Lipopolysaccharide and serum synergistically stimulate ornithine decarboxylase in Chinese hamster ovary cells

In Vitro ◽  
1984 ◽  
Vol 20 (11) ◽  
pp. 876-878 ◽  
Author(s):  
Anne Rissa L. Greenfield ◽  
Steven M. Taffet ◽  
Mari K. Haddox
Keyword(s):  
Ornithine Decarboxylase ◽  
Chinese Hamster Ovary ◽  
Chinese Hamster Ovary Cells ◽  
Chinese Hamster ◽  
Ovary Cells

scholarly journals Polyamine starvation causes accumulation of cadaverine and its derivatives in a polyamine-dependent strain of Chinese-hamster ovary cells

1983 ◽  
Vol 210 (3) ◽  
pp. 945-948 ◽  
Author(s):  
E Hölttä ◽  
P Pohjanpelto
Keyword(s):  
Cell Proliferation ◽  
Ornithine Decarboxylase ◽  
Chinese Hamster Ovary ◽  
Chinese Hamster Ovary Cells ◽  
Chinese Hamster ◽  
Specific Inhibitor ◽  
Ovary Cells ◽  
Serum Free ◽  
Dependent Strain

Starvation of the polyamine-dependent Chinese-hamster ovary cells for ornithine or ornithine-derived polyamines in serum-free culture resulted in the formation of cadaverine and its aminopropyl derivatives, N-(3-aminopropyl)cadaverine and NN'-bis(3-aminopropyl)cadaverine. The synthesis of these unusual amines was inhibited by treatment of the cells with DL-2-difluoromethylornithine, a specific inhibitor of ornithine decarboxylase (EC 4.1.1.17). In the absence of ornithine (the normal substrate), ornithine decarboxylase thus appeared to catalyse the decarboxylation of lysine to cadaverine. Cell proliferation was markedly inhibited by ornithine deprivation of the cells, and further depressed by exposure of the cultures to difluoromethylornithine.

scholarly journals Polyamine-mediated turnover of ornithine decarboxylase in Chinese-hamster ovary cells

1986 ◽  
Vol 236 (2) ◽  
pp. 351-357 ◽  
Author(s):  
J R Glass ◽  
E W Gerner
Keyword(s):  
Ornithine Decarboxylase ◽  
Chinese Hamster Ovary ◽  
Specific Activity ◽  
Binding Protein ◽  
Chinese Hamster Ovary Cells ◽  
Chinese Hamster ◽  
Defined Medium ◽  
Ovary Cells ◽  
Exogenous Substrate ◽  
Polyamine Content

We have used Chinese-hamster ovary (CHO) cells maintained in a chemically defined medium to study the regulation of ornithine decarboxylase (ODC) by polyamines. Cells maintained in the defined medium had no detectable putrescine, and approx. 1-3 units of ODC activity/10(6) cells, where 1 unit corresponds to 1 nmol of substrate decarboxylated in 30 min. The defined medium is ornithine-deficient, thus limiting the exogenous substrate for ODC, and subsequently decreasing intracellular polyamine accumulation. Restoration of intracellular putrescine and increased formation of spermidine by addition of exogenous ornithine or putrescine led to a marked decrease in ODC activity, which was paralleled by a decrease in a alpha-DL-difluoromethyl[3,4-3H]ornithine (DFMO)-binding protein of Mr approx. 53,000, which is precipitable with anti-ODC antibody. Calculation of DFMO binding per unit of activity showed no change in the specific activity of the enzyme. We identified [35S]methionine-labelled peptides corresponding to ODC by immunoprecipitation of radiolabeled whole cell proteins. Only one protein was precipitated, of Mr approx. 53 000, which co-migrated with the DFMO-binding protein. Immunoprecipitation of radiolabelled proteins from cells incubated in the presence of exogenous ornithine indicated that the observed activity decrease was not due to an inhibition of ODC protein synthesis. Analysis of immunoprecipitable ODC protein from cells that had been pulse-labelled with [35S]methionine, and then treated for 5 h with 100 microM-ornithine, -putrescine or -spermidine, revealed a distinct disappearance of labelled ODC protein after restoration of intracellular polyamine pools. No detectable turnover of ODC was observed in the absence of exogenous polyamine treatment. These data support the hypothesis that ODC protein, and subsequent activity, is regulated by intracellular polyamine content through mechanisms that influence turnover of the enzyme.

Amplification and expression of heterologous ornithine decarboxylase in Chinese hamster cells

1988 ◽  
Vol 8 (2) ◽  
pp. 764-769
Author(s):  
T R Chiang ◽  
L McConlogue
Keyword(s):  
Ornithine Decarboxylase ◽  
Chinese Hamster Ovary ◽  
Chinese Hamster Ovary Cells ◽  
Chinese Hamster ◽  
Cell Types ◽  
Wild Type ◽  
Dominant Marker ◽  
Ovary Cells ◽  
Mammalian Expression ◽  
Mammalian Expression Vector

We have developed an amplifiable mammalian expression vector based on the enzyme ornithine decarboxylase (ODC). We show greater than 700-fold amplification of this vector in ODC-deficient Chinese hamster ovary cells. A passive coamplified marker, dihydrofolate reductase (dhfr), was amplified and overexpressed 1,000-fold. This ODC vector was a dominant marker in a variety of cell types and displayed at least 300-fold amplification in wild-type Chinese hamster ovary cells.

scholarly journals Amplification and expression of heterologous ornithine decarboxylase in Chinese hamster cells.

1988 ◽  
Vol 8 (2) ◽  
pp. 764-769 ◽  
Author(s):  
T R Chiang ◽  
L McConlogue
Keyword(s):  
Ornithine Decarboxylase ◽  
Chinese Hamster Ovary ◽  
Chinese Hamster Ovary Cells ◽  
Chinese Hamster ◽  
Cell Types ◽  
Wild Type ◽  
Dominant Marker ◽  
Ovary Cells ◽  
Mammalian Expression ◽  
Mammalian Expression Vector

We have developed an amplifiable mammalian expression vector based on the enzyme ornithine decarboxylase (ODC). We show greater than 700-fold amplification of this vector in ODC-deficient Chinese hamster ovary cells. A passive coamplified marker, dihydrofolate reductase (dhfr), was amplified and overexpressed 1,000-fold. This ODC vector was a dominant marker in a variety of cell types and displayed at least 300-fold amplification in wild-type Chinese hamster ovary cells.

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