Influence of the human cohesion establishment factor Ctf4/AND-1 on DNA replication.
Ctf4/AND-1 is a highly conserved gene product required for both DNA replication and the establishment of sister chromatid cohesion. In this report, we examined the mechanism of action of human Ctf4 (hCtf4) in DNA replication both in vitro and in vivo. Our findings show that the purified hCtf4 exists as a dimer and that the hCtf4 SepB domain likely plays a primary role determining the dimeric structure. hCtf4 binds preferentially to DNA template-primer structures, interacts directly with the replicative DNA polymerases (alpha, delta, and epsilon), and markedly stimulates the polymerase activities of DNA polymerases alpha and epsilon in vitro. Depletion of hCtf4 in HeLa cells by small interfering RNA resulted in G(1)/S phase arrest. DNA fiber analysis revealed that cells depleted of hCtf4 exhibited a rate of DNA replication slower than cells treated with control small interfering RNA. These findings suggest that in human cells, hCtf4 plays an essential role in DNA replication and its ability to stimulate the replicative DNA polymerases may contribute to this effect.
Bermudez
Vladimir P
VP
Program of Molecular Biology, Memorial Sloan-Kettering Cancer Center, New York, New York 10065.
Farina
Andrea
A
Program of Molecular Biology, Memorial Sloan-Kettering Cancer Center, New York, New York 10065.
Tappin
Inger
I
Program of Molecular Biology, Memorial Sloan-Kettering Cancer Center, New York, New York 10065.
Hurwitz
Jerard
J
Program of Molecular Biology, Memorial Sloan-Kettering Cancer Center, New York, New York 10065. Electronic address: j-hurwitz@ski.mskcc.org.
D000818:Animals; D002453:Cell Cycle; D004247:DNA / Q000737:chemistry; D004256:DNA Polymerase I / Q000378:metabolism; D004261:DNA Replication; D004268:DNA-Binding Proteins / Q000737:chemistry / Q000502:physiology*; D019281:Dimerization; D005434:Flow Cytometry / Q000379:methods; D005786:Gene Expression Regulation; D006367:HeLa Cells; D006801:Humans; D007313:Insecta; D011485:Protein Binding; D034741:RNA, Small Interfering / Q000378:metabolism; D012854:Sister Chromatid Exchange; D014157:Transcription Factors / Q000378:metabolism*
D004268:DNA-Binding Proteins; D034741:RNA, Small Interfering; D014157:Transcription Factors; C544202:WDHD1 protein, human; D004247:DNA; D004256:DNA Polymerase I