Gene-specific recruitment of positive and negative elongation factors during stimulated transcription of the MKP-1 gene in neuroendocrine cells.
MAP kinase phosphatase-1 (MKP-1) controls nuclear MAP kinase activity with important consequences on cell growth or apoptosis. MKP-1 transcription is initiated constitutively but elongation is blocked within exon 1. It is unclear how induction of MKP-1 is controlled. Here, we report that the transcriptional elongation factors P-TEFb, DSIF and NELF regulate MKP-1 transcription in the pituitary GH4C1 cell line. Prior to stimulation, DSIF, NELF and RNA polymerase II (pol II) associate with the promoter-proximal region of the MKP-1 gene upstream of the elongation block site. Thyrotropin-releasing hormone (TRH) leads to recruitment of P-TEFb along the whole gene and a marked increase of DSIF and pol II downstream of the elongation block site, whereas NELF remains confined to the promoter-proximal region. 5,6-Dichloro-1-beta-d-ribofuranosylbenzimidazole (DRB) an inhibitor of P-TEFb eliminated TRH stimulation of MKP-1 transcription. DRB specifically inhibited TRH-induced recruitment of DSIF and P-TEFb to the MKP-1 gene. Furthermore, DRB treatment eliminated TRH-induced progression along the MKP-1 gene of pol II phosphorylated on Ser-2 of its CTD. These results indicate that P-TEFb is essential for gene-specific stimulated transcriptional elongation in mammalian cells via mechanisms which involve the activation of the DSIF-NELF complex and Ser-2 phosphorylation of pol II.
Fujita
Toshitsugu
T
Fondation pour Recherches Médicales, University of Geneva, 64 av. de la Roseraie, 1211 Geneva, Switzerland.
Ryser
Stephan
S
Tortola
Silvia
S
Piuz
Isabelle
I
Schlegel
Werner
W
D000818:Animals; D018797:Cell Cycle Proteins / Q000096:biosynthesis / Q000235:genetics*; D002460:Cell Line; D042863:Cyclin-Dependent Kinase 9 / Q000037:antagonists & inhibitors; D004004:Dichlororibofuranosylbenzimidazole / Q000494:pharmacology; D054638:Dual Specificity Phosphatase 1; D004791:Enzyme Inhibitors / Q000494:pharmacology; D015971:Gene Expression Regulation, Enzymologic / Q000187:drug effects; D017874:Immediate-Early Proteins / Q000096:biosynthesis / Q000235:genetics*; D008957:Models, Genetic; D010749:Phosphoprotein Phosphatases / Q000096:biosynthesis / Q000235:genetics*; D010902:Pituitary Gland / Q000166:cytology; D054645:Protein Phosphatase 1; D017434:Protein Structure, Tertiary; D017027:Protein Tyrosine Phosphatases / Q000096:biosynthesis / Q000235:genetics*; D012319:RNA Polymerase II / Q000737:chemistry / Q000378:metabolism; D051381:Rats; D012694:Serine / Q000378:metabolism; D013973:Thyrotropin-Releasing Hormone / Q000494:pharmacology; D014157:Transcription Factors / Q000378:metabolism; D014158:Transcription, Genetic; D015533:Transcriptional Activation / Q000187:drug effects; D035602:Transcriptional Elongation Factors / Q000037:antagonists & inhibitors / Q000378:metabolism*
D018797:Cell Cycle Proteins; D004791:Enzyme Inhibitors; D017874:Immediate-Early Proteins; D014157:Transcription Factors; D035602:Transcriptional Elongation Factors; C118437:negative elongation factor; D012694:Serine; D004004:Dichlororibofuranosylbenzimidazole; D013973:Thyrotropin-Releasing Hormone; D042863:Cyclin-Dependent Kinase 9; D012319:RNA Polymerase II; D010749:Phosphoprotein Phosphatases; D054645:Protein Phosphatase 1; D054638:Dual Specificity Phosphatase 1; C517021:Dusp1 protein, rat; D017027:Protein Tyrosine Phosphatases