title: microRNAs associated with the different human Argonaute proteins.
abstract: MicroRNAs (miRNAs) are small noncoding RNAs that function in literally all cellular processes. miRNAs interact with Argonaute (Ago) proteins and guide them to specific target sites located in the 3'-untranslated region (3'-UTR) of target mRNAs leading to translational repression and deadenylation-induced mRNA degradation. Most miRNAs are processed from hairpin-structured precursors by the consecutive action of the RNase III enzymes Drosha and Dicer. However, processing of miR-451 is Dicer independent and cleavage is mediated by the endonuclease Ago2. Here we have characterized miR-451 sequence and structure requirements for processing as well as sorting of miRNAs into different Ago proteins. Pre-miR-451 appears to be optimized for Ago2 cleavage and changes result in reduced processing. In addition, we show that the mature miR-451 only associates with Ago2 suggesting that mature miRNAs are not exchanged between different members of the Ago protein family. Based on cloning and deep sequencing of endogenous miRNAs associated with Ago1-3, we do not find evidence for miRNA sorting in human cells. However, Ago identity appears to influence the length of some miRNAs, while others remain unaffected.
authors: Biochemistry Center Regensburg (BZR), Laboratory for RNA Biology, University of Regensburg, Universitätsstrasse 31, 93053 Regensburg, Germany.
authors: Anne
authors: A
authors: Dueck
authors: Christian
authors: C
authors: Ziegler
authors: Alexander
authors: A
authors: Eichner
authors: Eugene
authors: E
authors: Berezikov
authors: Gunter
authors: G
authors: Meister
mesh_terms: D000818:Animals; D060565:Argonaute Proteins / Q000378:metabolism*; D002460:Cell Line; D006801:Humans; D051379:Mice; D008810:Mice, Inbred C57BL; D035683:MicroRNAs / Q000737:chemistry / Q000378:metabolism*; D012323:RNA Processing, Post-Transcriptional; D034741:RNA, Small Interfering / Q000378:metabolism
chemical_list: C466422:AGO2 protein, human; C526735:Ago2 protein, mouse; D060565:Argonaute Proteins; D035683:MicroRNAs; C550758:Mirn451 microRNA, mouse; D034741:RNA, Small Interfering