HRP-2, a heterogeneous nuclear ribonucleoprotein, is essential for embryogenesis and oogenesis in Caenorhabditis elegans.
Heterogeneous nuclear ribonucleoproteins (hnRNPs) have fundamental roles in the posttranscriptional control of gene expression. Here, we describe an hnRNP from Caenorhabditis elegans(HRP-2), which shares significant homology with mammalian hnRNP R, hnRNP Q and ACF, the essential complementation factor in ApoB mRNA editing. All four proteins possess a similar molecular architecture, with three closely linked RNA-binding domains and a C-terminus that contains RG/RGG repeat motifs. An HRP-2::GFP fusion protein was ubiquitously expressed in C. elegans during embryogenesis and subsequent larval development. Expression was also detected in the hermaphrodite gonad using a specific antibody, suggesting that HRP-2 is provided maternally. HRP-2 was predominantly localised to nuclei and analysis of transgenic lines expressing C-terminal deletions of HRP-2 defined a functional nuclear localisation signal. Analysis by RNAi demonstrated that HRP-2 was essential for embryogenesis and fertility. Cell divisions were slower in hrp-2(RNAi) embryos and the majority showed an early embryonic arrest phenotype. Shorter exposure to dsRNA allowed development to the twofold stage and the few embryos that hatched were abnormal. Adult worms that developed from embryos exposed to RNAi were completely sterile due to a failure in oocyte formation. These results demonstrate that HRP-2 or its RNA targets are essential for normal embryonic development and oogenesis in C. elegans.
Kinnaird
Jane H
JH
Veterinary Parasitology, Institute of Comparative Medicine, University of Glasgow, Glasgow G61 1QH, UK. j.kinnaird@vet.gla.ac.uk
Maitland
Kirsty
K
Walker
Glenda A
GA
Wheatley
Isla
I
Thompson
Fiona J
FJ
Devaney
Eileen
E
D000818:Animals; D017173:Caenorhabditis elegans / Q000166:cytology / Q000196:embryology* / Q000378:metabolism; D029742:Caenorhabditis elegans Proteins / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D002451:Cell Compartmentation / Q000235:genetics; D002467:Cell Nucleus / Q000235:genetics / Q000378:metabolism; D018076:DNA, Complementary / Q000032:analysis / Q000235:genetics; D015536:Down-Regulation / Q000235:genetics; D004625:Embryo, Nonmammalian / Q000166:cytology / Q000196:embryology* / Q000378:metabolism; D018507:Gene Expression Regulation, Developmental / Q000235:genetics*; D006066:Gonads / Q000166:cytology / Q000196:embryology / Q000378:metabolism; D034481:Heterogeneous-Nuclear Ribonucleoprotein Group A-B / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D034441:Heterogeneous-Nuclear Ribonucleoproteins / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D007814:Larva / Q000166:cytology / Q000254:growth & development / Q000378:metabolism; D008969:Molecular Sequence Data; D009866:Oogenesis / Q000235:genetics*; D010641:Phenotype; D011485:Protein Binding / Q000235:genetics; D017434:Protein Structure, Tertiary / Q000235:genetics; D012313:RNA / Q000235:genetics / Q000378:metabolism; D034622:RNA Interference; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D017386:Sequence Homology, Amino Acid; D012689:Sequence Homology, Nucleic Acid
D029742:Caenorhabditis elegans Proteins; D018076:DNA, Complementary; C491442:HRP-2 protein, C elegans; D034481:Heterogeneous-Nuclear Ribonucleoprotein Group A-B; D034441:Heterogeneous-Nuclear Ribonucleoproteins; D011993:Recombinant Fusion Proteins; D012313:RNA