Diversity and Regulation of S-Adenosylmethionine Dependent Methyltransferases in the Anhydrobiotic Midge
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
Anhydrobiosis Research Group, Molecular Biomimetics Research Unit, Institute of Agrobiological Sciences, National Institute of Agriculture and Food Research Organization (NARO), Tsukuba 305-0851, Japan
RIKEN-KFU Translational Genomics Unit, RIKEN Cluster for Science, Technology and Innovation Hub, RIKEN, Yokohama 230-0045, Japan
Author to whom correspondence should be addressed.
Received: 29 July 2020
Revised: 10 September 2020
Accepted: 14 September 2020
Published: 16 September 2020
Adaptation to anhydrobiotic conditions of Polypedilum vanderplanki at the larval stage is accompanied by specific genome features and related regulatory mechanisms. The unusual diversity of paralogous genes located in gene clusters with a strong dehydration specific response is thought to underlie the desiccation tolerance of the insect. One of the most representative clusters consists of the gene coding protein, L-isoaspartate O-methyltransferases (PIMT), but it remains poorly characterized. In our work, by applying the transcriptomic RNA-seq approach on desiccated-rehydrated larvae, we showed that these genes have significant dissimilarities in their transcriptional activity within the group, but also in comparison with the expression profiles of other defined types of S-adenosylmethionine dependent methyltransferases active in the larvae. We also showed the standard methylation activity of two PIMTs, while the rest of the 12 tested proteins lacked an enzymatic function in normal physiological conditions. These results, together with in silico modelling, determine the heterogeneity of the group in terms of its role in the adaptation to anhydrobiosis.