EAAT4, a glutamate transporter with properties of a chloride channel, is predominantly localized in Purkinje cell dendrites, and forms parasagittal compartments in rat cerebellum.
Glutamate transporters play a pivotal role in terminating glutamatergic transmission by eliminating glutamate from the synaptic cleft. Four different glutamate transporter cDNAs have been isolated thus far, and their tissue distribution has been investigated using northern blot and immunohistochemical analysis. We raised site-directed antisera against a synthetic oligopeptide corresponding to the C-terminal of EAAT4, a recently cloned human glutamate transporter, and investigated the distribution of EAAT4 in rat cerebellum. Western blot analysis demonstrated that the affinity-purified antiserum SAE4 recognized specifically a single band (about 62 kDa) in the rat cerebellum, cerebrum and spinal cord. The SAE4-immunoreactivity was localized predominantly in the dendritic spines and distal dendrites of Purkinje cells. The intensity of the immunoreactivity was uneven among Purkinje cells, forming parasagittal compartments. Since EAAT4 also has the properties of a glutamate-gated chloride channel, it should be able to modulate the transmission at the parallel fiber-Purkinje cell synapses.
Nagao
S
S
Department of Neurology, Institute for Brain Research, Faculty of Medicine, University of Tokyo, Bungkyo-ku, Japan.
Kwak
S
S
Kanazawa
I
I
D027322:Amino Acid Transport System X-AG; D000818:Animals; D002531:Cerebellum / Q000378:metabolism*; D018118:Chloride Channels / Q000378:metabolism*; D003712:Dendrites / Q000378:metabolism*; D050581:Excitatory Amino Acid Transporter 4; D050491:Glutamate Plasma Membrane Transport Proteins; D006801:Humans; D007150:Immunohistochemistry; D008854:Microscopy, Electron; D011689:Purkinje Cells / Q000378:metabolism*; D051381:Rats; D017470:Receptors, Glutamate / Q000378:metabolism*; D027981:Symporters; D014018:Tissue Distribution
D027322:Amino Acid Transport System X-AG; D018118:Chloride Channels; D050581:Excitatory Amino Acid Transporter 4; D050491:Glutamate Plasma Membrane Transport Proteins; D017470:Receptors, Glutamate; C493391:SLC1A6 protein, human; C493389:Slc1a6 protein, rat; D027981:Symporters