Genomic Organization and Chromosomal Localization of a New Member of the Murine Interferon-Induced Guanylate-Binding Protein Family

An RNA species has been identified whose nucleotide sequence is closely related to the mRNA encoding the murine interferon (IFN)-induced guanylate-binding protein-1 (mGBP1) and an mRNA encoding an isoprenylated protein that is constitutively expressed in various organs in the rat. Sequence analysis of the gene encoding this newly identified RNA reveals that in its 5'-region it is identical to a DNA fragment reported to represent the 5'-region of a gene termed mGBP2. In light of this homology, we term this newly identified gene product mGBP2. mGBP2 is inducible following IFN treatment in animals bearing Gbp1a alleles, in which mGBP1 is transcriptionally upregulated by IFN treatment, as well as in animals bearing Gbp1b alleles, in which mGBP1 is not induced in response to IFN treatment. The genomic organizations of the genes encoding mGBP1 and mGBP2 are similar, and the nucleotide sequences of their IFN-responsive-like elements and their relative locations are conserved. Gbp1 and Gbp2 map to a genetically indistinguishable site on the distal arm of chromosome 3.