title: Distinct ribonucleoprotein reservoirs for microRNA and siRNA populations in C. elegans.
abstract: MicroRNAs (miRNAs) are regulatory molecules that share both biosynthetic derivation (cleavage from short hairpin precursor RNAs) and functional roles (downregulation of specific mRNAs through targeted degradation and/or translational inhibition). A distinct family of small RNAs, termed siRNAs, have some common characteristics but exhibit distinct modes of biosynthesis and function. In this study, we report procedures for purification of a predominant species of miRNA-containing ribonucleoprotein complexes from Caenorhabditis elegans and demonstrate that this population is distinct from the predominant pool of siRNA-containing ribonucleoprotein complexes. An observed miRNP-associated RNA population consisting predominantly (>95%) of miRNAs supported the unique identity of miRNPs as biological effectors within the cell, provided clean material for analysis of changes in miRNA spectra during development, and provided strong evidence of miRNA character for a number of novel small RNAs. Likewise, the RNA spectrum derived from partial siRNP purification was useful in defining functional characteristics of this more diverse population of small RNAs.
authors.affiliation: Department of Molecular Cell and Developmental Biology, Center for Molecular Biology of RNA, University of California Santa Cruz 95064, USA.
authors.forename: Sam G
authors.initials: SG
authors.lastname: Gu
authors.forename: Julia
authors.initials: J
authors.lastname: Pak
authors.forename: Sergio
authors.initials: S
authors.lastname: Barberan-Soler
authors.forename: Mustapha
authors.initials: M
authors.lastname: Ali
authors.forename: Andrew
authors.initials: A
authors.lastname: Fire
authors.forename: Alan M
authors.initials: AM
authors.lastname: Zahler
mesh_terms: D000818:Animals; D017173:Caenorhabditis elegans / Q000235:genetics* / Q000378:metabolism*; D029742:Caenorhabditis elegans Proteins / Q000235:genetics / Q000378:metabolism*; D035683:MicroRNAs / Q000032:analysis / Q000302:isolation & purification / Q000378:metabolism*; D034741:RNA, Small Interfering / Q000032:analysis / Q000302:isolation & purification / Q000378:metabolism*; D012261:Ribonucleoproteins / Q000378:metabolism*
chemical_list: D029742:Caenorhabditis elegans Proteins; D035683:MicroRNAs; D034741:RNA, Small Interfering; D012261:Ribonucleoproteins