An intact Mcm10 coiled-coil interaction surface is important for origin melting, helicase assembly and the recruitment of Pol-α to Mcm2–7. Issue 12 (16th May 2017)

• Record Type: Journal Article
• Authors: Perez-Arnaiz, Patricia; Bruck, Irina; Colbert, Max K.; Kaplan, Daniel L.
• Is Part Of: Nucleic acids research. Volume 45:Issue 12(2017)
• Page Start: 7261
• Page End: 7275
• Publication Date: 2017-05-16
• Subjects: Nucleic acids -- Periodicals; Molecular biology -- Periodicals; 572.805
• DOI: 10.1093/nar/gkx438
• Languages: English
• ISSNs: 0305-1048

Abstract

Abstract: Mcm10 is an essential eukaryotic factor required for DNA replication. The replication fork helicase is composed of Cdc45, Mcm2–7 and GINS (CMG). DDK is an S-phase-specific kinase required for replication initiation, and the DNA primase-polymerase in eukaryotes is pol α. Mcm10 forms oligomers in vitro, mediated by the coiled-coil domain at the N-terminal region of the protein. We characterized an Mcm10 mutant at the N-terminal Domain (NTD), Mcm10-4A, defective for self-interaction. We found that the Mcm10-4A mutant was defective for stimulating DDK phosphorylation of Mcm2, binding to eighty-nucleotide ssDNA, and recruiting pol α to Mcm2–7 in vitro . Expression of wild-type levels of mcm10-4A resulted in severe growth and DNA replication defects in budding yeast cells, with diminished DDK phosphorylation of Mcm2. We then expressed the mcm10-4A in mcm5-bob1 mutant cells to bypass the defects mediated by diminished stimulation of DDK phosphorylation of Mcm2. Expression of wild-type levels of mcm10-4A in mcm5-bob1 mutant cells resulted in severe growth and DNA replication defects, along with diminished RPA signal at replication origins. We also detected diminished GINS and pol-α recruitment to the Mcm2–7 complex. We conclude that an intact Mcm10 coiled-coil interaction surface is important for origin melting, helicase assembly, and the recruitment of pol α to Mcm2–7.