Phosphorylation of eukaryotic translation initiation factor 4E is increased in Src-transformed cell lines.
Eukaryotic initiation factor 4F (eIF-4F) is a three-subunit complex that binds the 5' cap structure (m7GpppX, where X is any nucleotide) of eukaryotic mRNAs. This factor facilitates ribosome binding by unwinding the secondary structure in the mRNA 5' noncoding region. The limiting component of the 4F complex is believed to be the 24-kDa cap-binding phosphoprotein, eIF-4E. In this report, we describe the phosphorylation of eIF-4E in response to expression of the tyrosine kinase oncoproteins pp60v-src and pp60c-src527F. The results suggest that eIF-4E functions as a downstream target of the phosphorylation cascade induced by tyrosine-specific protein kinases as well as by effectors of the mitogenic response.
Frederickson
R M
RM
Department of Biochemistry, McGill University, Montreal, Quebec, Canada.
Montine
K S
KS
Sonenberg
N
N
D000818:Animals; D002460:Cell Line; D002471:Cell Transformation, Neoplastic; D002846:Chromatography, Affinity; D015180:Electrophoresis, Gel, Two-Dimensional; D004591:Electrophoresis, Polyacrylamide Gel; D039561:Eukaryotic Initiation Factor-4E; D016391:Genes, src; D007700:Kinetics; D046911:Macromolecular Substances; D051379:Mice; D015688:Oncogene Protein pp60(v-src) / Q000235:genetics / Q000378:metabolism*; D010448:Peptide Initiation Factors / Q000302:isolation & purification / Q000378:metabolism*; D010449:Peptide Mapping; D010748:Phosphopeptides / Q000302:isolation & purification; D010766:Phosphorylation; D011505:Protein-Tyrosine Kinases / Q000378:metabolism
D039561:Eukaryotic Initiation Factor-4E; D046911:Macromolecular Substances; D010448:Peptide Initiation Factors; D010748:Phosphopeptides; D011505:Protein-Tyrosine Kinases; D015688:Oncogene Protein pp60(v-src)