Phorbol esters and calcium ionophores differentially regulate the transcription of gamma-T-cell antigen receptor gene in human thymocytes.
The phorbol ester 12-O-tetradecanoylphorbol-13-acetate (TPA) and the calcium ionophore ionomycin differentially regulated the expression of the gamma-T-cell antigen receptor (gamma-TCR) gene in human thymocytes. Ionomycin induced an increase in gamma-TCR mRNA while TPA prevented this effect. The effects of ionomycin and TPA are completely reversed upon their removal. Protein kinase C-depleted cells are unable to respond to TPA but the induction of gamma-TCR by ionomycin was unimpaired. The regulation of gamma-TCR gene expression by TPA and ionomycin occurred at the level of gene transcription, whereas the rate of gamma-TCR mRNA degradation was unaffected by TPA or ionomycin.
Martinez-Valdez
H
H
Division of Immunology/Rheumatology, Hospital for Sick Children, Toronto, Ontario, Canada.
Thompson
E
E
Cohen
A
A
D002648:Child; D004591:Electrophoresis, Polyacrylamide Gel; D004987:Ethers / Q000494:pharmacology; D006801:Humans; D015759:Ionomycin; D009857:Oncogenes; D011493:Protein Kinase C / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism; D011948:Receptors, Antigen, T-Cell / Q000235:genetics*; D013601:T-Lymphocytes / Q000187:drug effects / Q000378:metabolism*; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology*; D014158:Transcription, Genetic / Q000187:drug effects*
D004987:Ethers; D012333:RNA, Messenger; D011948:Receptors, Antigen, T-Cell; D015759:Ionomycin; D011493:Protein Kinase C; D013755:Tetradecanoylphorbol Acetate