In Silico and In Vitro Characterization of mGBP4 Splice Variants

In a systematic approach to identify interferon-γ (IFN-γ)–regulated host effector molecules, we found several members of the 65 kDa guanylate-binding proteins (GBPs) highly upregulated. During extensive characterization of these guanosine triphosphatases (GTPases), we identified discrepancies between the cloned and published sequences of the murine GTPase mGBP4. Two splice variants of mGBP4 could be detected. One variant led to a premature stop codon after 312 bp. The second variant resulted in a transcript with a disrupted G2 domain and was deposited as mGBP4.1 to the GenBank. Interestingly, only mGBP4, not mGBP4.1 mRNA, was highly upregulated in mice after infection with Listeria monocytogenes.