FISH GLUCOCORTICOID RECEPTOR WITH SPLICING VARIANTS IN THE DNA-BINDING DOMAIN

Here we describe the isolation of a rainbow trout cDNA containing an e ntire GR coding region, Although the encoded protein is highly homolog ous to other GRs, especially in its DNA binding domain, it contains a nine amino acid insertion between the two zinc fingers. This novel for m is found in all rainbow trout tissues examined; however, the testis also contains a splice variant lacking this insert, making it complete ly continuous to other GRs. In transient transfection assays of cultur ed cells, the two rainbow trout GR variants activated transcription fr om the glucocorticoid-responsive mouse mammary tumor virus promoter to comparable levels.