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Updated: Jul 19, 2026

Method for the Isolation and Identification of mRNAs, microRNAs and Protein Components of Ribonucleoprotein Complexes from Cell Extracts using RIP-Chip
13:34

Method for the Isolation and Identification of mRNAs, microRNAs and Protein Components of Ribonucleoprotein Complexes from Cell Extracts using RIP-Chip

Published on: September 29, 2012

A microRNA in a multiple-turnover RNAi enzyme complex

György Hutvágner1, Phillip D Zamore

  • 1Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Lazare Research Building, Room 825, 364 Plantation Street, Worcester, MA 01605, USA.

Science (New York, N.Y.)
|August 3, 2002
PubMed

Insights

MicroRNAs (miRNAs) and small interfering RNAs (siRNAs) are tiny RNAs produced by Dicer. This study shows human let-7 miRNA enters the RNA interference (RNAi) pathway, suggesting target complementarity dictates miRNA function.

Area of Science:

  • Molecular Biology
  • Genetics
  • Biochemistry

Background:

  • Dicer enzyme produces distinct tiny RNAs: microRNAs (miRNAs) and small interfering RNAs (siRNAs).
  • miRNAs regulate messenger RNA (mRNA) translation.
  • siRNAs mediate RNA destruction through the RNA interference (RNAi) pathway.

Purpose of the Study:

  • To investigate the functional pathway of the human miRNA let-7.
  • To determine if miRNA function is solely dependent on target complementarity.
  • To characterize the ribonucleoprotein particle containing let-7.

Main Methods:

  • Analysis of human cell extracts.
  • Biochemical characterization of miRNA-containing ribonucleoprotein particles.
  • Investigation of RNA cleavage activity.

Main Results:

  • Human let-7 miRNA was found to naturally enter the RNAi pathway.
  • The miRNA-containing ribonucleoprotein particle functions as an RNAi enzyme complex.
  • Each let-7 complex facilitated multiple rounds of RNA cleavage, demonstrating high efficiency.

Conclusions:

  • The degree of complementarity between a miRNA and its target RNA may determine its function.
  • Human let-7 operates within the RNAi machinery.
  • The RNAi pathway exhibits remarkable efficiency in human cells due to these complexes.

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