ACTIVATION OF THE HERPES-SIMPLEX VIRUS IMMEDIATE-EARLY GENE PROMOTERSBY NEURONALLY EXPRESSED POU FAMILY TRANSCRIPTION FACTORS

Herpes simplex virus immediate-early (IE) promoters contain the TAATGA RAT motif which acts as a target site for the cellular POU family tran scription factors Oct-1 and Oct-2. Here we show that other members of the POU family that are expressed in sensory neurons can also affect I E promoter activity. In particular, two members of the Brn-3 family of POU proteins Brn-3a and Brn-3c can activate the IE-1 and IE-3 promote rs when co-transfected into fibroblasts and neuronal cells whereas a t hird member Brn-3b represses IE promoter activity. In contrast, Brn-3 proteins cannot overcome the inhibitory effect of neuronal Oct-2 on IE promoter activity in co-transfections nor do they prevent transactiva tion of the IE promoters by the Oct-1-Vmw65 complex. The potential reg ulation of the IE promoters by several different neuronally expressed POU proteins during the initiation, maintenance and re-activation of l atent infection in sensory neurons is discussed.