Expression mapping, quantification, and complex formation of GluD1 and GluD2 glutamate receptors in adult mouse brain.
In the cerebellum, GluD2 is exclusively expressed in Purkinje cells, where it regulates synapse formation and regeneration, synaptic plasticity, and motor learning. Delayed cognitive development in humans with GluD2 gene mutations suggests extracerebellar functions of GluD2. However, extracerebellar expression of GluD2 and its relationship with that of GluD1 are poorly understood. GluD2 mRNA and protein were widely detected, with relatively high levels observed in the olfactory glomerular layer, medial prefrontal cortex, cingulate cortex, retrosplenial granular cortex, olfactory tubercle, subiculum, striatum, lateral septum, anterodorsal thalamic nucleus, and arcuate hypothalamic nucleus. These regions were also enriched for GluD1, and many individual neurons coexpressed the two GluDs. In the retrosplenial granular cortex, GluD1 and GluD2 were selectively expressed at PSD-95-expressing glutamatergic synapses, and their coexpression on the same synapses was shown by SDS-digested freeze-fracture replica labeling. Biochemically, GluD1 and GluD2 formed coimmunoprecipitable complex formation in HEK293T cells and in the cerebral cortex and hippocampus. We further estimated the relative protein amount by quantitative immunoblotting using GluA2/GluD2 and GluA2/GluD1 chimeric proteins as standards for titration of GluD1 and GluD2 antibodies. Intriguingly, the relative amount of GluD2 was almost comparable to that of GluD1 in the postsynaptic density fraction prepared from the cerebral cortex and hippocampus. In contrast, GluD2 was overwhelmingly predominant in the cerebellum. Thus, we have determined the relative extracerebellar expression of GluD1 and GluD2 at regional, neuronal, and synaptic levels. These data provide a molecular-anatomical basis for possible competitive and cooperative interactions of GluD family members at synapses in various brain regions.
['Nakamoto|Chihiro|C|', 'Konno|Kohtarou|K|', 'Miyazaki|Taisuke|T|', 'Nakatsukasa|Ena|E|', 'Natsume|Rie|R|', 'Abe|Manabu|M|', 'Kawamura|Meiko|M|', 'Fukazawa|Yugo|Y|', 'Shigemoto|Ryuichi|R|', 'Yamasaki|Miwako|M|', 'Sakimura|Kenji|K|', 'Watanabe|Masahiko|M|0000-0001-5037-7138']
D000818:Animals D001921:Brain D020869:Gene Expression Profiling D005969:Glutamate Dehydrogenase D057809:HEK293 Cells D006801:Humans D051379:Mice D008810:Mice, Inbred C57BL D017470:Receptors, Glutamate
glutamate receptor mouse GluD1 (GluRδ1) GluD2 (GluRδ2) RRID: AB_2571611 RRID:AB_2113875 RRID:AB_2571601 RRID:AB_2571602 RRID:AB_2571608 RRID:AB_2571705 RRID:AB_2571757 RRID:AB_2571759 immunohistochemistry. RRID:AB_11181058 in situ hybridization