La autoantigen suppresses IRES-dependent translation of the hepatitis A virus.
The human RNA-binding protein La, is an essential trans-acting factor in IRES-dependent translation initiation of poliovirus, the prototypic picornavirus. For hepatitis A virus (HAV), an unusual member of this virus family, the role of host proteins in its inefficient translation and slow replication is unclear. Using small interfering RNA in vivo and purified La in vitro, we demonstrate for the first time that La suppresses HAV IRES-mediated translation and replication. We show that La binds specifically to distinct parts of the HAV IRES and that-unlike poliovirus-HAV proteinase 3C does not cleave La. The La-mediated suppression of HAV translation and stimulation of poliovirus translation implies unexpected mechanistic differences between viral IRES elements.
Cordes
Susann
S
Institute of Medical Molecular Biology, University of Lübeck, Ratzeburger Allee 160, D-23538 Lübeck, Germany.
Kusov
Yuri
Y
Heise
Tilman
T
Gauss-Müller
Verena
V
D000086042:3C Viral Proteases; D001324:Autoantigens / Q000378:metabolism / Q000502:physiology*; D045744:Cell Line, Tumor; D003546:Cysteine Endopeptidases / Q000378:metabolism; D030041:Hepatitis A virus / Q000187:drug effects*; D006801:Humans; D014176:Protein Biosynthesis / Q000187:drug effects*; D034622:RNA Interference; D012261:Ribonucleoproteins / Q000378:metabolism / Q000502:physiology*; D012270:Ribosomes / Q000502:physiology*; D014764:Viral Proteins / Q000378:metabolism; D000097585:SS-B Antigen
D000086042:3C Viral Proteases; D001324:Autoantigens; D003546:Cysteine Endopeptidases; D012261:Ribonucleoproteins; D014764:Viral Proteins; D000097585:SS-B Antigen