Characterization of the Ly491 promoter

Fourteen potential Ly49 genes have been identified in the C57Bl/6 mouse str ain. and cDNAs containing a complete coding region have been isolated for 1 0 members of this gene family. Ly49 proteins are primarily expressed in nat ural killer (NK) cells. Although the sequence of the Ly49a promoter region has been published, no study of the cell-specific activity of the promoter has been reported. A 12-kb genomic fragment of the Ly49I gene was isolated and characterized by DNA sequencing. Approximately 5 kb of DNA sequence ups tream of the first Ly49I exon was determined and this region was used to pe rform promoter analysis using luciferase reporter plasmid constructs. A cor e promoter was identified that was preferentially transcribed in a Ly49-exp ressing cell line, EL-4. Electrophoretic mobility shift assays using oligon ucleotide probes from the core Ly49i promoter and comparable regions from t he Ly49a promoter demonstrated the importance of TATA-related elements in g enerating EL-4 and NK cell-specific DNA/protein complexes.