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Effect of growth conditions on the activity of ornithine decarboxylase in cultured hepatoma cells. I. Effect of amino acid supply
Author(s) -
Hogan Brigid L. M.,
Murden Susan
Publication year - 1974
Publication title -
journal of cellular physiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.529
H-Index - 174
eISSN - 1097-4652
pISSN - 0021-9541
DOI - 10.1002/jcp.1040830304
Subject(s) - ornithine decarboxylase , proline , glycine , amino acid , asparagine , stimulation , glutamine , biochemistry , protein turnover , ornithine decarboxylase antizyme , ornithine , serine , chemistry , enzyme , protein biosynthesis , biology , arginine , endocrinology
Ornithine decarboxylase activity in high density, stationary phase rat hepatoma (HTC) cells in suspension culture has an extremely short half‐life of between 5 and 15 minutes, as measured after inhibiting protein synthesis. Following dilution of these cells into fresh medium there is a large increase in ornithine decarboxylase activity, reaching a peak often several hundred times the initial level at about four hours. At least part of this stimulation is due to an increase in the apparent half‐life of the enzyme, to between 30 and 90 minutes. Evidence is presented that the supply of amino acids can control the turnover of ODC under some conditions. For example supplementing high density cells with glutamine, asparagine, serine, glycine and proline, either singly or together, increases ODC activity and decreases its apparent turnover. The stimulation by amino acids is enhanced by serum.