title: Human polynucleotide phosphorylase (hPNPaseold-35): should I eat you or not--that is the question?
abstract: RNA degradation plays a fundamental role in maintaining cellular homeostasis whether it occurs as a surveillance mechanism eliminating aberrant mRNAs or during RNA processing to generate mature transcripts. 3'-5' exoribonucleases are essential mediators of RNA decay pathways, and one such evolutionarily conserved enzyme is polynucleotide phosphorylase (PNPase). The human homologue of this fascinating enzymatic protein (hPNPaseold-35) was cloned a decade ago in the context of terminal differentiation and senescence through a novel "overlapping pathway screening" approach. Since then, significant insights have been garnered about this exoribonuclease and its repertoire of expanding functions. The objective of this review is to provide an up-to-date perspective of the recent discoveries made relating to hPNPaseold-35 and the impact they continue to have on our comprehension of its expanding and diverse array of functions.
authors.affiliation: Department of Human and Molecular Genetics, Virginia Commonwealth University, School of Medicine, Richmond, Virginia, USA.
authors.forename: Upneet K
authors.initials: UK
authors.lastname: Sokhi
authors.forename: Swadesh K
authors.initials: SK
authors.lastname: Das
authors.forename: Santanu
authors.initials: S
authors.lastname: Dasgupta
authors.forename: Luni
authors.initials: L
authors.lastname: Emdad
authors.forename: Rita
authors.initials: R
authors.lastname: Shiang
authors.forename: Robert
authors.initials: R
authors.lastname: DeSalle
authors.forename: Devanand
authors.initials: D
authors.lastname: Sarkar
authors.forename: Paul B
authors.initials: PB
authors.lastname: Fisher
mesh_terms: D000818:Animals; D001426:Bacterial Proteins / Q000737:chemistry; D002454:Cell Differentiation; D045744:Cell Line, Tumor; D016922:Cellular Senescence; D005095:Exoribonucleases / Q000235:genetics / Q000378:metabolism; D015971:Gene Expression Regulation, Enzymologic; D015972:Gene Expression Regulation, Neoplastic; D006706:Homeostasis; D006801:Humans; D051379:Mice; D008954:Models, Biological; D010802:Phylogeny; D010940:Plant Proteins / Q000737:chemistry; D011117:Polyribonucleotide Nucleotidyltransferase / Q000235:genetics* / Q000502:physiology*; D017434:Protein Structure, Tertiary; D012313:RNA / Q000378:metabolism; D012323:RNA Processing, Post-Transcriptional; D012333:RNA, Messenger / Q000737:chemistry* / Q000235:genetics; D000077278:RNA, Mitochondrial; D013379:Substrate Specificity
chemical_list: D001426:Bacterial Proteins; D010940:Plant Proteins; D012333:RNA, Messenger; D000077278:RNA, Mitochondrial; D012313:RNA; D011117:Polyribonucleotide Nucleotidyltransferase; D005095:Exoribonucleases
keywords: Mitochondrial homeostasis; RNA degradation; Senescence; hPNPase(old-35); miRNA regulation