Polyribonucleotide nucleotidyltransferase 1, mitochondrial (PNPT1)

Polyribonucleotide nucleotidyltransferase 1, mitochondrial (PNPT1), commonly known as polynucleotide phosphorylase (PNPase), is a phosphate-dependent 3'-to-5' exoribonuclease primarily localized in the mitochondrial intermembrane space[2][3][5]. It is essential for several RNA metabolic processes, including the processive phosphorolysis of single-stranded RNA, mitochondrial RNA import, maturation and polyadenylation of mitochondrial transcripts, and degradation of non-coding and aberrant mitochondrial RNAs[2][5][6]. PNPT1 is a component of the mitochondrial degradosome (mtEXO) complex, necessary for the proper degradation of RNA within mitochondria[6]. Dysfunction or mutations in PNPT1 are linked to human diseases such as combined oxidative phosphorylation deficiency and autosomal-recessive nonsyndromic deafness, reflecting its crucial role in mitochondrial protein synthesis and electron transport chain maintenance[1][2][4]. In addition to its mitochondrial roles, PNPase can participate in cytoplasmic mRNA surveillance and degradation processes, including the degradation of specific microRNAs and the c-myc mRNA in response to interferon beta in tumor cells[2][5]. There are no currently approved drugs that directly target PNPT1[2][5].

Other names

Polynucleotide phosphorylase (PNPase)3'-5' RNA exonuclease OLD35Old-35PNPase old-35Polynucleotide phosphorylase 1Polynucleotide phosphorylase-like proteinCOXPD13DFNB70SCA25

Not applicable (no approved drugs directly targeting PNPT1; primarily a genetic/biological target)