Deamination-independent restriction of LINE-1 retrotransposition by APOBEC3H

Sci Rep. 2017 Sep 7;7(1):10881. doi: 10.1038/s41598-017-11344-4.

Abstract

The APOBEC3 family of cytosine deaminase enzymes are able to restrict replication of retroelements, such as LINE-1. However, each of the seven APOBEC3 enzymes have been reported to act differentially to prevent LINE-1 retrotransposition and the mechanisms of APOBEC3-mediated LINE-1 inhibition has not been well understood. The prevailing view for many years was that APOBEC3-mediated LINE-1 inhibition was deamination-independent and relied on APOBEC3s blocking the LINE-1 reverse transcriptase DNA polymerization or transport of the LINE-1 RNA into the nucleus. However, recently it was shown that APOBEC3A can deaminate cytosine, to form uracil, on transiently exposed single-stranded LINE-1 cDNA and this leads to LINE-1 cDNA degradation. In this study, we confirmed that APOBEC3A is a potent deamination-dependent inhibitor of LINE-1 retrotransposition, but show that in contrast, A3H haplotype II and haplotype V restrict LINE-1 activity using a deamination-independent mechanism. Our study supports the model that different APOBEC3 proteins have evolved to inhibit LINE-1 retrotransposition through distinct mechanisms.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Cytidine Deaminase / metabolism*
  • Deamination
  • HeLa Cells
  • Humans
  • Long Interspersed Nucleotide Elements*
  • Nuclear Proteins / metabolism*
  • Protein Processing, Post-Translational*
  • Proteins / metabolism*
  • RNA-Binding Proteins / metabolism*

Substances

  • L1RE1 protein, human
  • Nuclear Proteins
  • Proteins
  • RNA-Binding Proteins
  • APOBEC3A protein, human
  • Cytidine Deaminase