title: Effect of mRNA cap structure on eIF-4E phosphorylation and cap binding analyses using Ser209-mutated eIF-4Es.
abstract: The in vitro phosphorylation of human recombinant eIF-4E by protein kinase C was most effective in the absence of m7GTP, supporting a 'performed complex model' as the mRNA binding step of initiation, i. e., eIF-4E first forms an initiation complex eIF-4F and is phosphorylated before interacting with mRNA. On the other hand, the comparison of m7GTP-binding ability of wild-type eIF-4E with those of four Ser209-mutated ones (S209A, S209D, S209E and S209K) showed that the addition of anionic charge on Ser209 increases the cap affinity of eIF-4E by repressing the release of the cap from the complex, not by increasing the complex formation, suggesting the importance of a retractable ionic bridge between Ser209 and Lys159 in controlling the cap binding by eIF-4E phosphorylation.
authors.affiliation: Department of Physical Chemistry, Osaka University of Pharmaceutical Sciences, 4-20-1 Nasahara, Takatsuki, 569-1094, Japan.
authors.forename: S
authors.initials: S
authors.lastname: Shibata
authors.forename: S
authors.initials: S
authors.lastname: Morino
authors.forename: K
authors.initials: K
authors.lastname: Tomoo
authors.forename: Y
authors.initials: Y
authors.lastname: In
authors.forename: T
authors.initials: T
authors.lastname: Ishida
mesh_terms: D001665:Binding Sites; D039561:Eukaryotic Initiation Factor-4E; D006801:Humans; D066298:In Vitro Techniques; D016297:Mutagenesis, Site-Directed; D010448:Peptide Initiation Factors / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D010766:Phosphorylation; D011493:Protein Kinase C / Q000378:metabolism; D012315:RNA Caps / Q000737:chemistry* / Q000378:metabolism*; D012333:RNA, Messenger / Q000378:metabolism; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism; D012694:Serine / Q000737:chemistry
chemical_list: D039561:Eukaryotic Initiation Factor-4E; D010448:Peptide Initiation Factors; D012315:RNA Caps; D012333:RNA, Messenger; D011994:Recombinant Proteins; D012694:Serine; D011493:Protein Kinase C