title: Polynucleotide phosphorylase: an evolutionary conserved gene with an expanding repertoire of functions.
abstract: RNA metabolism plays a seminal role in regulating diverse physiological processes. Polynucleotide phosphorylase (PNPase) is an evolutionary conserved 3',5' exoribonuclease, which plays a central role in RNA processing in bacteria and plants. Human polynucleotide phosphorylase (hPNPase old-35) was cloned using an inventive strategy designed to identify genes regulating the fundamental physiological processes of differentiation and senescence. Although hPNPase old-35 structurally and biochemically resembles PNPase of other species, targeted overexpression and inhibition studies reveal that hPNPase old-35 has evolved to serve more specialized functions in humans. The present review provides a global perspective on the structure and function of PNPase and then focuses on hPNPase old-35 in the contexts of differentiation and senescence.
authors.affiliation: Department of Pathology, Herbert Irving Comprehensive Cancer Center, Columbia University Medical Center, College of Physicians and Surgeons, New York, NY 10032, USA.
authors.forename: Devanand
authors.initials: D
authors.lastname: Sarkar
authors.forename: Paul B
authors.initials: PB
authors.lastname: Fisher
mesh_terms: D003001:Cloning, Molecular; D005095:Exoribonucleases / Q000378:metabolism; D006801:Humans; D011117:Polyribonucleotide Nucleotidyltransferase / Q000235:genetics / Q000378:metabolism*; D011387:Prokaryotic Cells / Q000201:enzymology; D012313:RNA / Q000378:metabolism
chemical_list: D012313:RNA; D011117:Polyribonucleotide Nucleotidyltransferase; D005095:Exoribonucleases