TY - JOUR

T1 - Complementation of defective picornavirus internal ribosome entry site (IRES) elements by the coexpression of fragments of the IRES

AU - Roberts, Lisa O.

AU - Belsham, Graham J.

PY - 1997/1/6

Y1 - 1997/1/6

N2 - Mutant forms of the encephalomyocarditis virus (EMCV) internal ribosome entry site (IRES) have been produced and shown to be severely defective in directing internal initiation of protein synthesis within cells using the vaccinia/T7 RNA polymerase system. Mutants in different regions of the IRES were complemented in trans by coexpression of the intact EMCV IRES but not by coexpression of the related IRES elements from Theiler's murine encephalomyelitis virus (another cardiovirus) or from foot-and-mouth disease virus. Distinct, truncated regions of the EMCV IRES, insufficient to direct internal initiation, were also shown to complement defective EMCV I RES elements. It was necessary for the complementing molecule, whether truncated or full length, to be expressed in the positive sense orientation. RT-PCR analysis provided no support for the idea that any recombination event was responsible for the complementation. The data suggest that multiple activities are performed by distinct functional entities within the IRES in the process of internal initiation of protein synthesis. At least some of these different functions may be achieved by different molecules acting in trans.

AB - Mutant forms of the encephalomyocarditis virus (EMCV) internal ribosome entry site (IRES) have been produced and shown to be severely defective in directing internal initiation of protein synthesis within cells using the vaccinia/T7 RNA polymerase system. Mutants in different regions of the IRES were complemented in trans by coexpression of the intact EMCV IRES but not by coexpression of the related IRES elements from Theiler's murine encephalomyelitis virus (another cardiovirus) or from foot-and-mouth disease virus. Distinct, truncated regions of the EMCV IRES, insufficient to direct internal initiation, were also shown to complement defective EMCV I RES elements. It was necessary for the complementing molecule, whether truncated or full length, to be expressed in the positive sense orientation. RT-PCR analysis provided no support for the idea that any recombination event was responsible for the complementation. The data suggest that multiple activities are performed by distinct functional entities within the IRES in the process of internal initiation of protein synthesis. At least some of these different functions may be achieved by different molecules acting in trans.

UR - http://www.scopus.com/inward/record.url?scp=0031555658&partnerID=8YFLogxK

U2 - 10.1006/viro.1996.8312

DO - 10.1006/viro.1996.8312

M3 - Journal article

C2 - 9007058

AN - SCOPUS:0031555658

VL - 227

SP - 53

EP - 62

JO - Virology

JF - Virology

SN - 0042-6822

IS - 1

ER -