• BMB Reports
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• 제33권2호
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• pp.103-111
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• 2000

Phosphorylation of the eukaryotic elongation factor 2 (eEF-2) blocks the elongation step of translation and stops overall protein synthesis. Although the overall rate of protein synthesis in mitosis reduces to 20% of that in S phase, it is unclear how the protein translation procedure is regulated during the cell cycle, especially in the stage of peptide elongation. To delineate the regulation of the elongation step through eEF-2 function, the changes in phosphorylation of eEF-2, and in activity of corresponding $Ca^{2+}$/calmodulin (CaM)-dependent protein kinase III (CaMK-III) during the cell cycle of NIH 3T3 cells, were determined. The in vivo level of phosphorylated eEF-2 showed an 80% and 40% increase in the cells arrested at G1 and M, respectively. The activity of CaMK-III also changed in a similar pattern, more than a 2-fold increase when arrested at G1 and M. The activity change of the kinase during one turn of the cell cycle also demonstrated the activation at G1 and M phases. The activity change of cAMP-dependent protein kinase (PKA) was reciprocal to that of CaMK-III. These results indicated: (1) the activity of CaMK-III was cell cycle-dependent and (2) the level of eEF-2 phosphorylation followed the kinase activity change. Therefore, the elongation step of protein synthesis might be cell cycle dependently regulated.

• Molecules and Cells
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• 제21권2호
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• pp.294-301
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• 2006

We have previously reported that phosphorylation of eukaryotic elongation factor 2 (eEF2) is related to the differentiation of chick embryonic muscle cells in culture. In the present study, we found that eEF2 phosphorylation declined shortly after induction of differentiation of L6 myoblasts, when the cells prepare for terminal differentiation by withdrawing from the cell cycle. This decrease in phosphorylation was prevented by inhibitors of phosphoinositide 3-kinase (PI3-kinase) that strongly inhibit myoblast differentiation. We hypothesized that PI3-kinase plays an important role in myoblast differentiation by regulating eEF2 phosphorylation in the early stages of differentiation. To test this hypothesis, myoblasts were synchronized at in $G_2/M$ and cultured in fresh differentiation medium (DM) or growth medium (GM). In DM the released cells accumulated in $G_0$/$G_1$ while in GM they progressed to S phase. In addition, cyclin D1 was more rapidly degraded in DM than in GM, and eEF2 phosphorylation decreased more. Inhibitors of PI3-kinase increased eEF2 phosphorylation, but PI3-kinase became more activated when eEF2 phosphorylation declined. These results suggest that the regulation of L6 myoblast differentiation by PI3-kinase is related to eEF2 phosphorylation.

• Asian Pacific Journal of Cancer Prevention
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• 제14권11호
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• pp.6533-6535
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• 2013

Background: The purpose of this study was to evaluate a new type of tumor biomarker, eukaryotic elongation factor 2 (eEF2), in serum for the early diagnosis, confirmative diagnosis as well as assessment of treatment of non-small cell lung cancer (NSCLC). Methods: 130 patients with NSCLC and 50 healthy individuals undergoing physical examination in our hospital provided the observation and healthy control groups. An enzyme linked immune sorbent assay (ELISA) method was applied to determine serum eEF2 levels. Serum neuron specific enolase (NSE) and squamous cell carcinoma antigen (SCC) levels in the observation group were assessed with an automatic biochemical analyzer. Results: The median levels of eEF2 in the serum of NSCLC patients was found to be significantly higher than the healthy control group (p < 0.01) and it was markedly higher in stages III, IV than stages I, II (p < 0.05). eEF2 was higher with tumor size ${\geq}2$ cm than <2 cm (P< 0.01). Furthermore, two weeks after surgery patients showed a significant trend for eEF2 decrease (p < 0.05). Conclusions: The eukaryotic elongation factor 2 (eEF2) has certain clinical values for early diagnosis, verification, and prognosis as well as classification of lung cancer patients.

• International Journal of Industrial Entomology and Biomaterials
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• 제24권2호
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• pp.49-55
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• 2012

We previously isolated 9 clones that show stronger signal compared to B. mori cytoplasmic actin gene (BmA3) by using a dot blot hybridization. In this study, we focused on one clone among these clones which has high amino acid homology with elongation factor ${\alpha}$ gene of B. mori. This clone, named $bEF1{\alpha}$ (B. mori elongation factor ${\alpha}$) was ubiquitously expressed in all tissues and developmental stage of B. mori. As result of promoter assay using dual luciferase assay system, we found the highest transcription activity region (-702/+38) in the 5'-flanking region of $bEF1{\alpha}$ gene, which has about 20 fold more intensive promoter activity than BmA3 promoter. Moreover, the $bEF1{\alpha}$ promoter was normally regulated in Bm5, Sf9, and S2 cells. Therefore, we suggest that $bEF1{\alpha}$ promoter may be used more powerful and effectively for transgene expression in various insects containing B. mori as a universal promoter.

• 한국동물학회:학술대회논문집
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• 한국동물학회 1999년도 한국생물과학협회 학술발표대회
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• pp.257.2-257
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• 1999

No Abstract, See Full Text

• BMB Reports
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• 제45권4호
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• pp.227-232
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• 2012

In vertebrates, there are two variants of eukaryotic peptide elongation factor 1A (eEF1A; formerly eEF-$1{\alpha}$), eEF1A1 and eEF1A2, which have three well-conserved domains ($D_I$, $D_{II}$, and $D_{III}$). In neurons, eEF1A1 is the embryonic type, which is expressed during embryonic development as well as the first two postnatal weeks. In the present study, EGFP-tagged eEF1A1 truncates were expressed in cortical neurons isolated from rat embryo (E18-19). Live cell images of transfected neurons showed that $D_{III}$-containing EGFP-fusion proteins (EGFP-$D_{III}$, -$D_{II-III}$, -$D_{I-III}$) formed clusters that were confined within somatodendritic domains, while $D_{III}$-missing ones (EGFP-$D_I$, -$D_{II}$, -$D_{I-II}$) and control EGFP were homogeneously dispersed throughout the neuron including axons. In dendrites, EGFP-$D_{III}$ was targeted to the heads of spine- and filopodia-like protrusions, where it was colocalized with $SynGAP{\alpha}$, a postsynaptic marker. Our data indicate that $D_{III}$ of eEF1A1 mediates formation of clusters and localization to spines.

• Mycobiology
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• 제34권2호
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• pp.45-55
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• 2006

Although Fursarium oxysporum causes diseases in economically important plant hosts, identification of F. oxysporum formae speciales has been difficult due to confusing phenotypic classification systems. To resolve these complexity, we evaluated genetic relationship of nine formae speciales of F. oxysporum with random amplified polymorphic DNA (RAPD), amplified fragment length polymorphism (AFLP), and translation elongation factor-l alpha ($EF-1{\alpha}$) gene. In addition, the correlation between mycotoxin content of fusaric acid and isolates based on molecular marker data was evaluated using the modified Mantel's test. According to these result, these fusaric acid-producing strains could not identify clearly, and independent of geographic locations and host specificities. However, in the identification of F. oxysporum formae speciales, especially, AFLP analysis showed a higher discriminatory power than that of a the RAPD and $EF-1{\alpha}$ analyses, all three techniques were able to detect genetic variability among F. oxysporum formae speciales in this study.

• 한국식물병리학회:학술대회논문집
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• 한국식물병리학회 2003년도 정기총회 및 추계학술발표회
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• pp.117.2-117
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• 2003

The importance and diversity of the genus Stemphylium highlights the need for accurate identification of species. However, many Stemphylium isolates have been misidentified due to the use of spore size as the only identifying character. Molecular phylogenetic analyses were performed on fifty-four isolates covering 9 Stemphylium species collected in Korea. Phylogenetic analysis of the translation elongation factor -1 alpha (EF-1) and the calmodulin gene sequence data showed that Stemphylium species were segregated into seven distinct groups, most of w hichcorrelated with species identified by morphology. Analysis of EF-1 in particular was useful for establishing well- supported relationships among the species of Stemphylium.

• Journal of Microbiology and Biotechnology
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• 제31권1호
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• pp.16-24
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• 2021

Hepatitis B virus (HBV) genome P-encoded protein HBV DNA polymerase (Pol) has long been known as a reverse transcriptase during HBV replication. In this study, we investigated the impact of HBV Pol on host cellular processes, mainly apoptosis, and the underlying mechanisms. We showed a marked reduction in apoptotic rates in the HBV Pol-expressed HepG2 cells compared to controls. Moreover, a series of assays, i.e., yeast two-hybrid, GST pull-down, co-immunoprecipitation, and confocal laser scanning microscopy, identified the host factor eEF1A2 to be associated with HBV Pol. Furthermore, knockdown of eEF1A2 gene by siRNA abrogated the HBV Pol-mediated anti-apoptotic effect with apoptosis induced by endoplasmatic reticulum (ER) stress-inducer thapsigargin (TG), thus suggesting that the host factor eEF1A2 is essential for HBV Pol's anti-apoptosis properties. Our findings have revealed a novel role for HBV Pol in its modulation of apoptosis through integrating with eEF1A2.

• 한국잠사곤충학회지
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• 제37권1호
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• pp.68-73
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• 1995

미국흰불나방(Hyphantria cunea)의 유충에서 중장, 지방체, 말피기씨관에 Bacillus thuringiensis(Bt) var. kurstaki의 내독소 단백질의 독성효과로 인한 생리적 변화를 autoradiography와 Western blot으로 확인하였다. 단백질 합성과 번역연장민자-2에 미치는 영향을 조사한 결과, 앞의 모든 조직에서 단백질 합성이 급격히 저하되었으며, 번역연자인자-2의 활성도 병행하여 저하되었다.