Gene expression in mitochondria and chloroplasts is controlled by the nuclear genome and is regulated
predominantly at the post-transcriptional level. Currently, the understanding of the mechanisms involved in
processing and stability of RNAs in organelles is rather limited, although molecular consequences of these
processes are important in agriculture as well as in medicine. The main reason for this lack of knowledge is the
fact, that molecular and genetic analyses in organisms with complex mitochondrial genomes are difficult.
The yeast Saccharomyces cerevisiae is an excellent model system to study nucleo-mitochondrial interactions: it is
the only organism amenable to mitochondrial transformation and its mitochondrial genome is dispensable under
certain conditions. Moreover, powerful techniques to manipulate the nuclear genome are available for the yeast
model system.
We have previously identified a yeast nuclear gene, PET127, which is involved in 5` end processing of certain
mitochondrial transcripts and affects the stability of sever