title: DNA and RNA editing of retrotransposons accelerate mammalian genome evolution.
abstract: Genome evolution is commonly viewed as a gradual process that is driven by random mutations that accumulate over time. However, DNA- and RNA-editing enzymes have been identified that can accelerate evolution by actively modifying the genomically encoded information. The apolipoprotein B mRNA editing enzymes, catalytic polypeptide-like (APOBECs) are potent restriction factors that can inhibit retroelements by cytosine-to-uridine editing of retroelement DNA after reverse transcription. In some cases, a retroelement may successfully integrate into the genome despite being hypermutated. Such events introduce unique sequences into the genome and are thus a source of genomic innovation. adenosine deaminases that act on RNA (ADARs) catalyze adenosine-to-inosine editing in double-stranded RNA, commonly formed by oppositely oriented retroelements. The RNA editing confers plasticity to the transcriptome by generating many transcript variants from a single genomic locus. If the editing produces a beneficial variant, the genome may maintain the locus that produces the RNA-edited transcript for its novel function. Here, we discuss how these two powerful editing mechanisms, which both target inserted retroelements, facilitate expedited genome evolution.
authors.affiliation: The Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat-Gan, Israel.
authors.forename: Binyamin A
authors.initials: BA
authors.lastname: Knisbacher
authors.forename: Erez Y
authors.initials: EY
authors.lastname: Levanon
mesh_terms: D000071479:APOBEC-1 Deaminase; D000818:Animals; D003564:Cytidine Deaminase / Q000378:metabolism; D004247:DNA / Q000235:genetics* / Q000378:metabolism; D019143:Evolution, Molecular; D016678:Genome / Q000235:genetics*; D006801:Humans; D008957:Models, Genetic; D009154:Mutation; D017393:RNA Editing; D018626:Retroelements / Q000235:genetics*
chemical_list: D018626:Retroelements; D004247:DNA; D000071479:APOBEC-1 Deaminase; C000605089:APOBEC1 protein, human; D003564:Cytidine Deaminase
keywords: ADAR; APOBEC; DNA editing; RNA editing; genome evolution; retrotransposons