Department of Biochemistry, Indian Institute of Science, Bangalore 560012, India.
Department of Biochemistry, Indian Institute of Science, Bangalore 560012, India.
Biochim Biophys Acta Gen Subj. 2021 May;1865(5):129857. doi: 10.1016/j.bbagen.2021.129857. Epub 2021 Jan 27.
DNA, the genetic material of most of the organisms, is the crucial element of life. Integrity of DNA needs to be maintained for transmission of genetic material from one generation to another. All organisms are constantly challenged by the environmental conditions which can lead to the induction of DNA damage. Ionizing radiation (IR) has been known to induce DNA damage and IR sensitivity varies among different organisms. The causes for differential radiosensitivity among various organisms have not been studied in great detail.
We discuss DNA secondary structure formation, GC content of the genome, role of G-quadruplex formation, and its relationship with radiosensitivity of the genome.
In Deinococcus radiodurans, the bacterium that exhibits maximum radio resistance, multiple G-quadruplex forming motifs are reported. In human cells, G-quadruplex formation led to differential radiosensitivity. In this article, we have discussed, the role of secondary DNA structure formation like G-quadruplex in shielding the genome from radiation and its implications in understanding evolution of radio protective effect of an organism. We also discuss role of GC content and its correlation with radio resistance.
This review provides an insight into the role of G-quadruplexes in providing differential radiosensitivity at different site of the genome and in different organisms. It further discusses the possibility of higher GC content contributing towards reduced radiosensitivity in different organisms, evolution of radiosensitivity, and regulation of multiple cellular processes.
DNA 是大多数生物体的遗传物质，是生命的关键要素。为了将遗传物质从上一代传递到下一代，需要维持 DNA 的完整性。所有生物体都不断受到环境条件的挑战，这些条件可能导致 DNA 损伤的诱导。电离辐射（IR）已被证明会引起 DNA 损伤，不同生物体的 IR 敏感性也不同。不同生物体之间差异辐射敏感性的原因尚未得到深入研究。
我们讨论了 DNA 二级结构的形成、基因组的 GC 含量、G-四链体形成的作用及其与基因组辐射敏感性的关系。
在具有最大辐射抗性的细菌 Deinococcus radiodurans 中，报告了多个 G-四链体形成基序。在人类细胞中，G-四链体的形成导致了不同的辐射敏感性。在本文中，我们讨论了二级 DNA 结构形成（如 G-四链体）在保护基因组免受辐射方面的作用及其对理解生物体辐射保护效应进化的影响。我们还讨论了 GC 含量的作用及其与辐射抗性的相关性。
该综述深入探讨了 G-四链体在不同基因组和不同生物体中不同部位提供差异辐射敏感性的作用。它进一步讨论了较高的 GC 含量在不同生物体中降低辐射敏感性的可能性、辐射敏感性的进化以及多个细胞过程的调控。
