title: The Replication Initiation Protein Sld3/Treslin Orchestrates the Assembly of the Replication Fork Helicase during S Phase.
abstract: The initiation of DNA replication is a highly regulated process in eukaryotic cells, and central to the process of initiation is the assembly and activation of the replication fork helicase. The replication fork helicase is comprised of CMG (Cdc45, Mcm2-7, and GINS) in eukaryotic cells, and the mechanism underlying assembly of the CMG during S phase was studied in this article. We identified a point mutation of Sld3 that is specifically defective for Mcm3 and Mcm5 interaction (sld3-m10), and also identified a point mutation of Sld3 that is specifically defective for single-stranded DNA (ssDNA) interaction (sld3-m9). Expression of wild-type levels of sld3-m9 resulted in a severe DNA replication defect with no recruitment of GINS to Mcm2-7, whereas expression of wild-type levels of sld3-m10 resulted in a severe replication defect with no Cdc45 recruitment to Mcm2-7. We propose a model for Sld3-mediated control of replication initiation, wherein Sld3 manages the proper assembly of the CMG during S phase. We also find that the biochemical functions identified for Sld3 are conserved in human Treslin, suggesting that Treslin orchestrates assembly of the CMG in human cells.
authors.affiliation: Department of Biomedical Sciences, Florida State University College of Medicine, Tallahassee, Florida 32306.
authors.forename: Irina
authors.initials: I
authors.lastname: Bruck
authors.affiliation: Department of Biomedical Sciences, Florida State University College of Medicine, Tallahassee, Florida 32306. Electronic address: Daniel.Kaplan@med.fsu.edu.
authors.forename: Daniel L
authors.initials: DL
authors.lastname: Kaplan
mesh_terms: D018797:Cell Cycle Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D004265:DNA Helicases / Q000737:chemistry* / Q000378:metabolism*; D004261:DNA Replication / Q000235:genetics; D004277:DNA, Single-Stranded / Q000378:metabolism; D006801:Humans; D064126:Minichromosome Maintenance Complex Component 3 / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D008954:Models, Biological; D017354:Point Mutation; D055503:Protein Multimerization; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D016196:S Phase / Q000235:genetics; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000254:growth & development / Q000378:metabolism
chemical_list: D018797:Cell Cycle Proteins; D004277:DNA, Single-Stranded; C066470:MCM3 protein, human; C489423:MCM5 protein, human; D011994:Recombinant Proteins; C547406:TICRR protein, human; D004265:DNA Helicases; D064126:Minichromosome Maintenance Complex Component 3
keywords: DNA helicase; DNA replication; DNA-binding protein; cell division cycle 7-related protein kinase (Cdc7); cyclin-dependent kinase (CDK)