Poly(A) binding protein, C-terminally truncated by the hepatitis A virus proteinase 3C, inhibits viral translation
نویسندگان
چکیده
Proteolytic cleavage of translation initiation factors is a means to interfere with mRNA circularization and to induce translation arrest during picornaviral replication or apoptosis. It was shown that the regulated cleavages of eukaryotic initiation factor (eIF) 4G and poly(A)-binding protein (PABP) by viral proteinases correlated with early and late arrest of host cap-dependent and viral internal ribosome entry site (IRES)-dependent translation, respectively. Here we show that in contrast to coxsackievirus, eIF4G is not a substrate of proteinase 3C of hepatitis A virus (HAV 3C(pro)). However, PABP is cleaved by HAV 3C(pro) in vitro and in vivo, separating the N-terminal RNA-binding domain (NTD) of PABP from the C-terminal protein-interaction domain. In vitro, NTD has a dominant negative effect on HAV IRES-dependent translation and an enhanced binding affinity to the RNA structural element pY1 in the 5' nontranslated region of the HAV RNA that is essential for viral genome replication. The results point to a regulatory role of PABP cleavage in RNA template switching of viral translation to RNA synthesis.
منابع مشابه
Cleavage of poly(A)-binding protein by poliovirus 3C proteinase inhibits viral internal ribosome entry site-mediated translation.
The two enteroviral proteinases, 2A proteinase (2A(pro)) and 3C proteinase (3C(pro)), induce host cell translation shutoff in enterovirus-infected cells by cleaving canonical translation initiation factors. Cleavage of poly(A)-binding protein (PABP) by 3C(pro) has been shown to be a necessary component for host translation shutoff. Here we show that 3C(pro) inhibits cap-independent translation ...
متن کاملExploring the binding mechanism of the main proteinase in SARS-associated coronavirus and its implication to anti-SARS drug design.
The main proteinase of SARS-associated coronavirus (SARS-CoV) plays an important role in viral transcription and replication, and is an attractive target for anti-SARS drug development. The important thing is to understand its binding mechanism with possible ligands. In this study, we investigated possible noncanonical interactions, potential inhibitors, and binding pockets in the main proteina...
متن کاملPoly(A)-Binding Protein Cellular Translation by Cleavage of Calicivirus 3C-Like Proteinase Inhibits
متن کامل
Hepatitis A virus proteinase 3C binding to viral RNA: correlation with substrate binding and enzyme dimerization.
Proteinase 3C of hepatitis A virus (HAV) plays a key role in the viral life cycle by generating mature viral proteins from the precursor polyprotein. In addition to its proteolytic activity, 3C binds to viral RNA, and thus influences viral genome replication. In order to investigate the interplay between proteolytic activity and RNA binding at the molecular level, we subjected HAV 3C and three ...
متن کاملIdentification of Aptamer-Binding Sites in Hepatitis C Virus Envelope Glycoprotein E2
Hepatitis C Virus (HCV) encodes two envelope glycoproteins, E1 and E2. Our previous work selected a specific aptamer ZE2, which could bind to E2 with high affinity, with a great potential for developing new molecular probes as an early diagnostic reagents or therapeutic drugs targeting HCV. In this study, the binding sites between E2 and aptamer ZE2 were further explored. E2 was truncated to 15...
متن کامل