In vitro analysis of argonaute-mediated target cleavage and translational repression in plants

Abstract

MicroRNAs (miRNAs) are endogenous small RNAs, which negatively regulate expression of complementary target genes at the post-transcriptional level. In plants, miRNAs are mainly loaded onto ARGONAUTE1 to form RNA-induced silencing complexes (RISCs), which mediate target mRNA cleavage as well as translational repression. The cell-free system derived from tobacco BY-2 protoplasts has become a powerful tool not only for the analysis of RISC assembly mechanism but also for mechanistic dissection of plant RISC functions. Here we describe the detailed protocols for the preparation of BY-2 cell lysate and the procedure to analyze the dual function of plant RISC—target cleavage and translational repression—in vitro.