(515bh) Expression of Functional Human Prorenin Receptor in Silkworm Larvae Using Bmnpv Bacmid

The circulating renin-angiotensin system (RA system) is essential for the regulation of blood pressure and electrolyte balance. Recently, plasma prorenin has been reported to significantly increase its level in diabetes and to be possibly nonproteolytically activated by binding to the (pro)renin receptor (PRR) on the cell membrane reported in several tissues during circulation. Although many pathological aspects have been researched, there is no sufficient information on this human PRR (hPRR); thus, biochemical research on hPRR that will lead to future structural and functional research should be conducted. In this study, we established the BmNPV expression system with silkworm larvae as hosts, using the bacmid DNA developed in our laboratory for direct injection into the silkworm larvae.hPRR fused with the green fluorescence protein (GFPuv) was successfully expressed using BmNPV bacmid DNA in silkworm larvae. hPRR without a transmembrane domain was expressed in the hemolymph of silkworm larvae, but hPRR with a transmembrane domain, in the fat body of silkworm larvae. The equilibrium dissociation constant (Kd) for prorenin binding to hPRR was estimated to be 6.6 nM, suggesting that the expressed hPRR has enough bioactivity. These hPRRs can be purified separately from the fat body and hemolymph of silkworm larvae, respectively. hPRR preparations will, therefore, be useful for biomedical research related to PRR.