Title

Inhibition of APOBEC3G activity impedes double-stranded DNA repair

UMMS Affiliation

Department of Biochemistry and Molecular Pharmacology

Publication Date

2016-01-01

Document Type

Article

Disciplines

Biochemistry | Medicinal Chemistry and Pharmaceutics | Medicinal-Pharmaceutical Chemistry | Molecular Biology | Structural Biology | Virology

Abstract

The cellular cytidine deaminase APOBEC3G (A3G) was first described as an anti-HIV-1 restriction factor, acting by directly deaminating reverse transcripts of the viral genome. HIV-1 Vif neutralizes the activity of A3G, primarily by mediating degradation of A3G to establish effective infection in host target cells. Lymphoma cells, which express high amounts of A3G, can restrict Vif-deficient HIV-1. Interestingly, these cells are more stable in the face of treatments that result in double-stranded DNA damage, such as ionizing radiation and chemotherapies. Previously, we showed that the Vif-derived peptide (Vif25-39) efficiently inhibits A3G deamination, and increases the sensitivity of lymphoma cells to ionizing radiation. In the current study, we show that additional peptides derived from Vif, A3G, and APOBEC3F, which contain the LYYF motif, inhibit deamination activity. Each residue in the Vif25-39 sequence moderately contributes to the inhibitory effect, whereas replacing a single residue in the LYYF motif completely abrogates inhibition of deamination. Treatment of A3G-expressing lymphoma cells exposed to ionizing radiation with the new inhibitory peptides reduces double-strand break repair after irradiation. Incubation of cultured irradiated lymphoma cells with peptides that inhibit double-strand break repair halts their propagation. These results suggest that A3G may be a potential therapeutic target that is amenable to peptide and peptidomimetic inhibition.

Keywords

APOBEC3G, DNA binding, DNA repair, lymphoma cells, peptides

DOI of Published Version

10.1111/febs.13556

Source

FEBS J. 2016 Jan;283(1):112-29. doi: 10.1111/febs.13556. Epub 2015 Nov 6. Link to article on publisher's site

Journal/Book/Conference Title

The FEBS journal

Related Resources

Link to Article in PubMed

PubMed ID

26460502

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