Increased eIF-2 alpha expression in mitogen-activated primary T lymphocytes.
G0 human T cells synthesize protein at low rates and contain very low levels of eIF-2 alpha mRNA. eIF-2 alpha plays a pivotal role in the earliest regulated steps of translation initiation. We examined eIF-2 alpha gene expression in normal human T cells stimulated with PHA. Nuclear run-on assays indicate low rates of eIF-2 alpha gene transcription in G0 cells and these change 2-fold with PHA treatment. Actinomycin D chase experiments show that the t1/2 of eIF-2 alpha mRNA is similar in G0 and PHA-treated T cells. Analysis of nuclear RNA with probes specific for eIF-2 alpha intron sequences shows that increased eIF-2 alpha expression after PHA treatment is largely due to intranuclear stabilization of the primary transcript. The increase in eIF-2 alpha mRNA does not require new protein synthesis. Hence, expression of this gene appears to be a part of the primary response program of T cells when they are exposed to mitogen.
Laboratory of Molecular Hematology, National Heart, Lung and Blood Institute, National Institutes of Health, Bethesda, MD 20892.
R B
RB
Cohen
T R
TR
Boal
B
B
Safer
D002467:Cell Nucleus / Q000378:metabolism; D002478:Cells, Cultured; D015852:Eukaryotic Initiation Factor-2 / Q000235:genetics*; D006160:Guanosine Triphosphate / Q000378:metabolism; D006801:Humans; D007700:Kinetics; D008213:Lymphocyte Activation; D010835:Phytohemagglutinins / Q000494:pharmacology; D012313:RNA / Q000235:genetics / Q000302:isolation & purification; D012333:RNA, Messenger / Q000235:genetics / Q000302:isolation & purification; D013601:T-Lymphocytes / Q000276:immunology* / Q000378:metabolism; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology; D014158:Transcription, Genetic / Q000187:drug effects
D015852:Eukaryotic Initiation Factor-2; D010835:Phytohemagglutinins; D012333:RNA, Messenger; D012313:RNA; D006160:Guanosine Triphosphate; D013755:Tetradecanoylphorbol Acetate