GEMC1 is a TopBP1-interacting protein required for chromosomal DNA replication

被引:83
作者
Balestrini, Alessia
Cosentino, Claudia
Errico, Alessia [1 ]
Garner, Elizabeth
Costanzo, Vincenzo [1 ]
机构
[1] London Res Inst, Cell Cycle Labs, S Mimms EN6 3LD, Herts, England
基金
欧洲研究理事会;
关键词
POLYMERASE-ALPHA; XENOPUS; INITIATION; CHROMATIN; PHOSPHORYLATION; ORIGINS; GEMININ; BINDING; CDC45; SLD3;
D O I
10.1038/ncb2050
中图分类号
Q2 [细胞生物学];
学科分类号
071009 ; 090102 ;
摘要
Many of the factors required for chromosomal DNA replication have been identified in unicellular eukaryotes. However, DNA replication is poorly understood in multicellular organisms. Here, we report the identification of GEMC1 (geminin coiled-coil containing protein 1), a novel vertebrate protein required for chromosomal DNA replication. GEMC1 is highly conserved in vertebrates and is preferentially expressed in proliferating cells. Using Xenopus laevis egg extract we show that Xenopus GEMC1 (xGEMC1) binds to the checkpoint and replication factor TopBP1, which promotes binding of xGEMC1 to chromatin during pre-replication complex (pre-RC) formation. We demonstrate that xGEMC1 interacts directly with replication factors such as Cdc45 and the kinase Cdk2-CyclinE, through which it is heavily phosphorylated. Phosphorylated xGEMC1 stimulates initiation of DNA replication, whereas depletion of xGEMC1 prevents the onset of DNA replication owing to the impairment of Cdc45 loading onto chromatin. Similarly, downregulation of GEMC1 expression prevents DNA replication in embryonic and somatic vertebrate cells. These data suggest that GEMC1 promotes initiation of chromosomal DNA replication in multicellular organisms by mediating TopBP1- and Cdk2-dependent recruitment of Cdc45 onto replication origins.
引用
收藏
页码:484 / U156
页数:20
相关论文
共 36 条
[1]   INITIATION OF DNA-REPLICATION IN NUCLEI AND PURIFIED DNA BY A CELL-FREE-EXTRACT OF XENOPUS EGGS [J].
BLOW, JJ ;
LASKEY, RA .
CELL, 1986, 47 (04) :577-587
[2]  
Chong JPJ, 1997, METHOD ENZYMOL, V283, P549
[3]  
Costanzo V, 2004, METH MOL B, V241, P255
[4]   Regulation of early events in chromosome replication [J].
Diffley, JFX .
CURRENT BIOLOGY, 2004, 14 (18) :R778-R786
[5]   THE XENOPUS CDC2 PROTEIN IS A COMPONENT OF MPF, A CYTOPLASMIC REGULATOR OF MITOSIS [J].
DUNPHY, WG ;
BRIZUELA, L ;
BEACH, D ;
NEWPORT, J .
CELL, 1988, 54 (03) :423-431
[6]   Xenopus Cut5 is essential for a CDK-dependent process in the initiation of DNA replication [J].
Hashimoto, Y ;
Takisawa, H .
EMBO JOURNAL, 2003, 22 (10) :2526-2535
[7]   A developmental timer that regulates apoptosis at the onset of gastrulation [J].
Hensey, C ;
Gautier, J .
MECHANISMS OF DEVELOPMENT, 1997, 69 (1-2) :183-195
[8]   Sld3, which interacts with Cdc45 (Sld4), functions for chromosomal DNA replication in Saccharomyces cerevisiae [J].
Kamimura, Y ;
Tak, YS ;
Sugino, A ;
Araki, H .
EMBO JOURNAL, 2001, 20 (08) :2097-2107
[9]   Techniques and probes for the study of Xenopus tropicalis development [J].
Khokha, MK ;
Chung, C ;
Bustamante, EL ;
Gaw, LWK ;
Trott, KA ;
Yeh, J ;
Lim, N ;
Lin, JCY ;
Taverner, N ;
Amaya, E ;
Papalopulu, N ;
Smith, JC ;
Zorn, AM ;
Harland, RM ;
Grammer, TC .
DEVELOPMENTAL DYNAMICS, 2002, 225 (04) :499-510
[10]   Cdk1 and Cdk2 activity levels determine the efficiency of replication origin firing in Xenopus [J].
Krasinska, Liliana ;
Besnard, Emilie ;
Cot, Emilie ;
Dohet, Christiane ;
Mechali, Marcel ;
Lemaitre, Jean-Marc ;
Fisher, Daniel .
EMBO JOURNAL, 2008, 27 (05) :758-769