Back to Search
Start Over
Expression of a recoded nuclear gene inserted into yeast mitochondrial DNA is limited by mRNA-specific translational activation.
- Source :
-
Proceedings of the National Academy of Sciences of the United States of America [Proc Natl Acad Sci U S A] 1996 May 28; Vol. 93 (11), pp. 5253-7. - Publication Year :
- 1996
-
Abstract
- Genetic code differences prevent expression of nuclear genes within Saccharomyces cerevisiae mitochondria. To bridge this gap a synthetic gene, ARG8m, designed to specify an arginine biosynthetic enzyme when expressed inside mitochondria, has been inserted into yeast mtDNA in place of the COX3 structural gene. This mitochondrial cox3::ARG8m gene fully complements a nuclear arg8 deletion at the level of cell growth, and it is dependent for expression upon nuclear genes that encode subunits of the COX3 mRNA-specific translational activator. Thus, cox3::ARG8m serves as a mitochondrial reporter gene. Measurement of cox3::ARG8m expression at the levels of steady-state protein and enzymatic activity reveals that glucose repression operates within mitochondria. The levels of this reporter vary among strains whose nuclear genotypes lead to under- and overexpression of translational activator subunits, in particular Pet494p, indicating that mRNA-specific translational activation is a rate-limiting step in this organellar system. Whereas the steady-state level of cox3::ARG8m mRNA was also glucose repressed in an otherwise wild-type strain, absence of translational activation led to essentially repressed mRNA levels even under derepressing growth conditions. Thus, the mRNA is stabilized by translational activation, and variation in its level may be largely due to modulation of translation.
- Subjects :
- Arginine biosynthesis
DNA, Fungal metabolism
Electron Transport Complex IV genetics
Glucose pharmacology
Membrane Proteins genetics
Mitochondria metabolism
Molecular Sequence Data
RNA, Fungal metabolism
Saccharomyces cerevisiae Proteins
Transaminases metabolism
Cell Nucleus metabolism
DNA, Mitochondrial metabolism
Electron Transport Complex IV biosynthesis
Gene Expression Regulation, Fungal drug effects
Genes, Fungal
Genes, Synthetic
Membrane Proteins biosynthesis
Protein Biosynthesis
RNA, Messenger metabolism
Saccharomyces cerevisiae genetics
Transaminases biosynthesis
Subjects
Details
- Language :
- English
- ISSN :
- 0027-8424
- Volume :
- 93
- Issue :
- 11
- Database :
- MEDLINE
- Journal :
- Proceedings of the National Academy of Sciences of the United States of America
- Publication Type :
- Academic Journal
- Accession number :
- 8643562
- Full Text :
- https://doi.org/10.1073/pnas.93.11.5253