Figure 6.

Rps28 protein translated in cis from the RPS28B mRNA facilitates an Rps28-Edc3 interaction. (A) Working model of nascently synthesized Rps28 interacting better with Edc3 if Rps28 ORF lies immediately upstream of Edc3-bound RPS28B 3′UTR, which in turn aids PB assembly. (B, C) Log-phase WT, rps28aΔ and rps28bΔ strains transformed with empty vector and RPS28B were assessed for Rps28-Edc3 interaction by carrying out an IP for Edc3-GFP and probing for Rps28. Rps28 IP exposure is same duration as in input/supernatant lanes; longer Rps28 exposures are also shown to better quantify relative differences in Edc3-Rps28 interaction. Quantification of Rps28 band intensity is normalized to Edc3 IP band intensity with standard deviation shown. Images/quantification representative of 2 biological replicates. (D) ‘cis’ rps28bΔ yeast transformed with RPS28B ORF-RPS28B 3′UTR and ‘empty vector’ (tTA plasmid – pRB079); ‘trans’ rps28bΔ yeast transformed with PGK1 ORF-RPS28B 3′UTR and RPS28 ORF-CYC1 3′UTR, tTA (pRB388). Images, quantification and biological replicates as in (B) and (C).