The regulation of m6A-related proteins during whole-body freezing of the freeze-tolerant wood frog

Rana sylvatica (also known as Boreorana sylvatica) is one of the few vertebrates that spend extreme winters showing no physiological signs of life. Up to 70% of the total body water of the wood frog freezes as extracellular ice. Survival in extreme conditions requires regulation at transcriptional and translational levels to activate prosurvival pathways. N6-methyladenosine (m6A) methylation is one of the most common RNA modifications, regulating transcript processing and translation by executing important functions that affect regulatory pathways in stress conditions. In the study, regulation of m6A-related proteins in the liver of R. sylvatica was analyzed during 24 h frozen and 8 h thaw conditions. Decreases in the activity of demethylases of 28.44 + 0.4% and 24.1 + 0.9% of control values in frozen and thaw tissues, respectively, were observed. Total protein levels of m6A methyltransferase complex components methyltransferase-like 14 and Wilm's tumor associated protein were increased by 1.28-fold and 1.42-fold, respectively, during freezing. Demethylase fat mass and obesity, however, showed a decreasing trend, with a significant decrease in abundance during recovery from frozen conditions. Levels of mRNA degraders YTHDF2 and YTHDC2 also decreased under stress. Overall, increased levels of m6A methylation complex components, and suppressed levels of readers/erasers, provide evidence for the potential role of RNA methylation in freezing survival and its regulation in a hypometabolic state.

Automated summary

The regulation of m6A-related proteins in the liver of R. sylvatica during freezing and thawing conditions was analyzed. The study showed a decrease in the activity of demethylases and an increase in the total protein levels of m6A methyltransferase complex components during freezing. However, the demethylase fat mass and obesity showed a decreasing trend during recovery from frozen conditions. Levels of mRNA degraders also decreased under stress. Overall, the findings suggest the potential role of RNA methylation in freezing survival and its regulation in a hypometabolic state.