Identifying the target mRNA against miRNA is essential to understanding cellular regulatory networks. However, due to the low complementarity between a miRNA and its target mRNAs in mammals, identification of mammalian miRNA targets has been a challenge and only a few have been reported to date. Researchers at the Genome Research Laboratories, Wako Pure Chemical Industries, Japan propose that the ability to isolate and profile both the mRNA and miRNA components of the RISC complex has the potential to aid in the identification of miRNA targets. They have developed a protocol for isolation of endogenous RISC-associated miRNAs and mRNAs by immunoprecipitation with antibodies specific for Ago2, an Argonaute family protein that is the central RISC component. They used microRNA microarray to compare the profile the immunopurified RNA with that of total RNA. Microarray results suggested that Ago2-immunopurification could trap almost all expressed miRNA species. Subsequent cloning and analysis of both miRNAs and mRNAs correctly correlated a well-characterized miRNA with its target.
- Hayashida Y, Nishibu T, Inoue K, Kurokawa T. (2009) A useful approach to total analysis of RISC-associated RNA. BMC Res Notes 2,169. [abstract]