Induction of interleukin-2 receptor-alpha gene expression is regulated by post-translational activation of kappa B specific DNA binding proteins.
T cell mitogens induce the expression of specific trans-acting DNA binding proteins that in turn regulate the expression of the interleukin-2 receptor-alpha (IL-2R alpha) gene. To investigate whether de novo protein synthesis is required for the activation of these transacting factors and the induced expression of this receptor gene, Jurkat T cells were incubated with various inhibitors of protein synthesis prior to stimulation with phytohemagglutinin and phorbol 12-myristate 13-acetate (PMA). Despite the presence of cycloheximide or anisomycin at concentrations sufficient to block greater than 97% of cellular protein synthesis, phytohemagglutinin and phorbol 12-myristate 13-acetate effectively induced the expression of the IL-2R alpha gene as measured at the mRNA level. Similarly, gel retardation, DNA footprinting, and DNA-protein cross-linking studies revealed that these mitogens induced the activation of two predominant DNA binding proteins (50-55 and 80-90 kDa) in the presence or absence of cycloheximide and anisomycin. Both of these proteins specifically interacted with a kappa B-like binding site present in the IL-2R alpha promoter (-267 to -256) that is requisite for mitogen-induced expression of this receptor gene. These findings support a post-translational mechanism of induction of pre-existing, but inactive, DNA binding proteins which in turn bind to and activate the IL-2R alpha gene.
Böhnlein
E
E
Howard Hughes Medical Institute, Department of Medicine, Duke University Medical Center, Durham, North Carolina 27710.
Ballard
D W
DW
Bogerd
H
H
Peffer
N J
NJ
Lowenthal
J W
JW
Greene
W C
WC
D015152:Blotting, Northern; D002460:Cell Line; D004268:DNA-Binding Proteins / Q000235:genetics*; D005786:Gene Expression Regulation / Q000187:drug effects; D005796:Genes; D006801:Humans; D007376:Interleukin-2 / Q000378:metabolism*; D008213:Lymphocyte Activation; D009687:Nuclear Proteins / Q000378:metabolism; D011499:Protein Processing, Post-Translational; D011500:Protein Synthesis Inhibitors / Q000494:pharmacology; D015375:Receptors, Interleukin-2 / Q000096:biosynthesis / Q000235:genetics*; D013601:T-Lymphocytes; D014158:Transcription, Genetic
D004268:DNA-Binding Proteins; D007376:Interleukin-2; D009687:Nuclear Proteins; D011500:Protein Synthesis Inhibitors; D015375:Receptors, Interleukin-2