Critical Role of Transcript Cleavage in Arabidopsis RNA Polymerase II Transcriptional Elongation
Wojciech Antosz, Jules Deforges, Kevin Begcy, Astrid Bruckmann, Yves Poirier, Thomas Dresselhaus, Klaus D. Grasser
Abstract
plants provoked severe growth defects, transcriptomic changes and massive, transcription-related redistribution of elongating RNAPII within transcribed regions toward the transcriptional start site. The predominant site of RNAPII accumulation overlapped with the +1 nucleosome, suggesting that upon inhibition of RNA cleavage activity, RNAPII arrest prevalently occurs at this position. In the presence of TFIISmut, the amount of RNAPII was reduced, which could be reverted by inhibiting the proteasome, indicating proteasomal degradation of arrested RNAPII. Our findings suggest that polymerase backtracking/arrest frequently occurs in plant cells, and RNAPII-reactivation is essential for correct transcriptional output and proper growth/development.