Spt6 enhances the elongation rate of RNA polymerase II in vivo.
Several eukaryotic transcription factors have been shown to modulate the elongation rate of RNA polymerase II (Pol II) on naked or chromatin-reconstituted templates in vitro. However, none of the tested factors have been shown to directly affect the elongation rate of Pol II in vivo. We performed a directed RNAi knock-down (KD) screen targeting 141 candidate transcription factors and identified multiple factors, including Spt6, that alter the induced Hsp70 transcript levels in Drosophila S2 cells. Spt6 is known to interact with both nucleosome structure and Pol II, and it has properties consistent with having a role in elongation. Here, ChIP assays of the first wave of Pol II after heat shock in S2 cells show that KD of Spt6 reduces the rate of Pol II elongation. Also, fluorescence recovery after photobleaching assays of GFP-Pol II in salivary gland cells show that this Spt6-dependent effect on elongation rate persists during steady-state-induced transcription, reducing the elongation rate from approximately 1100 to 500 bp/min. Furthermore, RNAi depletion of Spt6 reveals its broad requirement during different stages of development.
Ardehali
M Behfar
MB
Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY 14853, USA.
Yao
Jie
J
Adelman
Karen
K
Fuda
Nicholas J
NJ
Petesch
Steven J
SJ
Webb
Watt W
WW
Lis
John T
JT
D000818:Animals; D030801:Animals, Genetically Modified; D002460:Cell Line; D002868:Chromosomal Proteins, Non-Histone / Q000235:genetics / Q000378:metabolism; D029721:Drosophila Proteins / Q000235:genetics / Q000378:metabolism*; D004331:Drosophila melanogaster / Q000235:genetics / Q000502:physiology*; D036681:Fluorescence Recovery After Photobleaching; D018840:HSP70 Heat-Shock Proteins / Q000235:genetics / Q000378:metabolism; D006360:Heat-Shock Proteins / Q000235:genetics / Q000378:metabolism; D006657:Histones / Q000378:metabolism; D010445:Peptide Elongation Factors / Q000235:genetics / Q000378:metabolism*; D034622:RNA Interference; D012319:RNA Polymerase II / Q000235:genetics / Q000378:metabolism*; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D014158:Transcription, Genetic; D035602:Transcriptional Elongation Factors / Q000235:genetics / Q000378:metabolism
D002868:Chromosomal Proteins, Non-Histone; D029721:Drosophila Proteins; D018840:HSP70 Heat-Shock Proteins; D006360:Heat-Shock Proteins; D006657:Histones; C089272:Hsp83 protein, Drosophila; D010445:Peptide Elongation Factors; D011993:Recombinant Fusion Proteins; C470423:Spt6 protein, Drosophila; D035602:Transcriptional Elongation Factors; C508976:atms protein, Drosophila; C018648:transcription factor S-II; C069940:SPT5 transcriptional elongation factor; D012319:RNA Polymerase II