Localization of Cdc7 Protein Kinase During DNA Replication in Saccharomyces cerevisiae

Cdc7 kinase is known to initiate DNA replication, but it is unknown where Cdc7 is found within the genome. We modified the Calling Cards method that uses the Ty5 retrotransposon to investigate Cdc7 binding in the genome. The Ty5 retrotransposon is inserted into the genome by DNA transcription factors or replication factors binding within the genome. We find that Cdc7 inserts Ty5 transposons throughout chromosomes and furthermore creates more Ty5 insertions into regions of DNA that are known to replicate early. Cdc7 does not solely integrate Ty5 at origins or replication, but rather throughout the genome.已知Cdc7激酶（Cdc7 kinase）能够启动DNA复制，但学界尚未明确Cdc7在基因组内的具体结合分布位置。我们对基于Ty5反转录转座子（Ty5 retrotransposon）的呼叫卡片法（Calling Cards）进行了改造，以研究Cdc7在基因组内的结合情况。Ty5反转录转座子可通过基因组内结合的DNA转录因子或复制因子介导插入基因组。我们发现，Cdc7可将Ty5转座子插入整条染色体的区域中，且在已知的早期复制DNA区域内产生的Ty5插入事件更多。Cdc7并非仅在复制起点处整合Ty5转座子，而是广泛分布于整个基因组中。