Measurement of in vivo RISC activity using an in vitro non-radioactive RISC assay

Kettner-Buhrow, D., Guenther, B., Kaelble, S., Joshua-Tor, L., Kracht, M. (April 2009) Measurement of in vivo RISC activity using an in vitro non-radioactive RISC assay. Naunyn-Schmiedebergs Archives of Pharmacology, 379 (281 Ab). p. 59. ISSN 0028-1298

DOI: 10.1007/s00210-009-0404-1


Argonaute 2 (Ago2) is the core catalytic enzyme of RISC (RNA-induced silencing complex) that mediates RNA cleavage by RNA-interference (RNAi). RNAi is an important gene regulatory mechanism, that depends on small interfering (si)RNAs. The minimal components of RISC are members of the Argonaute family of proteins plus small RNA guides. So far, Ago2 activity was assessed using 32P-cap-labelled in vitro synthesized mRNA targets and ATP as substrates. Cleavage products are detected after purification and separation of reaction mixtures by denaturing Urea-PAGE followed by autoradiography. This assay is time consuming, difficult to handle and only semiquantitative. Recently, we have reported the establishment of a non-radioactive RISC assay in vitro. GST-Ago2 was purified to near homogeneity from E.Coli and incubated with an 180bp or 723bp luciferase mRNA target. Cleavage reaction was started by addition of phosphorylated single stranded complementary RNA oligonucleotides and resulted in complete cleavage of the target RNA. Purified reaction mixtures were separated and visualized using RNA Chips on an Agilent 2100 Bioanalyzer instrument. Here we report, that after optimization with respect to specificity and efficacy it is also possible to use the established in vitro RISC assay to measuring activity of endogenous Ago2 isolated from cells. Thus, the non-radioactive Ago2 assay can be used to identify inhibitors or activators of Ago2 in cell-based assay systems.

Item Type: Paper
Additional Information: Meeting Abstract
Subjects: Investigative techniques and equipment > RNAI
bioinformatics > genomics and proteomics > genetics & nucleic acid processing > protein structure, function, modification > protein types > argonaute proteins
Investigative techniques and equipment > assays
Publication Type > Meeting Abstract
CSHL Authors:
Communities: CSHL labs > Joshua-Tor lab
Depositing User: CSHL Librarian
Date: April 2009
Date Deposited: 22 Mar 2012 15:00
Last Modified: 13 Mar 2018 18:52

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