Screening and identification of binding proteins to interferon-α from a cDNA library by yeast-two hybrid system

The aim of this study is to screen proteins interacting with interferon-α (IFN-α). The IFN-α gene was amplified by polymerase chain reaction (PCR) and cloned into pGBKT7 vector, then the resulted pGBKT7-IFN-α vector was transformed into yeast strain AH109. The transformed yeast AH109 was mated with yeast Y187 containing liver cDNA library plasmid in 2×YPDA medium. Diploid yeast was plated on synthetic dropout nutrient medium (SD/-Trp-Leu-His-Ade and SD/-Trp-Leu-His) containing X-α-gal for selection. After plasmid extraction and enzyme cutting analysis, the blue colonies were subjected to sequence analysis and the results were analyzed by bioinformatics. The results showed that IFN-α was successful cloned into the pGBKT7 vector. IFN-α was expressed and there was no self-activation and toxicity in AH109. Thirty-four positive colonies were obtained after yeast-two hybrid technique screening. After sequence analysis, eight clones were found to have a binding effect with IFN-α protein. IFN-α was successfully cloned into the pGBKT7 vector. IFN-α protein was expressed and there was no self-activation and toxicity in AH109. Eight proteins that interacted with IFN-α, including vitronectin, fibrinogen A alpha polypeptide, HIV-1 Tat interactive protein 2, arginase, NADH dehydrogenase 1 beta subcomplex, transferrin receptor 2 alpha (TFR2), HCC-1, alcohol dehydrogenase IB (ADH1B) have been identified as IFN-α-binding proteins.