Transcription of the Herpes Simplex Virus Genome during Productive and Latent Infection

Abstract

Publisher Summary Herpesviruses are nuclear-replicating, icosahedral, and enveloped DNA viruses that infect members of all groups of vertebrates. Herpesviruses are generally grouped into three divisions—namely, α-herpesviruses, β-herpesviruses, and γ-herpesviruses. Productive replication of all herpesviruses studied to date involves a regulated cascade of viral gene products in which control of viral messenger RNA abundance plays a central role. The plasticity in the structure and organization of herpesvirus genomes is indicative of a basic feature of productive viral replication—herpesvirus genomes are promoter-rich and generally the expression of a given protein is mediated by a specific promoter mapping at that gene. Herpes simplex virus type 1 (HSV 1) is the prototype and best studied representative of the α-herpesvirus group. It is neurotropic and establishes latent infections in sensory neurons. It is characterized by an extremely rapid productive replication cycle and can replicate in a large group of animals, tissues, and cultured cells. Productive infection of a cell by HSV involves a number of stages representing different levels of viral gene expression and interaction of viral gene products with host machinery. Virus entry requires sequential interaction between specific viral membrane glycoproteins and cellular receptors, notably heparan sulfate proteoglycans. The transcriptional events occurring during the programmed interplay between virus and host are shown in the chapter. All of the HSV promoters extensively analyzed are clearly representative of the types of cellular promoters and require cellular transcription factors for activity.