Variable pattern of jun and fos gene expression in different hematopoietic cell lines during interleukin 3-induced entry into the cell cycle.
Jun (c-jun, jun-B and jun-D) and fos (c-fos, fos-B and fra) proteins dimerize to form the family of AP-1 transcriptional activators. If each dimer exhibits unique transactivating properties, then any phenotypic change should show a characteristic pattern of jun and fos expression. To test this hypothesis we have assessed jun and fos RNA expression after stimulation of the factor-dependent cell lines 32D and FDCP1. These hematopoietic progenitor lines become quiescent in G0/G1 after interleukin 3 (IL-3) deprivation, and upon stimulation synchronously enter the cell cycle. 32D cells respond to IL-3 with rapid induction of jun-B and c-fos, followed by induction of jun-D and fra-1, but no rise in c-jun expression. FDCP1 cells show a very different pattern, with induction of c-jun, jun-D and fra-1. To investigate the response of a single cell line to different physiological stimuli we used a 32D subclone engineered to respond to colony stimulating factor 1 (CSF-1). This subclone showed identical induction of jun and fos after stimulation with either CSF-1 or IL-3. The conservation of response of a single cell line, but the disparate patterns demonstrated by different cells, suggest a fundamental difference in both the regulation and function of the fos/jun complexes in these cells.
Redner
R L
RL
Clinical Hematology Branch, NHLBI, National Institutes of Health, Bethesda, Maryland 20892.
Lee
A W
AW
Osawa
G A
GA
Nienhuis
A W
AW
D015152:Blotting, Northern; D002453:Cell Cycle / Q000187:drug effects*; D002460:Cell Line; D005786:Gene Expression Regulation / Q000187:drug effects / Q000502:physiology*; D016762:Genes, fos / Q000502:physiology*; D016758:Genes, jun / Q000502:physiology*; D007377:Interleukin-3 / Q000494:pharmacology*; D016173:Macrophage Colony-Stimulating Factor / Q000494:pharmacology*; D012313:RNA / Q000032:analysis*
D007377:Interleukin-3; D012313:RNA; D016173:Macrophage Colony-Stimulating Factor