TY - JOUR
T1 - Abundance of prereplicative complexes (Pre-RCs) facilitates recombinational repair under replication stress in fission yeast
AU - Maki, Kentaro
AU - Inoue, Takahiro
AU - Onaka, Atsushi
AU - Hashizume, Hiroko
AU - Somete, Naoko
AU - Kobayashi, Yuko
AU - Murakami, Shigefumi
AU - Shigaki, Chikako
AU - Takahashi, Tatsuro S.
AU - Masukata, Hisao
AU - Nakagawa, Takuro
PY - 2011/12/2
Y1 - 2011/12/2
N2 - Mcm2-7 complexes are loaded onto chromatin with the aid of Cdt1 and Cdc18/Cdc6 and form prereplicative complexes (pre- RCs) at multiple sites on each chromosome. Pre-RCs are essential for DNA replication and surviving replication stress. However, the mechanism by which pre-RCs contribute to surviving replication stress is largely unknown. Here, we isolated the fission yeast mcm6-S1 mutant that was hypersensitive to methyl methanesulfonate (MMS) and camptothecin (CPT), both of which cause forks to collapse. The mcm6-S1 mutation impaired the interaction with Cdt1 and decreased the binding of minichromosome maintenance (MCM) proteins to replication origins. Overexpression of Cdt1 restored MCM binding and suppressed the sensitivity to MMS and CPT, suggesting that the Cdt1-Mcm6 interaction is important for the assembly of pre-RCs and the repair of collapsed forks. MMS-induced Chk1 phosphorylation and Rad22/Rad52 focus formation occurred normally, whereas cells containing Rhp54/Rad54 foci, which are involved inDNAstrand exchange and dissociation of the joint molecules, were increased. Remarkably, G 1 phase extension through deletion of an S phase cyclin, Cig2, as well as Cdt1 overexpression restored pre-RC assembly and suppressed Rhp54 accumulation. A cdc18 mutation also caused hypersensitivity to MMS and CPT and accumulation of Rhp54 foci. These data suggest that an abundance of pre-RCs facilitates a late step in the recombinational repair of collapsed forks in the following S phase.
AB - Mcm2-7 complexes are loaded onto chromatin with the aid of Cdt1 and Cdc18/Cdc6 and form prereplicative complexes (pre- RCs) at multiple sites on each chromosome. Pre-RCs are essential for DNA replication and surviving replication stress. However, the mechanism by which pre-RCs contribute to surviving replication stress is largely unknown. Here, we isolated the fission yeast mcm6-S1 mutant that was hypersensitive to methyl methanesulfonate (MMS) and camptothecin (CPT), both of which cause forks to collapse. The mcm6-S1 mutation impaired the interaction with Cdt1 and decreased the binding of minichromosome maintenance (MCM) proteins to replication origins. Overexpression of Cdt1 restored MCM binding and suppressed the sensitivity to MMS and CPT, suggesting that the Cdt1-Mcm6 interaction is important for the assembly of pre-RCs and the repair of collapsed forks. MMS-induced Chk1 phosphorylation and Rad22/Rad52 focus formation occurred normally, whereas cells containing Rhp54/Rad54 foci, which are involved inDNAstrand exchange and dissociation of the joint molecules, were increased. Remarkably, G 1 phase extension through deletion of an S phase cyclin, Cig2, as well as Cdt1 overexpression restored pre-RC assembly and suppressed Rhp54 accumulation. A cdc18 mutation also caused hypersensitivity to MMS and CPT and accumulation of Rhp54 foci. These data suggest that an abundance of pre-RCs facilitates a late step in the recombinational repair of collapsed forks in the following S phase.
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U2 - 10.1074/jbc.M111.285619
DO - 10.1074/jbc.M111.285619
M3 - Article
C2 - 21971174
AN - SCOPUS:82355171921
VL - 286
SP - 41701
EP - 41710
JO - Journal of Biological Chemistry
JF - Journal of Biological Chemistry
SN - 0021-9258
IS - 48
ER -