A defined medium for and the effect of insulin on the growth, amino acid transport, and morphology of chinese hamster ovary cells, CHO-K1 (CCL 61) and the isolation of insulin “independent” mutants

1986 ◽  
Vol 22 (2) ◽  
pp. 66-74 ◽  
Author(s):  
Elizabeth Mendiaz ◽  
Michael Mamounas ◽  
John Moffett ◽  
Ellis Englesberg
Keyword(s):  
Amino Acid ◽  
Chinese Hamster Ovary ◽  
Amino Acid Transport ◽  
Chinese Hamster Ovary Cells ◽  
Chinese Hamster ◽  
Defined Medium ◽  
Acid Transport ◽  
Ovary Cells

scholarly journals Recessive constitutive mutant Chinese hamster ovary cells (CHO-K1) with an altered A system for amino acid transport and the mechanism of gene regulation of the A system.

1984 ◽  
Vol 4 (4) ◽  
pp. 799-808 ◽  
Author(s):  
J Moffett ◽  
E Englesberg
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Chinese Hamster Ovary ◽  
Amino Acid Transport ◽  
Actinomycin D ◽  
Chinese Hamster Ovary Cells ◽  
Chinese Hamster ◽  
Acid Transport ◽  
Ovary Cells ◽  
Proline Transport

Chinese hamster ovary cells (CHO-K1) starved for 24 h for amino acids show a severalfold increase in velocity of proline transport through the A system (Vmax is five times that of unstarved cells). This increase is inhibited by cycloheximide, actinomycin D, N-methyl-alpha-amino isobutyric acid (MeAIB, a non-metabolizable specific A system amino acid analog), and by other amino acids that are generally transported by the A system. However, transport by the A system is not a prerequisite for this repression, and all compounds that have affinity for the A system do not necessarily act as "co-repressors." The addition of proline, MeAIB, or other amino acids, as described above, to derepressed cells results in a rapid decrease in A system activity. As shown with proline and MeAIB, this decrease in activity is in part due to a rapid trans-inhibition and a slow, irreversible inactivation of the A system. Neither process is inhibited by cycloheximide or actinomycin D. Alanine antagonizes the growth of CHO-K1 pro cells by preventing proline transport, and alanine-resistant mutants (alar) have been isolated (Moffett et al., Somatic Cell Genet. 9:189-213, 1983). alar2 and alar4 are partial and full constitutive mutants for the A system and have two and six times the Vmax for proline uptake by the A system, respectively. The A system in alar4 is also immune to the co-repressor-induced inactivation. Both alar2 and alar4 phenotypes are recessive. Alar3 shows an increase in Vmax and Km for proline transport through the A system, and this phenotype is codominant. All three mutants have a pleiotropic effect, producing increases in activity of the ASC and P systems of amino acid transport. This increase is not due to an increase in the Na+ gradient. The ASC and P phenotypes behave similarly to the A system in hybrids. A model has been proposed incorporating these results.

Control of amino acid transport into Chinese hamster ovary cells

2018 ◽  
Vol 115 (12) ◽  
pp. 2908-2929 ◽  
Author(s):  
Darren Geoghegan ◽  
Claire Arnall ◽  
Diane Hatton ◽  
Joanne Noble-Longster ◽  
Christopher Sellick ◽  
...  
Keyword(s):  
Amino Acid ◽  
Chinese Hamster Ovary ◽  
Amino Acid Transport ◽  
Chinese Hamster Ovary Cells ◽  
Chinese Hamster ◽  
Acid Transport ◽  
Ovary Cells

Recessive constitutive mutant Chinese hamster ovary cells (CHO-K1) with an altered A system for amino acid transport and the mechanism of gene regulation of the A system

1984 ◽  
Vol 4 (4) ◽  
pp. 799-808
Author(s):  
J Moffett ◽  
E Englesberg
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Chinese Hamster Ovary ◽  
Amino Acid Transport ◽  
Actinomycin D ◽  
Chinese Hamster Ovary Cells ◽  
Chinese Hamster ◽  
Acid Transport ◽  
Ovary Cells ◽  
Proline Transport

Chinese hamster ovary cells (CHO-K1) starved for 24 h for amino acids show a severalfold increase in velocity of proline transport through the A system (Vmax is five times that of unstarved cells). This increase is inhibited by cycloheximide, actinomycin D, N-methyl-alpha-amino isobutyric acid (MeAIB, a non-metabolizable specific A system amino acid analog), and by other amino acids that are generally transported by the A system. However, transport by the A system is not a prerequisite for this repression, and all compounds that have affinity for the A system do not necessarily act as "co-repressors." The addition of proline, MeAIB, or other amino acids, as described above, to derepressed cells results in a rapid decrease in A system activity. As shown with proline and MeAIB, this decrease in activity is in part due to a rapid trans-inhibition and a slow, irreversible inactivation of the A system. Neither process is inhibited by cycloheximide or actinomycin D. Alanine antagonizes the growth of CHO-K1 pro cells by preventing proline transport, and alanine-resistant mutants (alar) have been isolated (Moffett et al., Somatic Cell Genet. 9:189-213, 1983). alar2 and alar4 are partial and full constitutive mutants for the A system and have two and six times the Vmax for proline uptake by the A system, respectively. The A system in alar4 is also immune to the co-repressor-induced inactivation. Both alar2 and alar4 phenotypes are recessive. Alar3 shows an increase in Vmax and Km for proline transport through the A system, and this phenotype is codominant. All three mutants have a pleiotropic effect, producing increases in activity of the ASC and P systems of amino acid transport. This increase is not due to an increase in the Na+ gradient. The ASC and P phenotypes behave similarly to the A system in hybrids. A model has been proposed incorporating these results.

Sign in / Sign up

Export Citation Format

Share Document