Human Argonaute2 mediates RNA cleavage targeted by miRNAs and siRNAs.
Argonaute proteins associate with small RNAs that guide mRNA degradation, translational repression, or a combination of both. The human Argonaute family has eight members, four of which (Ago1 through Ago4) are closely related and coexpressed in many cell types. To understand the biological function of the different Ago proteins, we set out to determine if Ago1 through Ago4 are associated with miRNAs as well as RISC activity in human cell lines. Our results suggest that miRNAs are incorporated indiscriminately of their sequence into Ago1 through Ago4 containing microRNPs (miRNPs). Purification of the FLAG/HA-epitope-tagged Ago containing complexes from different human cell lines revealed that endonuclease activity is exclusively associated with Ago2. Exogenously introduced siRNAs also associate with Ago2 for guiding target RNA cleavage. The specific role of Ago2 in guiding target RNA cleavage was confirmed independently by siRNA-based depletion of individual Ago members in combination with a sensitive positive-readout reporter assay.
Meister
Gunter
G
Laboratory of RNA Molecular Biology, The Rockefeller University, 1230 York Avenue, Box 186, New York, NY 10021, USA.
Landthaler
Markus
M
Patkaniowska
Agnieszka
A
Dorsett
Yair
Y
Teng
Grace
G
Tuschl
Thomas
T
D060565:Argonaute Proteins; D001665:Binding Sites; D029721:Drosophila Proteins / Q000235:genetics / Q000378:metabolism*; D020868:Gene Silencing; D017930:Genes, Reporter; D006367:HeLa Cells; D006801:Humans; D035683:MicroRNAs / Q000235:genetics*; D014176:Protein Biosynthesis; D012313:RNA / Q000235:genetics / Q000378:metabolism*; D016372:RNA, Antisense / Q000378:metabolism*; D012333:RNA, Messenger / Q000378:metabolism; D034741:RNA, Small Interfering / Q000235:genetics*; D034743:RNA-Induced Silencing Complex / Q000235:genetics / Q000378:metabolism*; D012261:Ribonucleoproteins / Q000235:genetics
C433807:AGO2 protein, Drosophila; D060565:Argonaute Proteins; D029721:Drosophila Proteins; D035683:MicroRNAs; D016372:RNA, Antisense; D012333:RNA, Messenger; D034741:RNA, Small Interfering; D034743:RNA-Induced Silencing Complex; D012261:Ribonucleoproteins; D012313:RNA