Related Experiment Video

Updated: Jun 25, 2026

Dynamic Proteomic and miRNA Analysis of Polysomes from Isolated Mouse Heart After Langendorff Perfusion
07:54

Dynamic Proteomic and miRNA Analysis of Polysomes from Isolated Mouse Heart After Langendorff Perfusion

Published on: August 29, 2018

Selective stabilization of mammalian microRNAs by 3' adenylation mediated by the cytoplasmic poly(A) polymerase GLD-2

Takayuki Katoh1, Yuriko Sakaguchi, Kenjyo Miyauchi

  • 1Department of Chemistry and Biotechnology, Graduate School of Engineering, University of Tokyo, Bunkyo-ku, Tokyo 113-8656, Japan.

Genes & Development
|February 26, 2009
PubMed

Insights

The enzyme GLD-2 adds a tail to microRNA-122 (miR-122), stabilizing it in the liver. This post-transcriptional modification by GLD-2 is crucial for maintaining mature miR-122 levels.

Area of Science:

  • Molecular Biology
  • Biochemistry
  • Genetics

Background:

  • MicroRNAs (miRNAs) regulate gene expression post-transcriptionally.
  • Some miRNAs undergo modifications like adenylation or uridylation at their 3' ends.
  • The liver-specific microRNA, miR-122, is critical for liver function.

Purpose of the Study:

  • To investigate the post-transcriptional regulation of miR-122.
  • To identify the enzyme responsible for 3'-terminal adenylation of miR-122.
  • To determine the role of this modification in miR-122 stability.

Main Methods:

  • Isolation of miR-122 from human hepatocytes and mouse livers.
  • Mass spectrometry to analyze miRNA variants.
  • Identification of the poly(A) polymerase GLD-2.
  • Analysis of miR-122 levels in GLD-2-null mice.

Main Results:

  • A variant of miR-122 with a 3'-terminal adenosine was identified.
  • GLD-2 was confirmed as the enzyme responsible for this adenylation.
  • GLD-2 deficiency led to significantly lower levels of mature miR-122 in mouse livers.
  • Levels of pre-miR-122 remained unaffected in GLD-2-null mice.

Conclusions:

  • 3'-terminal adenylation by GLD-2 is a key post-transcriptional process for miR-122.
  • This modification by GLD-2 is essential for the selective stabilization of mature miR-122 in the liver.
  • GLD-2 plays a critical role in maintaining hepatic miR-122 homeostasis.

More Related Videos

MicroRNA Amplification and Recognition through Locked-nucleic-acid In situ Hybridization as a Novel Detection and Quantification Method09:06

MicroRNA Amplification and Recognition through Locked-nucleic-acid In situ Hybridization as a Novel Detection and Quantification Method

Published on: October 7, 2025

Genome-wide Screen for miRNA Targets Using the MISSION Target ID Library08:40

Genome-wide Screen for miRNA Targets Using the MISSION Target ID Library

Published on: April 6, 2012

Related Concept Videos

MicroRNAs01:22

MicroRNAs

MicroRNA (miRNA) are short, regulatory RNA transcribed from introns (non-coding regions of a gene) or intergenic regions (stretches of DNA present between genes). Several processing steps are required to form biologically active, mature miRNA. The initial transcript, called primary miRNA (pri-mRNA), base-pairs with itself, forming a stem-loop structure. Within the nucleus, an endonuclease enzyme, called Drosha, shortens the stem-loop structure into hairpin-shaped pre-miRNA. After the pre-miRNA...
MicroRNAs01:22

MicroRNAs

MicroRNA (miRNA) are short, regulatory RNA transcribed from introns—non-coding regions of a gene—or intergenic regions—stretches of DNA present between genes. Several processing steps are required to form biologically active, mature miRNA. The initial transcript, called primary miRNA (pri-mRNA), base-pairs with itself forming a stem-loop structure. Within the nucleus, an endonuclease enzyme, called Drosha, shortens the stem-loop structure into hairpin-shaped pre-miRNA. After the pre-miRNA ends...
mRNA Stability and Gene Expression02:51

mRNA Stability and Gene Expression

The structure and stability of mRNA molecules regulates gene expression, as mRNAs are a key step in the pathway from gene to protein. In eukaryotes, the half-life of mRNA varies from a few minutes up to several days. mRNA stability is essential in growth and development. The absence of the proteins regulating its stability, such as tristetraprolin in mice, can cause systemic issues, including bone marrow overgrowth, inflammation, and autoimmunity.
Cis-acting Elements involved in mRNA stability
RNA Stability01:53

RNA Stability

Intact DNA strands can be found in fossils, while scientists sometimes struggle to keep RNA intact under laboratory conditions. The structural variations between RNA and DNA underlie the differences in their stability and longevity. Because DNA is double-stranded, it is inherently more stable. The single-stranded structure of RNA is less stable but also more flexible and can form weak internal bonds. Additionally, most RNAs in the cell are relatively short, while DNA can be up to 250 million...
RNA Editing02:23

RNA Editing

RNA editing is a post-transcriptional modification where a precursor mRNA (pre-mRNA) nucleotide sequence is changed by base insertion, deletion, or modification. The extent of RNA editing varies from a few hundred bases, in mitochondrial DNA of trypanosomes, to a just single base, in nuclear genes of mammals. Even a single base change in the pre-mRNA can convert a codon for one amino acid into the codon for another amino acid or a stop codon. This type of re-coding can significantly affect the...