RNA turnover in human mitochondria: more questions than answers?

Protein complexes responsible for RNA degradation play important role in three key aspects of RNA metabolism: they control stability of physiologically functional transcripts, remove the unnecessary RNA processing intermediates and destroy aberrantly formed RNAs. In mitochondria the post-transcriptional events seem to play a major role in regulation of gene expression, therefore RNA turnover is of particular importance. Despite many years of research, the details of this process are still a challenge. This review summarizes emerging landscape of interplay between the Suv3p helicase (SUPV3L1, Suv3), poly(A) polymerase and polynucleotide phosphorylase in controlling RNA degradation in human mitochondria.