Role of RNase H in hybrid-arrested translation by antisense oligonucleotides.

AUTOR(ES)

Walder, R Y

RESUMO

The mechanism of hybrid-arrested translation by antisense oligodeoxynucleotides has been investigated with the rabbit reticulocyte lysate system. The oligonucleotides studied were directed against different regions of mouse alpha- or beta-globin mRNAs. Freshly prepared reticulocyte lysates were found to contain 1-2% of the level of RNase H in nucleated cells. This level of activity was sufficient to cleave nearly 100% of the targeted mRNA at the site of hybridization with a complementary oligodeoxynucleotide in 1 hr under conditions of active translation. Using poly(rA).oligo(dT) as a competitive inhibitor of the enzyme, hybrid arrest by oligodeoxynucleotides complementary to the sequence spanning the initiation codon or to a sequence in the coding region was found to be due entirely to cleavage of mRNA by RNase H. Hybridization of oligodeoxynucleotides adjacent to the cap site of beta-globin mRNA, but not the alpha-globin mRNA, also inhibited protein synthesis directly. Even in this case, however, cleavage of the mRNA by RNase H was the predominant pathway of inhibition.

Documentos Relacionados

• Parvovirus genome: nucleotide sequence of H-1 and mapping of its genes by hybrid-arrested translation.
• Structural gene identification and mapping by DNA-mRNA hybrid-arrested cell-free translation.
• Inhibition of translation initiation by antisense oligonucleotides via an RNase-H independent mechanism.
• Inhibition of dengue virus by novel, modified antisense oligonucleotides.
• Inhibition of lymphocyte mediated cytotoxicity by perforin antisense oligonucleotides.