Open AccessEukaryotic initiation factor 3 is required for poliovirus 2A protease-induced cleavage of the p220 component of eukaryotic initiation factor 4F.
Author(s) -
Elizabeth E. Wyckoff,
John W.B. Hershey,
Ellie Ehrenfeld
Publication year - 1990
Publication title -
proceedings of the national academy of sciences of the united states of america
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.011
H-Index - 771
eISSN - 1091-6490
pISSN - 0027-8424
DOI - 10.1073/pnas.87.24.9529
Subject(s) - cleavage (geology) , initiation factor , poliovirus , eukaryotic initiation factor , microbiology and biotechnology , eukaryotic translation , chemistry , eukaryotic translation initiation factor 4 gamma , internal ribosome entry site , cleavage stimulation factor , ribosome , protein subunit , biology , cleavage factor , translation (biology) , biochemistry , messenger rna , rna , virology , virus , fracture (geology) , gene , paleontology
After cultured cells are infected with poliovirus, cellular mRNA fails to bind to ribosomes, and synthesis of the majority of cellular proteins ceases. The defective step has been localized to the cap-dependent activity of the eukaryotic translation initiation factor 4F. Inactivation of this factor correlates with the cleavage of its largest subunit, p220, into characteristic products observed in infected cells. This cleavage is mediated by the poliovirus protease 2Apro. Previous work suggests that 2Apro does not catalyze the reaction directly, suggesting that one or more cellular proteins is required for the degradation of p220. To identify such a protein, we have developed an assay in which cleavage of a p220 substrate in the presence of poliovirus 2Apro is dependent upon the addition of HeLa cell proteins. By using this assay, we show that another factor, eukaryotic translation initiation factor 3, is required for 2Apro-dependent cleavage of p220.