The establishment of a library screening method based on yeast two-hybrid system and its use to determine the potential interactions of liver proteins in ayu, Plecoglossus altivelis

Knowledge of specific protein–protein interaction (PPI) is an important component in understanding biological processes and regulatory mechanisms. A library to library screening method (LLS) was established based on yeast two-hybrid (YTH) system in this research, and applied to study the PPIs in ayu liver. In total, 23 out of 55 interaction pairs were found positive through phenotypic identification, with a positive rate of 41.8%. Of the 11 unique PPIs, 9 interactions including FGB/FGG, CaM/Spna2, C9/Apo-AI-1, α2M/Ft, RPL10/RPL5, C8α/C9, FGG/Apo-AI-1, LECT2/Tf, and Apo-AI-2/C9 were previously reported. The other two PPIs including FGG/CLR and Wap65/C3 are novel, and in vitro co-immunoprecipitation (co-IP) experiments further confirmed these interactions. FGG/CLR interaction might play a role in regulating the inflammatory response. The interaction between Wap65 and C3 hints that Wap65 might function through the complement activation pathways when microbial infection occurs.