Fig. 2. 2′-O-Methylation of Gm2922 is necessary and sufficient for robust cell growth and nuclear export of the nascent large ribosomal subunit.
a, Design of synthetic snoRNA gene SNRG2922 to direct 2′-O-methylation of Gm2922, catalyzed by the box C/D snoRNP complex at the fifth nucleotide upstream of box D, depicted in green. b, Expression of SNRG2922 overcomes the growth defect of the methyltransferase-defective spb1-D52A mutant in a repressible SPB1 strain (glucose, endogenous SPB1 repressed; galactose, expressed). c, Sucrose gradient sedimentation profiles for the indicated SPB1 and snoRNA alleles. d, Primer extension assay to probe 2′-O-methylation at G2922. Autoradiography of PAGE-separated primer extension products of RNAse T1-digested RNA. The experiment was repeated twice with similar results. e, Fluorescence microscopy to monitor localization of large subunit (Rpl25–enhanced (e)GFP) and nucleolus (Nop56–basic red fluorescent protein (mRFP)). The experiment was repeated twice with similar results. Scale bar, 5 µm. DIC, differential interference contrast.