Cooperative modulation by eIF4G of eIF4E-binding to the mRNA 5′ cap in yeast involves a site partially shared by p20

被引:125
作者
Ptushkina, M
von der Haar, T
Vasilescu, S
Frank, R
Birkenhäger, R
McCarthy, JEG
机构
[1] Univ Manchester, Inst Sci & Technol, Dept Biomol Sci, Posttranscript Control Grp, Manchester M60 1QD, Lancs, England
[2] Gesell Biotechnol Forsch GmbH, Mol Recognit Res Grp, D-38124 Braunschweig, Germany
关键词
cooperativity; eIF4E and eIF4G; interaction sites; regulation by 4E-binding proteins; yeast gene expression;
D O I
10.1093/emboj/17.16.4798
中图分类号
Q5 [生物化学]; Q7 [分子生物学];
学科分类号
071010 ; 081704 ;
摘要
Interaction between the mRNA 5'-cap-binding protein eIF4E and the multiadaptor protein eIF4G has been demonstrated in all eukaryotic translation assemblies examined so far, This study uses immunological, genetic and biochemical methods to map the surface amino acids on eIF4E that contribute to eIF4G binding. Cap-analogue chromatography and surface plasmon resonance (SPR) analyses demonstrate that one class of mutations in these surface regions disrupts eIF4E eIF4G association, and thereby polysome formation and growth. The residues at these positions in wildtype eIF4E mediate positive cooperativity between the binding of eIF4G to eIF4E and the latter's cap-affinity. Moreover, two of the mutations confer temperature sensitivity in eIF4G binding to eIF4E which correlates with the formation of large numbers of inactive ribosome 80S couples in vivo and the loss of cellular protein synthesis activity. The yeast 4E-binding protein p20 is estimated by SPR to have a ten times lower binding affinity than eIF4G for eIF4E, Investigation of a second class of eIF4E mutations reveals that p20 shares only part of eIF4G's binding site on the cap-binding protein. The results presented provide a basis for understanding how cycling of eIF4E and eIF4G occurs in yeast translation and explains how p20 can act as a fine, but not as a coarse, regulator of protein synthesis.
引用
收藏
页码:4798 / 4808
页数:11
相关论文
共 46 条
[41]   Association of the yeast poly(A) tail binding protein with translation initiation factor eIF-4G [J].
Tarun, SZ ;
Sachs, AB .
EMBO JOURNAL, 1996, 15 (24) :7168-7177
[42]  
TARUN SZ, 1997, P NATL ACAD SCI USA, V94, P9045
[43]   EXPRESSION OF A SYNTHETIC GENE FOR HUMAN CAP BINDING-PROTEIN (HUMAN IF-4E) IN ESCHERICHIA-COLI AND FLUORESCENCE STUDIES ON INTERACTION WITH MESSENGER-RNA CAP STRUCTURE ANALOGS [J].
UEDA, H ;
MARUYAMA, H ;
DOI, M ;
INOUE, M ;
ISHIDA, T ;
MORIOKA, H ;
TANAKA, T ;
NISHIKAWA, S ;
UESUGI, S .
JOURNAL OF BIOCHEMISTRY, 1991, 109 (06) :882-889
[44]   Mutants of eukaryotic initiation factor eIF-4E with altered mRNA cap binding specificity reprogram mRNA selection by ribosomes in Saccharomyces cerevisiae [J].
Vasilescu, S ;
Ptushkina, M ;
Linz, B ;
Muller, PP ;
McCarthy, JEG .
JOURNAL OF BIOLOGICAL CHEMISTRY, 1996, 271 (12) :7030-7037
[45]   CHARACTERIZATION OF THE IN-VIVO PHOSPHORYLATION SITES OF THE MESSENGER-RNA-CENTER-DOT-CAP-BINDING COMPLEX PROTEINS EUKARYOTIC INITIATION FACTOR-4E AND P20 IN SACCHAROMYCES-CEREVISIAE [J].
ZANCHIN, NIT ;
MCCARTHY, JEG .
JOURNAL OF BIOLOGICAL CHEMISTRY, 1995, 270 (44) :26505-26510
[46]   THE YEAST SIS1-PROTEIN, A DNAJ HOMOLOG, IS REQUIRED FOR THE INITIATION OF TRANSLATION [J].
ZHONG, T ;
ARNDT, KT .
CELL, 1993, 73 (06) :1175-1186