NELF and DSIF cause promoter proximal pausing on the hsp70 promoter in Drosophila
AUTOR(ES)
Wu, Chwen-Huey
FONTE
Cold Spring Harbor Laboratory Press
RESUMO
NELF and DSIF collaborate to inhibit elongation by RNA polymerase IIa in extracts from human cells. A multifaceted approach was taken to investigate the potential role of these factors in promoter proximal pausing on the hsp70 gene in Drosophila. Immunodepletion of DSIF from a Drosophila nuclear extract reduced the level of polymerase that paused in the promoter proximal region of hsp70. Depletion of one NELF subunit in salivary glands using RNA interference also reduced the level of paused polymerase. In vivo protein–DNA cross-linking showed that NELF and DSIF associate with the promoter region before heat shock. Immunofluorescence analysis of polytene chromosomes corroborated the cross-linking result and showed that NELF, DSIF, and RNA polymerase IIa colocalize at the hsp70 genes, small heat shock genes, and many other chromosomal locations. Finally, following heat shock induction, DSIF and polymerase but not NELF were strongly recruited to chromosomal puffs harboring the hsp70 genes. We propose that NELF and DSIF cause polymerase to pause in the promoter proximal region of hsp70. The transcriptional activator, HSF, might cause NELF to dissociate from the elongation complex. DSIF continues to associate with the elongation complex and could serve a positive role in elongation.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=196072Documentos Relacionados
- Promoter-Proximal Pausing on the hsp70 Promoter in Drosophila melanogaster Depends on the Upstream Regulator
- Nucleosomes are not necessary for promoter-proximal pausing in vitro on the Drosophila hsp70 promoter.
- Analyses of promoter-proximal pausing by RNA polymerase II on the hsp70 heat shock gene promoter in a Drosophila nuclear extract.
- Analysis of Core Promoter Sequences Located Downstream from the TATA Element in the hsp70 Promoter from Drosophila melanogaster
- Preferential deadenylation of Hsp70 mRNA plays a key role in regulating Hsp70 expression in Drosophila melanogaster.