Up-regulation of tRNA biosynthesis affects translational readthrough in maf1-delta mutant of Saccharomyces cerevisiae.
Maf1p is a negative effector of RNA polymerase III in yeast. The maf1-delta mutation caused an increase in the level of cellular tRNAs, but a decrease of translational readthrough at nonsense codons. Using the lacZ- luc dual gene reporter system, we detected an almost twofold diminution of UAA and UAG readthrough in maf1-delta compared with the parental strain. The maf1-delta mutation did not affect the rate of protein biosynthesis and growth at standard conditions, but resulted in temperature-sensitive growth on non-fermentable carbon sources. We examined the correlation of the temperature sensitive and antisuppression phenotypes of maf1- Delta using a colour phenotype assay in the ade2-1 SUP11 strain. Antisuppression, but not the temperature-sensitive growth defect, was compensated either by increased dosage of SUP11or by [PSI(+)], the prion form of the translation termination factor Sup35p. Summarizing, the elevated tRNA levels in maf1- Delta increase translational fidelity and, independently, affect growth under special conditions.
Kwapisz
Marta
M
Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Pawińskiego 5a, 02-106 Warsaw, Poland.
Smagowicz
Wiesław J
WJ
Oficjalska
Danuta
D
Hatin
Isabelle
I
Rousset
Jean-Pierre
JP
Zoładek
Teresa
T
Boguta
Magdalena
M
D018389:Codon, Nonsense; D018388:Codon, Terminator; D005656:Fungal Proteins / Q000235:genetics / Q000378:metabolism; D009154:Mutation; D010454:Peptide Termination Factors; D010641:Phenotype; D011328:Prions / Q000235:genetics / Q000378:metabolism; D014176:Protein Biosynthesis; D012343:RNA, Transfer / Q000096:biosynthesis*; D012441:Saccharomyces cerevisiae / Q000235:genetics* / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics* / Q000378:metabolism; D013489:Suppression, Genetic; D014157:Transcription Factors / Q000235:genetics* / Q000378:metabolism; D015854:Up-Regulation
D018389:Codon, Nonsense; D018388:Codon, Terminator; D005656:Fungal Proteins; C104954:MAF1 protein, S cerevisiae; D010454:Peptide Termination Factors; D011328:Prions; C074265:SUP11 protein, S cerevisiae; C068068:SUP35 protein, S cerevisiae; D029701:Saccharomyces cerevisiae Proteins; D014157:Transcription Factors; D012343:RNA, Transfer