Figure 2.

Effects of gar2 mutations on 18S rRNA accumulation. 25-to-18S ratios were measured on three samples of RNAs from each strain, after extraction, resolution on agarose gel under denaturing conditions, ethidium bromide staining, and observation under UV light to evaluate the deficit in 18S rRNA. Overexpression of gar2 either without its N-terminal or GAR domain restores normal 18S rRNA accumulation in the Sp91 (gar2-null) strain. Overexpression of gar2 lacking its RBDs increases the deficit in 18S rRNA, and point mutations in the conserved RNP1 motifs of the RBDs prevent total restoration of 18S level. The Sp108 strain expressing the gar2ΔRBDs protein under the control of the gar2 promoter also exhibits stronger deficit in 18S rRNA than the gar2-null strain.