InterPro domain: IPR003191

Guanylate-binding protein is a GTPase that is induced by interferon (IFN)-gamma. GTPases induced by IFN-gamma are key to the protective immunity against microbial and viral pathogens. These GTPases are classified into three groups: the small 47-kd GTPases, the Mx proteins, and the large 65- to 67-kd GTPases. Guanylate-binding proteins (GBP) fall into the last class. In humans, there are seven GBPs (hGBP1-7) [ 1 ]. Structurally, hGBP1 consists of two domains: a compact globular N-terminal domain harbouring the GTPase function ( IPR015894 ), and an alpha-helical finger-like C-terminal domain. Human GBP1 is secreted from cells without the need of a leader peptide, and has been shown to exhibit antiviral activity against Vesicular stomatitis virus and Encephalomyocarditis virus, as well as being able to regulate the inhibition of proliferation and invasion of endothelial cells in response to IFN-gamma [ 2 ].

This entry represents the C-terminal domain of the guanylate-binding protein. Proteins containing this domain also include Atlastin2/3. They are GTPases tethering membranes through formation of trans-homooligomers and mediating homotypic fusion of endoplasmic reticulum membranes [ 3 ].

1. Unique features of different members of the human guanylate-binding protein family. J. Interferon Cytokine Res. 27, 44-52
2. Human guanylate binding protein-1 is a secreted GTPase present in increased concentrations in the cerebrospinal fluid of patients with bacterial meningitis. Am. J. Pathol. 169, 1088-99
3. A class of dynamin-like GTPases involved in the generation of the tubular ER network. Cell 138, 549-61