A mutation in the tRNA nucleotidyltransferase gene promotes stabilization of mRNAs in Saccharomyces cerevisiae.
To identify trans-acting factors involved in mRNA decay in the yeast Saccharomyces cerevisiae, we have begun to characterize conditional lethal mutants that affect mRNA steady-state levels. A screen of a collection of temperature-sensitive mutants identified ts352, a mutant that accumulated moderately stable and unstable mRNAs after a shift from 23 to 37 degrees C (M. Aebi, G. Kirchner, J.-Y. Chen, U. Vijayraghavan, A. Jacobson, N.C. Martin, and J. Abelson, J. Biol. Chem. 265:16216-16220, 1990). ts352 has a defect in the CCA1 gene, which codes for tRNA nucleotidyltransferase, the enzyme that adds 3' CCA termini to tRNAs (Aebi et al., J. Biol. Chem., 1990). In a shift to the nonpermissive temperature, ts352 (cca1-1) cells rapidly cease protein synthesis, reduce the rates of degradation of the CDC4, TCM1, and PAB1 mRNAs three- to fivefold, and increase the relative number of ribosomes associated with mRNAs and the overall size of polysomes. These results were analogous to those observed for cycloheximide-treated cells and are generally consistent with models that invoke a role for translational elongation in the process of mRNA turnover.
Peltz
S W
SW
Department of Molecular Genetics and Microbiology, University of Massachusetts Medical School, Worcester 01655.
Donahue
J L
JL
Jacobson
A
A
D003513:Cycloheximide / Q000494:pharmacology; D005656:Fungal Proteins / Q000096:biosynthesis; D007700:Kinetics; D009154:Mutation; D011132:Polyribosomes / Q000378:metabolism; D014176:Protein Biosynthesis; D012316:RNA Nucleotidyltransferases / Q000235:genetics* / Q000378:metabolism; D012331:RNA, Fungal / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism*; D012343:RNA, Transfer / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000201:enzymology / Q000235:genetics* / Q000254:growth & development; D013696:Temperature
D005656:Fungal Proteins; D012331:RNA, Fungal; D012333:RNA, Messenger; D012343:RNA, Transfer; D003513:Cycloheximide; D012316:RNA Nucleotidyltransferases; C023198:tRNA nucleotidyltransferase