Deviatiiarov Ruslan, Ayupov Rustam, Laikov Alexander, Shagimardanova Elena, Kikawada Takahiro, Gusev Oleg
Institute of Fundamental Medicine and Biology, Kazan Federal University, Kazan, Tatarstan 420008, Russia.
Department of Cell Biology, SUNY Downstate Health Sciences University, Brooklyn, NY 11203, USA.
Insects. 2020 Sep 16;11(9):634. doi: 10.3390/insects11090634.
Multiple co-localized paralogs of genes in genome have strong transcriptional response to dehydration and considered to be a part of adaptation machinery at the larvae stage. One group of such genes represented by L-isoaspartate O-methyltransferases (PIMT). In order to highlight specific role of PIMT paralogization in desiccation tolerance of the larvae we annotated and compared S-adenosylmethionine (SAM) dependent methyltransferases of four insect species. From another side we applied co-expression analysis in desiccation/rehydration time course and showed that PIMT coding genes could be separated into five clusters by expression profile. We found that among PIMTs only PIMT1 and PIMT2 have enzymatic activity in normal physiological conditions. From in silico analysis of the protein structures we found two highly variable regions outside of the active center, but also amino acid substitutions which may affect SAM stabilization. Overall, in this study we demonstrated features of PIMT coding paralogs related to different roles in desiccation tolerance of the larvae. Our results also suggest a role of different SAM-methyltransferases in the adaptation, including GSMT, JHAMT, and candidates from other classes, which could be considered in future studies.
基因组中多个共定位的基因旁系同源物对脱水具有强烈的转录反应，并被认为是幼虫阶段适应机制的一部分。一组这样的基因以L-异天冬氨酸O-甲基转移酶（PIMT）为代表。为了突出PIMT旁系同源化在幼虫耐干燥性中的特定作用，我们注释并比较了四种昆虫物种的S-腺苷甲硫氨酸（SAM）依赖性甲基转移酶。另一方面，我们在干燥/复水时间进程中进行了共表达分析，结果表明PIMT编码基因可根据表达谱分为五个簇。我们发现，在PIMT中，只有PIMT1和PIMT2在正常生理条件下具有酶活性。通过对蛋白质结构的计算机分析，我们在活性中心之外发现了两个高度可变的区域，同时也发现了可能影响SAM稳定性的氨基酸替换。总体而言，在本研究中，我们展示了PIMT编码旁系同源物在幼虫耐干燥性中不同作用的相关特征。我们的结果还表明，不同的SAM甲基转移酶在适应过程中发挥作用，包括GSMT、JHAMT以及其他类别的候选酶，这些在未来的研究中值得考虑。
