FACT relieves DSIF/NELF-mediated inhibition of transcriptional elongation and reveals functional differences between P-TEFb and TFIIH.
Wada T,
Orphanides G,
Hasegawa J,
Kim DK,
Shima D,
Yamaguchi Y,
Fukuda A,
Hisatake K,
Oh S,
Reinberg D,
Handa H.
Faculty of Bioscience and Biotechnology, Tokyo Institute of Technology, Yokohama, Japan.
We report that the chromatin-specific transcription elongation factor FACT functions in conjunction with the RNA polymerase II CTD kinase P-TEFb to alleviate transcription inhibition by DSIF (DRB sensitivity-inducing factor) and NELF (negative elongation factor). We find that the kinase activity of TFIIH is dispensable for this activity, demonstrating that TFIIH-mediated CTD phosphorylation is not involved in the regulation of FACT and DSIF/NELF activities. Thus, we propose a novel transcriptional regulatory network in which DSIF/NELF inhibition of transcription is prevented by P-TEFb in cooperation with FACT. This study uncovers a novel role for FACT in the regulation of transcription on naked DNA that is independent of its activities on chromatin templates. In addition, this study reveals functional differences between P-TEFb and TFIIH in the regulation of transcription.
PMID: 10912001 [PubMed - indexed for MEDLINE]