Rhesus lymphocryptovirus latent membrane protein 2A activates beta-catenin signaling and inhibits differentiation in epithelial cells.

摘要

Rhesus lymphocryptovirus (LCV) is a gamma-herpesvirus closely related to Epstein-Barr virus (EBV). The rhesus latent membrane protein 2A (LMP2A) is highly homologous to EBV LMP2A. EBV LMP2A activates the phosphatidylinositol 3-kinase (PI3K) and beta-catenin signaling pathways in epithelial cells and affects differentiation. In the present study, the biochemical and biological properties of rhesus LMP2A in epithelial cells were investigated. The expression of rhesus LMP2A in epithelial cells induced Akt activation, GSK3beta inactivation and accumulation of beta-catenin in the cytoplasm and nucleus. The nuclear translocation, but not accumulation of beta-catenin was dependent on Akt activation. Rhesus LMP2A also impaired epithelial cell differentiation; however, this process was not dependent upon Akt activation. A mutant rhesus LMP2A lacking six transmembrane domains functioned similarly to wild-type rhesus LMP2A indicating that the full number of transmembrane domains is not required for effects on beta-catenin or cell differentiation. These results underscore the similarity of LCV to EBV and the suitability of the macaque as an animal model for studying EBV pathogenesis.