Figure 2

Hairy1 and Sap18 protein interaction evaluated by the yeast two-hybrid assay. Baits were expressed as Gal4 DNA-BD fusion proteins in the pGBKT7 plasmid and transformed into the Y187 yeast strain; preys were expressed as Gal4 AD fusion proteins in pGADT7 vector and transformed into the AH109 strain. Bait- and prey-transformed strains were mated and the resulting diploids were cultured in SD-Leu/-Trp medium, selecting for the presence of both plasmids and also in SD-Leu/-Trp/-His/-Ade/X-α-gal medium, were only the diploids presenting protein interactions are capable of growth. 20-fold serial dilutions were performed prior to colony plating to ensure growth on the selective medium is dependent solely on HIS3, ADE2 and MEL1 reporter gene expression. β-galactosidase activity was assayed for each strain and is presented relative to that obtained for the Hairy1/Hairy1 interaction. In all assays, Hairy1/Hairy1 protein interaction was used as a positive control and the empty vectors were employed in the negative controls. (DNA-BD: DNA binding domain; AD: activation domain).