title: Polarity-dependent asymmetric distribution and MEX-5/6-mediated translational activation of the Era-1 mRNA in C. elegans embryos.
abstract: The early C. elegans embryo is an attractive model system to investigate fundamental developmental processes. With the exception of mex-3 mRNA, maternally contributed mRNAs are thought to be distributed uniformly in the one-cell embryo. Here, we report and characterize the striking distribution of the mRNA encoding the novel protein ERA-1. We found that era-1 mRNA is enriched in the anterior of the one-cell embryo and present solely in anterior blastomeres thereafter. Although era-1 is not an essential gene, we uncovered that era-1 null mutant embryos are sensitive to slight impairment of embryonic polarity. We found that the asymmetric distribution of era-1 mRNA depends on anterior-posterior polarity cues and on the era-1 3'UTR. Similarly to the era-1 mRNA, the YFP-ERA-1 protein is enriched in anterior blastomeres. Interestingly, we found that the RNA-binding protein MEX-5 is required for era-1 mRNA asymmetry. Furthermore, we show that MEX-5, together with its partially redundant partner MEX-6, are needed to activate era-1 mRNA translation in anterior blastomeres. These findings lead us to propose that MEX-5/6-mediated regulation of era-1 mRNA contributes to robust embryonic development.
authors.affiliation: Swiss Institute for Experimental Cancer Research (ISREC), School of Life Sciences, Swiss Federal Institute of Technology (EPFL) Lausanne, Lausanne, Switzerland.
authors.forename: Zoltán
authors.initials: Z
authors.lastname: Spiró
authors.affiliation: Swiss Institute for Experimental Cancer Research (ISREC), School of Life Sciences, Swiss Federal Institute of Technology (EPFL) Lausanne, Lausanne, Switzerland.
authors.forename: Pierre
authors.initials: P
authors.lastname: Gönczy
mesh_terms: D020413:3' Untranslated Regions / Q000235:genetics; D000818:Animals; D001757:Blastomeres / Q000378:metabolism; D017173:Caenorhabditis elegans / Q000235:genetics*; D029742:Caenorhabditis elegans Proteins / Q000235:genetics*; D016764:Cell Polarity / Q000235:genetics; D004625:Embryo, Nonmammalian / Q000378:metabolism; D018507:Gene Expression Regulation, Developmental / Q000235:genetics*; D017238:Genes, Helminth / Q000235:genetics*; D005854:Germ Cells / Q000378:metabolism; D014176:Protein Biosynthesis / Q000235:genetics*; D023121:RNA, Messenger, Stored / Q000235:genetics*
chemical_list: D020413:3' Untranslated Regions; D029742:Caenorhabditis elegans Proteins; C410587:MEX-5 protein, C elegans; C410589:MEX-6 protein, C elegans; D023121:RNA, Messenger, Stored
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