OBJECTIVETo study the regulatory role of interferon-stimulated response elements (ISREs) located on the retinoic acid-induced gene G (RIG-G) promoter in RIG-G expression.

METHODSBy using point mutation technique, the authors constructed the wide type and site mutant reporter gene plasmids according to the ISRE sequence on RIG-G promoter, and detected the functional activities by luciferase reporter assay.

RESULTSMutation in ISRE II alone had no obvious effect on the expression of the reporter gene, whereas mutation in ISRE I dramatically inhibited the transactivity of RIG-G promoter. Mutation in both ISRE I and ISRE II resulted in complete loss of its response to the transcription factors for the reporter gene.

CONCLUSIONBoth ISRE I and ISRE II on the RIG-G promoter are the binding sites for the complex of transcription factors. They are required for RIG-G expression, and ISRE I has a preferential role over ISRE II.