title: Regulation of pre-miRNA processing.
abstract: microRNAs are endogenously expressed  21 nucleotide noncoding RNAs. microRNA-mediated regulation of the translation of specific mRNA is implicated in a range of developmental processes and pathologies. As such, miRNA expression is tightly controlled in normal development by both transcriptional and post-transcriptional mechanisms. This chapter is concerned with the control of pre-miRNA processing of individual miRNAs by specific factors. It is focussed on the regulation of a subset of miRNAs by the RNA-binding protein Lin28/LIN-28. We discuss how Lin28/LIN-28 can sequester pre-let-7 miRNA precursor to prevent Dicer-mediated processing. We describe how interaction of pre-let-7 with Lin28/ LIN-28 leads to pre-let-7 uridylation and subsequent degradation. Finally, we analyze how let-7 and Lin28/LIN-28 together act as a highly conserved developmental switch that controls stem cell differentiation in C. elegans and mammals.
authors.affiliation: Wellcome Trust Cancer Research UK Gurdon Institute and Department of Biochemistry, University of Cambridge, The Henry Wellcome Building of Cancer and Developmental Biology, Tennis Court Rd, Cambridge CB2 1QN, UK.
authors.forename: Nicolas J
authors.initials: NJ
authors.lastname: Lehrbach
authors.forename: Eric A
authors.initials: EA
authors.lastname: Miska
mesh_terms: D000818:Animals; D017173:Caenorhabditis elegans / Q000235:genetics*; D029742:Caenorhabditis elegans Proteins / Q000502:physiology; D035683:MicroRNAs / Q000502:physiology; D012322:RNA Precursors / Q000502:physiology*; D012097:Repressor Proteins / Q000502:physiology
chemical_list: D029742:Caenorhabditis elegans Proteins; C452195:LIN-28 protein, C elegans; D035683:MicroRNAs; D012322:RNA Precursors; D012097:Repressor Proteins; C474488:let-7 microRNA, C elegans