Identification of an intragenic interferon-stimulated response element sequence of the mouse class I major histocompatibility complex H-2Kb gene.

A 5'-enhancer-lacking construct of the mouse MHC class I H-2Kb gene is stimulated by interferons in a similar manner as a 5'-enhancer-containing H-2Kb gene. This ability is markedly reduced upon introducing a second deletion removing the first and second intron of the H-2Kb gene. Computational analysis of the deleted stretch reveals the presence of the interferon-stimulated response element (ISRE) in the middle of the second intron. The identified sequence exhibits typical ISRE characteristics in gel retardation experiments. A fragment containing the 5'-enhancer interferon responsive sequence competes effectively in the binding reactions. These results strongly suggest that the second intron of the H-2Kb gene participates in interferon stimulation via the identified ISRE sequence.