Thursday, March 05, 2009

Making Sense of Antisense

David Tyler posted an entry at the ARN ID blog titled Post details: Hidden biological information via antisense transcription. DNA is double stranded and the terms sense and antisense are used to distinguish the strands with respect to the transcription process. Tyler links to the press release Mammalian Transcriptome Mapped, and It Makes Antisense. The press release contains this informative description:

RNA, which is a single strand of nucleotides, is made by enzymes as an exact base-to-base copy of DNA. Since DNA is double-stranded, only one of these strands, the so-called sense strand, encodes for proteins. In normal DNA transcription, the two strands are split apart, and only the sense strand is copied. The other DNA strand, the "antisense" strand, can also be transcribed into RNA. Antisense transcription is the "reverse" expression of genomic DNA. If the same molecule of DNA is transcribed into antisense RNA, then the transcript has the reverse sequence as the original DNA sequence.

Antisense RNA transcripts can exert function because they can bind to the RNA transcripts for which they are complementary messengers and modulate their expression into proteins. In fact, synthetic antisense molecules have been widely used to inhibit conventional genes, including applications as anti-viral and anti-cancer drugs, which are currently on the market or in clinical trials.

The complementary nature of nucleotde bases makes regulatory functions a natural outgrowth of base pairing.

Hat Tip to Clare



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