Scientific Publications by FDA Staff

Virology 2008 Aug 15;378(1):118-22

Cleavage of eukaryotic initiation factor eIF5B by enterovirus 3C proteases.

de Breyne S, Bonderoff JM, Chumakov KM, Lloyd RE, Hellen CU

Hellen, CUT, Suny Downstate Med Ctr, Dept Microbiol & Immunol, 450 Clarkson Ave,Box 44, Brooklyn, NY 11203 USA Suny Downstate Med Ctr, Dept Microbiol & Immunol, Brooklyn, NY 11203 USA Baylor Coll Med, Dept Mol Virol & Microbiol, Houston, TX 77030 USA US FDA, Ctr Biol Evaluat & Res, Rockville, MD 20852 USA

The enteroviruses poliovirus (PV), Coxsackie B virus (CVB) and rhinovirus (HRV) are members of Picornaviridae that inhibit host cell translation early in infection. Enterovirus translation soon predominates in infected cells, but eventually also shuts off. This complex pattern of modulation of translation suggests regulation by a multifactorial mechanism. We report here that eIF5B is proteolytically cleaved during PV and CVB infection of cultured cells, beginning at 3 hours post-infection and increasing thereafter. Recombinant PV, CVB and HRV 3C(pro) cleaved purified native rabbit eukaryotic initiation factor (eIF) 5B in vitro at a single site (VVEQ downward arrowG, equivalent to VMEQ downward arrowG(479) in human eIF5B) that is consistent with the cleavage specificity of enterovirus 3C proteases. Cleavage separates the N-terminal domain of eIF5B from its essential conserved central GTPase and C-terminal domains. 3C(pro)-mediated cleavage of eIF5B may thus play an accessory role in the shutoff of translation that occurs in enterovirus-infected cells.