• BMB Reports
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• 제33권4호
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• pp.349-352
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• 2000

Proteins that are involved in cellular signal cascade experience phosphorylation and dephosphorylation cycles in their tyrosine residue(s) during cell adhesion. In order to identify the protein(s), which tyrosine desidues are specifically phosphorylated when the cells attached to the substrate, we compared the tyrosine phosphorylation level of proteins between suspension and adhered culture condition in rat fibroblast 3Yl cells. We found that a cluster of 70 kDa protein was specifically phosphorylated when the cells adhered to the substrate, but did not effect the cells held in suspension. The phosphorylated protein is identified as paxillin, a focal adhesion protein in immunoprecipitation and immunobloting analysis. These results suggest that the tyrosine phosphorylation of paxillin may play a role in cell-substrate adhesion.

• Asian-Australasian Journal of Animal Sciences
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• 제18권6호
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• pp.884-891
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• 2005

This paper describes the purification and properties of a multicatalytic proteinase complex, proteasome, from bovine skeletal muscle, in comparision with proteasome prepared from other species or organs. The purified bovine skeletal muscle proteasome exhibited a single band on polyacrylamide gel electrophoresis under nondenaturing conditions. Bovine skeletal muscle proteasome degraded synthetic peptides maximally at pH 8.0. Relative to pH 8.0, activities were gradually decreased with the lowering pH, but the extent of decrease was substrate-dependent, and the activity at pH 5.5 still retained 78-10% of the activity at pH 8.0, indicating the possibility that the proteasome is active in muscle during aging. When the proteasome was heated at 60$^{\circ}C$ for 15 or 30 min and treated in the presence of 0.0125% SDS, the activity increased over 1.8 and 3.1 times (LLVY (Suc-Leu-Leu-Val-Tyr-NH-Mec) as a substrate), respectively. These results (activation with heat or SDS) indicate that the hydrolytic activity of proteasome was stimulated under mild denaturing conditions. The characteristics of the bovine skeletal muscle proteasome obtained in our experiment were almost the same as those of the proteasome prepared from other species or organs.

• 대한수의학회지
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• 제44권2호
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• pp.251-257
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• 2004

This study was designed to determine optimal condition for expression of cloned Shigatoxin2e(Stx2e) gene from transformed E. coli PED18, to compare the cytotoxicity titer between cloned Stx2e and Stx2e from original strain, and to confirm of receptor binding affinity of Stx2e for use of development of receptor binding ELISA to detect of Stx2e. The optimum composition of medium for expression of Stx2e gene in E.coli host-vector system was definded as the medium containing 0.5% glucose and 0.5 mM IPTG. The cytotoxicity titer of expressed Stx2e for Vero cell was 1000 fold higher than that of Stx2e from original strain AY93258. The binding affinity of Stx2e to receptor globotetraosyl ceramide($Gb_4$) was confirmed by immunobloting.

• 한국응용곤충학회지
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• 제43권3호
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• pp.225-231
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• 2004

내부기생봉의 일종인 프루텔고치별(Cotesia plutellae)이 배추좀나방(Plutellae xylostella)을 대상으로 생물적 방제제로 이용되고 있다. 이 기생봉은 생식기관에 폴리드나바이러스를 공생시키고, 이 바이러스의 존재는 기생봉의 성공적 기생에 필수적이다. 본 연구는 암컷 프루텔고치벌 성장에 따라 플리드나바이러스의 복제시기를 결정하였으며, 또한 교미나 기주 요인에 따른 암컷의 생식 능력을 분석하였다. 기생봉은 $25^{\circ}C$ 발육조건에서 용화 2일째 겹눈과 날개와 같은 성충조직을 발달시키기 시작했으며, 5일째에는 촉각을 포함한 모든 성충조직이 발달되어 우화 직전 단계의 모습을 보였다. 프루텔고치벌 폴리드나바이러스에 대한 다클론성항체에 의한 면역블로팅 분석은 용화 4일째에서 바이러스 복제를 확인할 수 있었다. 바이러스 입자들은 용화 5일째 산란관 내부에서 투과전자현미경으로 관찰되었다. 우화후 난소소관의 길이는 변하지 않았지만, 독샘과 난소받침의 크기는 증가했다. 교미한 암컷은 $25^{\circ}C$에서 약 8일관 생존하였으며, 초기 4일동안 집중된($60\%$ 이상) 산란을 보였다. 미교미 암컷은 교미한 암컷에 비해 낮은 산란을 보였으며, 이 미수정난은 모두 수컷으로 발육하였다. 프루텔고치벌은 배추좀나방과 미국흰불나방(Hyphantria cunea)모두를 기생시킬 수 있었다. 그러나 배추좀나방에서 더 빠르고, 높은 기생율을 보였다.

• Journal of Animal Science and Technology
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• 제64권5호
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• pp.922-936
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• 2022

5-Hydroxytryptamine (5-HT), a monoamine, as a local regulator in the mammary gland is a chemical signal produced by the mammary epithelium cell. In cows, studies have shown that 5-HT is associated with epithelial cell apoptosis during the degenerative phase of the mammary gland. However, studies in other tissues have shown that 5-HT can effectively promote cell viability. Whether 5-HT could have an effect on mammary cell viability in dairy cows is still unknown. The purpose of this study was to determine: (1) effect of 5-HT on the viability of bovine mammary epithelial cells and its related signaling pathways, (2) interaction between prolactin (PRL) and 5-HT on the cell viability. The bovine mammary alveolar cell-T (MAC-T) were cultured with different concentrations of 5-HT for 12, 24, 48 or 72 hours, and then were assayed using cell counting kit-8, polymerase chain reaction (PCR) and immunobloting. The results suggested that 20 μM 5-HT treatment for 12 or 24 h promote cell viability, which was mainly induced by the activation of 5-HT receptor (5-HTR) 1B and 4, because the increase caused by 5-HT vanished when 5-HTR 1B and 4 was blocked by SB224289 and SB204070. And protein expression of mammalian target of rapamycin (mTOR), eukaryotic translation elongation factor 2 (eEF2), janus kinase 2 (JAK2) and signal transducer and activator of transcription 5 (STAT5) were decreased after blocking 5-HT 1B and 4 receptors. When MAC-T cells were treated with 5-HT and PRL simultaneously for 24 h, both the cell viability and the level of mTOR protein were significantly higher than that cultured with 5-HT or PRL alone. In conclusion, our study suggested that 5-HT promotes the viability of MAC-T cells by 5-HTR 1B and/or 4. Furthermore, there is a reciprocal relationship between PRL and 5-HT.