DNA polymerase epsilon associates with the elongating form of RNA polymerase II and nascent transcripts.
DNA polymerase epsilon co-operates with polymerases alpha and delta in the replicative DNA synthesis of eukaryotic cells. We describe here a specific physical interaction between DNA polymerase epsilon and RNA polymerase II, evidenced by reciprocal immunoprecipitation experiments. The interacting RNA polymerase II was the hyperphosphorylated IIO form implicated in transcriptional elongation, as inferred from (a) its reduced electrophoretic mobility that was lost upon phosphatase treatment, (b) correlation of the interaction with phosphorylation of Ser5 of the C-terminal domain heptapeptide repeat, and (c) the ability of C-terminal domain kinase inhibitors to abolish it. Polymerase epsilon was also shown to UV crosslink specifically alpha-amanitin-sensitive transcripts, unlike DNA polymerase alpha that crosslinked only to RNA-primed nascent DNA. Immunofluorescence microscopy revealed partial colocalization of RNA polymerase IIO and DNA polymerase epsilon, and immunoelectron microscopy revealed RNA polymerase IIO and DNA polymerase epsilon in defined nuclear clusters at various cell cycle stages. The RNA polymerase IIO-DNA polymerase epsilon complex did not relocalize to specific sites of DNA damage after focal UV damage. Their interaction was also independent of active DNA synthesis or defined cell cycle stage.
Rytkönen
Anna K
AK
Biocenter Oulu and Department of Biochemistry, University of Oulu, Finland.
Hillukkala
Tomi
T
Vaara
Markku
M
Sokka
Miiko
M
Jokela
Maarit
M
Sormunen
Raija
R
Nasheuer
Heinz-Peter
HP
Nethanel
Tamar
T
Kaufmann
Gabriel
G
Pospiech
Helmut
H
Syväoja
Juhani E
JE
D045744:Cell Line, Tumor; D002467:Cell Nucleus / Q000737:chemistry / Q000378:metabolism*; D004247:DNA / Q000096:biosynthesis; D004257:DNA Polymerase II / Q000032:analysis / Q000378:metabolism* / Q000528:radiation effects; D004260:DNA Repair; D004261:DNA Replication / Q000235:genetics; D006367:HeLa Cells; D006801:Humans; D010766:Phosphorylation; D011485:Protein Binding / Q000235:genetics / Q000528:radiation effects; D020033:Protein Isoforms / Q000378:metabolism; D012313:RNA / Q000378:metabolism* / Q000528:radiation effects; D012319:RNA Polymerase II / Q000032:analysis / Q000378:metabolism*; D014158:Transcription, Genetic; D014466:Ultraviolet Rays
D020033:Protein Isoforms; D012313:RNA; D004247:DNA; D012319:RNA Polymerase II; D004257:DNA Polymerase II