Turnover rate of yeast PGK mRNA can be changed by specific alterations in its trailer structure.
The effect of insertions in the 5'- and 3'-untranslated regions (UTR) of the Saccharomyces cerevisiae mRNA encoding phosphoglycerate kinase (PGK) on the stability of the transcript in vivo was determined. None of the structural alterations in the 5'-UTR affected mRNA turnover significantly, despite the strong negative effect on translational efficiency of some of these alterations previously observed. We conclude that the structure of the 5'-UTR is not important for the relatively high affinity of PGK mRNA in yeast cells. Moreover, translation cannot be a major factor in determining the rate of turnover of this mRNA. Insertion of either a polyG or polyU, but not a polyA or polyC, tract into the 3'-UTR of PGK mRNA increased its half-life by a factor of about two. Introduction of a hairpin structure containing 18 G.C base pairs had only a slight stabilizing effect. We argue that the stabilization by the structural changes in the 3'-UTR is due to altered folding of the mutant mRNA which retards a rate-limiting endonucleolytic cleavage step in the normal turnover pathway of PGK mRNA. The stabilizing effect of local structural alterations in the 3'-UTR opens the possibility for further increasing the product yield of a (heterologous) gene cloned in yeast cells.
Vreken
P
P
Biochemisch Laboratorium, Vrije Universiteit, Amsterdam, The Netherlands.
van der Veen
R
R
de Regt
V C
VC
de Maat
A L
AL
Planta
R J
RJ
Raué
H A
HA
D001483:Base Sequence; D001665:Binding Sites; D002874:Chromosome Mapping; D004252:DNA Mutational Analysis; D008969:Molecular Sequence Data; D016254:Mutagenesis, Insertional; D010735:Phosphoglycerate Kinase / Q000235:genetics* / Q000378:metabolism; D011068:Poly G / Q000235:genetics; D011072:Poly U / Q000235:genetics; D014176:Protein Biosynthesis; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism*; D012441:Saccharomyces cerevisiae / Q000235:genetics*; D014158:Transcription, Genetic
D012333:RNA, Messenger; D011068:Poly G; D011072:Poly U; D010735:Phosphoglycerate Kinase