The foci of DNA double strand break-recognition proteins localize with gammaH2AX after heat treatment.
The foci of DNA double strand break-recognition proteins localize with gammaH2AX after heat treatment.
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DOI：
10.1269/jrr.09111
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发表时间：
2010
影响因子：
2
通讯作者：
A. Takahashi;Eiichiro Mori;T. Ohnishi
中科院分区：
文献类型：
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作者：
A. Takahashi;Eiichiro Mori;T. Ohnishi
近来，已经有许多关于能够识别DNA双链断裂（DSB）的蛋白质的报道，并且这样的蛋白质包括在丝氨酸139处磷酸化的组蛋白H2 AX（gammaH 2AX），共济失调毛细血管扩张突变（ATM）磷酸丝氨酸1981，DNA依赖性蛋白激酶催化亚基（DNA-PKcs）磷酸-苏氨酸2609、奈梅亨断裂综合征1（NBS 1）磷酸-丝氨酸343、检查点激酶2（CHK 2）、磷酸-苏氨酸68和染色体1的结构维持（SMC 1）磷酸-丝氨酸966。因此，应该可以使用免疫组织化学方法与多种抗体来检测这些蛋白质来跟踪DSB的形成及其修复。当正常人成纤维细胞（AG 1522细胞）暴露于3戈伊的X射线作为对照时，检测到这些蛋白质的清晰可辨的病灶，并且这些病灶定位于γ H2 AX病灶。在45.5 ℃下热处理20分钟后，这些蛋白质部分定位于γ H2 AX焦点。在这里，我们发现，有轻微的差异，这些蛋白质之间的定位模式，如从核（磷酸ATM）和易位到细胞质（磷酸NBS 1）在热处理后30分钟的消失，和一些灶（磷酸DNA PKcs和磷酸CHK 2）出现在热处理后8小时。这些结果进行了讨论的角度，热诱导的蛋白质变性和DSB的形成。
Recently, there have been many reports concerning proteins which can recognize DNA double strand break (DSBs), and such proteins include histone H2AX phosphorylated at serine 139 (gammaH2AX), ataxia telangiectasia mutated (ATM) phospho-serine 1981, DNA-dependent protein kinase catalytic subunit (DNA-PKcs) phospho-threonine 2609, Nijmegen breakage syndrome 1 (NBS1) phospho-serine 343, checkpoint kinase 2 (CHK2), phospho-threonine 68, and structural maintenance of chromosomes 1 (SMC1) phospho-serine 966. Thus, it should be possible to follow the formation of DSBs and their repair using immunohistochemical methods with multiple antibodies to detect these proteins. When normal human fibroblasts (AG1522 cells) were exposed to 3 Gy of X-rays as a control, clearly discernable foci for these proteins were detected, and these foci localized with gammaH2AX foci. After heat treatment at 45.5 degrees C for 20 min, these proteins are partially localized with gammaH2AX foci. Here we show that there were slight differences in the localization pattern among these proteins, such as a disappearance from the nucleus (phospho-ATM) and translocation to the cytoplasm (phospho-NBS1) at 30 min after heat treatment, and some foci (phospho-DNA-PKcs and phospho-CHK2) appeared at 8 h after heat treatment. These results are discussed from perspectives of heat-induced denaturation of proteins and formation of DSBs.