Antisense RNA is a single-stranded RNA that is complementary to messenger RNA and can inhibit its translation by base pairing and physically obstructing translation machinery. An example is the hok/sok system in E. coli where the sok RNA antitoxin inhibits the hok toxin RNA. Antisense RNA has roles such as inactivating genes for polygalacturonase and ethylene synthesis. It also has potential applications in gene therapy and developing therapies for viruses and conditions like high blood pressure.

1. ANTISENSE RNADesh Bandhu 10/pbt/006

2. INTRODUCTIONAntisense RNA is a single-stranded RNA that is complementary to a messenger RNA (mRNA) strand transcribed within a cell.Antisense RNA may be introduced into a cell to inhibit translation of a complementary mRNA by base pairing to it and physically obstructing the translation machinery.An example of naturally occurring mRNA antisense mechanism is the hok/sok system of the E.coli R1 plasmid.

3. INVITRO MECHANISM

4. Hok/sok system(Natural mechanism)The hok/sok system involves three genes:hok, host killing - a long lived (half-life 20 minutes) toxin.sok, suppression of killing - a short lived (half-life 30 seconds) RNA antitoxinmok, modulation of killing - required for hok translation

6. ROLE OF ANTESENSE RNATo inactivate the polygalacturonase gene.To inactivate ethylene synthesis.Reduction of starch content in vegetables.Modification of flower colour in various decorative plant.Mammalian genomes encode numerous natural antisense transcripts, but the function of these transcripts is not well understood.

7. FUTURE PROSPECTSIn Gene therapy.To develop more effective therapies for infection with certain virus such as HIV and hepapetitis B virus.To reduced the elevated blood pressure.