Cap-independent translation conferred by the 5′ leader of tobacco etch virus is eukaryotic initiation factor 4G dependent

被引:100
作者
Gallie, DR [1 ]
机构
[1] Univ Calif Riverside, Dept Biochem, Riverside, CA 92521 USA
关键词
D O I
10.1128/JVI.75.24.12141-12152.2001
中图分类号
Q93 [微生物学];
学科分类号
071005 ; 100705 ;
摘要
The 5' leader of tobacco etch virus (TEV) genomic RNA directs efficient translation from the naturally uncapped viral mRNA. Two distinct regions within the TEV 143-nucleotide leader confer cap-independent translation in vivo even when present in the intercistronic region of a discistronic mRNA, indicating that the TEV leader contains an internal ribosome entry site (IRES). In this study, the requirements for TEV IRES activity were investigated. The TEV IRES enhanced translation of monocistronic or dicistronic mRNAs in vitro under competitive conditions, i.e., at high RNA concentration or in lysate partially depleted of eukaryotic initiation factor 4F (eIF4F) and eIFiso4F, the two cap binding complexes in plants. The translational advantage conferred by the TEV IRES under these conditions was lost when the lysate reduced in eIF4F and eIFiso4F was supplemented with eIF4F (or, to a lesser extent, eIFiso4F) but not when supplemented with eIF4E, eIFiso4E, eIF4A, or eIF4B. eIF4G, the large subunit of eIF4F, was responsible for the competitive advantage conferred by the TEV IRES. TEV IRES activity was enhanced moderately by the poly(A)-binding protein. These observations suggest that the TEV IRES directs cap-independent translation through a mechanism that involves eIF4G specifically.
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页码:12141 / 12152
页数:12
相关论文
共 50 条
[1]  
ABRAMSON RD, 1988, J BIOL CHEM, V263, P5462
[2]   A SACCHAROMYCES-CEREVISIAE HOMOLOG OF MAMMALIAN TRANSLATION INITIATION FACTOR-4B CONTRIBUTES TO RNA HELICASE ACTIVITY [J].
ALTMANN, M ;
MULLER, PP ;
WITTMER, B ;
RUCHTI, F ;
LANKER, S ;
TRACHSEL, H .
EMBO JOURNAL, 1993, 12 (10) :3997-4003
[3]  
Belsham GJ, 2000, COLD SPRING HARBOR M, V39, P869
[4]   Intact eukaryotic initiation factor 4G is required for hepatitis A virus internal initiation of translation [J].
Borman, AM ;
Kean, KM .
VIROLOGY, 1997, 237 (01) :129-136
[5]  
BROWNING KS, 1987, J BIOL CHEM, V262, P11228
[6]  
BROWNING KS, 1992, J BIOL CHEM, V267, P10096
[7]  
BROWNING KS, 1987, J BIOL CHEM, V262, P538
[8]   Disruption of the interaction of mammalian protein synthesis eukaryotic initiation factor 4B with the poly(A)-binding protein by caspase- and viral protease-mediated cleavages [J].
Bushell, M ;
Wood, W ;
Carpenter, G ;
Pain, VM ;
Morley, SJ ;
Clemens, MJ .
JOURNAL OF BIOLOGICAL CHEMISTRY, 2001, 276 (26) :23922-23928
[9]   CAP-INDEPENDENT ENHANCEMENT OF TRANSLATION BY A PLANT POTYVIRUS 5' NONTRANSLATED REGION [J].
CARRINGTON, JC ;
FREED, DD .
JOURNAL OF VIROLOGY, 1990, 64 (04) :1590-1597
[10]   THE TOBACCO ETCH VIRAL 5'-LEADER AND POLY(A) TAIL ARE FUNCTIONALLY SYNERGISTIC REGULATORS OF TRANSLATION [J].
GALLIE, DR ;
TANGUAY, RL ;
LEATHERS, V .
GENE, 1995, 165 (02) :233-238