Metabotropic glutamate receptor 1 splice variants mGluR1a and -mGluRlb combine in mGluRla/b dimers in vivo
Abstract
The assembly of two covalently linked monomers into dimeric complexes is a prerequisite for metabotropic glutamate receptor 1 (mGluR1) function. The former concept of a strictly homodimeric subunit contribution in metabotropic glutamate receptor complexes-has recently been brought into question.
Alternative splicing of the GRM1 gene results in expression of variants that vary within their intracellular C-termini. Here we bring evidence that the short mGluRlb variant is found preferentially in a complex with the long mGluR1 a variant in the rodent brain.
The mGluRla and mGluRlb variants distribution overlaps in Purkinje cells and the two variants colocalize in their spines. However mGluR1 a and mGluRlb show distinct sub-cellular localization when expressed alone in neurons.
We discovered that trafficking of mGluRlb to distal dendrites is reliant on its association with mGluRla and that the long Cterminus of mGluR1 a within the mGluRla/b dimer is necessary for trafficking of the complex. (C) 2014 Elsevier Ltd. All rights reserved.