Cell-cycle-dependent expression of human ornithine decarboxylase.
A human ornithine decarboxylase (ODC) gene probe has been isolated from a Jurkat T-cell cDNA expression library, sequenced, and used to analyze ODC mRNA levels in untransformed human lymphocytes and fibroblasts stimulated to proliferate by various mitogens. The partial cDNA sequence is 86% homologous to the mouse ODC cDNA, and Northern blots indicate that the human and mouse mRNA species are similar in size. ODC mRNA is barely detectable in quiescent human T lymphocytes and undetectable in density-arrested W138 fibroblasts. Following stimulation of T-lymphocyte proliferation with phytohemagglutinin, the ODC mRNA level rises to a peak around mid G1 phase and decreases as the cells enter S phase. Serum stimulation of density-arrested fibroblasts results in an elevation of the ODC mRNA level which persists throughout the cell cycle. Epidermal growth factor (20 ng/ml) but not insulin (10 mg/ml) or dexamethasone (55 ng/ml) stimulates ODC expression in quiescent W138 fibroblasts. Southern blots suggest that human cells have a single copy of the ODC gene.
Kaczmarek
L
L
Department of Pathology, Temple University School of Medicine, Philadelphia, Pennsylvania 19140.
Calabretta
B
B
Ferrari
S
S
de Riel
J K
JK
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D002453:Cell Cycle; D004247:DNA / Q000378:metabolism; D003907:Dexamethasone / Q000494:pharmacology; D004815:Epidermal Growth Factor / Q000494:pharmacology; D005347:Fibroblasts / Q000378:metabolism; D006801:Humans; D007328:Insulin / Q000494:pharmacology; D051379:Mice; D008969:Molecular Sequence Data; D009955:Ornithine Decarboxylase / Q000096:biosynthesis / Q000235:genetics*; D012333:RNA, Messenger / Q000378:metabolism; D013601:T-Lymphocytes / Q000378:metabolism
D007328:Insulin; D012333:RNA, Messenger; D004815:Epidermal Growth Factor; D003907:Dexamethasone; D004247:DNA; D009955:Ornithine Decarboxylase