Display of the human (pro)renin receptor on Bombyx mori nucleopolyhedrovirus (BmNPV) particles using Bm cells

The human (pro)renin receptor (hPRR) was displayed on the surface of Bombyx mori nucleopolyhedrovirus (BmNPV) with and without fusion to glycoprotein 64 (GP64) of the BmNPV. hPRR1 is a native hPRR with an additional FLAG peptide sequence inserted between the signal peptide and prorenin-binding domain. hPRR2 has the prorenin-binding domain inserted between amino acid residues 81Asp and 82Pro of GP64. hPRR4 has the prorenin-binding domain inserted in 81Asp and 320Met of partially deleted GP64. Incorporation of hPRR was confirmed in recombinant BmNPV (rBmNPV) but not in cysteine protease-deleted rBmNPV. hPRR1 was observed in ER, but hPRR2 and hPRR4 were observed around the endoplasmic reticulum (ER) and in its periphery. rBmNPV-hPRR1 and -hPRR2, carrying hPRR1 and hPRR2 respectively, showed binding affinity to human renin, but rBmNPV-hPRR4 did not. The presence of hPRR4 of rBmNPV-hPRR4 was confirmed in western blotting under nonreducing conditions, suggesting that although hPRR4 was incorporated in rBmNPV-hPRR4, it behaved as a non-functional aggregate. This rBmNPV display system can also be used for analyzing a ligand–receptor interaction.