• 약학회지
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• 제51권3호
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• pp.214-218
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• 2007

In the previous reports, we developed the CO5 by introducing genes for the first and second urea cycle enzymes, carbamoyl phosphate synthetase I (CPS I) and ornithine transcarbamoylase (OTC) into the IBE cell lines producing erythropoietin (EPO). The CO5 have been found out to have 15-20% higher cell growth rate and produce 2-times more EPO than the parental cell line, IBE. To investigate the role of CPS I in CO5 cell line for the cell growth and amount of EPO, we knock-downed CPS I gene expression via siRNA treatment. Expression level of EPO in cell lysate of CO5 was 3-5 fold higher than that of IBE. After siRNA treatment, the cell growth of CO5 was decreased 8-21% and the EPO productivity in the cell Iysate was significantly decreased. However, these changes of the cell growth and EPO productivity were not observed in IBE. These results indicate that CPS I gene expression is important for the increased cell growth and EPO productivity of CO5 cell line.

• 대한유전성대사질환학회지
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• 제18권1호
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• pp.18-22
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• 2018

Carbamoyl phosphate synthetase I (CPS1) 결핍은 상염색체 열성 유전을 하는 드문 요소회로 대사 이상 질환으로, 요소회로의 첫번째 단계 효소인 CPS1 결핍에 의해 고암모니아혈증이 발생하여 신경학적 이상을 초래하게 되는 질환이다. CPS1 결핍은 신생아기부터 성인까지 여러 시기에 발현될 수 있으나, 주로 신생아기에 증상이 발현하고, 신생아기에 증상이 발생할 경우 치명적인 고암모니아혈증이 발생하여 예후가 불량하여 사망에 이를 수 있다. 본 증례는 고암모니아혈증이 발견되어 투석 및 집중 치료하였음에도 심한 뇌손상이 빠르게 진행되어 사망한 신생아로, CPS1 유전자의 동종 접합자 변이를 확인하여 확진 되었으며 이후 시행한 가족 검사에서 부모와 생존한 자매가 모두 이종 접합자 보인자로 확인되어 보고하는 바이다.

• Journal of Microbiology and Biotechnology
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• 제14권4호
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• pp.844-851
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• 2004

Efficient mammalian erythropoietin (EPO)-expression systems are required for therapeutic applications. The accumulation of ammonia is a major problem in the production of recombinant proteins in cultured animal cells. To counter this problem we introduced the first two genes of the urea cycle, carbamoyl phosphate synthetase (CPSI) and ornithine transcarbamylase (OTC), into IBE Chinese Hamster Ovary (CHO) cells by stable transfection. The resulting cell line, CO5, had a higher growth rate and accumulated less ammonia per cell than the parental cell line, IBE. In addition, it produced 2 times more EPO than the parent, and the purified EPO contained a higher proportion of acidic isoforms with approximately 15% more sialic acid.

• BMB Reports
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• 제38권1호
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• pp.28-33
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• 2005

A gene coding a novel isoform of carbamyl phosphate synthetase I (CPS1) was cloned from a human testicular library. As shown by cDNA microarray hybridization, this gene was expressed at a higher level in human adult testes than in fetal testes. The full length of its cDNA was 3831 bp, with a 3149 bp open reading frame, encoding a 1050-amino-acid protein. The cDNA sequence was deposited in the GenBank (AY317138). Sequence analysis showed that it was homologous to the human CPS1 gene. The putative protein contained functional domains composing the intact large subunit of carbamoyl phosphate synthetase, thus indicated it has the capability of arginine biosynthesis. A multiple tissue expression profile showed high expression of this gene in human testis, suggesting the novel alternative splicing form of CPS1 may be correlated with human spermatogenesis.

• Archives of Pharmacal Research
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• 제28권2호
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• pp.220-226
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• 2005

Temperature and medium composition were changed with the aim of increasing growth and erythropoietin (EPO) production in EPO-producing Chinese hamster ovary (CHO) cells. We used the CHO cell line, IBE, and its derivative, CO5, which over-expresses the first two enzymes of the urea cycle, carbamoyl phosphate synthetase I (CPS I) and ornithine transcar-bamoylase (OTC). When supplements were added to the medium at $33\;^{\circ}C$, the growth of IBE and CO5 cells increased by $27\%\;and;26\%$, respectively and the maximum yield of EPO was increased by $40\%$ in both cell lines. The absolute EPO concentration in the CO5 cells was always $55{\sim}60\%$ higher than in the IBE cells. In addition, when the two cell lines were continuously cultured with supplements at $33\;^{\circ}C$ until their growth rates approached those at $37\;^{\circ}C$, the growth rates of both IBE and CO5 cells increased by $54\%$ and their maximum EPO levels increased by up to $73\%\;and\;56\%$, respectively. Therefore, the growth and EPO expression levels of CO5 cells increased 2.2-fold and 2.6-fold, respectively, compared to those of the IBE cells. These results indicate that adaptation to lower temperature as well as medium supplementation could be important for improving cell growth and EPO production.