TY - JOUR
T1 - Requirement of Rad18 protein for replication through DNA lesions in mouse and human cells
AU - Yoon, Jung Hoon
AU - Prakash, Satya
AU - Prakash, Louise
PY - 2012/5/15
Y1 - 2012/5/15
N2 - In yeast, the Rad6-Rad18 ubiquitin conjugating enzyme plays a critical role in promoting replication although DNA lesions by translesion synthesis (TLS). In striking contrast, a number of studies have indicated that TLS can occur in the absence of Rad18 in human and other mammalian cells, and also in chicken cells. In this study, we determine the role of Rad18 in TLS that occurs during replication in human and mouse cells, and show that in the absence of Rad18, replication of duplex plasmids containing a cis-syn TT dimer or a (6-4) TT photoproduct is severely inhibited in human cells and that mutagenesis resulting from TLS opposite cyclobutane pyrimidine dimers and (6-4) photoproducts formed at the TT, TC, and CC dipyrimidine sites in the chromosomal cII gene in UV-irradiated mouse cells is abolished. From these and other observations with Rad18, we conclude that the Rad6-Rad18 enzyme plays an essential role in promoting replication through DNA lesions by TLS in mammalian cells. In contrast, the dispensability of Rad18 for TLS in chicken DT40 cells would suggest that the role of the Rad6-Rad18 enzyme complex has diverged considerably between chicken and mammals, raising the possibility that TLS mechanisms differ among them.
AB - In yeast, the Rad6-Rad18 ubiquitin conjugating enzyme plays a critical role in promoting replication although DNA lesions by translesion synthesis (TLS). In striking contrast, a number of studies have indicated that TLS can occur in the absence of Rad18 in human and other mammalian cells, and also in chicken cells. In this study, we determine the role of Rad18 in TLS that occurs during replication in human and mouse cells, and show that in the absence of Rad18, replication of duplex plasmids containing a cis-syn TT dimer or a (6-4) TT photoproduct is severely inhibited in human cells and that mutagenesis resulting from TLS opposite cyclobutane pyrimidine dimers and (6-4) photoproducts formed at the TT, TC, and CC dipyrimidine sites in the chromosomal cII gene in UV-irradiated mouse cells is abolished. From these and other observations with Rad18, we conclude that the Rad6-Rad18 enzyme plays an essential role in promoting replication through DNA lesions by TLS in mammalian cells. In contrast, the dispensability of Rad18 for TLS in chicken DT40 cells would suggest that the role of the Rad6-Rad18 enzyme complex has diverged considerably between chicken and mammals, raising the possibility that TLS mechanisms differ among them.
KW - Human rad6-rad18 enzyme
KW - Lesion bypass
KW - UV damage
UR - http://www.scopus.com/inward/record.url?scp=84861215489&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84861215489&partnerID=8YFLogxK
U2 - 10.1073/pnas.1204105109
DO - 10.1073/pnas.1204105109
M3 - Article
C2 - 22547805
AN - SCOPUS:84861215489
SN - 0027-8424
VL - 109
SP - 7799
EP - 7804
JO - Proceedings of the National Academy of Sciences of the United States of America
JF - Proceedings of the National Academy of Sciences of the United States of America
IS - 20
ER -