Localization of human (pro)renin receptor lacking the transmembrane domain on budded baculovirus of Autographa californica multiple nucleopolyhedrovirus

Human (pro)renin receptor (hPRR), a construct with native transmembrane and cytoplasmic domains (hPRR-wTM), and hPRR lacking both (hPRR-w/oTM) were expressed using insect cells. The hPRR-wTM was expressed in the peripheral domains of the nucleus in infected Sf-9 cells, and its localization was observed in endoplasmic reticulum (ER). However, it could not be extracted from recombinant Autographa californica multiple nucleopolyhedrovirus (AcMNPV) by Triton X-100 treatment at 4°C. In contrast, hPRR-w/oTM was observed in punctate domains in the cytoplasm of infected Sf-9 cells, but intracellular hPRR-w/oTM did not co-localize in the Golgi apparatus and lysosomes. This indicates that hPRR-wTM and hPRR-w/oTM is localized in the ER and cytoplasmic organelles of Sf-9 cell, respectively. Moreover, the localization of hPRR-w/oTM in budded baculovirus of recombinant AcMNPV was confirmed by Western blotting. This is the first finding of the association of a foreign protein lacking a transmembrane domain with a baculovirus. If this finding is available for double displaying system, being capable of expression on the envelope and the capsid of baculovirus, it will lead to new methodology of baculovirus display system for tissue- and cell-specific targeting and intracellular targeting.