Transcription elongation factors are involved in programming hormone production in pituitary neuroendocrine GH4C1 cells.
Transcription elongation of many eukaryotic genes is regulated. Two negative transcription elongation factors, 5,6-dichloro-1-beta-D-ribofuranosylbenzimidazole (DRB) sensitivity-inducing factor (DSIF) and negative elongation factor (NELF) are known to stall collaboratively RNA polymerase II promoter proximally. We discovered that DSIF and NELF are linked to hormone expression in rat pituitary GH4C1 cells. When NELF-E, a subunit of NELF or Spt5, a subunit of DSIF was stably knocked-down, prolactin (PRL) expression was increased both at the mRNA and protein levels. In contrast, stable knock-down of only Spt5 abolished growth hormone (GH) expression. Transient NELF-E knock-down increased coincidentally PRL expression and enhanced transcription of a PRL-promoter reporter gene. However, no direct interaction of NELF with the PRL gene could be demonstrated by chromatin immuno-precipitation. Thus, NELF suppressed PRL promoter activity indirectly. In conclusion, transcription regulation by NELF and DSIF is continuously involved in the control of hormone production and may contribute to neuroendocrine cell differentiation.
Fujita
Toshitsugu
T
Fondation pour Recherches Médicales, Medical Faculty of the University of Geneva, Geneva, Switzerland.
Piuz
Isabelle
I
Schlegel
Werner
W
D000818:Animals; D015153:Blotting, Western; D002460:Cell Line; D002478:Cells, Cultured; D047369:Chromatin Immunoprecipitation; D004797:Enzyme-Linked Immunosorbent Assay; D017930:Genes, Reporter / Q000235:genetics; D013006:Growth Hormone / Q000235:genetics / Q000378:metabolism; D009687:Nuclear Proteins / Q000235:genetics / Q000378:metabolism*; D010903:Pituitary Gland, Anterior / Q000166:cytology / Q000378:metabolism*; D011388:Prolactin / Q000235:genetics / Q000378:metabolism; D011401:Promoter Regions, Genetic / Q000235:genetics; D034622:RNA Interference / Q000502:physiology; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D051381:Rats; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013997:Time Factors; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*; D035602:Transcriptional Elongation Factors / Q000235:genetics / Q000378:metabolism
D009687:Nuclear Proteins; D012333:RNA, Messenger; C112224:SUPT5H protein, human; D014157:Transcription Factors; D035602:Transcriptional Elongation Factors; C118437:negative elongation factor; D011388:Prolactin; D013006:Growth Hormone