The histone 3'-terminal stem-loop-binding protein enhances translation through a functional and physical interaction with eukaryotic initiation factor 4G (eIF4G) and eIF3.
Metazoan cell cycle-regulated histone mRNAs are unique cellular mRNAs in that they terminate in a highly conserved stem-loop structure instead of a poly(A) tail. Not only is the stem-loop structure necessary for 3'-end formation but it regulates the stability and translational efficiency of histone mRNAs. The histone stem-loop structure is recognized by the stem-loop-binding protein (SLBP), which is required for the regulation of mRNA processing and turnover. In this study, we show that SLBP is required for the translation of mRNAs containing the histone stem-loop structure. Moreover, we show that the translation of mRNAs ending in the histone stem-loop is stimulated in Saccharomyces cerevisiae cells expressing mammalian SLBP. The translational function of SLBP genetically required eukaryotic initiation factor 4E (eIF4E), eIF4G, and eIF3, and expressed SLBP coisolated with S. cerevisiae initiation factor complexes that bound the 5' cap in a manner dependent on eIF4G and eIF3. Furthermore, eIF4G coimmunoprecipitated with endogenous SLBP in mammalian cell extracts and recombinant SLBP and eIF4G coisolated. These data indicate that SLBP stimulates the translation of histone mRNAs through a functional interaction with both the mRNA stem-loop and the 5' cap that is mediated by eIF4G and eIF3.
Ling
Jun
J
Department of Biochemistry, University of California, Riverside, California 92521-0129, USA.
Morley
Simon J
SJ
Pain
Virginia M
VM
Marzluff
William F
WF
Gallie
Daniel R
DR
D002460:Cell Line; D039621:Eukaryotic Initiation Factor-3 / Q000378:metabolism*; D039561:Eukaryotic Initiation Factor-4E / Q000378:metabolism; D039562:Eukaryotic Initiation Factor-4F / Q000378:metabolism; D039603:Eukaryotic Initiation Factor-4G / Q000378:metabolism*; D017930:Genes, Reporter; D006657:Histones / Q000235:genetics* / Q000378:metabolism; D006801:Humans; D046911:Macromolecular Substances; D009687:Nuclear Proteins / Q000235:genetics / Q000378:metabolism; D009690:Nucleic Acid Conformation; D039102:Poly(A)-Binding Proteins / Q000378:metabolism; D011485:Protein Binding; D014176:Protein Biosynthesis; D012315:RNA Caps; D012333:RNA, Messenger / Q000378:metabolism; D016601:RNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000502:physiology; D039221:mRNA Cleavage and Polyadenylation Factors
D039621:Eukaryotic Initiation Factor-3; D039561:Eukaryotic Initiation Factor-4E; D039562:Eukaryotic Initiation Factor-4F; D039603:Eukaryotic Initiation Factor-4G; D006657:Histones; D046911:Macromolecular Substances; D009687:Nuclear Proteins; D039102:Poly(A)-Binding Proteins; D012315:RNA Caps; D012333:RNA, Messenger; D016601:RNA-Binding Proteins; D011993:Recombinant Fusion Proteins; C092663:SLBP protein, human; D039221:mRNA Cleavage and Polyadenylation Factors