Multiple maternal proteins coordinate to restrict the translation of C. elegans nanos-2 to primordial germ cells.
Although germ cell formation has been relatively well understood in worms and insects, how germ cell-specific developmental programs are initiated is not clear. In Caenorhabditis elegans, translational activation of maternal nos-2 mRNA is the earliest known molecular event specific to the germline founder cell P(4). Cis-elements in nos-2 3'UTR have been shown to mediate translational control; however, the trans-acting proteins are not known. Here, we provide evidence that four maternal RNA-binding proteins, OMA-1, OMA-2, MEX-3 and SPN-4, bind nos-2 3'UTR to suppress its translation, and POS-1, another maternal RNA-binding protein, relieves this suppression in P(4). The POS-1: SPN-4 ratio in P(4) increases significantly over its precursor, P(3); and POS-1 competes with SPN-4 for binding to nos-2 RNA in vitro. We propose temporal changes in the relative concentrations of POS-1 and SPN-4, through their effect on the translational status of maternal mRNAs such as nos-2, initiate germ cell-specific developmental programs in C. elegans.
Jadhav
Shreyas
S
Department of Biological Sciences and Bioengineering, Indian Institute of Technology, Kanpur 208016, India.
Rana
Mainpal
M
Subramaniam
Kuppuswamy
K
D020413:3' Untranslated Regions; D000818:Animals; D030801:Animals, Genetically Modified; D001483:Base Sequence; D017173:Caenorhabditis elegans / Q000196:embryology / Q000235:genetics / Q000502:physiology*; D029742:Caenorhabditis elegans Proteins / Q000096:biosynthesis / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D002352:Carrier Proteins / Q000378:metabolism / Q000502:physiology; D018797:Cell Cycle Proteins / Q000378:metabolism; D018507:Gene Expression Regulation, Developmental; D005854:Germ Cells / Q000378:metabolism / Q000502:physiology*; D008969:Molecular Sequence Data; D009865:Oocytes / Q000254:growth & development / Q000502:physiology; D016601:RNA-Binding Proteins / Q000378:metabolism
D020413:3' Untranslated Regions; D029742:Caenorhabditis elegans Proteins; D002352:Carrier Proteins; D018797:Cell Cycle Proteins; C102175:MEX-3 protein, C elegans; C440205:OMA-1 protein, C elegans; C117258:POS-1 protein, C elegans; D016601:RNA-Binding Proteins; C442231:SPN-4 protein, C elegans; C400703:nos-2 protein, C elegans; C473076:oma-2 protein, C elegans