Nucleic Acids Research Advance Access originally published online on January 31, 2007
Nucleic Acids Research 2007 35(4):1289-1300; doi:10.1093/nar/gkm016
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Nucleic Acids Research, 2007, Vol. 35, No. 4 1289-1300
© 2007 The Author(s).
This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/2.0/uk/) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.
Genomics |
Identification and characterization of human Mex-3 proteins, a novel family of evolutionarily conserved RNA-binding proteins differentially localized to processing bodies
1Université de Lyon, Lyon, F-69003, France; université Lyon 1, Domaine Rockefeller, Lyon, F-69003, France; CNRS UMR 5201, Laboratoire de Génétique Moléculaire, Signalisation et Cancer, Lyon, F-69003, France, 2CNRS UPR 2167, 6 avenue de la Terrasse, 91198 Gif sur Yvette, France, 3Service Central dAnatomie et Cytologie Pathologiques, Hôpital Edouard Herriot, 69437 Lyon, France, 4CNRS UMR 5558, 16 rue Dubois, 69622 Villeurbanne Cedex, France and 5INSERM U682, 3 avenue Molière, 67200 Strasbourg, France
*To whom correspondence should be addressed. Tel: (+33) 478 77 72 14; Fax: (+33) 478 77 72 20; E-mail: billaud{at}univ-lyon1.fr
Received September 15, 2006. Revised December 22, 2006. Accepted December 22, 2006.
In Caenorhabditis elegans, the Mex-3 protein is a translational regulator that specifies the posterior blastomere identity in the early embryo and contributes to the maintenance of the germline totipotency. We have now identified a family of four homologous human Mex-3 genes, called hMex-3A to -3D that encode proteins containing two heterogeneous nuclear ribonucleoprotein K homology (KH) domains and one carboxy-terminal RING finger module. The hMex-3 are phosphoproteins that bind RNA through their KH domains and shuttle between the nucleus and the cytoplasm via the CRM1-dependent export pathway. Our analysis further revealed that hMex-3A and hMex-3B, but not hMex-3C, colocalize with both the hDcp1a decapping factor and Argonaute (Ago) proteins in processing bodies (P bodies), recently characterized as centers of mRNA turnover. Taken together, these findings indicate that hMex-3 proteins constitute a novel family of evolutionarily conserved RNA-binding proteins, differentially recruited to P bodies and potentially involved in post-transcriptional regulatory mechanisms.
The authors wish it to be known that, in their opinion, the first two authors should be regarded as joint First Authors.