title: Half-lives of ornithine decarboxylase and S-adenosylmethionine decarboxylase activities during the cell cycle of Chinese hamster ovary cells.
abstract: Cells in mitosis were seeded immediately after being harvested by the mitotic shake off technique from a culture of exponentially growing Chinese hamster ovary cells. At 2, 5, 7, 10, and 12 h after seeding, cycloheximide was added. Cells were sampled at various times after cycloheximide addition and the ornithine decarboxylase (ODC) and S-adenosylmethionine decarboxylase (AdoMetDC) activities were determined. Flow cytometric analysis showed that cells sampled at 2, 5, 7, 10, and 12 h after seeding were found in mid G(1), at the G(1)/S transition, in mid S phase, at the S/G(2) transition, and in late G(2), respectively. The half-lives of ODC and AdoMetDC activities varied during the cell cycle. The half-life of ODC activity showed a biphasic pattern with increases in connection to the G(1)/S and S/G(2) transitions while the half-life of AdoMetDC activity increased only at the G(1)/S transition.
authors.affiliation: Department of Animal Physiology, Lund University, Helgonavägen 3 B, Lund, SE-223 62, Sweden. Pia.Berntsson@zoofyz.lu.se
authors.forename: P S
authors.initials: PS
authors.lastname: Berntsson
authors.forename: K
authors.initials: K
authors.lastname: Alm
authors.forename: S M
authors.initials: SM
authors.lastname: Oredsson
mesh_terms: D012437:Adenosylmethionine Decarboxylase / Q000378:metabolism*; D000818:Animals; D015317:Biogenic Polyamines / Q000096:biosynthesis; D016466:CHO Cells; D002453:Cell Cycle / Q000502:physiology*; D006224:Cricetinae; D003513:Cycloheximide / Q000494:pharmacology; D016193:G1 Phase / Q000502:physiology; D016195:G2 Phase / Q000502:physiology; D006207:Half-Life; D009955:Ornithine Decarboxylase / Q000378:metabolism*; D011500:Protein Synthesis Inhibitors / Q000494:pharmacology; D016196:S Phase / Q000502:physiology
chemical_list: D015317:Biogenic Polyamines; D011500:Protein Synthesis Inhibitors; D003513:Cycloheximide; D009955:Ornithine Decarboxylase; D012437:Adenosylmethionine Decarboxylase