The proteasomal de-ubiquitinating enzyme POH1 promotes the double-strand DNA break response.
The regulation of Ubiquitin (Ub) conjugates generated by the complex network of proteins that promote the mammalian DNA double-strand break (DSB) response is not fully understood. We show here that the Ub protease POH1/rpn11/PSMD14 resident in the 19S proteasome regulatory particle is required for processing poly-Ub formed in the DSB response. Proteasome activity is required to restrict tudor domain-dependent 53BP1 accumulation at sites of DNA damage. This occurs both through antagonism of RNF8/RNF168-mediated lysine 63-linked poly-Ub and through the promotion of JMJD2A retention on chromatin. Consistent with this role POH1 acts in opposition to RNF8/RNF168 to modulate end-joining DNA repair. Additionally, POH1 acts independently of 53BP1 in homologous recombination repair to promote RAD51 loading. Accordingly, POH1-deficient cells are sensitive to DNA damaging agents. These data demonstrate that proteasomal POH1 is a key de-ubiquitinating enzyme that regulates ubiquitin conjugates generated in response to damage and that several aspects of the DSB response are regulated by the proteasome.
School of Cancer Sciences, College of Medical & Dental Sciences, University of Birmingham, Birmingham, UK.
Laura R
LR
Butler
Ruth M
RM
Densham
Junying
J
Jia
Alexander J
AJ
Garvin
Helen R
HR
Stone
Vandna
V
Shah
Daniel
D
Weekes
Frederic
F
Festy
James
J
Beesley
Joanna R
JR
Morris
D002460:Cell Line; D002843:Chromatin / Q000378:metabolism; D053903:DNA Breaks, Double-Stranded; D004260:DNA Repair / Q000502:physiology*; D004268:DNA-Binding Proteins / Q000378:metabolism; D006801:Humans; D047908:Intracellular Signaling Peptides and Proteins / Q000378:metabolism; D056484:Jumonji Domain-Containing Histone Demethylases / Q000378:metabolism; D008239:Lysine / Q000378:metabolism; D025821:Polyubiquitin / Q000378:metabolism; D046988:Proteasome Endopeptidase Complex / Q000378:metabolism*; D051135:Rad51 Recombinase / Q000378:metabolism; D015534:Trans-Activators / Q000378:metabolism*; D000071857:Tumor Suppressor p53-Binding Protein 1; D044767:Ubiquitin-Protein Ligases / Q000378:metabolism
D002843:Chromatin; D004268:DNA-Binding Proteins; D047908:Intracellular Signaling Peptides and Proteins; C109285:PSMD14 protein, human; C486521:RNF8 protein, human; C498301:TP53BP1 protein, human; D015534:Trans-Activators; D000071857:Tumor Suppressor p53-Binding Protein 1; D025821:Polyubiquitin; D056484:Jumonji Domain-Containing Histone Demethylases; C494424:KDM4A protein, human; C535210:RNF168 protein, human; D044767:Ubiquitin-Protein Ligases; C495153:RAD51 protein, human; D051135:Rad51 Recombinase; D046988:Proteasome Endopeptidase Complex; D008239:Lysine