title: RNA recognition by the embryonic cell fate determinant and germline totipotency factor MEX-3.
abstract: Totipotent stem cells have the potential to differentiate into every cell type. Renewal of totipotent stem cells in the germline and cellular differentiation during early embryogenesis rely upon posttranscriptional regulatory mechanisms. The Caenorhabditis elegans RNA binding protein, MEX-3, plays a key role in both processes. MEX-3 is a maternally-supplied factor that controls the RNA metabolism of transcripts encoding critical cell fate determinants. However, the nucleotide sequence specificity and requirements of MEX-3 mRNA recognition remain unclear. Only a few candidate regulatory targets have been identified, and the full extent of the network of MEX-3 targets is not known. Here, we define the consensus sequence required for MEX-3 RNA recognition and demonstrate that this element is required for MEX-3 dependent regulation of gene expression in live worms. Based on this work, we identify several candidate MEX-3 targets that help explain its dual role in regulating germline stem cell totipotency and embryonic cell fate specification.
authors.affiliation: Department of Biochemistry and Molecular Pharmacology, 364 Plantation Street, LRB-906, University of Massachusetts Medical School, Worcester, MA 01605, USA.
authors.forename: John M
authors.initials: JM
authors.lastname: Pagano
authors.forename: Brian M
authors.initials: BM
authors.lastname: Farley
authors.forename: Kingsley I
authors.initials: KI
authors.lastname: Essien
authors.forename: Sean P
authors.initials: SP
authors.lastname: Ryder
mesh_terms: D000818:Animals; D052157:Aptamers, Nucleotide / Q000378:metabolism*; D001483:Base Sequence; D001665:Binding Sites / Q000235:genetics; D019470:Biolistics; D017173:Caenorhabditis elegans; D029742:Caenorhabditis elegans Proteins / Q000378:metabolism*; D002454:Cell Differentiation / Q000235:genetics / Q000502:physiology*; D019295:Computational Biology; D018076:DNA, Complementary / Q000235:genetics; D024202:Electrophoretic Mobility Shift Assay; D018507:Gene Expression Regulation, Developmental / Q000235:genetics / Q000502:physiology*; D008969:Molecular Sequence Data; D016601:RNA-Binding Proteins / Q000378:metabolism*; D017422:Sequence Analysis, DNA; D039901:Totipotent Stem Cells / Q000166:cytology / Q000378:metabolism*
chemical_list: D052157:Aptamers, Nucleotide; D029742:Caenorhabditis elegans Proteins; D018076:DNA, Complementary; C102175:MEX-3 protein, C elegans; D016601:RNA-Binding Proteins