Reversal of RNA polymerase II ubiquitylation by the ubiquitin protease Ubp3.
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.
Kvint
Kristian
K
Cancer Research UK London Research Institute, Clare Hall Laboratories, Blanche Lane, South Mimms, Herts EN6 3LD, UK.
Uhler
Jay P
JP
Taschner
Michael J
MJ
Sigurdsson
Stefan
S
Erdjument-Bromage
Hediye
H
Tempst
Paul
P
Svejstrup
Jesper Q
JQ
D000963:Antimetabolites / Q000378:metabolism; D002470:Cell Survival; D004260:DNA Repair; D010450:Endopeptidases / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D012319:RNA Polymerase II / Q000235:genetics / Q000378:metabolism*; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics / Q000378:metabolism*; D035602:Transcriptional Elongation Factors / Q000235:genetics / Q000378:metabolism; D054875:Ubiquitination; D014466:Ultraviolet Rays; D014498:Uracil / Q000031:analogs & derivatives / Q000378:metabolism
D000963:Antimetabolites; D029701:Saccharomyces cerevisiae Proteins; D035602:Transcriptional Elongation Factors; D014498:Uracil; D012319:RNA Polymerase II; D010450:Endopeptidases; C101111:UBP3 protein, S cerevisiae; C100248:azauracil