Reversal of RNA polymerase II ubiquitylation by the ubiquitin protease Ubp3.
Mol Cell
; 30(4): 498-506, 2008 May 23.
Article
in En
| MEDLINE
| ID: mdl-18498751
ABSTRACT
The final outcome of protein polyubiquitylation is often proteasome-mediated proteolysis, meaning that "proofreading" of ubiquitylation by ubiquitin proteases (UBPs) is crucial. Transcriptional arrest can trigger ubiquitin-mediated proteolysis of RNA polymerase II (RNAPII) so a UBP reversing RNAPII ubiquitylation might be expected. Here, we show that Ubp3 deubiquitylates RNAPII in yeast. Genetic characterization of ubp3 cells is consistent with a role in elongation, and Ubp3 can be purified with RNAPII, Def1, and the elongation factors Spt5 and TFIIF. This Ubp3 complex deubiquitylates both mono- and polyubiquitylated RNAPII in vitro, and ubp3 cells have elevated levels of ubiquitylated RNAPII in vivo. Moreover, RNAPII is degraded faster in a ubp3 mutant after UV irradiation. Problems posed by damage-arrested RNAPII are thought to be resolved either by removing the damage or degrading the polymerase. In agreement with this, cells with compromised DNA repair are better equipped to survive UV damage when UPB3 is deleted.
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Endopeptidases
/
RNA Polymerase II
/
Saccharomyces cerevisiae Proteins
Limits:
Humans
Language:
En
Journal:
Mol Cell
Journal subject:
BIOLOGIA MOLECULAR
Year:
2008
Document type:
Article
Affiliation country:
United kingdom