Cloning and characterization of seizure-related gene, SEZ-6.

SEZ-6 is a brain-specific cDNA. Its expression is increased by convulsant drug and it encodes membrane protein with five copies of short consensus repeat (SCR; complement C3b/C4b binding site) and two repeated sequences which are partially similar to CUB domain (complement Clr/s-like repeat). In this study, we analyzed the gene product of SEZ-6 by antibody raised against SEZ-6 peptide. In vitro translation and immunoblot revealed that SEZ-6 protein is modified post-translationally and expressed in the cerebrum and the cerebellum. To analyze the SEZ-6 expression in detail, we searched for other types of SEZ-6 cDNA by the polymerase chain reaction. Two additional types of cDNAs were isolated and sequence analysis showed that one cDNA encodes membrane protein with a different C-terminal region and the other encodes secreted protein with two SCRs and one CUB-like domain.