Biochemical Basis for LRP1 Interaction With Rift Valley Fever Virus Glycoprotein and Its Role in Viral Entry

Area of Science:

• Virology
• Molecular Biology
• Structural Biology

Background:

• The LDL receptor related protein 1 (LRP1) acts as a host entry factor for Rift Valley Fever Virus (RVFV).
• RVFV glycoproteins (GnGc) interact with LRP1 clusters II and IV to facilitate viral entry.
• The precise mechanism of RVFV GnGc binding to LRP1 remains incompletely understood.

Purpose of the Study:

• To characterize the binding mechanism between RVFV GnGc and LRP1.
• To identify specific LRP1 domains responsible for RVFV GnGc interaction.
• To explore the potential of LRP1 domains in therapeutic strategies against RVFV.

Main Methods:

• Mapping of individual LRP1 ligand-binding regions (CR domains).
• Biochemical assays to assess RVFV GnGc binding affinity to LRP1 CR domains.
• Site-directed mutagenesis to investigate the role of specific residues in LRP1-GnGc interaction.
• In vitro infection inhibition assays using LRP1 CR domains.

Main Results:

• The LRP1 CR25 domain was identified as sufficient for high-affinity RVFV GnGc binding.
• A key aromatic residue within CR25 is critical for LRP1-GnGc binding.
• LRP1 exhibits redundant binding modes with RVFV GnGc.
• More than two contiguous LRP1 CR domains are required for effective in vitro neutralization of RVFV infection.

Conclusions:

• This study provides a biochemical foundation for LRP1-RVFV GnGc interactions.
• The findings suggest conserved binding mechanisms for LRP1 in infections by various emerging viruses.
• Truncated LRP1 ectodomains show potential for immunogen design and therapeutic targeting against viral infections.