DIFFERENTIAL INTERNALIZATION OF MGLUR1 SPLICE VARIANTS IN RESPONSE TOAGONIST AND PHORBOL ESTERS IN PERMANENTLY TRANSFECTED BHK CELLS

The internalisation of metabotropic glutamate receptor (mGluR1 alpha) and its splice variant (mGluR1 beta), in response to agonist and phorb ol esters (PMA), has been studied, Both mGluR1 alpha and mGluR1 beta e xhibit a similar rate of internalisation following PMA treatment, with a shift in their distribution from plasma membrane to endosome-enrich ed membrane fractions, Agonist challenge however caused a rapid loss, within 5-10 min, of mGluR1 beta but not mGluR1 alpha from the cell sur face. These results show that the two forms of mGluR1 show different i nternalisation responses to agonist and suggest that the C-terminal re gion of the molecule plays an important role in this phenomenon. (C) 1 997 Federation of European Biochemical Societies.