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Journal of Biomedicine and Biotechnology
Volume 2006 (2006), Article ID 16806, 7 pages
http://dx.doi.org/10.1155/JBB/2006/16806
Research Article

Hypothesis: A Role for Fragile X Mental Retardation Protein in Mediating and Relieving MicroRNA-Guided Translational Repression?

1Centre de Recherche en Rhumatologie et Immunologie, Centre de Recherche du CHUL (CHUQ), 2705 Boulevard, Sainte-Foy, Québec, Laurier, Canada G1V 4G2
2Department of Anatomy and physiology, Faculty of Medicine, Laval University, Québec, Canada G1K 7P4

Received 8 April 2006; Accepted 2 May 2006

Copyright © 2006 Isabelle Plante and Patrick Provost. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

MicroRNA (miRNA)-guided messenger RNA (mRNA) translational repression is believed to be mediated by effector miRNA-containing ribonucleoprotein (miRNP) complexes harboring fragile X mental retardation protein (FMRP). Recent studies documented the nucleic acid chaperone properties of FMRP and characterized its role and importance in RNA silencing in mammalian cells. We propose a model in which FMRP could facilitate miRNA assembly on target mRNAs in a process involving recognition of G quartet structures. Functioning within a duplex miRNP, FMRP may also mediate mRNA targeting through a strand exchange mechanism, in which the miRNA* of the duplex is swapped for the mRNA. Furthermore, FMRP may contribute to the relief of miRNA-guided mRNA repression through a reverse strand exchange reaction, possibly initiated by a specific cellular signal, that would liberate the mRNA for translation. Suboptimal utilization of miRNAs may thus account for some of themolecular defects in patients with the fragile X syndrome.