Recognizing the SINEs of Infection: Regulation of Retrotransposon Expression and Modulation of Host Cell Processes

Short interspersed elements (SINEs) are a family of retrotransposons evolutionarily derived from cellular RNA polymerase III transcripts. Over evolutionary time, SINEs have expanded throughout the human genome and today comprise similar to 11% of total chromosomal DNA. While generally transcriptionally silent in healthy somatic cells, SINE expression increases during a variety of types of stresses, including DNA virus infection. The relevance of SINE expression to viral infection was largely unexplored, however, recent years have seen great progress towards defining the impact of SINE expression on viral replication and host gene expression. Here we review the origin and diversity of SINE elements and their transcriptional control, with an emphasis on how their expression impacts host cell biology during viral infection.