Molecular cloning, gene structure, expression profile and functional characterization of the mouse glutamate transporter (EAAT3) interacting protein GTRAP3-18

Gene. 2002 Jun 12;292(1-2):81-90. doi: 10.1016/s0378-1119(02)00669-8.


Glutamate is an important amino acid implicated in energy metabolism, protein biosynthesis and neurotransmission. The Na(+)-dependent high-affinity excitatory amino acid transporter EAAT3 (EAAC1) facilitates glutamate uptake into most cells. Recently, a novel rat EAAT3-interacting protein called GTRAP3-18 has been identified by a yeast two-hybrid screening. GTRAP3-18 functions as a negative modulator of EAAT3-mediated glutamate transport. In order to further understand the function and regulation of GTRAP3-18, we cloned the mouse orthologue to GTRAP3-18 and determined its gene structure and its expression pattern. GTRAP3-18 encodes a 188-residue hydrophobic protein whose sequence is highly conserved amongst vertebrates. Mouse and human GTRAP3-18 genes contain three exons separated by two introns. The GTRAP3-18 gene is found on mouse chromosome 6D3 and on human chromosome 3p14, a susceptibility locus for cancer and epilepsy. GTRAP3-18 protein and RNA were found both in neuronal rich regions of the brain and in non-neuronal tissues such as the kidney, heart and skeletal muscle. Mouse GTRAP3-18 inhibited EAAT3-mediated glutamate transport in a dose-dependent manner. These studies show that GTRAP3-18 is a ubiquitously expressed protein that functions as a negative regulator of EAAT3 function.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Amino Acid Transport System X-AG*
  • Animals
  • Base Sequence
  • Carrier Proteins / genetics*
  • Carrier Proteins / metabolism*
  • Cell Line
  • Cloning, Molecular
  • DNA, Complementary / chemistry
  • DNA, Complementary / genetics
  • Excitatory Amino Acid Transporter 3
  • Gene Expression Profiling*
  • Genes / genetics
  • Glutamate Plasma Membrane Transport Proteins
  • Glutamic Acid / drug effects
  • Glutamic Acid / pharmacokinetics
  • Heat-Shock Proteins
  • Immunoblotting
  • Immunohistochemistry
  • Male
  • Membrane Transport Proteins
  • Mice
  • Mice, Inbred C57BL
  • Molecular Sequence Data
  • RNA / genetics
  • RNA / metabolism
  • Sequence Alignment
  • Sequence Analysis, DNA
  • Sequence Homology, Amino Acid
  • Symporters*


  • Amino Acid Transport System X-AG
  • Arl6ip5 protein, mouse
  • Carrier Proteins
  • DNA, Complementary
  • Excitatory Amino Acid Transporter 3
  • Glutamate Plasma Membrane Transport Proteins
  • Heat-Shock Proteins
  • Membrane Transport Proteins
  • Slc1a1 protein, mouse
  • Symporters
  • Glutamic Acid
  • RNA

Associated data

  • GENBANK/AF421860