A thermosensitive mutant of HRV2 2A proteinase: evidence for direct cleavage of eIF4GI and eIF4GII.
Infection of mammalian cells with picornaviruses like entero-, rhino-, and aphthoviruses leads to an inhibition of cap-dependent cellular protein synthesis by the cleavage of both translation initiation factors, eIF4GI and eIF4GII. In entero- and rhinovirus infection this cleavage process is mediated by the viral 2A proteinase (2A(pro)). In order to discriminate between a direct mode of eIF4G cleavage and an indirect cleavage via activation of a cellular proteinase, a thermosensitive 2A(pro) mutant (ts-2A(pro)) of human rhinovirus 2 was employed. Temperature shift experiments of cytoplasmic HeLa cell extracts incubated with ts-2A(pro) strongly support a direct mode of cleavage of eIF4GI and eIF4GII by the viral 2A(pro).
Institute of Medical Biochemistry, Division of Biochemistry, University of Vienna, Dr. Bohrgasse 9/3, 1030, Vienna, Austria.
Hans Dieter
HD
Liebig
Joachim
J
Seipelt
Elena
E
Vassilieva
Alessandra
A
Gradi
Ernst
E
Kuechler
D010450:Endopeptidases / Q000235:genetics / Q000378:metabolism*; D004795:Enzyme Stability; D039603:Eukaryotic Initiation Factor-4G; D006367:HeLa Cells / Q000378:metabolism; D006801:Humans; D006868:Hydrolysis; D010446:Peptide Fragments / Q000378:metabolism*; D010448:Peptide Initiation Factors / Q000378:metabolism*; D017354:Point Mutation; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism; D012229:Rhinovirus / Q000201:enzymology*; D013696:Temperature
C113920:EIF4G1 protein, human; C491300:EIF4G2 protein, human; D039603:Eukaryotic Initiation Factor-4G; D010446:Peptide Fragments; D010448:Peptide Initiation Factors; D011994:Recombinant Proteins; D010450:Endopeptidases