title: Schizosaccharomyces pombe minichromosome maintenance-binding protein (MCM-BP) antagonizes MCM helicase.
abstract: The minichromosome maintenance (MCM) complex, a replicative helicase, is a heterohexamer essential for DNA duplication and genome stability. We identified Schizosaccharomyces pombe mcb1(+) (Mcm-binding protein 1), an apparent orthologue of the human MCM-binding protein that associates with a subset of MCM complex proteins. mcb1(+) is an essential gene. Deletion of mcb1(+) caused cell cycle arrest after several generations with a cdc phenotype and disrupted nuclear structure. Mcb1 is an abundant protein, constitutively present across the cell cycle. It is widely distributed in cytoplasm and nucleoplasm and bound to chromatin. Co-immunoprecipitation suggested that Mcb1 interacts robustly with Mcm3-7 but not Mcm2. Overproduction of Mcb1 disrupted the association of Mcm2 with other MCM proteins, resulting in inhibition of DNA replication, DNA damage, and activation of the checkpoint kinase Chk1. Thus, Mcb1 appears to antagonize the function of MCM helicase.
authors.affiliation: Molecular and Computational Biology Program, University of Southern California, Los Angeles, California 90089-2910, USA.
authors.forename: Lin
authors.initials: L
authors.lastname: Ding
authors.forename: Susan L
authors.initials: SL
authors.lastname: Forsburg
mesh_terms: D002352:Carrier Proteins / Q000737:chemistry / Q000378:metabolism*; D018797:Cell Cycle Proteins / Q000378:metabolism; D002843:Chromatin / Q000378:metabolism; D015825:Chromosomes, Fungal / Q000378:metabolism; D004249:DNA Damage; D004265:DNA Helicases / Q000037:antagonists & inhibitors* / Q000378:metabolism; D017353:Gene Deletion; D006801:Humans; D046912:Multiprotein Complexes / Q000378:metabolism; D021381:Protein Transport; D016196:S Phase; D012568:Schizosaccharomyces / Q000201:enzymology*; D029702:Schizosaccharomyces pombe Proteins / Q000737:chemistry / Q000378:metabolism*; D013172:Spores, Fungal / Q000378:metabolism
chemical_list: D002352:Carrier Proteins; D018797:Cell Cycle Proteins; D002843:Chromatin; D046912:Multiprotein Complexes; D029702:Schizosaccharomyces pombe Proteins; D004265:DNA Helicases; C085710:mcm2 protein, S pombe