title: Vigilin binding selectively inhibits cleavage of the vitellogenin mRNA 3'-untranslated region by the mRNA endonuclease polysomal ribonuclease 1.
abstract: In Xenopus, estrogen induces the stabilization of vitellogenin mRNA and the destabilization of albumin mRNA. These processes correlate with increased polysomal activity of a sequence-selective mRNA endonuclease, PMR-1, and a hnRNP K homology-domain RNA-binding protein, vigilin. Vigilin binds to a region of the vitellogenin mRNA 3'-untranslated region (3'-UTR) implicated in estrogen-mediated stabilization. The vigilin-binding site in the vitellogenin B1 mRNA 3'-UTR contains two consensus PMR-1 cleavage sites. The availability of purified PMR-1 and recombinant vigilin made it possible to test the hypothesis that RNA-binding proteins interact with cis-acting elements to stabilize target mRNAs by blocking cleavage by site-specific mRNA endonucleases. Vigilin binds to the vitellogenin mRNA 3'-UTR site with at least 30-fold higher affinity than it exhibits for the albumin mRNA segment containing the mapped PMR-1 cleavage sites. This differential binding affinity correlates with differential in vitro susceptibility of the protein-RNA complexes to cleavage by PMR-1. Whereas recombinant vigilin has no detectable protective effect on PMR-1 cleavage of albumin mRNA, it retards in vitro cleavage of the vitellogenin mRNA 3'-UTR by purified PMR-1. The PMR-1 sites in the vitellogenin mRNA 3'-UTR are functional because they are readily cleaved in vitro by purified PMR-1. These results provide direct evidence for differential susceptibility to endonuclease-mediated mRNA decay resulting from the differential affinity of a RNA-binding protein for cis-acting stability determinants.
authors.affiliation: Department of Molecular and Cellular Biochemistry, The Comprehensive Cancer Center, and Ohio State Biochemistry Program, Ohio State University, Columbus, OH 43210, USA.
authors.forename: K S
authors.initials: KS
authors.lastname: Cunningham
authors.forename: R E
authors.initials: RE
authors.lastname: Dodson
authors.forename: M A
authors.initials: MA
authors.lastname: Nagel
authors.forename: D J
authors.initials: DJ
authors.lastname: Shapiro
authors.forename: D R
authors.initials: DR
authors.lastname: Schoenberg
mesh_terms: D020413:3' Untranslated Regions / Q000737:chemistry / Q000378:metabolism*; D000818:Animals; D001483:Base Sequence; D002352:Carrier Proteins; D002460:Cell Line; D004722:Endoribonucleases / Q000378:metabolism*; D006801:Humans; D008297:Male; D008969:Molecular Sequence Data; D009690:Nucleic Acid Conformation; D016601:RNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D018411:Spodoptera / Q000166:cytology; D013379:Substrate Specificity; D014819:Vitellogenins / Q000235:genetics*; D014981:Xenopus
chemical_list: D020413:3' Untranslated Regions; D002352:Carrier Proteins; D016601:RNA-Binding Proteins; D011993:Recombinant Fusion Proteins; D014819:Vitellogenins; C075197:high density lipoprotein binding protein; D004722:Endoribonucleases; C116181:polysomal RNase 1