USE OF PROTEINS WITH AFFINITY FOR SHORT RNAS WITH POST-TRANSCRIPTIONAL GENE SILENCING-SUPPRESSOR ACTIVITY

摘要

The invention relates to the use of a protein that can specifically bind or capture populations of short double-stranded RNA of a given size. Fusions to said proteins can be used as an affinity support in order to isolate and purify specific RNAs present in eukaryotic cells, such as double-stranded short interfering RNAs. They can also be used to suppress post-transcriptional gene silencing (PTGS) in a specific and conditional manner if the presence of the protein in the cells is controlled. In addition, they can be fused to a specific polypeptide sequence that directs protein p19, which may or may not be bound to RNA, towards specific cells to which the transported function is to be directed. Protein p19 of the tombusviruses (tomato bushy virus group) can be used as the preferred protein, said protein binding 21-nt siRNAs with great affinity, with 2 nt at the protruding 3' end and phosphate groups at 5'.