May play a role in RNA metabolism in both nuclei and mitochondria. In the nucleus binds to HNRPA1-associated poly(A) mRNAs and is part of nmRNP complexes at late stages of mRNA maturation which are possibly associated with nuclear mRNA export. Positively modulates nuclear export of mRNAs containing the EIF4E sensitivity element (4ESE) by binding simultaneously to both EIF4E and the 4ESE and acting as a platform for assembly for the RNA export complex (PubMed:19262567, PubMed:28325843). Also binds to exportin XPO1/CRM1 to engage the nuclear pore and traffic the bound mRNAs to the cytoplasm (PubMed:28325843). May bind mature mRNA in the nucleus outer membrane. In mitochondria binds to poly(A) mRNA. Plays a role in translation or stability of mitochondrially encoded cytochrome c oxidase (COX) subunits. May be involved in transcription regulation. Cooperates with PPARGC1A to regulate certain mitochondrially encoded genes and gluconeogenic genes and may regulate docking of PPARGC1A to transcription factors. Seems to be involved in the transcription regulation of the multidrug-related genes MDR1 and MVP. Part of a nuclear factor that binds to the invMED1 element of MDR1 and MVP gene promoters. Binds single-stranded DNA (By similarity). Required for maintaining mitochondrial potential (PubMed:23822101). Suppresses the initiation of basal levels of autophagy and mitophagy by sustaining BCL2 levels (PubMed:23822101). {ECO:0000250, ECO:0000269|PubMed:11585913, ECO:0000269|PubMed:12832482, ECO:0000269|PubMed:15081402, ECO:0000269|PubMed:15139850, ECO:0000269|PubMed:15272088, ECO:0000269|PubMed:17050673, ECO:0000269|PubMed:19262567, ECO:0000269|PubMed:23822101, ECO:0000269|PubMed:28325843}. This is the function of ENSG00000138095 (LRPPRC, leucine rich pentatricopeptide repeat containing).