosphorylation of 4E-BP1, and increased expression levels of mTOR, ERK1/2, p70S6K, and Raf-1 in a concentration-dependent manner. NNK also caused perturbation of normal cell cycle progression. Taken together, NNK might cause toxicity through the combination of restoration of 4E-BP1 phosphorylation and increase of elF4E as well as mTOR protein expression, interruption of Raf1/ERK as well as the cyclin G-associated p53 network. Our data could be applied towards elucidation of the molecular basis for lung cancer treatment.

• The Korean Journal of Air & Space Law and Policy
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• v.22 no.2
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• pp.27-51
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• 2007

The cumulative result of the work by the ICAO Secretariat, the Secretariat Study Group and the Council Special Group on the Modernization of the Rome Convention of 1952 are two draft Conventions, namely: "Draft Convention on Compensation for Damage Caused by Aircraft to Third Parties, in case of Unlawful Interference", and "Draft Convention on Compensation for Damage Caused by Aircraft to Third Parties" The core provisions of the former draft Convention are as follows: The liability of the operator is strict, that is, without the necessity of proof of fault. It would be liable for damage sustained by third parties on condition only that the damage was caused by an aircraft in flight(Article 3). However, such liability is caped based on the weight of the aircraft(Article 4). It is envisaged to create an independent organization called the Supplementary Compensation Mechanism, with the principle purpose to pay compensation to persons suffering damage in the territory of a State Party, and to provide financial support(Article 8). Compensation shall be paid by the SCM to the extent that the total amount of damages exceeds the Article 4 limits(Article 19). The main issues on the farmer draft Convention are relating to breaking away from Montreal Convention 1999, no limits on individual claims but a global limitation on air carrier liability, insurance coverage, cap of operators' strict liability, and Supplementary Compensation Mechanism. The core provisions of the latter draft Convention are as follows: the liability of the operator is strict, up to a certain threshold tentatively set at 250,000 to 500,000 SDRs. Beyond that, the operator is liable for all damages unless it proves that such damage were not due to its negligence or that the damages were solely due to the negligence of another person(Article 3). The provisions relating to the SCM and compensation thereunder do not operate under this Convention, as the operator is potentially for the full amount of damages caused. The main issues on the latter draft Convention are relating to liability limit of operator, and definition of general risks. In conclusion, we urge ICAO to move forward expeditiously on the draft Convention to establish a third party liability and compensation system that can stand ready to protect both third party victims and the aviation industry before another 9/11-scale event occurs.

• Journal of Life Science
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• v.7 no.4
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• pp.392-401
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• 1997

The poliovirus is a small, and non-enveloped virus. The RNA genome of poliovirus is continuous, linear, and has a single open reading frame. This polyprotein precursor is cleaved proteolytically to yield mature products. Most of the cleavages occur by viral protease. The mature proteins derived from the P1 polyprotein precursor are the structural components of the viral capsid. The initial cleavage by 2A protease is indirectly involved in the cleavage of a cellular protein p220, a subunit of the eukaryotic translation initiation factor 4F. This cleavage leads to the shut-off of cap-dependent host cell translation, and allows poliovirus to utilize the host cell machinery exclusively for translation its own RNA, which is initiated by internal ribosome entry via a cap-independent mechanism. The functional role of the 2B, 2C and 2BC proteins are not much known. 2B, 2C, 2BC and 3CD proteins are involved in the replication complex of virus induced vesicles. All newly synthesized viral RNAs are linked with VPg. VPg is a 22 amino acid polypeptide which is derived from 3AB. The 3C and 3CD are protease and process most of the cleavage sites of the polyprotein precursor. The 3C protein is also involved in inhibition of RNA polymerase II and III mediated transcription by converting host transcription factor to an inactive form. The 3D is the RNA dependent RNA polymerase. It is known that poliovirus replication follows the general pattern of positive strand RNA virus. Plus strand RNA is transcribed into complementary minus strand RNA that, in turn, is transcribed for the synthesis of plus strand RNA is transcribed into complementary minus strand RNA that, in turn, is transcribed for the synthesis of plus strand RNA strands. Poliovirus RNA synthesis occurs in a membranous environment but how the template RNA and proteins required for RNA replication assemble in the membrane is not much known. The RNA requirements for the encapsidation of the poliovirus genome (packaging signal) are totally unknown. The poliovirus infection cycle lasts approximately 6 hours.