Background

Discovering of non-coding RNA (ncRNA) and reverse transcription of virus composes the central dogma that was declared by Francis Crick. Since ncRNAs do not encode any proteins, they had been thought that they don’t have any functions. However, it was proved that they do have many functions. For example, some ncRNAs reduce the efficiency of translation, while others promote that. (C. Claudia et al., 2012^[1]).

There are ncRNAs called anti-sense RNA (asRNA), which down-regulate translation. An asRNA has a complement sequence of its target mRNA and reduces the translation efficiency by hybridizing. asRNA can be easily synthesized, but there is no clear method to make stable, highly efficient asRNA.

Fig. 1 An asRNA hybridizes with target mRNA and interrupts entry of ribosome.

Fig. 2 Stem structure stabilizes asRNA

In this situation, Nakashima and his colleagues discovered asRNA that is sandwiched by 38 base pairs of repeated sequence is stable and regulates translation at a high efficiency (N. Nakashima et al., 2006^[2]).

Many iGEM teams prepare their project using asRNA, but how many teams use the asRNA that is designed on clear concepts? This year, we provide you a BioBrick standardized procedure to design asRNA.

Our procedure to design asRNAs will assure you that

• The asRNA are based on a clear design concept.
• They are calculated to have ideal second structures.
• They have high efficiency to regulate translation, based on our results.

Using this procedure, we arranged these projects.

• Declared a standard procedure to design asRNA that has modified stem sequence.
• Synthesized B0034 (BBa_B0034) - most popular RBS - specific asRNA, and widely regulated translation efficiency.
• Synthesized various length asRNA and determined the optimum length.

Our project provides not only highly efficient asRNA but also brand new viewpoints to your project. As yet, almost all the projects presented to iGEM have focused on to regulate the behavior of E. coli, only by transforming plasmids. But now, you can use our asRNA and regulate expression of the genes which are on genome.

Hybridization of a mRNA and a specific asRNA seems like a love story in the RNA world, so we named our project "RNA in love". Let’s watch over RNA in love!

1. C. Claudiaet al. (2012) Long non-coding antisense RNA controls Uchl1 translation through an embedded SINEB2 repeat. Nature 491: 7424 454-
2. N. Nakashima et al. (2006) Paired termini stabilize antisense RNAs and enhance conditional gene silencing in Escherichia coli. Nucleic Acids Res 34: 20 e138