Related Experiment Video

Updated: May 8, 2026

Analysis of LINE-1 Retrotransposition at the Single Nucleus Level
11:52

Analysis of LINE-1 Retrotransposition at the Single Nucleus Level

Published on: April 23, 2016

The Microprocessor controls the activity of mammalian retrotransposons

Sara R Heras1, Sara Macias, Mireya Plass

  • 11] Medical Research Council Human Genetics Unit, Institute of Genetics and Molecular Medicine, University of Edinburgh, Edinburgh, UK. [2] Centre for Genomics and Oncological Research: Pfizer, University of Granada, Andalusian Regional Government (GENYO), Granada, Spain. [3].

Nature Structural & Molecular Biology
|September 3, 2013
PubMed

Insights

The Microprocessor complex (Drosha-DGCR8) represses transposable elements like LINE-1 and Alu. This discovery reveals a new role for the Microprocessor in maintaining human genome integrity.

Area of Science:

  • Genetics
  • Molecular Biology
  • Epigenetics

Background:

  • Transposable elements constitute over half of the human genome.
  • Their mobilization drives genetic diversity, but host regulation remains unclear.

Purpose of the Study:

  • Investigate the Microprocessor complex's role in regulating transposable element activity.
  • Determine if the Microprocessor complex impacts LINE-1, Alu, and SVA retrotransposons.

Main Methods:

  • RNA immunoprecipitation to identify Microprocessor binding targets.
  • Expression analysis in cells with and without functional Microprocessor.
  • In vitro cleavage assays using Drosha.
  • Cell culture-based retrotransposition assays.

Main Results:

  • The Microprocessor complex binds RNAs from LINE-1, Alu, and SVA retrotransposons.
  • Cells lacking Microprocessor show increased LINE-1 mRNA and protein.
  • Drosha cleaves LINE-1 mRNA structures in vitro.
  • Microprocessor negatively regulates LINE-1 and Alu retrotransposition in vivo.

Conclusions:

  • The Microprocessor complex acts as a post-transcriptional repressor of mammalian retrotransposons.
  • This function contributes to the maintenance of human genome integrity.
  • Identifies a novel defense mechanism against mobile genetic elements.

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