HERPES-SIMPLEX VIRUS TYPE-1 IMMEDIATE-EARLY PROTEIN VMW110 BINDS STRONGLY AND SPECIFICALLY TO A 135-KDA CELLULAR PROTEIN

Herpes simplex virus type 1 encodes five immediate-early gene products , at least three of which are required for fully efficient viral gene expression. One of these three, Vmw110 (or ICPO), is a potent and nons pecific activator of gene expression in transfection assays. Viruses w hich fail to express functional Vmw110 have a cell-type and multiplici ty-dependent defect in viral gene expression. In addition, Vmw110 has been implicated in the reactivation of latent virus in mouse and tissu e culture model systems. In this report we show that Vmw110 can be iso lated as a fast-sedimenting complex from infected cells and that this complex contains a cellular protein which is immune precipitated in as sociation with Vmw110. This association can be reconstructed by adding purified Vmw110 to lysates of several different cell types. By using a GST fusion protein, we have found that the isolated C-terminal porti on of Vmw110 can complex strongly and specifically with a similar cell ular protein. The relevance of this observation to the roles of Vmw110 in latent and lytic virus infection is discussed. (C) 1994 Academic P ress, Inc.