Calpain-mediated proteolysis of GluR1 subunits in organotypic hippocampal cultures following kainic acid treatment.

The present study examined changes in GluR1 subunits after kainic acid (KA) treatment of organotypic hippocampal cultures. Immunoblots labeled with antibodies directed at the C-terminal domain of GluR1 revealed a large decrease in GluR1 immunoreactivity at 6 h and 24 h, while immunoblots labeled with antibodies directed at the N-terminal domain indicated that KA treatment produced changes in structure but not amount of GluR1 protein. Changes in GluR1 subunits were significantly reduced by the calpain inhibitor, calpeptin. These results indicate that KA-induced changes in GluR1 properties are mediated by calpain activation.