Heterologous complementation reveals that mutant alleles of QSR1 render 60S ribosomal subunits unstable and translationally inactive.
QSR1 is a highly conserved gene which encodes a 60S ribosomal subunit protein that is required for joining of large and small ribosomal subunits. In this report we demonstrate heterologous complementation of a yeast QSR1 deletion strain with both the human and corn homologs and show that the human and corn proteins are assembled into hybrid yeast/human and yeast/corn ribosomes. While the homologous genes complement lethality of the QSR1 deletion, they also result in a diminished growth rate. Analyses of the translation rates of ribosomes containing the human and corn proteins reveal a partial loss of function. Velocity gradient analyses of the hybrid ribosomes after exposure to high concentrations of salt indicate that the decreased activity is due to lability of the hybrid 60S subunits.
Dick
F A
FA
Department of Biochemistry, Dartmouth Medical School, Hanover, NH 03755, USA.
Trumpower
B L
BL
D000483:Alleles; D000595:Amino Acid Sequence; D005656:Fungal Proteins / Q000235:genetics*; D005816:Genetic Complementation Test; D006801:Humans; D008969:Molecular Sequence Data; D009154:Mutation; D010441:Peptide Chain Elongation, Translational / Q000235:genetics; D011132:Polyribosomes; D011189:Potassium Chloride / Q000494:pharmacology; D014176:Protein Biosynthesis / Q000235:genetics*; D012269:Ribosomal Proteins / Q000235:genetics*; D012270:Ribosomes / Q000235:genetics*; D012441:Saccharomyces cerevisiae / Q000235:genetics; D029701:Saccharomyces cerevisiae Proteins; D012689:Sequence Homology, Nucleic Acid; D013045:Species Specificity; D003313:Zea mays / Q000235:genetics
D005656:Fungal Proteins; C093333:RPL10 protein, S cerevisiae; D012269:Ribosomal Proteins; D029701:Saccharomyces cerevisiae Proteins; D011189:Potassium Chloride