mGluR5

Metabotropic glutamate receptors (mGluRs) are G-protein coupled receptors activated by glutamate. Based on sequence similarity, transduction mechanisms and agonist potencies, mGluRs are subdivided into three groups: mGluR1/mGluR5, mGluR2/mGluR3, and mGluR4/mGluR6/mGluR7/mGluR8. mGluRs are widely distributed throughout the nervous system and are expressed by both neurons and glial cells. mGluRs have been suggested to play a variety of functional roles, among which is involvement in synaptic plasticity underlying learning and memory as well as chronic pain.

Human metabotropic glutamate receptor 5 (mGluR5; also mGluR5b) is a 150 kDa, 7-transmembrane glycoprotein that belongs to group I of the C-family of G-protein coupled receptors. mGluR5 is constitutively expressed and regulates neuronal ion channel activity. Human mGluR5 is 1212 aa in length and contains an N-terminal extracellular domain (ECD) of 558 amino acids. There is one alternate splice form (mGluR5a) that shows a 32 aa deletion between aa 877 - 908 in the cytoplasmic tail. Over aa 19 - 509, human mGluR5 is 98% aa identical to mouse, rat and dog mGluR5.

Image: Human metabotropic glutamate receptor 5 (mGluR5) staining of paraffin-embedded human cerebellum sections using 25 µg/mL mouse anti-human mGluR5 monoclonal antibody.  Tissue was stained usin HRP-DAB (brown) and counterstained with hematoxylin (blue).  This antibody specifically recognizes human mGluR5. This antibody has not yet been tested in other species.