Mitochondria are subcellular organelles present in eukaryotic cells that play a central role in the conversion of metabolic fuels to a readily utilisable source of energy in form of ATP. One of the most distinct features of mitochondria from the other organelles of metazoan cells is the possession of their own genome. The mammalian mitochondrial genome encodes only 13 peptides all of which are involved in respiratory chain in addition to the RNA components of mitochondrial translation machinery. However, the majority of mitochondrial proteins are encoded in the nucleus, synthesized in cytoplasm and then imported into the mitochondria. In mammals, all mRNA encoded by mitochondrial DNA exhibit stable 50-60 nt poly(A) tails, suggesting the existence of mitochondrial poly(A) binding protein. To date, no such protein has been isolated. To investigate the function(s) of polyadenylation in human mitochondria we decided to disturb its role(s) by targeting an exogenous poly(A) binding protein (PABP) into the organelles. Anticipating that the exogenous PABP will interact with mt-mRNA poly(A) region, we expect possible changes in mt-mRNA metabolism and translation. By using this alternative approach we hope to clarify whether or not there is a mitochondrial poly(A) binding protein and whether it plays a role in transcript stability or translation.