Inactivation of mouse Hus1 results in genomic instability and impaired responses to genotoxic stress.
Inactivation of mouse Hus1 results in genomic instability and impaired responses to genotoxic stress.
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DOI：
10.1101/gad.14.15.1886
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发表时间：
2000-08
影响因子：
10.5
通讯作者：
Robert S. Weiss;Tamar Enoch;Philip Leder
中科院分区：
文献类型：
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作者：
Robert S. Weiss;Tamar Enoch;Philip Leder
真核细胞周期由被称为检查点的调节机制监督，该机制对DNA损伤、有丝分裂纺锤体缺陷和细胞周期事件的顺序错误做出反应。裂殖酵母Pombe的DNA复制和DNA损伤细胞周期检查点需要HUS1(+)(羟基脲敏感)基因。为了确定小鼠HUS1(+)的同源基因在小鼠发育和细胞周期检查点功能中的作用，我们对小鼠HUS1进行了靶向干扰。HUS1的失活会导致胚胎死亡，这是由于大量的细胞凋亡和必要的胚胎外组织发育缺陷所致。在HUS1缺失的胚胎中，DNA损伤诱导基因表达上调，来自HUS1缺失胚胎的原代细胞含有更多的自发染色体异常，这表明HUS1的缺失导致了基因组损伤的积累。缺乏Hus1的胚胎成纤维细胞不能在体外增殖，但p21的失活可以使Hus1缺失的细胞继续生长。Hus1(-/-)p21(-/-)细胞对羟基脲、DNA复制抑制剂和紫外线的敏感度显著增加，但对电离辐射的敏感度仅略有增加。综上所述，这些结果表明，小鼠Hus1在维持基因组稳定性方面发挥了作用，并另外确定了Hus1在介导细胞对遗传毒素的反应中具有进化保守的作用。
The eukaryotic cell cycle is overseen by regulatory mechanisms, termed checkpoints, that respond to DNA damage, mitotic spindle defects, and errors in the ordering of cell cycle events. The DNA replication and DNA damage cell cycle checkpoints of the fission yeast Schizosaccharomyces pombe require the hus1(+) (hydroxyurea sensitive) gene. To determine the role of the mouse homolog of hus1(+) in murine development and cell cycle checkpoint function, we produced a targeted disruption of mouse Hus1. Inactivation of Hus1 results in mid-gestational embryonic lethality due to widespread apoptosis and defective development of essential extra-embryonic tissues. DNA damage-inducible genes are up-regulated in Hus1-deficient embryos, and primary cells from Hus1-null embryos contain increased spontaneous chromosomal abnormalities, suggesting that loss of Hus1 leads to an accumulation of genome damage. Embryonic fibroblasts lacking Hus1 fail to proliferate in vitro, but inactivation of p21 allows for the continued growth of Hus1-deficient cells. Hus1(-/-)p21(-/-) cells display a unique profile of significantly heightened sensitivity to hydroxyurea, a DNA replication inhibitor, and ultraviolet light, but only slightly increased sensitivity to ionizing radiation. Taken together, these results indicate that mouse Hus1 functions in the maintenance of genomic stability and additionally identify an evolutionarily-conserved role for Hus1 in mediating cellular responses to genotoxins.