• KSBB Journal
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• v.18 no.4
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• pp.255-260
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• 2003

In vivo bioassays for biological medicines have been considered final resort to unequivocally assess the biological activities for them because there are some cases in which the biological activities obtained from in vivo bioassay and in vitro bioassay quite differ each other. The in vivo biological activity of EPO depends on its sialic acid contents which confer microheterogeneity-isoforms to this protein. We have devise a method which consists of a in vitro bioassay using BaF3 cell line and a capillary zone electrophoresis (CZE) for the measurement of the EPO isoform distribution. The biological activity of EPO obtained using in vitro bioassay with BaF3 cell line showed good correlation (C.V.(％) 7.34, 5.85, 8,16, 8.08, 8.8) to EPO content measured either spectrophotometric assay (A280 0.1 ％ ＝0.743) or radio immunoassay. The assay validation results of in vitro bioassay with 3 lot of in house EPO showed good results to EPO content measured either in vivo assay or radio immunoassay. and also showed good results the robustness of our method in terms of precision, accuracy, repeatability. The isoform distribution for EPO-BRP (1 : 1 mixture of epoetin-${\alpha}$ and epoetin-${\beta}$, European Pharmacopoeia) by CZE method resulted in isoform 2 through isoform 8. The major peaks in electrophoregram were composed of isoform 3 through 7. Our recombinant EPO (epoetin-${\alpha}$) having equivalent in vivo biological activity showed the isoform distribution of isoform 3 through 9. The major peaks consisted of isoform 4 through 8. The peak area of isoform 4 was always smaller than that of isoform 5. The preparations of recombinant epoetin-${\alpha}$ with lower in vivo biological activity than EPO-BRP showed the isoform 2 through 8 in their electrophoregrams whose major peaks consisted of the isoform 3 through 7. The peak area of isoform 4 was larger than that of isoform 5.

• Biomedical Science Letters
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• v.6 no.3
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• pp.171-179
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• 2000

The lengths of thick and thin filaments in the sarcomeres of most vertebrate skeletal muscles are precisely regulated and are important structural parameters in understanding muscle contraction. Nebulin is a usually large protein that spans the whole length of thin filaments in the sarcomeres of skeletal muscles. In this paper we used SDS-PAGE and immunoblot to identify nebulin isoform proteins in muscle and non-muscle tissues. We prepared embryonic chicken tissues including skeletal muscle, cardiac muscle, smooth muscle, brain, liver to compare nebulin isoform proteins. The proteins were divided into soluble and insoluble fraction. As a result, we identified tissue specific expression of various nebulin isoform proteins in muscle and non-muscle tissues of chicken. Nebulin was detected in skeletal muscle of adult chicken about 500 kDa. Nebulett was expressed in cardiac muscle of embryonic and adult chicken about 107 kDa. A giant protein with molecular mass of about 380 kDa was identified in brain of non-muscle of chicken. This giant protein was detected in the soluble fraction of chicken embryo. The unequal distribution of the nebulin isoform proteins suggests tissue specific regulation of the isoform expression and indicates a functional specialization of the encoded isoform subtypes.

• BMB Reports
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• v.48 no.12
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• pp.696-701
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• 2015

Toll-like receptor 3 (TLR3) recognizes viral double-stranded RNA. It stimulates pro-inflammatory cytokine and interferon production. Here we reported the expression of a novel isoform of TLR3 in human astrocyte cell lines whose message is generated by alternative splicing. The isoform represents the N-terminus of the protein. It lacks many of the leucine-rich repeat domains, the transmembrane domain, and the intracellular Toll/interleukin-1 receptor domain of TLR3. Type I interferons (interferon-α and interferon-β) induced the expression of this isoform. Exogenous overexpression of this isoform inhibited interferon regulatory factor 3, signal transducers and activators of transcription 1, and Inhibitor of kappa B α signaling following stimulation. This isoform of TLR3 also inhibited the production of chemokine interferon-γ-inducible protein 10. Our study clearly demonstrated that the expression of this isoform of TLR3 was a negative regulator of signaling pathways and that it was inducible by type I interferons. We also found that this isoform could modulate inflammation in the brain.

• Proceedings of the Korea Contents Association Conference
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• 2018.05a
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• pp.317-318
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• 2018

유전자는 alternative splicing으로 환경에 맞는 전사체를 발현함으로써 생명체의 복잡성을 야기한다. 하지만 대부분의 유전자는 dominant한 isoform 하나만이 주로 발현되며 그 외는 극히 미약하게 발현을 한다. 정상 대비 암조직에서 dominant하게 발현되는 isoform은 암의 생성과 발달에 영향을 끼칠 것으로 보인다. 이에 정상과 비교하여 암 특이적인 isoform, 즉 isoform switch가 일어나는 유전자를 찾기 위해 TCGA의 RNA-seq 데이터를 다운로드하여 isoform switch가 일어나는 유전자를 뽑았다. 12 조직에 대한 2,925 유전자는 기능분석을 통해 암과 밀접하게 연관되어 있음을 알 수 있었다.

• Korean Journal Plant Pathology
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• v.12 no.1
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• pp.1-10
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• 1996

Xanthomonas campestris pv. vesicatoria의 감염으로 토마토 잎조직에 $\beta$-1, 3-Glucanases와 chitinases가 합성, 축적되었다. 그러나 접종되지 않은 건전한 잎에서는 위의 두 가지 가수분해 효소는 매우 낮은 수준으로 유지되었고, 이 두 가지 효소는 친화적 상호작용에서보다는 불친화적 상호작용에서 더욱 높은 수준으로 존재하였다. 이것은 $\beta$-1, 3-glucanases와 chitinases가 X. c. pv. vesicatoria의 생육에 대한 방어기작으로서 중요한 역할을 한다는 것을 시사해 주고 있다. Native PAGE 젤 상에서 $\beta$-1, 3-glucanases를 분리한 결과, 병징 발현이나 저항성 발현에 중요한 역할을 하는 것으로 생각되는 산성 isoform Ga 1과 염기성 isoform Gb 1의 isoform bands만 확인되었다. Isoelectric focusing을 이용하였을 때, 적어도 pI 6.4와 pI 8.6을 지닌 두 개의 $\beta$-1, 3-glucanases의 isoform을 확인할 수 있었고, 특히 불친화적 상호작용에서 더욱 뚜렷하게 유도되었다. 이것은 병 진전과정에서 X. c. pv. vesicatoria에 대해 저항성 발현에 관여한다는 것을 나타내고 있다. 산성 chitinase isoform인 Ca 1의 활성은 병원균의 감염이 진전되는 동안 감소하였다. 또한 다섯 개의 염기성 chitinase isoform이 감염된 토마토 잎 조직에서 발견되었는데, 특히 토마토의 방어기작에 관여하여 병원화적 균주 Bv5-4a에 감염된 잎에서만 유도, 축적되었다. Isoelectric focusing(IEF)을 이용한 후 적어도 2개의 산성과 4개의 염기성 chitinase isoform이 감염된 토마토 잎 추출액에서 확인되었다. Native PAGE 젤에서 isoform Cb 1에 해당되는 pI 9.5를 지닌 chitinase isoform은 오직 불친화적 상호작용에서만 확인되었다. 이온이 제거된 Triton X-100을 처리하여 renaturation 시킨 후에 SDS-PAGE 젤 상태에서 23 kDa과 26 kDa을 지닌 2개의 chitinase isoform을 확인하였다.

• BMB Reports
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• v.36 no.4
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• pp.409-416
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• 2003

The isoform 1 of cyclodextrin glycosyltransferase (CGTase, EC 2.4.1.19) from Paenibacillus sp. A11 was purified by a preparative gel electrophoresis. The importance of histidine, tryptophan, tyrosine, and carboxylic amino acids for isoform 1 activity is suggested by the modification of the isoform 1 with various group-specific reagents. Activity loss, when incubated with diethylpyrocarbonate (DEP), a histidine modifying reagent, could be protected by adding 25 mM methyl-$\beta$-cyclodextrin substrate prior to the modification. Inactivation kinetics of isoform 1 with DEP resulted in second-order rate constants ($k_{inactivation}$) of $29.5\;M^{-1}s^{-1}$. The specificity of the DEP-modified reaction for the histidine residue was shown by the correlation between the loss of isoform activity and the increase in the absorbance at 246 nm of N-carbethoxyhistidine. The number of histidines that were modified by DEP in the absence and presence of a protective substrate was estimated from the increase in the absorbance using a specific extinction coefficient of N-carbethoxyhistidine of $3,200\;M^{-1}cm^{-1}$. It was discovered that methyl-$\beta$-CD protected per mole of isoform 1, two histidine residues from the modification by DEP. To localize essential histidines, the native, the DEP-modified, and the protected forms of isoform 1 were digested by trypsin. The resulting peptides were separated by HPLC. The peptides of interest were those with $R_t$ 11.34 and 40.93 min. The molecular masses of the two peptides were 5,732 and 2,540 daltons, respectively. When the data from the peptide analysis were checked with the sequence of CGTase, then His-140 and His-327 were identified as essential histidines in the active site of isoform 1.

• Journal of Chest Surgery
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• v.36 no.9
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• pp.666-673
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• 2003

Cigarette smoking is the leading cause of the lung cancer. However, mechanism of action underlying the carcinogenesis in the lung still remains to be elucidated. The present study attempted to look into the carcinogenic potential of tobacco-specific nitrosamine, NNK (4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone) and the effects of protein kinase C (PKC) isoforms in an immortalized human epithelial cell model. Material and Method: Immortalized human epithelial cells were exposed with NNK and examined for its carcinogenic potential as measured by saturation density, soft-agar colony formation, and cell aggregation assay. The specific isoform of PKCs involved in the cellular transformation was analysed through western blot with monoclonal antibody and measured separately in cytosolic fraction and membrane fraction. Result: Human epithelial cells exposed with NNK showed prominent carcinogenic potential in saturation density, soft agar colony formation, and cell aggregation assay. PKC isoform analysis results are as follows: PKC- $\alpha$ showed significant translocation of protein levels from cytosolic fraction to membrane fraction, as analyzed by immunoblot. PKC- $\varepsilon$ showed a dose-dependent increase of translocation. PKC- λ was not affected by NNK treatment. Conclusion: The study demonstrated that there was a certain specificity in the patterns of isoform induction following chemical carcinogen exposure. Thus, it is suggested that identification of specific isoform be a clue to find target molecules in the carcinogenesis.

• Fisheries and Aquatic Sciences
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• v.17 no.4
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• pp.471-478
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• 2014

Genomic organization, including the structural characteristics of 5'-flanking regions of two 65-kDa protein (WAP65) isoform genes associated with warm temperature acclimation, were characterized and their transcriptional responses to immune challenges were examined in the intestine, kidney and spleen of the mud loach (Misgurnus mizolepis; Cypriniformes). Both mud loach Wap65 isoform genes displayed a 10-exon structure that is common to most teleostean Wap65 genes. The two mud loach Wap65 isoforms were predicted to possess various stress- and immune-related transcription factor binding sites in their regulatory regions; however, the predicted motif profiles differed between the two isoforms, and the inflammation-related transcription factor binding motifs, such as NF-${\kappa}B$ and CREBP sites, were more highlighted in the Wap65-2 isoform than the Wap65-1 isoform. The results of qRT-PCR indicated that experimental immune challenges using Edwardsiella tarda, lipopolysaccharide or polyI:C induced the Wap65-2 isoform more than Wap65-1 isoform, although modulation patterns in response to these challenges were tissue- and stimulant-dependent. This study confirms that functional diversification between the two mud loach Wap65 isoforms (i.e., closer involvement of Wap65-2 in the acute phase of inflammation and innate immunity) occurs at the mRNA level in multiple tissues, and suggests that such differential modulation patterns between the two isoforms are related to the different transcription factor binding profiles in their regulatory regions.

• Journal of the Korean Data and Information Science Society
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• v.27 no.1
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• pp.225-243
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• 2016

Thanks to recent advance of next generation sequencing techniques, RNA-seq enabled to have an unprecedented opportunity to identify transcript variants with isoform diversity and allelic imbalance (Anders et al., 2012) by different transcriptional rates. To date, it is well known that those features might be associated with the aberrant patterns of disease complexity such as tissue (Anders and Huber, 2010; Anders et al., 2012; Nariai et al., 2014) specific differential expression at isoform levels or tissue specific allelic imbalance in mal-functionality of disease processes, etc. Nevertheless, the knowledge of post-transcriptional modification and AI in transcriptomic and genomic areas has been little known in the traditional platforms due to the limitation of technology and insufficient resolution. We here stress the potential of isoform variability and allelic specific expression that are relevant to the abnormality of disease mechanisms in transcriptional genetic regulatory networks. In addition, we systematically review how robust Bayesian approaches in RNA-seq have been developed and utilized in this regard in the field.

• YAKHAK HOEJI
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• v.40 no.6
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• pp.734-738
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• 1996

The development of the alpha2 isoform of (Na,K)ATPase which is high affinity ouabain receptors was studied in the differentiating nonfusing muscle cell line BC3H-1. T he differentiation process of BC3H-1 cell line was confirmed by 2-dexy-D-[$^3$H] glucose uptake experiment and the quantity of the expression of ${\alpha}_2$ isoform was measured using a whole cell [$^3$H] ouabain-binding assay. Undifferentiated growing BC3H-1 cells, myoblasts, exhibited low levels of insulin-stimulated glucose uptake and [$^3$H] ouabain-binding sites. In contrast, differentiated BC3H-1 cells, myocytes, had a 5.6-fold increase in insulin-stimulated glucose uptake and 5-fold increase in [$^3$H] ouabain-binding sites. Scatchard analysis showed that myocytes developed more [$^3$H] ouabain-binding sites than myoblasts vath a dissociation constant (kd) of 6${\times}10^{-8}$M and capacity of 6.l${\times}10^{-5}$ sites/cell. Therefore. it seems that myoblasts express low levels of ${\alpha}_2$ subunit and probably the majority of ${\alpha}_1$ subunit, whereas myocytes express high levels of ${\alpha}_2$ isoform. The results indicate that the expression of ${\alpha}_2$ isoform is developmentally regulated during differentiation and that BC3H-1 culture system provides an excellent model for the study of differentiation and mechanism of (Na,K)ATPase action in muscle which requires electrical excitability.