NRP1 is a transmembrane receptor that is involved in numerous biological processes, including angiogenesis, vascular permeability, axon guidance, and mitochondrial iron transport. In October 2020, NRP1 was first demonstrated to facilitate SARS-CoV-2 entry (J. L. Daly et al., Science 10.1126/science.abd3072 (2020)). After the SARS-CoV-2 Spike protein binds to the endogenous ACE2 receptor, the Spike protein is cleaved into two polypeptides: S1 and S2. The C-end rule motif on the S1 polypeptide binds to NRP1. Inhibition of this interaction reduces viral entry.
Figure 1. Human NRP1 protein domains. There are two isoforms of human NRP1 proteins: the large isoform 1 (Product 230-30178) and the small one (Product 230-30176). Both NRP1 isoforms have b1b2 domains binding to SARS-CoV-2 S1 subunit CendR domains (Product 230-30179, 230-30180). The numbers below the domains show the amino acid position.