Comparative analyses of disease-linked missense mutations in the RNA exosome modeled in budding yeast reveal distinct functional consequences in translation

Distinct translation defects in rrp4-G226D, rrp40-W195R, and rrp46-L191H mutant cells. (A,C) Sucrose density gradients of wild-type, rrp4-G226D, rrp40-W195R, and rrp46-L191H cells that were grown at 30°C are shown. Clarified cell extracts were resolved on a 10%–50% sucrose gradient and scanned at 260 nm. Arrows indicate halfmers. (B,D) Northern blots of gradient fractions indicating the distribution of 5.8S rRNA and 7S pre-rRNA. Samples in C and D were treated with 2.5 mM puromycin after lysis.