RIC-8 (Synembryn): a novel conserved protein that is required for G(q)alpha signaling in the C. elegans nervous system

Neuron. 2000 Aug;27(2):289-99. doi: 10.1016/s0896-6273(00)00037-4.


Recent studies describe a network of signaling proteins centered around G(o)alpha and G(q)alpha that regulates neurotransmitter secretion in C. elegans by controlling the production and consumption of diacylglycerol (DAG). We sought other components of the Goalpha-G(q)alpha signaling network by screening for aldicarb-resistant mutants with phenotypes similar to egl-30 (G(q)alpha) mutants. In so doing, we identified ric-8, which encodes a novel protein named RIC-8 (synembryn). Through cDNA analysis, we show that RIC-8 is conserved in vertebrates. Through immunostaining, we show that RIC-8 is concentrated in the cytoplasm of neurons. Exogenous application of phorbol esters or loss of DGK-1 (diacylglycerol kinase) rescues ric-8 mutant phenotypes. A genetic analysis suggests that RIC-8 functions upstream of, or in conjunction with, EGL-30 (G(q)alpha).

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Aging / metabolism
  • Animals
  • Caenorhabditis elegans / genetics*
  • Caenorhabditis elegans / metabolism
  • Caenorhabditis elegans Proteins*
  • Conserved Sequence / genetics
  • Diacylglycerol Kinase / deficiency
  • Diacylglycerol Kinase / genetics
  • Fluorescent Antibody Technique
  • GTP-Binding Protein alpha Subunits, Gq-G11
  • GTP-Binding Proteins / metabolism*
  • Guanine Nucleotide Exchange Factors
  • Molecular Sequence Data
  • Mutagenesis, Site-Directed
  • Nervous System / metabolism*
  • Nuclear Proteins / genetics
  • Nuclear Proteins / metabolism*
  • Organ Specificity
  • Phenotype
  • Sequence Analysis, DNA
  • Sequence Homology, Amino Acid
  • Signal Transduction / physiology*
  • Synaptic Transmission / genetics
  • Tetradecanoylphorbol Acetate / pharmacology


  • Caenorhabditis elegans Proteins
  • Guanine Nucleotide Exchange Factors
  • Nuclear Proteins
  • RIC-8 protein, C elegans
  • Ric8a protein, mouse
  • Diacylglycerol Kinase
  • GTP-Binding Proteins
  • GTP-Binding Protein alpha Subunits, Gq-G11
  • Tetradecanoylphorbol Acetate

Associated data

  • GENBANK/AF288812
  • GENBANK/AF288813