RNA polymerase II accumulation in the promoter-proximal region of the dihydrofolate reductase and gamma-actin genes.
The carboxyl-terminal domain (CTD) of RNA polymerase II (Pol II) can be phosphorylated at serine 2 (Ser-2) and serine 5 (Ser-5) of the CTD heptad repeat YSPTSPS, and this phosphorylation is important in coupling transcription to RNA processing, including 5' capping, splicing, and polyadenylation. The mammalian endogenous dihydrofolate reductase and gamma-actin genes have been used to study the association of Pol II with different regions of transcribed genes (promoter-proximal compared to distal regions) and the phosphorylation status of its CTD. For both genes, Pol II is more concentrated in the promoter-proximal regions than in the interior regions. Moreover, different phosphorylation forms of Pol II are associated with distinct regions. Ser-5 phosphorylation of Pol II is concentrated near the promoter, while Ser-2 phosphorylation is observed throughout the gene. These results suggest that the accumulation of paused Pol II in promoter-proximal regions may be a common feature of gene regulation in mammalian cells.
Cheng
Chonghui
C
Center for Cancer Research, Massachusetts Institute of Technology, Cambridge, MA 02139-4307, USA.
Sharp
Phillip A
PA
D000199:Actins / Q000235:genetics*; D002843:Chromatin / Q000378:metabolism / Q000648:ultrastructure; D006367:HeLa Cells; D006801:Humans; D009363:Neoplasm Proteins / Q000378:metabolism; D010766:Phosphorylation; D011401:Promoter Regions, Genetic; D011499:Protein Processing, Post-Translational; D017434:Protein Structure, Tertiary; D012319:RNA Polymerase II / Q000737:chemistry / Q000378:metabolism*; D013762:Tetrahydrofolate Dehydrogenase / Q000235:genetics*; D014158:Transcription, Genetic
D000199:Actins; D002843:Chromatin; D009363:Neoplasm Proteins; D013762:Tetrahydrofolate Dehydrogenase; D012319:RNA Polymerase II