Method to trigger RNA interference

摘要

A method to generate siRNAs in vivo is described, as are constructs and compositions useful in the method. The method does not depend on the use of DNA or synthetic constructs that contain inverted duplications or dual promoters so as to form perfect or largely double-stranded RNA. Rather, the method depends on constructs that yield single-stranded RNA transcripts, and exploits endogenous or in vivo-produced miRNAs or siRNAs to initiate production of siRNAs. The miRNAs or siRNAs guide cleavage of the transcript and set the register for production of siRNAs (usually 21 nucleotides in length) encoded adjacent to the initiation cleavage site within the construct. The method results in specific formation of siRNAs of predictable size and register (phase) relative to the initiation cleavage site. The method can be used to produce specific siRNAs in vivo for inactivation or suppression of one or more target genes or other entities, such as pathogens.

主权项

1. An engineered single-stranded RNA transcript comprising:
an engineered initiator sequence of about 20 to 25 nucleotides with an initiation cleavage site between the tenth and eleventh or eleventh and twelfth nucleotides counted from the 3′ end of the initiator sequence, wherein the initiator sequence is recognized by a RNA-induced Silencing Complex guided by an siRNA or a miRNA that has sufficient complementarity to the initiator sequence to initiate cleavage in 21-nucleotide register from the initiation cleavage site; and at least one gene suppressing segment engineered to be in about 21-nucleotide register counted either upstream or downstream from the initiation cleavage site, wherein the gene suppressing segment or its complement is complementary to RNA transcribed from a target gene selected for siRNA inhibition.