PDF(Pubmed)
Abstract：
The CK1 family are conserved serine/threonine kinases with numerous substrates and cellular functions. The fission yeast CK1 orthologues Hhp1 and Hhp2 were first characterized as regulators of DNA repair, but the mechanism(s) by which CK1 activity promotes DNA repair had not been investigated. Here, we found that deleting Hhp1 and Hhp2 or inhibiting CK1 catalytic activities in yeast or in human cells activated the DNA damage checkpoint due to persistent double-strand breaks (DSBs). The primary pathways to repair DSBs, homologous recombination and non-homologous end joining, were both less efficient in cells lacking Hhp1 and Hhp2 activity. In order to understand how Hhp1 and Hhp2 promote DSB repair, we identified new substrates using quantitative phosphoproteomics. We confirmed that Arp8, a component of the INO80 chromatin remodeling complex, is a bona fide substrate of Hhp1 and Hhp2 that is important for DSB repair. Our data suggest that Hhp1 and Hhp2 facilitate DSB repair by phosphorylating multiple substrates, including Arp8.
摘要：
CK1家族是保守的丝氨酸/苏氨酸激酶,具有许多底物和细胞功能。裂变酵母CK1直系同源物Hhp1和Hhp2首先被表征为DNA修复的调节因子，但CK1活性促进DNA修复的机制尚未被研究。这里,我们发现，由于持续的双链断裂（DSB），在酵母或人类细胞中删除Hhp1和Hhp2或抑制CK1催化活性激活了DNA损伤检查点。修复DSB的主要途径，同源重组和非同源末端连接，在缺乏Hhp1和Hhp2活性的细胞中效率均较低。为了了解Hhp1和Hhp2如何促进DSB修复，我们使用定量磷酸化蛋白质组学鉴定了新的底物。我们证实了Arp8，INO80染色质重塑复合物的一个组成部分，是Hhp1和Hhp2的真正基底，对DSB修复很重要。我们的数据表明，Hhp1和Hhp2通过磷酸化多个底物促进DSB修复，包括Arp8。
