Mouse APOBEC1 cytidine deaminase can induce somatic mutations in chromosomal DNA

APOBEC1 (A1) enzymes are cytidine deaminases involved in RNA editing. In addition to this activity, a few A1 enzymes have been shown to be active on single stranded DNA. As two human ssDNA cytidine deaminases APOBEC3A (A3A), APOBEC3B (A3B) and related enzymes across the spectrum of placental mammals have been shown to introduce somatic mutations into nuclear DNA of cancer genomes, we explored the mutagenic threat of A1 cytidine deaminases to chromosomal DNA.