Conditional expression of RNA polymerase II in mammalian cells. Deletion of the carboxyl-terminal domain of the large subunit affects early steps in transcription.
The carboxyl-terminal domain (CTD) of the large subunit of mammalian RNA polymerase II contains 52 repeats of a heptapeptide that is the target of a variety of kinases. The hyperphosphorylated CTD recruits important factors for mRNA capping, splicing, and 3'-processing. The role of the CTD for the transcription process in vivo, however, is not yet clear. We have conditionally expressed an alpha-amanitin-resistant large subunit with an almost entirely deleted CTD (LS*Delta5) in B-cells. These cells have a defect in global transcription of cellular genes in the presence of alpha-amanitin. Moreover, pol II harboring LS*Delta5 failed to transcribe up to the promoter-proximal pause sites in the hsp70A and c-fos gene promoters. The results indicate that the CTD is already required for steps that occur before promoter-proximal pausing and maturation of mRNA.
Meininghaus
M
M
Institute for Clinical Molecular Biology and Tumor Genetics, GSF-Research Center for Environment and Health, Marchioninistrasse 25, D-81377 Munich, Germany.
Chapman
R D
RD
Horndasch
M
M
Eick
D
D
D020413:3' Untranslated Regions / Q000235:genetics; D000546:Amanitins / Q000494:pharmacology; D000818:Animals; D002051:Burkitt Lymphoma; D003001:Cloning, Molecular; D016762:Genes, fos; D018840:HSP70 Heat-Shock Proteins / Q000235:genetics; D006801:Humans; D046911:Macromolecular Substances; D051379:Mice; D010766:Phosphorylation; D011401:Promoter Regions, Genetic; D012319:RNA Polymerase II / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D012326:RNA Splicing; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D017384:Sequence Deletion; D014158:Transcription, Genetic; D014407:Tumor Cells, Cultured
D020413:3' Untranslated Regions; D000546:Amanitins; D018840:HSP70 Heat-Shock Proteins; D046911:Macromolecular Substances; D011994:Recombinant Proteins; D012319:RNA Polymerase II