Kundnani Deepali L, Yang Taehwan, Gombolay Alli L, Mukherjee Kuntal, Newnam Gary, Meers Chance, Verma Ishika, Chhatlani Kirti, Mehta Zeel H, Mouawad Celine, Storici Francesca
School of Biological Sciences, Georgia Institute of Technology, Atlanta, GA 30332, USA.
Bacterial Special Pathogens Branch, Centers for Disease Control and Prevention, Atlanta, GA 30333, USA.
iScience. 2024 May 16;27(6):110012. doi: 10.1016/j.isci.2024.110012. eCollection 2024 Jun 21.
Ribonucleoside monophosphates (rNMPs) are abundantly found within genomic DNA of cells. The embedded rNMPs alter DNA properties and impact genome stability. Mutations in ribonuclease (RNase) H2, a key enzyme for rNMP removal, are associated with the Aicardi-Goutières syndrome (AGS), a severe neurological disorder. Here, we engineered orthologs of the human RNASEH2A-G37S and RNASEH2C-R69W AGS mutations in yeast : -G42S and -K46W. Using the ribose-seq technique and the Ribose-Map bioinformatics toolkit, we unveiled rNMP abundance, composition, hotspots, and sequence context in these AGS-ortholog mutants. We found a high rNMP presence in the nuclear genome of -G42S-mutant cells, and an elevated rCMP content in both mutants, reflecting preferential cleavage of RNase H2 at rGMP. We discovered unique rNMP patterns in each mutant, showing differential activity of the AGS mutants on the leading or lagging replication strands. This study guides future research on rNMP characteristics in human genomes with AGS mutations.
核糖核苷单磷酸(rNMPs)大量存在于细胞的基因组DNA中。嵌入的rNMPs会改变DNA特性并影响基因组稳定性。核糖核酸酶(RNase)H2是去除rNMPs的关键酶,其突变与一种严重的神经疾病——艾卡迪-古铁雷斯综合征(AGS)相关。在此,我们在酵母中构建了人类RNASEH2A - G37S和RNASEH2C - R69W AGS突变的直系同源突变体:-G42S和-K46W。利用核糖测序技术和核糖图谱生物信息学工具包,我们揭示了这些AGS直系同源突变体中的rNMP丰度、组成、热点和序列背景。我们发现-G42S突变体细胞的核基因组中rNMP含量很高,且两个突变体中的rCMP含量均升高,这反映了RNase H2对rGMP的优先切割。我们在每个突变体中发现了独特的rNMP模式,表明AGS突变体在前导或滞后复制链上具有不同的活性。这项研究为未来关于具有AGS突变的人类基因组中rNMP特征的研究提供了指导。