APOBEC3 proteins inhibit LINE-1 retrotransposition in the absence of ORF1p binding

Ann N Y Acad Sci. 2009 Oct:1178:268-75. doi: 10.1111/j.1749-6632.2009.05006.x.

Abstract

Members of the apolipoprotein B mRNA editing complex polypeptide 1-like (APOBEC) family of enzymes exhibit inhibitory activity against a variety of exogenous and endogenous retroviruses including retrotransposons, such as long interspersed element 1 (LINE-1). Indeed, human APOBEC3A, APOBEC3B, and APOBEC3F inhibit retrotransposition of human LINE-1, mouse IAP and MusD retrotransposons. In our study, we examined whether the inhibitory effect of APOBEC3 proteins correlates with APOBEC3 ability to bind the LINE-1 ORF1 protein. We examined the interactions between the LINE-1 ORF1 protein and the most potent LINE-1 retrotransposon inhibitors, human APOBEC3A and APOBEC3B, by immunofluorescence and immunoprecipitation. Although human APOBEC3A shows the highest inhibitory potency against LINE-1 retrotransposon, no direct interactions were identified either by immunofluorescence or by co-immunoprecipitation. APOBEC3B binds to LINE-1 ORF1 protein, yet no co-localization was detected. We concluded that APOBEC3 proteins interfere indirectly with the LINE-1 retrotransposition pathway, probably through interference with RNA targeting.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • APOBEC-1 Deaminase
  • Animals
  • Binding Sites
  • Cytidine Deaminase / genetics
  • Cytidine Deaminase / metabolism*
  • Fluorescent Antibody Technique
  • HeLa Cells
  • Humans
  • Long Interspersed Nucleotide Elements*
  • Mice
  • Open Reading Frames / genetics*
  • Transfection

Substances

  • APOBEC-1 Deaminase
  • APOBEC1 protein, human
  • Apobec1 protein, mouse
  • Cytidine Deaminase