The role and regulation of the preRC component Cdc6 in the initiation of premeiotic DNA replication.
In all eukaryotes, the initiation of DNA replication is regulated by the ordered assembly of DNA/protein complexes on origins of DNA replication. In this report, we examine the role of Cdc6, a component of the prereplication complex, in the initiation of premeiotic DNA replication in budding yeast. We show that in the meiotic cycle, Cdc6 is required for DNA synthesis and sporulation. Moreover, similarly to the regulation in the mitotic cell cycle, Cdc6 is specifically degraded upon entry into the meiotic S phase. By contrast, chromatin-immunoprecipitation analysis reveals that the origin-bound Cdc6 is stable throughout the meiotic cycle. Preliminary evidence suggests that this protection reflects a change in chromatin structure that occurs in meiosis. Using the cdc28-degron allele, we show that depletion of Cdc28 leads to stabilization of Cdc6 in the mitotic cycle, but not in the meiotic cycle. We show physical association between Cdc6 and the meiosis-specific hCDK2 homolog Ime2. These results suggest that under meiotic conditions, Ime2, rather than Cdc28, regulates the stability of Cdc6. Chromatin-immunoprecipitation analysis reveals that similarly to the mitotic cell cycle, Mcm2 binds origins in G1 and meiotic S phases, and at the end of the second meiotic division, it is gradually removed from chromatin.
Ofir
Yaara
Y
Department of Biology, Technion-Israel Institute of Technology, Haifa 32000 Israel.
Sagee
Shira
S
Guttmann-Raviv
Noga
N
Pnueli
Lilach
L
Kassir
Yona
Y
D017489:CDC28 Protein Kinase, S cerevisiae / Q000235:genetics / Q000378:metabolism; D018797:Cell Cycle Proteins / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D002843:Chromatin / Q000378:metabolism; D002868:Chromosomal Proteins, Non-Histone; D004261:DNA Replication / Q000235:genetics / Q000502:physiology*; D004268:DNA-Binding Proteins; D005434:Flow Cytometry; D005656:Fungal Proteins / Q000378:metabolism; D017353:Gene Deletion; D047468:Immunoprecipitation; D047908:Intracellular Signaling Peptides and Proteins; D008540:Meiosis / Q000187:drug effects / Q000502:physiology; D008938:Mitosis / Q000187:drug effects / Q000502:physiology; D015739:Nocodazole / Q000494:pharmacology; D011485:Protein Binding; D025941:Protein Interaction Mapping; D011494:Protein Kinases / Q000235:genetics / Q000378:metabolism; D017346:Protein Serine-Threonine Kinases; D018741:Replication Origin; D012441:Saccharomyces cerevisiae / Q000235:genetics* / Q000378:metabolism / Q000502:physiology; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D020798:Two-Hybrid System Techniques
C066503:CDC6 protein, S cerevisiae; D018797:Cell Cycle Proteins; D002843:Chromatin; D002868:Chromosomal Proteins, Non-Histone; D004268:DNA-Binding Proteins; D005656:Fungal Proteins; D047908:Intracellular Signaling Peptides and Proteins; D029701:Saccharomyces cerevisiae Proteins; D011494:Protein Kinases; C064979:IME2 protein, S cerevisiae; D017346:Protein Serine-Threonine Kinases; D017489:CDC28 Protein Kinase, S cerevisiae; C069199:MCM2 protein, S cerevisiae; D015739:Nocodazole