title: Caspase-3 is necessary and sufficient for cleavage of protein synthesis eukaryotic initiation factor 4G during apoptosis.
abstract: Induction of apoptosis BJAB cells is accompanied by the rapid cleavage of protein synthesis eukaryotic initiation factor 4G and the appearance of a fragment of approximately 76 kDa. Inhibition of apoptotic proteases (caspases) has previously been shown to prevent the cleavage of eukaryotic initiation factor 4G. In MCF-7 breast carcinoma cells, which are deficient in caspase-3, eukaryotic initiation factor 4G is not cleaved but in vivo expression of caspase-3 restores eukaryotic initiation factor 4G cleavage following induction of apoptosis. Recombinant caspase-3 can also cleave eukaryotic initiation factor 4G to yield the 76 kDa fragment both in cell extracts and when the eukaryotic initiation factor 4G is presented in a purified eukaryotic initiation factor 4F complex. These results indicate that caspase-3 activity is necessary and sufficient for eukaryotic initiation factor 4G degradation.
authors.affiliation: Biochemistry Group, School of Biological Sciences, University of Sussex, Brighton, UK.
authors.forename: M
authors.initials: M
authors.lastname: Bushell
authors.forename: L
authors.initials: L
authors.lastname: McKendrick
authors.forename: R U
authors.initials: RU
authors.lastname: Jänicke
authors.forename: M J
authors.initials: MJ
authors.lastname: Clemens
authors.forename: S J
authors.initials: SJ
authors.lastname: Morley
mesh_terms: D017209:Apoptosis / Q000235:genetics; D053148:Caspase 3; D020169:Caspases / Q000235:genetics / Q000378:metabolism*; D004789:Enzyme Activation; D039603:Eukaryotic Initiation Factor-4G; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D010448:Peptide Initiation Factors / Q000235:genetics / Q000378:metabolism*; D015398:Signal Transduction; D014407:Tumor Cells, Cultured
chemical_list: D039603:Eukaryotic Initiation Factor-4G; D010448:Peptide Initiation Factors; C505407:CASP3 protein, human; D053148:Caspase 3; D020169:Caspases