Severe fever with thrombocytopenia syndrome virus glycoproteins Gn and Gc (SFTSV Gn/Gc)

The Severe fever with thrombocytopenia syndrome virus (SFTSV) glycoproteins Gn and Gc are the primary surface proteins of the virus, encoded by the M genomic segment (UniProt: P0C7M7). These proteins are initially synthesized as a polyprotein precursor that is post-translationally cleaved by host proteases into the N-terminal Gn and C-terminal Gc subunits. They assemble into heterodimers that form the viral spikes necessary for recognizing and binding to host cell receptors, including DC-SIGN and L-SIGN (PubMed: 24453369). Gc specifically functions as a class II membrane fusion protein, facilitating the release of the viral genome into the cytoplasm following pH-dependent endocytosis (PubMed: 28250443). Because they are exposed on the virion surface, Gn and Gc are the principal targets for the host's neutralizing antibody response and are central to vaccine design and therapeutic development. Strategies targeting these glycoproteins focus on blocking viral attachment or inhibiting the conformational changes required for membrane fusion (PubMed: 30894446). While no specific small-molecule inhibitors are currently approved for clinical use, several monoclonal antibodies, such as MAb 4-5 and MAb 1B8, are under investigation for their ability to provide passive immunity and reduce viral load in infected patients. Understanding the structural biology of these glycoproteins is crucial for developing effective countermeasures against the high mortality associated with SFTSV infections.

Other names

SFTSV M segment polyproteinDabie bandavirus glycoproteinsGn and Gc envelope proteinsSFTSV GnSFTSV GcSFTSV envelope glycoproteins

Neutralization of viral entry by blocking receptor binding or inhibiting pH-dependent membrane fusion