SELECTIVE EXPRESSION OF THE GLUTAMATE-RECEPTOR CHANNEL DELTA-2 SUBUNIT IN CEREBELLAR PURKINJE-CELLS

The primary structure of a putative subunit of the mouse glutamate receptor channel, designated as the δ2 subunit, has been deduced by cloning and sequencing the cDNA. The δ2 subunit has four putative transmembrane segments characteristic for neurotransmitter-gated ion channels, and shares 56% amino acid sequence identity with the δ1 subunit of the mouse glutamate receptor channel and 14-24% identity with the subunits of the AMPA-, kainate- or NMDA-selective glutamate receptor channel. RNA blot and in situ hybridization analyses show that the δ2 subunit mRNA is localized in cerebellar Purkinje cells. Furthermore, immunoblot and immunohistochemical analyses suggest that the δ2 subunit protein is actually expressed in vivo in Purkinje neurons. The selective localization of the δ2 subunit in Purkinje cells may imply a role of the δ2 subunit in Purkinje cell-specific function such as the cerebellar LTD. © 1993 Academic Press, Inc.