Fig 1.

RAC/Ssb inhibits expression of polylysine proteins. (A) Schematic view of Luc-stop and Luc-tag luciferase reporter constructs. Luc-tag constructs contain sequences coding for different stretches of consecutive amino acids located 5′ of the termination codon (see also Fig. S1 in the supplemental material). (B) Expression level of Luc-stop and Luc-tag constructs in wild-type yeast. Luc-Lys constructs contain 12 (Luc-Lys12), 16 (Luc-Lys16), or 20 (Luc-Lys20) lysines at the very C terminus. Luc-Arg12 and Luc-Ser12 contain 12 arginine or serine residues, respectively. Total cell extracts corresponding to the same amount of total protein were analyzed via immunoblotting using antibodies specific for luciferase and, as a loading control, Sse1. Because the levels of expression of luciferase reporters differed significantly, a short exposure (exp.) and a long exposure of the same immunoblot are displayed. (C) The level of Luc-stop and Luc-tag constructs expressed in wild-type, Δzuo1, and Δssb1 Δssb2 strains was analyzed as described for panel B.