Expression of carbamoyl phosphate synthetase I and ornithine transcarbamoylase genes in Chinese hamster ovary dhfr-cells decreases accumulation of ammonium ion in culture media

Hyo Soon Park, Ik Hwan Kim, Ick Young Kim, Ki Ho Kim, Hong Jin Kim

Research output: Contribution to journalArticle

32 Citations (Scopus)

Abstract

Ammonium ion accumulation in mammalian cell culture media causes toxicity which inhibits cell growth and productivity. To reduce the level of the accumulated ammonium ion, carbamoyl phosphate synthetase I (CPS I) and ornithine transcarbamoylase (OTC) were used, which catalyze the first and second steps of the urea cycle in the liver. To examine the effects of overexpressed CPS I and OTC genes on the concentration of the ammonium ion in culture media, the two genes were introduced into Chinese hamster ovary (CHO) dhfr-cells. The CPS I expressing cell lines (CPS I-CHO) and both CPS I and OTC expressing cell lines (CPS I/OTC-CHO) were confirmed at the mRNA level and analyzed in terms of the cell growth and the accumulation of ammonium ion in culture media. The accumulation of ammonium ion was ≃25-33% less in CPS I/OTC-CHO than in either CPS I-CHO or the vector-control cell lines. Interestingly however, the cell growth was ≃15-30% faster in both CPS I-CHO and CPS I/OTC-CHO than in the control cell lines. Forced expression of urea cycle enzymes in the CHO cells revealed that both the expression of CPS I and OTC can reduce the accumulation of ammonium ion in the culture media. (C) 2000 Elsevier Science B.V.

Original languageEnglish
Pages (from-to)129-140
Number of pages12
JournalJournal of Biotechnology
Volume81
Issue number2-3
DOIs
Publication statusPublished - 2000 Aug 25

Keywords

  • Ammonium ion
  • CHO cells
  • Carbamoyl phosphate synthetase
  • Ornithine transcarbamoylase
  • Urea cycle

ASJC Scopus subject areas

  • Biotechnology
  • Bioengineering
  • Applied Microbiology and Biotechnology

Fingerprint Dive into the research topics of 'Expression of carbamoyl phosphate synthetase I and ornithine transcarbamoylase genes in Chinese hamster ovary dhfr-cells decreases accumulation of ammonium ion in culture media'. Together they form a unique fingerprint.

  • Cite this