Antisense 2'-O-methyloligoribonucleotides hybridized to RNA block a nuclear, ATP-dependent 3'-5' exonuclease.
RNA hybridized to 2'-O-methyloligoribonucleotides and incubated in nuclear extracts from HeLa cells is truncated, resulting in a distinct product terminated at the 5' end of the antisense oligonucleotide. The activity responsible for this effect is not RNase H but rather a novel exonuclease degrading RNA in the 3' to 5' direction. The enzymes requires ATP and Mg2+ ions. Except for dATP, no other nucleoside triphosphate or nonhydrolyzable ATP analog supports the exonucleolytic activity. In spite of the nuclear origin and activity requirements similar to those required for pre-mRNA splicing, the exonuclease operates with equal efficiency on intron-containing and intronless RNAs, excluding the possibility that it is associated with the splicing machinery.
Dominski
Z
Z
Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill 27599, USA.
Ferree
P
P
Kole
R
R
D000255:Adenosine Triphosphate / Q000378:metabolism; D004791:Enzyme Inhibitors / Q000737:chemistry / Q000494:pharmacology*; D043211:Exodeoxyribonuclease V; D005090:Exodeoxyribonucleases / Q000037:antagonists & inhibitors*; D006367:HeLa Cells; D006657:Histones / Q000096:biosynthesis / Q000235:genetics; D006801:Humans; D007438:Introns; D008274:Magnesium / Q000378:metabolism; D008745:Methylation; D016376:Oligonucleotides, Antisense / Q000737:chemistry / Q000494:pharmacology*; D012322:RNA Precursors / Q000235:genetics / Q000378:metabolism*; D012326:RNA Splicing; D012260:Ribonucleases
D004791:Enzyme Inhibitors; D006657:Histones; D016376:Oligonucleotides, Antisense; D012322:RNA Precursors; D000255:Adenosine Triphosphate; D005090:Exodeoxyribonucleases; D012260:Ribonucleases; D043211:Exodeoxyribonuclease V; D008274:Magnesium