The protein encoded by this gene belongs to the evolutionary conserved polynucleotide phosphorylase family comprised of phosphate dependent 3-to-5 exoribonucleases implicated in RNA processing and degradation. This enzyme is predominantly localized in the mitochondrial intermembrane space and is involved in import of RNA to mitochondria. Mutations in this gene have been associated with combined oxidative phosphorylation deficiency-13 and autosomal recessive nonsyndromic deafness-70. Related pseudogenes are found on chromosomes 3 and 7. [provided by RefSeq, Dec 2012],catalytic activity:RNA(n+1) + phosphate = RNA(n) + a nucleoside diphosphate.,function:Involved in mRNA degradation. Hydrolyzes single-stranded polyribonucleotides processively in the 3- to 5-direction.,induction:Up-regulated in cells upon senescence and terminal differentiation. Up-regulated after treatment with interferon beta (IFN-beta).,PTM:Phosphorylated upon DNA damage, probably by ATM or ATR.,similarity:Belongs to the polyribonucleotide nucleotidyltransferase family.,similarity:Contains 1 KH domain.,similarity:Contains 1 S1 motif domain.,subunit:Homotrimer (Potential). Interacts with TCL1A, the interaction has no effect on PNPT1 exonuclease activity.,
