Agency of Industrial Science and Technology Ministry of International

Satoshi Nishikawa

Hidekatsu Maeda

Kazunari Taira

The invention provides a recombinant plasmid containing a sequence encoding any genes inserted between 5' and 3' self-cleavage ribozymes. The recombinant plasmid can be amplified in vivo as well as in vitro while growing the host cell. When obtaining RNA transcripts of the inserted sequence, the recombinant plasmid does not require a restriction enzyme digestion step (run-off transcription) since cis-acting ribozymes perform self-catalyzed cleavage at 5' and 3' sides of the inserted sequence once it is transcribed. In this specific example, the trans-acting RNA enzyme sequence is inserted between 5' and 3' cleavage ribozymes. However, the trans-acting ribozyme sequence in the recombinant plasmid can be replaceable with any other sequence (e.g., antisense RNA, RNAs of HIV-1, HDV and other RNA viruses etc.). This construct is especially useful since each unit, consisting of 5' processing ribozyme, inserted sequence, and 3' processing ribozyme, can be connected in tandem. By so doing, ribozymes targeted to various sites can initially be transcribed as a long RNA chain which subsequently undergoes cleavage to produce independent trans-acting ribozymes, each possessing a specific target site.

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Tsukuba, Japan

Satoshi Nishikawa