Cell-cycle-dependent expression of human ornithine decarboxylase

✍ Scribed by Leszek Kaczmarek; Bruno Calabretta; Sergio Ferrari; Jon K. de Riel

• Publisher: John Wiley and Sons
• Year: 1987
• Tongue: English
• Weight: 751 KB
• Volume: 132
• Category: Article
• ISSN: 0021-9541
• DOI: 10.1002/jcp.1041320318

✦ Synopsis

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 densityarrested W138 fibroblasts. Following stimulation of T-lymphocyte proliferation with phytohemagglutinin, the ODC mRNA level rises to a peak around mid GI phase and decreases as t h e 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 mglml) or dexamethasone (55 nglml) stimulates ODC expression in quiescent W138 fibroblasts. Southern blots suggest that human celIs have a single copy of the ODC gene.