Lassa virus glycoprotein: stopping a moving target.

Area of Science:

• Virology
• Structural Biology
• Immunology

Background:

• The prefusion structure of the arenavirus glycoprotein complex (GPC) remained elusive due to the unstable association between its subunits.
• Previous studies lacked structural data on the complete prefusion GPC trimer for any arenavirus.

Purpose of the Study:

• To determine the structure of a stabilized prefusion arenavirus GPC trimer.
• To compare the structural features of Old World (Lassa virus) and New World arenavirus GPCs.
• To provide insights for rational arenavirus vaccine design.

Main Methods:

• Protein engineering to stabilize the Lassa virus GPC in its native, cleaved state.
• X-ray crystallography to determine the 3D structure of the prefusion GPC trimer.
• Comparative structural analysis with known arenavirus glycoprotein structures.

Main Results:

• The first structure of any arenavirus prefusion GPC trimer was determined using stabilized Lassa virus GPC.
• Lassa virus GP1 subunit exhibits conformational lability, contrasting with the stable GP1 of New World arenaviruses.
• The arenavirus GPC adopts a unique trimeric conformation distinct from other viral fusion glycoproteins.

Conclusions:

• The determined structure provides critical insights into arenavirus glycoprotein organization and dynamics.
• Structural differences between Old World and New World arenavirus GP1 subunits have implications for receptor binding and viral entry.
• The findings lay the groundwork for designing targeted vaccines against arenavirus infections.