Regulation of the transcriptional activity of poised RNA polymerase II by the elongation factor ELL.
Many developmentally regulated genes contain a poised RNA polymerase II (Pol II) at their promoters under conditions where full-length transcripts are undetectable. It has been proposed that the transcriptional activity of such promoters is regulated at the elongation stage of Pol II transcription. In Drosophila, the heat-shock loci expressing the Hsp70 genes have been used as a model for the regulation of the transcriptional activity of poised Pol II. Drosophila ELL (dELL) is a Pol II elongation factor capable of stimulating the rate of transcription both in vivo and in vitro. Although ELL and the elongation factor Elongin A have indistinguishable effects on RNA polymerase in vitro, the loss-of-function studies indicate that these proteins are not redundant in vivo. In this article, we use RNAi to investigate the physiological properties of dELL and a dELL-associated factor (dEaf) in a living organism. Both ELL and Eaf are essential for fly development. dELL is recruited to heat shock loci upon induction, and its presence with Pol II at such loci is required for proper heat-shock gene expression. Consistent with a role in elongation, dELL knockdown reduces the levels of phosphorylated Pol II at heat-shock loci. This study implicates dELL in the expression of loci regulated by Pol II elongation.
Smith
Edwin R
ER
Stowers Institute for Medical Research, 1000 East 50th Street, Kansas City, MO 64110, USA.
Winter
Benjamin
B
Eissenberg
Joel C
JC
Shilatifard
Ali
A
D000818:Animals; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D029721:Drosophila Proteins / Q000235:genetics / Q000378:metabolism*; D004331:Drosophila melanogaster / Q000235:genetics / Q000378:metabolism; D005260:Female; D005786:Gene Expression Regulation; D018840:HSP70 Heat-Shock Proteins / Q000378:metabolism; D008297:Male; D008856:Microscopy, Fluorescence; D034622:RNA Interference; D012319:RNA Polymerase II / Q000378:metabolism*; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*; D014158:Transcription, Genetic
D004268:DNA-Binding Proteins; D029721:Drosophila Proteins; D018840:HSP70 Heat-Shock Proteins; C460142:Su(Tpl) protein, Drosophila; D014157:Transcription Factors; D012319:RNA Polymerase II