RRC ID 19688
Author Santosa V, Martha S, Hirose N, Tanaka K.
Title The fission yeast minichromosome maintenance (MCM)-binding protein (MCM-BP), Mcb1, regulates MCM function during prereplicative complex formation in DNA replication.
Journal J. Biol. Chem.
Abstract The minichromosome maintenance (MCM) complex is a replicative helicase, which is essential for chromosome DNA replication. In recent years, the identification of a novel MCM-binding protein (MCM-BP) in most eukaryotes has led to numerous studies investigating its function and its relationship to the MCM complex. However, the mechanisms by which MCM-BP functions and associates with MCM complexes are not well understood; in addition, the functional role of MCM-BP remains controversial and may vary between model organisms. The present study aims to elucidate the nature and biological function of the MCM-BP ortholog, Mcb1, in fission yeast. The Mcb1 protein continuously interacts with MCM proteins during the cell cycle in vivo and can interact with any individual MCM subunit in vitro. To understand the detailed characteristics of mcb1(+), two temperature-sensitive mcb1 gene mutants (mcb1(ts)) were isolated. Extensive genetic analysis showed that the mcb1(ts) mutants were suppressed by a mcm5(+) multicopy plasmid and displayed synthetic defects with many S-phase-related gene mutants. Moreover, cyclin-dependent kinase modulation by Cig2 repression or Rum1 overproduction suppressed the mcb1(ts) mutants, suggesting the involvement of Mcb1 in pre-RC formation during DNA replication. These data are consistent with the observation that Mcm7 loading onto replication origins is reduced and S-phase progression is delayed in mcb1(ts) mutants. Furthermore, the mcb1(ts) mutation led to the redistribution of MCM subunits to the cytoplasm, and this redistribution was dependent on an active nuclear export system. These results strongly suggest that Mcb1 promotes efficient pre-RC formation during DNA replication by regulating the MCM complex.
Volume 288(10)
Pages 6864-80
Published 2013-3-8
DOI 10.1074/jbc.M112.432393
PII M112.432393
PMID 23322785
PMC PMC3591596
MeSH Adaptor Proteins, Signal Transducing / genetics* Adaptor Proteins, Signal Transducing / metabolism Amino Acid Sequence Blotting, Western Cell Cycle / genetics Cell Cycle Proteins / genetics Cell Cycle Proteins / metabolism Chromosomes, Fungal / genetics* Cyclin B / genetics Cyclin B / metabolism DNA Helicases / genetics DNA Helicases / metabolism DNA Replication* DNA, Fungal / genetics DNA, Fungal / metabolism DNA-Binding Proteins / genetics DNA-Binding Proteins / metabolism Gene Expression Regulation, Fungal Luminescent Proteins / genetics Luminescent Proteins / metabolism Microscopy, Fluorescence Minichromosome Maintenance Complex Component 7 Molecular Sequence Data Mutation Nuclear Proteins / genetics* Nuclear Proteins / metabolism Protein Binding Schizosaccharomyces / genetics* Schizosaccharomyces / metabolism Schizosaccharomyces pombe Proteins / genetics* Schizosaccharomyces pombe Proteins / metabolism Sequence Homology, Amino Acid Two-Hybrid System Techniques
IF 4.106
Times Cited 6
Yeast genome library (pTN-L1)