Changes in BiP (GRP78) levels upon HSV-1 infection are strain dependent

BiP (grp78) is a chaperone protein which can also regulate the unfolded protein response of the cell. Levels of BiP increased in cells infected by the small plaque producing, cell associated, neuroinvasive strains of HSV-1 (SP7, 490) but decreased in cells infected with KOS, a large plaque, attenuated strain. BiP protein synthesis continued early in infection and BiP was sequestered and its degradation was limited during SP7 infection. BiP protein synthesis stopped and the protein was degraded in KOS infected cells. These viral strain dependent differences in BiP concentration may influence other aspects of the viral interaction with the target cell and its host.