Abstract
Resistance to environmental stress and synthesis of recombinant proteins (r-Prots) are both complex, strongly interconnected biological traits relying on orchestrated contribution of multiple genes. This, in turn, makes their engineering a challenging task. One of the possible strategies is to modify the operation of transcription factors (TFs) associated with these complex traits. The aim of this study was to examine the potential implications of selected five TFs (HSF1-YALI0E13948g, GZF1-YALI0D20482g, CRF1-YALI0B08206g, SKN7-YALI0D14520g, and YAP-like-YALI0D07744g) in stress resistance and/or r-Prot synthesis in Yarrowia lipolytica. The selected TFs were over-expressed or deleted (OE/KO) in a host strain synthesizing a reporter r-Prot. The strains were subjected to phenotype screening under different environmental conditions (pH, oxygen availability, temperature, and osmolality), and the obtained data processing was assisted by mathematical modeling. The results demonstrated that growth and the r-Prot yields under specific conditions can be significantly increased or decreased due to the TFs' engineering. Environmental factors "awakening" individual TFs were indicated, and their contribution was mathematically described. For example, OE of Yap-like TF was proven to alleviate growth retardation under high pH, while Gzf1 and Hsf1 were shown to serve as universal enhancers of r-Prot production in Y. lipolytica. On the other hand, KO of SKN7 and HSF1 disabled growth under hyperosmotic stress. This research demonstrates the usefulness of the TFs engineering approach in the manipulation of complex traits and evidences newly identified functions of the studied TFs. KEY POINTS: • Function and implication in complex traits of 5 TFs in Y. lipolytica were studied. • Gzf1 and Hsf1 are the universal r-Prots synthesis enhancers in Y. lipolytica. • Yap-like TF's activity is pH-dependent; Skn7 and Hsf1 act in osmostress response.