Inhibition of translation initiation by antisense oligonucleotides via an RNase-H independent mechanism.
We have used alpha-oligomers as antisense oligonucleotides complementary to three different sequences of the rabbit beta-globin mRNA: a region adjacent to the cap site, a region spanning the AUG initiation codon or a sequence in the coding region. These alpha-oligonucleotides were synthesized either with a free 5' OH group or linked to an acridine derivative. The effect of these oligonucleotides on mRNA translation was investigated in cell-free extracts and in Xenopus oocytes. In rabbit reticulocyte lysate and in wheat germ extracts oligomers targeted to the cap site and the initiation codon reduced beta-globin synthesis in a dose-dependent manner, whereas the target mRNA remained intact. The anti-cap alpha-oligomer was even more efficient that its beta-counterpart in rabbit reticulocyte lysate. In contrast, only the alpha-oligomer, linked to the acridine derivative, complementary to the cap region displayed significant antisense properties in Xenopus oocytes. Therefore initiation of translation can be arrested by oligonucleotide/RNA hybrids which are not substrates for RNase-H.
Boiziau
C
C
Laboratoire de Biophysique, Muséum National d'Histoire Naturelle, Paris, France.
Kurfurst
R
R
Cazenave
C
C
Roig
V
V
Thuong
N T
NT
Toulmé
J J
JJ
D000818:Animals; D001483:Base Sequence; D002474:Cell-Free System; D004722:Endoribonucleases / Q000378:metabolism*; D005260:Female; D005914:Globins / Q000235:genetics*; D008969:Molecular Sequence Data; D016376:Oligonucleotides, Antisense; D014176:Protein Biosynthesis; D012333:RNA, Messenger / Q000096:biosynthesis* / Q000378:metabolism; D011817:Rabbits; D016914:Ribonuclease H; D014981:Xenopus
D016376:Oligonucleotides, Antisense; D012333:RNA, Messenger; D005914:Globins; D004722:Endoribonucleases; D016914:Ribonuclease H