MCM3 COMPLEX REQUIRED FOR CELL-CYCLE REGULATION OF DNA-REPLICATION IN VERTEBRATE CELLS
MCM3 COMPLEX REQUIRED FOR CELL-CYCLE REGULATION OF DNA-REPLICATION IN VERTEBRATE CELLS
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DOI：
10.1038/375421a0
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发表时间：
1995-06-01
期刊：
影响因子：
64.8
通讯作者：
LASKEY, RA
中科院分区：
文献类型：
--
作者：
MADINE, MA;KHOO, CY;LASKEY, RA
一个完整的核膜将DNA复制限制在每个细胞周期中只有一轮，显然是通过排除整个间期(1-5)的基本复制许可因素。相关的酵母复制蛋白家族MCM2、3和5(在细胞分裂周期后也称为CDC46)类似于许可因子，仅在有丝分裂(6-8)期间进入细胞核。我们克隆了非洲爪哇MCM3的同源物(XMCM3)，并提高了针对表达蛋白的抗体。非洲爪蛙卵提取物的免疫耗竭去除了MCM2、3和5同源物的复合体，并抑制了非洲爪哇精子核或可渗透的G2 HeLa核的复制。然而，G1 HeLa核仍然可以高效复制。模拟耗尽的提取物复制了所有三个模板。XMCM3在复制前在细胞核内蓄积，但在复制过程中抗XMCM3染色减弱。这些结果可以解释为什么复制的核不能在单个细胞周期内重新启动复制。
AN intact nuclear membrane restricts DNA replication to only one round in each cell cycle, apparently by excluding an essential replication-licensing factor throughout interphase(1-5). A family of related yeast replication proteins, MCM2, 3 and 5 (also called, after cell-division cycle, CDC46), resemble licensing factor, entering the nucleus only during mitosis(6-8). We have cloned a Xenopus homologue of MCM3 (XMCM3) and raised antibodies against expressed protein, Immunodepletion of Xenopus egg extracts removes a complex of MCM2, 3 and 5 homologues and inhibits replication of Xenopus sperm nuclei or permeable G2 HeLa nuclei. However, G1 HeLa nuclei still replicate efficiently. Mock-depleted extracts replicate all three templates. XMCM3 accumulates in nuclei before replication but anti-XMCM3 staining decreases during replication. These results can explain why replicated nuclei are unable to reinitiate replication in a single cell cycle.