Early Proteins Coded by the Adenovirus Genome: Functional Aspects

Abstract

The adenovirus early proteins are defined as those viruscoded proteins that are synthesized prior to and in the absence of viral DNA replication. The functions of these early viral proteins provide new insights into regulatory mechanisms of gene expression and DNA replication in higher eukaryotic cells. At present, there are at least 25 early adenovirus proteins identified so far. Some of these early adenovirus gene products regulate transcription in both a positive (1,2,3) and a negative (4,5,6) mode. Other early proteins may be involved in RNA processing (7,8), while at least three early proteins are required for DNA replication (9,10,11,12). A subset of the early viral proteins are both necessary and sufficient for virus-induced cellular transformation (13,14,15,16). Other early gene products can affect the frequency of transformation (17,18,19). Finally, there are indications that some of the early viral functions may influence the host range of the human adenoviruses (7).