Plasmolipin, PmPLP1, from Penaeus monodon is a potential receptor for yellow head virus infection

Plasmolipin has been characterized as a cell entry receptor for mouse endogenous retrovirus. In black tiger shrimp, two isoforms of plasmolipin genes, PmPLP1 and PmPLP2, have been identified from the Penaeus monodon EST database. The PmPLP1 is highly up-regulated in yellow head virus (YHV)-infected shrimp. Herein, the function of PmPLP1 is shown to be involved in YHV infection. The immunoblotting and immunolocalization showed that the PmPLP1 protein was highly expressed and located at the plasma membrane of gills from YHV-infected shrimp. Moreover, the PmPLP1 expressed in the Sf9 insect cells resided at the cell membrane rendering the cells more susceptible to YHV infection. Using the ELISA binding and mortality assays, the synthetic external loop of PmPLP1 was shown to bind the purified YHV and neutralize the virus resulting in the decrease in YHV infection. Our results suggested that the PmPLP1 was likely a receptor of YHV in shrimp.