Stress-Induced Reprogramming of tRNA Epitranscriptome in the Industrially Important Yeast Komagataella phaffii

Further supporting lysidine biology in <i>K. phaffii</i> was the identification of a putative lysidine synthase in its genome. Exposure to equitoxic doses of methyl methanesulfonate and hydrogen peroxide induced extensive and structured remodeling of tRNA modification levels in both species. Several wobble uridine modifications associated with codon-biased translation exhibited stress- and species-dependent responses, while hierarchical clustering revealed distinct modification signatures that segregated primarily by stress type and secondarily by yeast species.

Although the overall architecture of the tRNA modification system was conserved, the magnitude and direction of stress-induced remodeling differed substantially between species. These findings support a model in which conserved epitranscriptome machinery is differentially regulated to shape species-specific codon-biased translation during stress adaptation, which has implications for industrial applications of the yeast species.