Fig. 4.

PUF-8 and TCER-1 interact with mRNA processing/export components in the yeast two-hybrid assay. Growth of yeast strains carrying the various constructs (labelled at top) in media lacking the indicated nutrients (left). In row 2, the minimal medium used contains 2 mM 3-aminotriazole (3-AT). PUF-8 was expressed as a Gal4BD fusion and all others were Gal4AD fusions. Panels marked with a single protein are negative controls expressing the indicated fusion protein along with either Gal4BD or Gal4AD alone. SC, synthetic complete medium; LEU, leucine; URA, uracil; HIS, histidine; ADE, adenine. Growth observed in rows 2 and 3 indicates activation of the HIS3 and ADE2 reporters, respectively. These two reporters are under the control of two different GAL4-responsive promoters; activation of both reporters provides strong support for the functional reconstitution of GAL4 by the interacting protein pairs (James et al., 1996). Therefore, to avoid potential false positives, only those fusion protein pairs showing robust growth on both selection plates (rows 2 and 3) were scored as interacting pairs.