Essential role of MCM proteins in premeiotic DNA replication.
A critical event in eukaryotic DNA replication involves association of minichromosome maintenance (MCM2-7) proteins with origins, to form prereplicative complexes (pre-RCs) that are competent for initiation. The ability of mutants defective in MCM2-7 function to complete meiosis had suggested that pre-RC components could be irrelevant to premeiotic S phase. We show here that MCM2-7 proteins bind to chromatin in fission yeast cells preparing for meiosis and during premeiotic S phase in a manner suggesting they in fact are required for DNA replication in the meiotic cycle. This is confirmed by analysis of a degron mcm4 mutant, which cannot carry out premeiotic DNA replication. Later in meiosis, Mcm4 chromatin association is blocked between meiotic nuclear divisions, presumably accounting for the absence of a second round of DNA replication. Together, these results emphasize similarity between replication mechanisms in mitotic and meiotic cell cycles.
Lindner
Karola
K
Department of Zoology, University of Oxford, Oxford, OX1 3PS United Kingdom.
Gregán
Juraj
J
Montgomery
Stuart
S
Kearsey
Stephen E
SE
D018797:Cell Cycle Proteins / Q000502:physiology*; D002843:Chromatin / Q000378:metabolism; D004261:DNA Replication / Q000502:physiology*; D004271:DNA, Fungal / Q000502:physiology; D005656:Fungal Proteins / Q000502:physiology*; D008540:Meiosis / Q000502:physiology; D011485:Protein Binding / Q000502:physiology; D016196:S Phase / Q000502:physiology; D012441:Saccharomyces cerevisiae / Q000166:cytology / Q000502:physiology*
D018797:Cell Cycle Proteins; D002843:Chromatin; D004271:DNA, Fungal; D005656:Fungal Proteins