The STAR protein, GLD-1, is a translational regulator of sexual identity in Caenorhabditis elegans.
The Caenorhabditis elegans sex determination gene, tra-2, is translationally regulated by elements in the 3'-untranslated region called TGEs. TGEs govern the translation of mRNAs in both invertebrates and vertebrates, indicating that this is a highly conserved mechanism for controlling gene activity. A factor called DRF, found in worm extracts binds the TGEs and may be a repressor of translation. Using the yeast three-hybrid screen and RNA gel shift analysis, we have found that the protein GLD-1, a germline-specific protein and a member of the STAR family of RNA-binding proteins, specifically binds to the TGEs. GLD-1 is essential for oogenesis, and is also necessary for spermatogenesis and inhibition of germ cell proliferation. Several lines of evidence demonstrate that GLD-1 is a translational repressor acting through the TGEs to repress tra-2 translation. GLD-1 can repress the translation of reporter RNAs via the TGEs both in vitro and in vivo, and is required to maintain low TRA-2A protein levels in the germline. Genetic analysis indicates that GLD-1 acts upstream of the TGE control. Finally, we show that endogenous GLD-1 is a component of DRF. The conservation of the TGE control and the STAR family suggests that at least a subset of STAR proteins may work through the TGEs to control translation.
Jan
E
E
Department of Cell and Molecular Biology and Lurie Cancer Center, Northwestern University Medical School, Chicago, IL 60611, USA.
Motzny
C K
CK
Graves
L E
LE
Goodwin
E B
EB
D000818:Animals; D030801:Animals, Genetically Modified; D001483:Base Sequence; D017173:Caenorhabditis elegans / Q000235:genetics* / Q000254:growth & development* / Q000502:physiology; D029742:Caenorhabditis elegans Proteins; D005260:Female; D017238:Genes, Helminth; D015801:Helminth Proteins / Q000235:genetics* / Q000502:physiology*; D008297:Male; D008565:Membrane Proteins / Q000235:genetics / Q000502:physiology; D008969:Molecular Sequence Data; D009154:Mutation; D010641:Phenotype; D014176:Protein Biosynthesis; D018510:RNA, Helminth / Q000235:genetics; D012441:Saccharomyces cerevisiae / Q000235:genetics; D019849:Sex Determination Processes
D029742:Caenorhabditis elegans Proteins; C094448:GLD-1 protein, C elegans; D015801:Helminth Proteins; D008565:Membrane Proteins; D018510:RNA, Helminth; C076107:tra-2 protein, C elegans