Cloning of SEZ-12 encoding seizure-related and membrane-bound adhesion protein.

SEZ-12 is one of the seizure-related cDNAs which was isolated by differential hybridization from primary cultured neurons from the mouse cerebral cortex with or without pentylenetetrazol (PTZ). SEZ-12 expression is transiently down-regulated in the mouse brain by injection of PTZ. To characterize SEZ-12, isolation of full-length cDNA and nucleotide sequence analysis were performed. The deduced amino acid sequence of SEZ-12 revealed that it encodes membrane-bound C-type lectin and has a significant homology to that of human cDNA, DGCR2 and IDD, which were cloned from a balanced translocation breakpoint associated with the DiGeorge syndrome. The isolated cDNA was about 4 kb in length and the message was expressed ubiquitously in various organs with low-abundance. Previously, we also cloned a transmembrane protein which is probably involved in cell-cell interaction by the differential hybridization technique. These findings suggest that transmembrane signaling in neuronal cells may have an important role in PTZ-induced seizure.