FIG. 5.

Analysis of the SAP 155-U2AF interaction by the yeast two-hybrid assay. (A) β-Galactosidase filter lift assays were done with cells transformed with the indicated bait and fish vectors. (B) Structure of U2AF⁶⁵ and derivatives of U2AF⁶⁵ that were used as baits for two-hybrid assays. U2AF³⁵ and SAP 155 (aa 171 to 775) were used as fish. The interactions were assayed with the β-galactosidase filter assay. +, interactions between the fish and bait (blue color production on the filter). −, no interaction (relative to the VP16 negative control). (C) The percent identity between Homo sapiens, S. pombe, and S. cerevisiae SAP 155, U2AF³⁵, U2AF⁶⁵ homologs is shown. (D) Two-hybrid assays of S. pombe (sp) U2AF⁶⁵, U2AF³⁵, and SAP 155. The fish and baits are indicated. As with human SAP 155, S. pombe SAP 155 used as a bait transactivates the β-galactosidase (β-gal) promoter in the absence of a fish construct.