Effect of Depurination on Cellular and Viral RNA

Abstract

Abasic sites in DNA arise from spontaneous damage and, if left unrepaired, contribute to mutations. Dedicated pathways have evolved to repair abasic DNA; however, the biological implications and cellular fate of RNA possessing these lesions are not well characterized. In this chapter, we review advances in the area of RNA depurination, which produces the dominant form of abasic RNA in vivo. We discuss the biochemistry of RNA depurination, the varied impacts of cellular and viral RNA depurination, and the numerous methods available for detecting abasic RNA. Given the abundance of RNA in cells and the relative stability of abasic RNA compared with DNA, depurinated RNA likely has physiological significance. Recent work suggests a link between RNA depurination and some age-related diseases as well as downstream signalling pathways that induce apoptosis. In addition, pathogens with RNA genomes are influenced by depurination. For example, abasic sites of HIV-1 RNA may contribute to adaptation by mutation and recombination. Therefore, effects of RNA depurination have medical relevance that warrants continued study.