title: Human hepatic glyceraldehyde-3-phosphate dehydrogenase binds to the poly(U) tract of the 3' non-coding region of hepatitis C virus genomic RNA.
abstract: The unique poly(U/UC) tract, the middle part of the tripartite 3' non-coding region (3'NCR) of hepatitis C virus (HCV) genomic RNA, may represent a recognition signal for the HCV replicase complex. In this study, several proteins binding specifically to immobilized ribooligonucleotide r(U)(25) mimicking this structure were identified using cytosolic extracts from HCV-negative or -positive liver explants, and a prominent 36 kDa protein was studied further. Competition experiments including homoribopolymers revealed binding affinities in the order: oligo/poly(U)>(A)>(C)>(G). The protein was identified as glyceraldehyde-3-phosphate dehydrogenase (GAPDH), a multifunctional protein known to bind RNA. GAPDH bound efficiently to the full-length HCV RNA and binding to various 3'NCR constructs revealed critical dependence upon the presence of the middle part of the 3'NCR. Polypyrimidine tract-binding protein, described previously to bind the 3'NCR, did not bind efficiently to the middle part of 3'NCR and was captured from liver extracts in considerably smaller quantities.
authors.affiliation: Departments of Haematology1 and Medicine2, University of Cambridge, School of Clinical Medicine, Cambridge, UK.
authors.forename: Juraj
authors.initials: J
authors.lastname: Petrik
authors.affiliation: Departments of Haematology1 and Medicine2, University of Cambridge, School of Clinical Medicine, Cambridge, UK.
authors.forename: Hayley
authors.initials: H
authors.lastname: Parker
authors.affiliation: Departments of Haematology1 and Medicine2, University of Cambridge, School of Clinical Medicine, Cambridge, UK.
authors.forename: Graeme J M
authors.initials: GJM
authors.lastname: Alexander
mesh_terms: D020413:3' Untranslated Regions / Q000235:genetics / Q000378:metabolism*; D016679:Genome, Viral; D005987:Glyceraldehyde-3-Phosphate Dehydrogenases / Q000378:metabolism*; D016174:Hepacivirus / Q000235:genetics* / Q000378:metabolism; D006526:Hepatitis C / Q000821:virology; D006801:Humans; D008099:Liver / Q000201:enzymology* / Q000821:virology; D009843:Oligoribonucleotides / Q000378:metabolism; D011072:Poly U / Q000235:genetics / Q000378:metabolism*; D011131:Polyribonucleotides / Q000378:metabolism; D012367:RNA, Viral / Q000235:genetics / Q000378:metabolism*
chemical_list: D020413:3' Untranslated Regions; D009843:Oligoribonucleotides; D011131:Polyribonucleotides; D012367:RNA, Viral; D011072:Poly U; D005987:Glyceraldehyde-3-Phosphate Dehydrogenases