title: A fraction of MCM 2 proteins remain associated with replication foci during a major part of S phase.
abstract: The essential role of MCM 2-7 proteins in the initiation of DNA replication in all eukaryotes is well known. Their role in replication elongation is supported by numerous studies, but there is still a knowledge gap in this respect. Even though biochemical studies have established an association of MCM proteins with replication forks, previous immunofluorescence studies in mammalian cells have suggested that MCM 2-7 proteins are displaced after replication initiation from sites of DNA replication. Therefore, we used a robust statistical method to more precisely analyse immunofluorescence localization of MCM 2 proteins with respect to the DNA replication foci. We show that despite the predominantly different localization of MCM 2 and replication signals, there is still a small but significant fraction of MCM 2 proteins that co-localize with DNA replication foci during most of S phase. The fluorescence localization of the MCM 2 proteins and DNA replication may thus reflect an active function of MCM 2 proteins associated with the replication foci and partially explain one facet of the "MCM paradox".
authors: Max Delbrück Center for Molecular Medicine, Berlin, Germany.
authors: M
authors: M
authors: Mašata
authors: P
authors: P
authors: Juda
authors: O
authors: O
authors: Raška
authors: M C
authors: MC
authors: Cardoso
authors: I
authors: I
authors: Raška
mesh_terms: D018797:Cell Cycle Proteins / Q000378:metabolism*; D002467:Cell Nucleus / Q000378:metabolism*; D002843:Chromatin / Q000378:metabolism*; D005455:Fluorescent Antibody Technique; D006367:HeLa Cells; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods; D018613:Microscopy, Confocal; D064111:Minichromosome Maintenance Complex Component 2; D009687:Nuclear Proteins / Q000378:metabolism*; D018741:Replication Origin; D016196:S Phase; D018709:Statistics, Nonparametric
chemical_list: D018797:Cell Cycle Proteins; D002843:Chromatin; D009687:Nuclear Proteins; C084859:MCM2 protein, human; D064111:Minichromosome Maintenance Complex Component 2