Nuclear Export of MicroRNA Precursors

  title={Nuclear Export of MicroRNA Precursors},
  author={Elsebet Lund and Stephan Güttinger and {\^A}ngelo Calado and James Eric Dahlberg and Ulrike Kutay},
  pages={95 - 98}
MicroRNAs (miRNAs), which function as regulators of gene expression in eukaryotes, are processed from larger transcripts by sequential action of nuclear and cytoplasmic ribonuclease III–like endonucleases. We show that Exportin-5 (Exp5) mediates efficient nuclear export of short miRNA precursors (pre-miRNAs) and that its depletion by RNA interference results in reduced miRNA levels. Exp5 binds correctly processed pre-miRNAs directly and specifically, in a Ran guanosine triphosphate–dependent… 

Dynamics of MicroRNA Biogenesis

  • M. Fareh
  • Biology
    Biophysics of RNA-Protein Interactions
  • 2019
This book chapter focuses on recent biophysical and single-molecule studies that have revealed important molecular bases and dynamic processes governing the biogenesis of microRNA with an unprecedented high spatiotemporal resolution, thus, uncovering hidden steps and intermediate conformations that are difficult to obtain using conventional approaches.

miRNAs on the move: miRNA biogenesis and the RNAi machinery.

Regulation of microRNA biogenesis and function.

Recent advances in the understanding of how miRNA activity is regulated in mammalian cells are summarised and discussed in this review article.

Versatile microRNA biogenesis in animals and their viruses

This work highlights non-canonical pathways that generate miRNAs using a variety of molecular machineries that play fundamental roles in the biogenesis and processing of other classes of cellular RNAs.

Regulation of microRNA biogenesis

Small non-coding RNAs that function as guide molecules in RNA silencing are involved in nearly all developmental and pathological processes in animals and their dysregulation is associated with many human diseases.

Post-transcriptional regulation of miRNA biogenesis and functions

Several distinct mechanisms are emerging to regulate the biogenesis, stability and function of miRNAs at post-transcriptional level, such as specific binding to terminal loops of miRNA precursors (primiRNAs or pre-miRNAs) by RNA-binding proteins and 3′-terminal modifications by particular enzymes.

Identification of microRNA Precursor-Associated Proteins.

In a pulldown experiment using the pri-miRNA hairpin as immobilized bait, cognate RBPs can be isolated and analyzed by immunoblotting or mass spectrometry, allowing for the discovery or analysis of protein regulators of miRNA biogenesis.

Exportin T and Exportin 5: tRNA and miRNA biogenesis – and beyond

This work compares the cellular function of Exp5 and Exp-t with focus on Exp5 substrates and its role in diseases.

SmD1 Modulates the miRNA Pathway Independently of Its Pre-mRNA Splicing Function

It is shown that SmD1, a core component of the Drosophila small nuclear ribonucleoprotein particle (snRNP) implicated in splicing, is required for miRNA biogenesis and function and indicates that the dual roles of splicing factors in post-transcriptional gene regulation may be evolutionarily widespread.



MicroRNA maturation: stepwise processing and subcellular localization

In vivo and in vitro evidence is presented that these clustered miRNAs are expressed polycistronically and are processed through at least two sequential steps, including the two processing steps and the nuclear export step, suggesting that the regulation of miRNA expression may occur at multiple levels.

The nuclear RNase III Drosha initiates microRNA processing

The two RNase III proteins, Drosha and Dicer, may collaborate in the stepwise processing of miRNAs, and have key roles in miRNA-mediated gene regulation in processes such as development and differentiation.

Role of MicroRNAs in Plant and Animal Development

Small RNAs, including microRNAs (miRNAs) and short interfering RNAs (siRNAs), are key components of an evolutionarily conserved system of RNA-based gene regulation in eukaryotes. They are involved in

Macro effects of microRNAs in plants.

Sequence requirements for micro RNA processing and function in human cells.

The results suggest that miRNAs, and the closely similar small interfering RNAs, cannot totally discriminate between RNA targets differing by a single nucleotide.

A Cellular Function for the RNA-Interference Enzyme Dicer in the Maturation of the let-7 Small Temporal RNA

In Drosophila melanogaster a developmentally regulated precursor RNA is cleaved by an RNA interference-like mechanism to produce mature let-7 stRNA, which regulates developmental timing in Caenorhabditis elegans and probably in other bilateral animals.

Dicer functions in RNA interference and in synthesis of small RNA involved in developmental timing in C. elegans.

A combination of phenotypic abnormalities and RNA analysis suggests a role for dcr-1 in a regulatory pathway comprised of small temporal RNA (let-7) and its target (e.g., lin-41).

Exportin-5 Mediates Nuclear Export of Minihelix-containing RNAs*

In vivo and in vitro competition experiments using various VA1-derived, but also artificial and cellular, RNAs lead to the conclusion that exportin-5 preferentially recognizes and transports minihelix motif-containing RNAs.

Human Dicer preferentially cleaves dsRNAs at their termini without a requirement for ATP

The purification and properties of a recombinant human Dicer are described and it is suggested that if ATP participates in the Dicer reaction in mammalian cells, it might be involved in product release needed for the multiple turnover of the enzyme.

In vivo selection of RNAs that localize in the nucleus

Nuclear localization of an RNA is affected by cis‐acting elements (NLEs) that lead to nuclear import or retention or to blockage of export from the nucleus. To identify such elements, we selected and