Prados-Carvajal Rosario, Rodriguez-Real Guillermo, Gutierrez-Pozo Gabriel, Huertas Pablo
Universidad de Sevilla-CSIC-Universidad Pablo de Olavide, Sevilla, 41092, Spain.
Departamento de Genítica, Universidad de Sevilla, Sevilla, 41080, Spain.
RNA. 2020 Dec 9;27(3):303-23. doi: 10.1261/rna.078519.120.
In order to survive to the exposure of DNA damaging agents, cells activate a complex response that coordinates the cellular metabolism, cell cycle progression and DNA repair. Among many other events, recent evidence has described global changes in mRNA splicing in cells treated with genotoxic agents. Here, we explore further this DNA damage-dependent alternative splicing. Indeed, we show that both the splicing factor SF3B2 and the repair protein CtIP contribute to the global pattern of splicing both in cells treated or not to DNA damaging agents. Additionally, we focus on a specific DNA damage- and CtIP-dependent alternative splicing event of the helicase PIF1 and explore its relevance for the survival of cells upon exposure to ionizing radiation. Indeed, we described how the nuclear, active form of PIF1 is substituted by a splicing variant, named vPIF1, in a fashion that requires both the presence of DNA damage and CtIP. Interestingly, timely expression of vPIF1 is required for optimal survival to exposure to DNA damaging agents, but early expression of this isoform delays early events of the DNA damage response. On the contrary, expression of the full length PIF1 facilitates those early events, but increases the sensitivity to DNA damaging agents if the expression is maintained long-term.
为了在暴露于DNA损伤剂的情况下存活，细胞会激活一种复杂的反应，该反应协调细胞代谢、细胞周期进程和DNA修复。在许多其他事件中，最近的证据描述了用基因毒性剂处理的细胞中mRNA剪接的全局变化。在这里，我们进一步探索这种DNA损伤依赖性可变剪接。实际上，我们表明剪接因子SF3B2和修复蛋白CtIP在处理或未处理DNA损伤剂的细胞中都对剪接的全局模式有贡献。此外，我们关注解旋酶PIF1的一种特定的DNA损伤和CtIP依赖性可变剪接事件，并探讨其在细胞暴露于电离辐射后存活中的相关性。实际上，我们描述了核内活性形式的PIF1如何被一种名为vPIF1的剪接变体取代，这种取代方式既需要DNA损伤的存在，也需要CtIP。有趣的是，vPIF1的及时表达是细胞在暴露于DNA损伤剂时实现最佳存活所必需的，但这种异构体的早期表达会延迟DNA损伤反应的早期事件。相反，全长PIF1的表达促进了这些早期事件，但如果长期维持表达，则会增加对DNA损伤剂的敏感性。
