Human Interaction Network Ontology

Last uploaded: June 27, 2014
Preferred Name

Cdc45 associates with the pre-replicative complex at the origin
Synonyms
Definitions

Once the Mcm2-7 complex has been assembled onto the origin of replication, the next step is the assembly of Cdc45, an essential replication protein, in late G1. The assembly of Cdc45 onto origins of replication forms a complex distinct from the pre-replicative complex, sometimes called the pre-initiation complex. The assembly of Cdc45 onto origins correlates with the time of initiation. Like the Mcm2-7 proteins, Cdc45 binds specifically to origins in the G1 phase of the cell cycle and then to non-origin DNA during S phase and is therefore thought to travel with the replication fork. Indeed, S. cerevisiae Cdc45 is required for DNA replication elongation as well as replication initiation. Cdc45 is required for the association of alpha DNA polymerase:primase with chromatin. Based on this observation and the observation that in S. cerevisiae, cCdc45 has been found in large complexes with some components of Mcm2-7 complex, it has been suggested that Cdc45 plays a scaffolding role at the replication fork, coupling Pol-alpha:primase to the replication fork through the helicase. Association of Cdc45 with origin DNA is regulated in the cell cycle and its association is dependent on the activity of cyclin-dependent kinases but not the Cdc7/Dbf4 kinase. In Xenopus egg extracts, association of Cdc45 with chromatin is dependent on Xmus101. TopBP1, the human homolog of Xmus1, is essential for DNA replication and interacts with DNA polymerase epsilon, one of the polymerases involved in replicating the genome. TopBP1 homologs have been found in S. cerevisiae and S. pombe. Sld3, an additional protein required for Cdc45 association with chromatin in S. cerevisiae and S. pombe, has no known human homolog.

ID

http://purl.obolibrary.org/obo/HINO_0014868

comment

Once the Mcm2-7 complex has been assembled onto the origin of replication, the next step is the assembly of Cdc45, an essential replication protein, in late G1. The assembly of Cdc45 onto origins of replication forms a complex distinct from the pre-replicative complex, sometimes called the pre-initiation complex. The assembly of Cdc45 onto origins correlates with the time of initiation. Like the Mcm2-7 proteins, Cdc45 binds specifically to origins in the G1 phase of the cell cycle and then to non-origin DNA during S phase and is therefore thought to travel with the replication fork. Indeed, S. cerevisiae Cdc45 is required for DNA replication elongation as well as replication initiation. Cdc45 is required for the association of alpha DNA polymerase:primase with chromatin. Based on this observation and the observation that in S. cerevisiae, cCdc45 has been found in large complexes with some components of Mcm2-7 complex, it has been suggested that Cdc45 plays a scaffolding role at the replication fork, coupling Pol-alpha:primase to the replication fork through the helicase. Association of Cdc45 with origin DNA is regulated in the cell cycle and its association is dependent on the activity of cyclin-dependent kinases but not the Cdc7/Dbf4 kinase. In Xenopus egg extracts, association of Cdc45 with chromatin is dependent on Xmus101. TopBP1, the human homolog of Xmus1, is essential for DNA replication and interacts with DNA polymerase epsilon, one of the polymerases involved in replicating the genome. TopBP1 homologs have been found in S. cerevisiae and S. pombe. Sld3, an additional protein required for Cdc45 association with chromatin in S. cerevisiae and S. pombe, has no known human homolog.

definition source

Pubmed9554851

Pubmed10757793

Pubmed11296242

Reactome, http://www.reactome.org

Pubmed7708676

Pubmed12438414

Pubmed9335335

Pubmed9660782

Pubmed11756551

Pubmed10430907

Pubmed10790374

Pubmed10518787

has input

http://purl.obolibrary.org/obo/HINO_0013902

http://purl.obolibrary.org/obo/UniProt_O75419

has output

http://purl.obolibrary.org/obo/HINO_0013788

label

Cdc45 associates with the pre-replicative complex at the origin

prefixIRI

HINO:0014868

prefLabel

Cdc45 associates with the pre-replicative complex at the origin

seeAlso

Reactome Database ID Release 4368917

ReactomeREACT_135

subClassOf

http://purl.obolibrary.org/obo/INO_0000040

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