From analysis of deep‑sequencing data it is apparent that sequence differences occur between the genome and miRNAs. Changes from genomic A to an apparent G in miRNA can be accounted for by the editing activity of ADARs. Questions that arise from this observation are: How many miRNAs are...

During the last decade of the 20th century a totally novel way of gene regulation was revealed. Findings that at first glance appeared freak features of plants or C. elegans turned out to be mechanistically related and deeply conserved throughout evolution. This important insight was primed by...

microRNAs (miRNAs) are small noncoding RNAs that down‑regulate gene expression by reducing stability and/or translation of target mRNAs. In animals, miRNAs arise from sequential processing of hairpin primary transcripts by two RNAse III domain‑containing enzymes, namely Drosha and Dicer,...

Recent evidence suggests that the canonical miRNA processing pathway can be regulated by a number of positive and negative trans‑acting factors. This chapter provides an overview of hnRNP A1‑mediated regulation of miR‑18a biogenesis. Our laboratory has recently established that the...

microRNAs (miRNAs) are small (∼22 nucleotides (nt)), noncoding RNAs that play a critical role in diverse biological functions by modulating mRNA stability and translational control. Numerous miRNA profiling studies have indicated that the levels of miRNAs are tightly controlled during...

microRNAs (miRNAs) are small noncoding RNAs that regulate numerous target mRNAs through an antisense mechanism. Initially thought to be very stable with half‑lives on the order of days, mature miRNAs have recently been shown to be subject to degradation by ‘microRNases’ (miRNases) in...

The Microprocessor, comprising the ribonuclease Drosha and its essential cofactor, the double‑stranded RNA‑binding protein, DGCR8, is essential for the first step of the miRNA biogenesis pathway. It specifically cleaves double‑stranded RNA within stem‑loop structures of primary miRNA...

Gene expression in eukaryotes is subject to extensive regulation at posttran-scriptional levels. One of the most important sites of control involves mRNA 3′ untranslated regions (3'UTRs), which are recognized by RNA‑binding proteins (RBPs) and microRNAs (miRNAs). These factors greatly...

microRNAs (miRNAs) and small interfering RNAs (siRNAs) play important roles in gene regulation and defense responses against transposons and viruses in eukaryotes. These small RNAs generally trigger the silencing of cognate sequences through a variety of mechanisms, including RNA degradation,...

The maturation of primary microRNAs (pri‑miRNAs) to precursor miRNAs (pre‑miRNAs) is mediated by the “microprocessor” complex minimally comprimising two core components, Drosha and DGCR8. However, the roles of RNA‑binding proteins associated with these core units in the large Drosha...

Trim‑NHL proteins are defined by RING, B‑Box and Coiled‑coil protein motifs (referred to collectively as the Trim domain) coupled to an NHL domain. The C. elegans, D. melanogaster, mouse and human Trim‑NHL proteins are potential and in several cases confirmed, E3 ubiquitin ligases....

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...