Translation of equine infectious anemia virus bicistronic tat-rev mRNA requires leaky ribosome scanning of the tat CTG initiation codon.

AUTOR(ES)

Carroll, R

RESUMO

We have examined the translational regulation of the equine infectious anemia virus (EIAV) bicistronic tat-rev mRNA. Site-directed mutagenesis of the tat leader region followed by expression of the tat-rev cDNA both in vitro and in transiently transfected cells established that tat translation is initiated exclusively at a CTG codon. Increasing the efficiency of tat translation by altering the CTG initiator to ATG resulted in a dramatic decrease in translation of the downstream (rev) cistron, indicating that leaky scanning of the tat CTG initiation codon permitted translation of the downstream rev cistron. Since the tat leader sequences precede the major EIAV splice donor and are therefore present at the 5' termini of both spliced and unspliced viral mRNAs, the expression of all EIAV structural and regulatory proteins is dependent on leaky scanning of the tat initiator.

Documentos Relacionados

• Efficient initiation of mammalian mRNA translation at a CUG codon.
• Equine infectious anemia virus trans-regulatory protein Rev controls viral mRNA stability, accumulation, and alternative splicing.
• Translation of Sindbis virus mRNA: effects of sequences downstream of the initiating codon.
• Selective translation initiation on bicistronic simian virus 40 late mRNA.
• Leaky Scanning Is the Predominant Mechanism for Translation of Human Papillomavirus Type 16 E7 Oncoprotein from E6/E7 Bicistronic mRNA