Antisense RNA

Is a transcript of a gene or transposon that may inhibit translation by pairing with the 5′ end of the correct (sense) mRNA and thus prevent its ribosome binding and expression. In several bacterial plasmids, by inhibiting the synthesis of the replication initiator protein, the antisense RNA limits copy number. Some synthetic oligonucleotide analogs may block replication and transcription, interfere with splicing of exons, disrupt RNA structure, destabilize mRNA by interfering with 5′ capping of mRNA, inhibit polyadenylation, activate ribonuclease H. When coupled to alkylating agents they can cross-link nucleic acids at the recognized sequences, can be used as vehicles for targeted DNA cleavage, may inhibit receptors, etc. The various functions require a large variety of specific antisense constructs. Usually, the antisense oligonucleotides are 12–50-nucleotide long. According to calculations in the human genome, any 17-base sequence occurs only once, and in the mRNA populations,...