Mcm10 and And-1/CTF4 recruit DNA polymerase alpha to chromatin for initiation of DNA replication.
The MCM2-7 helicase complex is loaded on DNA replication origins during the G1 phase of the cell cycle to license the origins for replication in S phase. How the initiator primase-polymerase complex, DNA polymerase alpha (pol alpha), is brought to the origins is still unclear. We show that And-1/Ctf4 (Chromosome transmission fidelity 4) interacts with Mcm10, which associates with MCM2-7, and with the p180 subunit of DNA pol alpha. And-1 is essential for DNA synthesis and the stability of p180 in mammalian cells. In Xenopus egg extracts And-1 is loaded on the chromatin after Mcm10, concurrently with DNA pol alpha, and is required for efficient DNA synthesis. Mcm10 is required for chromatin loading of And-1 and an antibody that disrupts the Mcm10-And-1 interaction interferes with the loading of And-1 and of pol alpha, inhibiting DNA synthesis. And-1/Ctf4 is therefore a new replication initiation factor that brings together the MCM2-7 helicase and the DNA pol alpha-primase complex, analogous to the linker between helicase and primase or helicase and polymerase that is seen in the bacterial replication machinery. The discovery also adds to the connection between replication initiation and sister chromatid cohesion.
Zhu
Wenge
W
Department of Biochemistry and Molecular Genetics, University of Virginia School of Medicine, Charlottesville, VA 22908, USA.
Ukomadu
Chinweike
C
Jha
Sudhakar
S
Senga
Takeshi
T
Dhar
Suman K
SK
Wohlschlegel
James A
JA
Nutt
Leta K
LK
Kornbluth
Sally
S
Dutta
Anindya
A
D000818:Animals; D018797:Cell Cycle Proteins / Q000378:metabolism* / Q000502:physiology; D002478:Cells, Cultured; D002843:Chromatin / Q000378:metabolism*; D004256:DNA Polymerase I / Q000378:metabolism* / Q000502:physiology; D004261:DNA Replication / Q000502:physiology*; D004268:DNA-Binding Proteins / Q000378:metabolism* / Q000502:physiology; D045325:HCT116 Cells; D006801:Humans; D064110:Minichromosome Maintenance Proteins; D008954:Models, Biological; D011485:Protein Binding; D018411:Spodoptera; D014981:Xenopus; D029867:Xenopus Proteins / Q000378:metabolism* / Q000502:physiology
D018797:Cell Cycle Proteins; D002843:Chromatin; D004268:DNA-Binding Proteins; C489613:MCM10 protein, human; C106931:WDHD1 protein, Xenopus; D029867:Xenopus Proteins; D004256:DNA Polymerase I; D064110:Minichromosome Maintenance Proteins