Interaction of a limited set of proteins with different mRNAs and protection of 5'-caps against pyrophosphatase digestion in initiation complexes.
A variety of 5'-3H-methyl-labeled, oxidized viral mRNAs were used as probes for detecting in wheat germ initiation complexes proteins that interact with, and can be cross-linked to, the 5'-cap structure. A limited and reproducible set of specific proteins was obtained with the different mRNAs. The binding of these proteins to the 5'-end of mRNA apparently results in protection against nucleotide pyrophosphatase digestion of the cap even in initiation complexes in which the 5'-end is susceptible to pancreatic RNase digestion. Cross-linked proteins from mammalian initiation complexes comigrated with several of the subunits of similarly treated eIF-3. A model for cap binding protein interaction with mRNA cap during initiation of translation is suggested.
D000818:Animals; D046911:Macromolecular Substances; D008970:Molecular Weight; D010442:Peptide Chain Initiation, Translational; D010448:Peptide Initiation Factors / Q000378:metabolism; D010944:Plants / Q000378:metabolism; D012315:RNA Caps / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism; D011817:Rabbits; D012087:Reoviridae; D012156:Reticulocytes / Q000378:metabolism; D012269:Ribosomal Proteins / Q000378:metabolism; D014908:Triticum / Q000378:metabolism; D014616:Vaccinia virus
D046911:Macromolecular Substances; D010448:Peptide Initiation Factors; D012315:RNA Caps; D012333:RNA, Messenger; D012269:Ribosomal Proteins