PNPT1 RNA-binding protein implicated in numerous RNA metabolic processes. Catalyzes the phosphorolysis of single-stranded polyribonucleotides processively in the 3'-to-5' direction. Mitochondrial intermembrane factor with RNA-processing exoribonulease activity. Component of the mitochondrial degradosome (mtEXO) complex, that degrades 3' overhang double-stranded RNA with a 3'-to-5' directionality in an ATP-dependent manner. Required for correct processing and polyadenylation of mitochondrial mRNAs. Plays a role as a cytoplasmic RNA import factor that mediates the translocation of small RNA components, like the 5S RNA, the RNA subunit of ribonuclease P and the mitochondrial RNA-processing (MRP) RNA, into the mitochondrial matrix. Plays a role in mitochondrial morphogenesis and respiration; regulates the expression of the electron transport chain (ETC) components at the mRNA and protein levels. In the cytoplasm, shows a 3'-to-5' exoribonuclease mediating mRNA degradation activity; degrades c-myc mRNA upon treatment with IFNB1/IFN-beta, resulting in a growth arrest in melanoma cells. Regulates the stability of specific mature miRNAs in melanoma cells; specifically and selectively degrades miR-221, preferentially. Plays also a role in RNA cell surveillance by cleaning up oxidized RNAs. Binds to the RNA subunit of ribonuclease P, MRP RNA and miR-221 microRNA. Belongs to the polyribonucleotide nucleotidyltransferase family. Note: This description may include information from UniProtKB.
Protein type: EC; Mitochondrial; Nucleotide Metabolism - purine; Nucleotide Metabolism - pyrimidine; RNA-binding; Transferase
Chromosomal Location of human Ortholog: 2p16.1
Cellular Component:  cytoplasm; cytosol; endoplasmic reticulum membrane; mitochondrial degradosome; mitochondrial intermembrane space; mitochondrial matrix; mitochondrion; polysomal ribosome
Molecular Function:  3'-5'-RNA exonuclease activity; identical protein binding; miRNA binding; poly(G) binding; poly(U) RNA binding; polyribonucleotide nucleotidyltransferase activity; protein binding
Biological Process:  cellular response to interferon-beta; cellular response to oxidative stress; liver regeneration; mitochondrial mRNA catabolic process; mitochondrial mRNA polyadenylation; mitochondrial RNA 3'-end processing; mitochondrial RNA 5'-end processing; mitochondrial RNA catabolic process; mitochondrion morphogenesis; mRNA catabolic process; mRNA processing; negative regulation of growth; nuclear polyadenylation-dependent mRNA catabolic process; positive regulation of miRNA catabolic process; positive regulation of mitochondrial RNA catabolic process; positive regulation of mRNA catabolic process; protein homooligomerization; protein homotrimerization; regulation of cell cycle; regulation of cellular respiration; regulation of cellular senescence; response to cAMP; response to growth hormone; RNA catabolic process; RNA import into mitochondrion; rRNA import into mitochondrion
Disease: Combined Oxidative Phosphorylation Deficiency 13; Deafness, Autosomal Recessive 70; Spinocerebellar Ataxia 25
Reference #:  Q8TCS8 (UniProtKB)
Alt. Names/Synonyms: 3'-5' RNA exonuclease OLD35; COXPD13; DFNB70; DKFZp762K1914; old-35; OLD35; PNPASE; PNPase 1; PNPase old-35; PNPT1; Polynucleotide phosphorylase 1; Polynucleotide phosphorylase-like protein; polyribonucleotide nucleotidyltransferase 1; Polyribonucleotide nucleotidyltransferase 1, mitochondrial
Gene Symbols: PNPT1
Molecular weight: 85,951 Da
Basal Isoelectric point: 7.87  Predict pI for various phosphorylation states
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Protein Structure Not Found.

Cross-references to other databases:  AlphaFold  |  STRING  |  cBioPortal  |  Wikipedia  |  neXtProt  |  Protein Atlas  |  BioGPS  |  Pfam  |  RCSB PDB  |  ENZYME  |  Phospho.ELM  |  NetworKIN  |  UniProtKB  |  Entrez-Gene  |  GenPept  |  Ensembl Gene  |  Ensembl Protein