RT Journal Article
SR Electronic
T1 Mechanism of replication-coupled DNA-protein crosslink proteolysis by SPRTN and the proteasome
JF bioRxiv
FD Cold Spring Harbor Laboratory
SP 381889
DO 10.1101/381889
A1 Alan Gao
A1 Nicolai B. Larsen
A1 Justin L. Sparks
A1 Irene Gallina
A1 Matthias Mann
A1 Markus Räschle
A1 Johannes C. Walter
A1 Julien P. Duxin
YR 2018
UL http://biorxiv.org/content/early/2018/08/01/381889.abstract
AB DNA-protein crosslinks (DPCs) are bulky DNA lesions that interfere with DNA metabolism and therefore threaten genomic integrity. Recent studies implicate the metalloprotease SPRTN in S-phase removal of DPCs, but how SPRTN activity is coupled to DNA replication is unknown. Using Xenopus egg extracts that recapitulate replication-coupled DPC proteolysis, we show that DPCs can be degraded by SPRTN or the proteasome, which act as independent DPC proteases. Proteasome recruitment requires DPC polyubiquitylation, which is triggered by single-stranded DNA, a byproduct of DNA replication. In contrast, SPRTN-mediated DPC degradation is independent of DPC polyubiquitylation but requires polymerase extension of a nascent strand to the lesion. Thus, SPRTN and proteasome activities are coupled to DNA replication by distinct mechanisms and together promote replication across immovable protein barriers.HighlightsThe proteasome, in addition to SPRTN, degrades DPCs during DNA replicationProteasome-dependent DPC degradation requires DPC ubiquitylationDPC ubiquitylation is triggered by ssDNA and does not require the replisomeSPRTN-dependent DPC degradation is a post-replicative process