TY - JOUR
T1 - Replication-dependent and -independent Responses of RAD18 to DNA damage in human cells
AU - Nakajima, Satoshi
AU - Lan, Li
AU - Kanno, Shin Ichiro
AU - Usami, Noriko
AU - Kobayashi, Katsumi
AU - Mori, Masahiko
AU - Shiomi, Tadahiro
AU - Yasui, Akira
PY - 2006/11/10
Y1 - 2006/11/10
N2 - Postreplication repair facilitates tolerance of DNA damage during replication, overcoming termination of replication at sites of DNA damage. A major post-replication repair pathway in mammalian cells is translesion synthesis, which is carried out by specialized polymerase(s), such as polymerase η, and is identified by focus formation by the polymerase after irradiation with UVC light. The formation of these foci depends on RAD18, which ubiquitinates PCNA for the exchange of polymerases. To understand the initial processes in translesion synthesis, we have here analyzed the response to damage of RAD18 in human cells. We find that human RAD18 accumulates very rapidly and remains for a long period of time at sites of different types of DNA damage, including UVC light-induced lesions, and x-ray microbeam- and laser-induced single-strand breaks, in a cell cycle-independent manner. The accumulation of RAD18 at DNA damage is observed even when DNA replication is inhibited, and a small region containing a zinc finger motif located in the middle of RAD18 is essential and sufficient for the replication-independent damage accumulation. The zinc finger motif of RAD18 is not necessary for UV-induced polymerase η focus formation, but another SAP (SAF-A/B, Acinus and PIAS) motif near the zinc finger is required. These data indicate that RAD18 responds to DNA damage in two distinct ways, one replication-dependent and one replication-independent, involving the SAP and zinc finger motifs, respectively.
AB - Postreplication repair facilitates tolerance of DNA damage during replication, overcoming termination of replication at sites of DNA damage. A major post-replication repair pathway in mammalian cells is translesion synthesis, which is carried out by specialized polymerase(s), such as polymerase η, and is identified by focus formation by the polymerase after irradiation with UVC light. The formation of these foci depends on RAD18, which ubiquitinates PCNA for the exchange of polymerases. To understand the initial processes in translesion synthesis, we have here analyzed the response to damage of RAD18 in human cells. We find that human RAD18 accumulates very rapidly and remains for a long period of time at sites of different types of DNA damage, including UVC light-induced lesions, and x-ray microbeam- and laser-induced single-strand breaks, in a cell cycle-independent manner. The accumulation of RAD18 at DNA damage is observed even when DNA replication is inhibited, and a small region containing a zinc finger motif located in the middle of RAD18 is essential and sufficient for the replication-independent damage accumulation. The zinc finger motif of RAD18 is not necessary for UV-induced polymerase η focus formation, but another SAP (SAF-A/B, Acinus and PIAS) motif near the zinc finger is required. These data indicate that RAD18 responds to DNA damage in two distinct ways, one replication-dependent and one replication-independent, involving the SAP and zinc finger motifs, respectively.
UR - http://www.scopus.com/inward/record.url?scp=33845933389&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=33845933389&partnerID=8YFLogxK
U2 - 10.1074/jbc.M605545200
DO - 10.1074/jbc.M605545200
M3 - Article
C2 - 16980296
AN - SCOPUS:33845933389
VL - 281
SP - 34687
EP - 34695
JO - Journal of Biological Chemistry
JF - Journal of Biological Chemistry
SN - 0021-9258
IS - 45
ER -