Functions, structure, and read-through alternative splicing of feline APOBEC3 genes

  • Background Over the past years a variety of host restriction genes have been identified in human and mammals that modulate retrovirus infectivity, replication, assembly, and/or cross-species transmission. Among these host-encoded restriction factors, the APOBEC3 (A3; apolipoprotein B mRNA-editing catalytic polypeptide 3) proteins are potent inhibitors of retroviruses and retrotransposons. While primates encode seven of these genes (A3A to A3H), rodents carry only a single A3 gene. Results Here we identified and characterized several A3 genes in the genome of domestic cat (Felis catus) by analyzing the genomic A3 locus. The cat genome presents one A3H gene and three very similar A3C genes (a-c), probably generated after two consecutive gene duplications. In addition to these four one-domain A3 proteins, a fifth A3, designated A3CH, is expressed by read-through alternative splicing. Specific feline A3 proteins selectively inactivated only defined genera of feline retroviruses: Bet-deficient feline foamy virus was mainly inactivated by feA3Ca, feA3Cb, and feA3Cc, while feA3H and feA3CH were only weakly active. The infectivity of Vif-deficient feline immunodeficiency virus and feline leukemia virus was reduced only by feA3H and feA3CH, but not by any of the feA3Cs. Within Felidae, A3C sequences show significant adaptive selection, but unexpectedly, the A3H sequences present more sites that are under purifying selection. Conclusion Our data support a complex evolutionary history of expansion, divergence, selection and individual extinction of antiviral A3 genes that parallels the early evolution of Placentalia, becoming more intricate in taxa in which the arms race between host and retroviruses is harsher.
Author:Carsten Münk, Thomas Beck, Jörg Zielonka, Agnes Hotz-Wagenblatt, Sarah Chareza, Marion Battenberg, Jens Thielebein, Klaus CichutekGND, Ignacio G. Bravo, Stephen J. O'Brien, Martin Löchelt, Naoya Yuhki
Pubmed Id:
Parent Title (English):Genome biology
Publisher:BioMed Central
Place of publication:London
Document Type:Article
Date of Publication (online):2008/05/20
Date of first Publication:2008/03/03
Publishing Institution:Universitätsbibliothek Johann Christian Senckenberg
Release Date:2008/05/20
Issue:3, Art. R48
Page Number:20
First Page:1
Last Page:20
© 2008 Münk et al.; licensee BioMed Central Ltd. This is an open access article distributed under the terms of the Creative Commons Attribution License  (, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Source:Genome Biology 2008, 9:R48 (doi:10.1186/gb-2008-9-3-r48)
Institutes:Biowissenschaften / Biowissenschaften
Dewey Decimal Classification:5 Naturwissenschaften und Mathematik / 57 Biowissenschaften; Biologie / 570 Biowissenschaften; Biologie
Sammlungen:Sammlung Biologie / Sondersammelgebiets-Volltexte
Licence (German):License LogoCreative Commons - Namensnennung 2.0