Human brain synembryn interacts with Gsalpha and Gqalpha and is translocated to the plasma membrane in response to isoproterenol and carbachol

J Cell Physiol. 2003 May;195(2):151-7. doi: 10.1002/jcp.10300.


Heterotrimeric G-proteins transduce signals from heptahelical transmembrane receptors to different effector systems, regulating diverse complex intracellular pathways and functions. In brain, facilitation of depolarization-induced neurotransmitter release for synaptic transmission is mediated by Gsalpha and Gqalpha. To identify effectors for Galpha-proteins, we performed a yeast two-hybrid screening of a human brain cDNA library, using the human Galphas protein as a bait. We identified a protein member of the synembryn family as one of the interacting proteins. Extending the study to other Galpha subunits, we found that Gqalpha also interacts with synembryn, and these interactions were confirmed by in vitro pull down studies and by in vivo confocal laser microscopy analysis. Furthermore, synembryn was shown to translocate to the plasma membrane in response to carbachol and isoproterenol. This study supports recent findings in C. elegans where, through genetic studies, synembryn was shown to act together with Gqalpha regulating neuronal transmitter release. Based on these observations, we propose that synembryn is playing a similar role in human neuronal cells.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adrenergic alpha-Agonists / pharmacology
  • Animals
  • Brain / drug effects
  • Brain / metabolism*
  • Caenorhabditis elegans Proteins / metabolism*
  • Carbachol / pharmacology
  • Cell Membrane / drug effects
  • Cell Membrane / metabolism*
  • Cholinergic Agonists / pharmacology
  • Cytosol / drug effects
  • Cytosol / metabolism
  • GTP-Binding Protein alpha Subunits, Gq-G11
  • GTP-Binding Protein alpha Subunits, Gs / metabolism*
  • GTP-Binding Proteins / metabolism*
  • Guanine Nucleotide Exchange Factors*
  • Heterotrimeric GTP-Binding Proteins / metabolism
  • Humans
  • Isoproterenol / pharmacology
  • Molecular Sequence Data
  • Neurons / drug effects
  • Neurons / metabolism*
  • Nuclear Proteins / metabolism*
  • PC12 Cells
  • Protein Transport / drug effects
  • Protein Transport / physiology*
  • Rats
  • Two-Hybrid System Techniques


  • Adrenergic alpha-Agonists
  • Caenorhabditis elegans Proteins
  • Cholinergic Agonists
  • Guanine Nucleotide Exchange Factors
  • Nuclear Proteins
  • Ric8a protein, rat
  • Carbachol
  • GTP-Binding Proteins
  • GTP-Binding Protein alpha Subunits, Gq-G11
  • GTP-Binding Protein alpha Subunits, Gs
  • Heterotrimeric GTP-Binding Proteins
  • Isoproterenol

Associated data

  • GENBANK/AY221116