Chromatin organization revealed by nanostructure of irradiation induced γH2AX, 53BP1 and Rad51 foci.
Chromatin organization revealed by nanostructure of irradiation induced γH2AX, 53BP1 and Rad51 foci.
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DOI：
10.1038/srep40616
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发表时间：
2017-01-17
影响因子：
4.6
通讯作者：
Dollinger G
中科院分区：
文献类型：
--
作者：
Reindl J;Girst S;Walsh DW;Greubel C;Schwarz B;Siebenwirth C;Drexler GA;Friedl AA;Dollinger G
用超分辨扫描电子显微镜研究了低、高线性能量转移(LET)照射后DSB修复因子γH_2AX、53BP1和RAD51在HeLa细胞电离辐射诱导灶中的空间分布。53BP1和γH_2AX在高LET照射后形成平均尺寸为(540 ± 40)nm的免疫荧光，而低LET照射后平均尺寸明显减小。两种修复因子的IRIF都显示出部分反相关的纳米结构。这些结构与γH2 AX标记的染色质区域内形成的结构域有关，而53BP1主要位于染色质周围区域。纳米结构的平均尺寸为(12 9 ± 6)nm，并且与所施加的LET和标记的损伤标记无关。相反，RAD51没有纳米结构，平均尺寸为(143 ± 13)nm，与LET无关。虽然RAD51被53BP1包围，但它强烈地反相关，这意味着当同源DSB修复决定发生时，53BP1被排除在DSB旁边。
The spatial distribution of DSB repair factors γH2AX, 53BP1 and Rad51 in ionizing radiation induced foci (IRIF) in HeLa cells using super resolution STED nanoscopy after low and high linear energy transfer (LET) irradiation was investigated. 53BP1 and γH2AX form IRIF with same mean size of (540 ± 40) nm after high LET irradiation while the size after low LET irradiation is significantly smaller. The IRIF of both repair factors show nanostructures with partial anti-correlation. These structures are related to domains formed within the chromatin territories marked by γH2AX while 53BP1 is mainly situated in the perichromatin region. The nanostructures have a mean size of (129 ± 6) nm and are found to be irrespective of the applied LET and the labelled damage marker. In contrast, Rad51 shows no nanostructure and a mean size of (143 ± 13) nm independent of LET. Although Rad51 is surrounded by 53BP1 it strongly anti-correlates meaning an exclusion of 53BP1 next to DSB when decision for homologous DSB repair happened.