Proteasomal ATPases are associated with rDNA: the ubiquitin proteasome system plays a direct role in RNA polymerase I transcription.
Significant amount of data have accumulated in the last several years pointing to the essential role of the ubiquitin proteasome system in the regulation of RNA polymerase II transcription; however, its involvement in RNA polymerase I transcription has remained largely unexplored. In this study, we demonstrate that proteasome activity is required for pre-rRNA synthesis. We can detect the association of proteasomal ATPases with both the rDNA promoter and coding region. Additionally, we show that the RNA polymerase I associated transcription factor, TIF-IA interacts with proteasomal ATPases, representing a potential link via which proteasomes and/or proteasome related complexes are recruited to rRNA genes. In summary, our findings suggest that the ubiquitin proteasome system is directly involved in RNA polymerase I transcription in analogy to the RNA polymerase II system.
Fátyol
Károly
K
Division of Molecular Biology of the Cell II, German Cancer Research Center, D-69120, Heidelberg, Germany. kfatyol@hotmail.com
Grummt
Ingrid
I
D000251:Adenosine Triphosphatases / Q000378:metabolism / Q000502:physiology*; D000818:Animals; D004275:DNA, Ribosomal / Q000378:metabolism*; D019084:Fluorescent Antibody Technique, Indirect; D006801:Humans; D051379:Mice; D008954:Models, Biological; D008957:Models, Genetic; D041681:NIH 3T3 Cells; D046988:Proteasome Endopeptidase Complex / Q000378:metabolism*; D012318:RNA Polymerase I / Q000378:metabolism*; D012319:RNA Polymerase II / Q000378:metabolism; D012335:RNA, Ribosomal / Q000378:metabolism; D014158:Transcription, Genetic; D025801:Ubiquitin / Q000737:chemistry*
D004275:DNA, Ribosomal; D012335:RNA, Ribosomal; C097639:RNA, ribosomal, 19S; D025801:Ubiquitin; D012319:RNA Polymerase II; D012318:RNA Polymerase I; D046988:Proteasome Endopeptidase Complex; D000251:Adenosine Triphosphatases