Characteristics of Antisense Transcript Promoters and the Regulation of Their Activity

Recently, an increasing number of studies on natural antisense transcripts have been reported, especially regarding their classification, temporal and spatial expression patterns, regulatory functions and mechanisms. It is well established that natural antisense transcripts are produced from the strand opposite to the strand encoding a protein. Despite the pivotal roles of natural antisense transcripts in regulating the expression of target genes, the transcriptional mechanisms initiated by antisense promoters (ASPs) remain unknown. To date, nearly all of the studies conducted on this topic have focused on the ASP of a single gene of interest, whereas no study has systematically analyzed the locations of ASPs in the genome, ASP activity, or factors influencing this activity. This review focuses on elaborating on and summarizing the characteristics of ASPs to extend our knowledge about the mechanisms of antisense transcript initiation.