PNPT1
Definition: PNPT1 is a subunit of the exosome complex, which is involved in 3-prime-to-5-prime exoribonuclease activity for RNA processing and degradation.
Human polynucleotide phosphorylase (hPNPase) is an RNA-processing enzyme induced in response to type I interferons and during terminal differentiation and cellular senescence.
hPNPase was thought to contribute to cellular senescence through its RNA-degrading activity in the cytosol.
However, hPNPase localizes to the mitochondrial intermembrane space (IMS) and has a crucial role in maintaining mitochondrial homeostasis. Initial studies have also linked hPNPase to tumorigenesis and the cellular response to viral infection.
References
Chen HW, Koehler CM, Teitell MA. Human polynucleotide phosphorylase: location matters. Trends Cell Biol. 2007 Dec;17(12):600-8. PMID: 17983748