title: Processing of primary microRNAs by the Microprocessor complex.
abstract: Mature microRNAs (miRNAs) are generated via a two-step processing pathway to yield approximately 22-nucleotide small RNAs that regulate gene expression at the post-transcriptional level. Initial cleavage is catalysed by Drosha, a nuclease of the RNase III family, which acts on primary miRNA transcripts (pri-miRNAs) in the nucleus. Here we show that Drosha exists in a multiprotein complex, the Microprocessor, and begin the process of deconstructing that complex into its constituent components. Along with Drosha, the Microprocessor also contains Pasha (partner of Drosha), a double-stranded RNA binding protein. Suppression of Pasha expression in Drosophila cells or Caenorhabditis elegans interferes with pri-miRNA processing, leading to an accumulation of pri-miRNAs and a reduction in mature miRNAs. Finally, depletion or mutation of pash-1 in C. elegans causes de-repression of a let-7 reporter and the appearance of phenotypic defects overlapping those observed upon examination of worms with lesions in Dicer (dcr-1) or Drosha (drsh-1). Considered together, these results indicate a role for Pasha in miRNA maturation and miRNA-mediated gene regulation.
authors.affiliation: Cold Spring Harbor Laboratory, Watson School of Biological Sciences, 1 Bungtown Road, Cold Spring Harbor, New York 11724, USA.
authors.forename: Ahmet M
authors.initials: AM
authors.lastname: Denli
authors.forename: Bastiaan B J
authors.initials: BB
authors.lastname: Tops
authors.forename: Ronald H A
authors.initials: RH
authors.lastname: Plasterk
authors.forename: René F
authors.initials: RF
authors.lastname: Ketting
authors.forename: Gregory J
authors.initials: GJ
authors.lastname: Hannon
mesh_terms: D000818:Animals; D017173:Caenorhabditis elegans / Q000235:genetics / Q000378:metabolism; D029742:Caenorhabditis elegans Proteins / Q000235:genetics / Q000378:metabolism*; D002460:Cell Line; D029721:Drosophila Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D004331:Drosophila melanogaster / Q000235:genetics / Q000378:metabolism; D004722:Endoribonucleases / Q000235:genetics / Q000378:metabolism; D017930:Genes, Reporter / Q000235:genetics; D006801:Humans; D035683:MicroRNAs / Q000235:genetics / Q000378:metabolism*; D046912:Multiprotein Complexes; D010641:Phenotype; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D012323:RNA Processing, Post-Transcriptional; D016601:RNA-Binding Proteins / Q000737:chemistry / Q000378:metabolism*; D043244:Ribonuclease III / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*
chemical_list: D029742:Caenorhabditis elegans Proteins; D029721:Drosophila Proteins; D035683:MicroRNAs; D046912:Multiprotein Complexes; D016601:RNA-Binding Proteins; D004722:Endoribonucleases; C118116:dcr-1 protein, C elegans; D043244:Ribonuclease III; C493335:drosha protein, Drosophila; C493336:drsh-1 protein, C elegans