title: Determinants of FIV and HIV Vif sensitivity of feline APOBEC3 restriction factors.
abstract: Feline immunodeficiency virus (FIV) is a global pathogen of Felidae species and a model system for Human immunodeficiency virus (HIV)-induced AIDS. In felids such as the domestic cat (Felis catus), APOBEC3 (A3) genes encode for single-domain A3Z2s, A3Z3 and double-domain A3Z2Z3 anti-viral cytidine deaminases. The feline A3Z2Z3 is expressed following read-through transcription and alternative splicing, introducing a previously untranslated exon in frame, encoding a domain insertion called linker. Only A3Z3 and A3Z2Z3 inhibit Vif-deficient FIV. Feline A3s also are restriction factors for HIV and Simian immunodeficiency viruses (SIV). Surprisingly, HIV-2/SIV Vifs can counteract feline A3Z2Z3.
  
  
  
  To identify residues in feline A3s that Vifs need for interaction and degradation, chimeric human-feline A3s were tested. Here we describe the molecular direct interaction of feline A3s with Vif proteins from cat FIV and present the first structural A3 model locating these interaction regions. In the Z3 domain we have identified residues involved in binding of FIV Vif, and their mutation blocked Vif-induced A3Z3 degradation. We further identified additional essential residues for FIV Vif interaction in the A3Z2 domain, allowing the generation of FIV Vif resistant A3Z2Z3. Mutated feline A3s also showed resistance to the Vif of a lion-specific FIV, indicating an evolutionary conserved Vif-A3 binding. Comparative modelling of feline A3Z2Z3 suggests that the residues interacting with FIV Vif have, unlike Vif-interacting residues in human A3s, a unique location at the domain interface of Z2 and Z3 and that the linker forms a homeobox-like domain protruding of the Z2Z3 core. HIV-2/SIV Vifs efficiently degrade feline A3Z2Z3 by possible targeting the linker stretch connecting both Z-domains.
  
  
  
  Here we identified in feline A3s residues important for binding of FIV Vif and a unique protein domain insertion (linker). To understand Vif evolution, a structural model of the feline A3 was developed. Our results show that HIV Vif binds human A3s differently than FIV Vif feline A3s. The linker insertion is suggested to form a homeo-box domain, which is unique to A3s of cats and related species, and not found in human and mouse A3s. Together, these findings indicate a specific and different A3 evolution in cats and human.
authors.affiliation: Clinic for Gastroenterology, Hepatology, and Infectiology, Medical Faculty, Heinrich-Heine-University Düsseldorf, Building 23.12.U1.82, Moorenstr. 5, 40225, Düsseldorf, Germany.
authors.forename: Zeli
authors.initials: Z
authors.lastname: Zhang
authors.affiliation: Clinic for Gastroenterology, Hepatology, and Infectiology, Medical Faculty, Heinrich-Heine-University Düsseldorf, Building 23.12.U1.82, Moorenstr. 5, 40225, Düsseldorf, Germany.
authors.forename: Qinyong
authors.initials: Q
authors.lastname: Gu
authors.affiliation: Clinic for Gastroenterology, Hepatology, and Infectiology, Medical Faculty, Heinrich-Heine-University Düsseldorf, Building 23.12.U1.82, Moorenstr. 5, 40225, Düsseldorf, Germany.
authors.forename: Ananda Ayyappan
authors.initials: AA
authors.lastname: Jaguva Vasudevan
authors.affiliation: Clinic for Gastroenterology, Hepatology, and Infectiology, Medical Faculty, Heinrich-Heine-University Düsseldorf, Building 23.12.U1.82, Moorenstr. 5, 40225, Düsseldorf, Germany.
authors.forename: Anika
authors.initials: A
authors.lastname: Hain
authors.affiliation: Department of Medical Biotechnology, Paul-Ehrlich-Institute, Paul-Ehrlich-Str. 51-59, 63225, Langen, Germany.|BioNTech RNA Pharmaceuticals GmbH, An der Goldgrube 12, 55131, Mainz, Germany.
authors.forename: Björn-Philipp
authors.initials: BP
authors.lastname: Kloke
authors.affiliation: Clinic for Gastroenterology, Hepatology, and Infectiology, Medical Faculty, Heinrich-Heine-University Düsseldorf, Building 23.12.U1.82, Moorenstr. 5, 40225, Düsseldorf, Germany.
authors.forename: Sascha
authors.initials: S
authors.lastname: Hasheminasab
authors.affiliation: Institute of Pharmaceutical and Medicinal Chemistry, Heinrich Heine University Düsseldorf, Universitätsstr. 1, 40225, Düsseldorf, Germany.
authors.forename: Daniel
authors.initials: D
authors.lastname: Mulnaes
authors.affiliation: Laboratory of Viral Pathogenesis, Institute for Virus Research, Kyoto University, Kyoto, 6068507, Japan.|CREST, Japan Science and Technology Agency, Saitama, 3220012, Japan.
authors.forename: Kei
authors.initials: K
authors.lastname: Sato
authors.affiliation: Department of Medical Biotechnology, Paul-Ehrlich-Institute, Paul-Ehrlich-Str. 51-59, 63225, Langen, Germany.
authors.forename: Klaus
authors.initials: K
authors.lastname: Cichutek
authors.affiliation: Clinic for Gastroenterology, Hepatology, and Infectiology, Medical Faculty, Heinrich-Heine-University Düsseldorf, Building 23.12.U1.82, Moorenstr. 5, 40225, Düsseldorf, Germany.
authors.forename: Dieter
authors.initials: D
authors.lastname: Häussinger
authors.affiliation: MIVEGEC (UMR CNRS 5290, IRD 224, UM), National Center of Scientific Research (CNRS), 34394, Montpellier, France.
authors.forename: Ignacio G
authors.initials: IG
authors.lastname: Bravo
authors.affiliation: Institute of Biochemistry, Heinrich Heine University Düsseldorf, Universitätsstr. 1, 40225, Düsseldorf, Germany.
authors.forename: Sander H J
authors.initials: SH
authors.lastname: Smits
authors.affiliation: Institute of Pharmaceutical and Medicinal Chemistry, Heinrich Heine University Düsseldorf, Universitätsstr. 1, 40225, Düsseldorf, Germany.
authors.forename: Holger
authors.initials: H
authors.lastname: Gohlke
authors.affiliation: Clinic for Gastroenterology, Hepatology, and Infectiology, Medical Faculty, Heinrich-Heine-University Düsseldorf, Building 23.12.U1.82, Moorenstr. 5, 40225, Düsseldorf, Germany. carsten.muenk@med.uni-duesseldorf.de.
authors.forename: Carsten
authors.identifier: 0000-0002-8026-9311
authors.initials: C
authors.lastname: Münk
mesh_terms: D000818:Animals; D002415:Cats; D002460:Cell Line; D003564:Cytidine Deaminase / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D019143:Evolution, Molecular; D016346:Gene Products, vif / Q000235:genetics / Q000378:metabolism*; D005801:Genes, Homeobox; D015497:HIV-1 / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D016089:Immunodeficiency Virus, Feline / Q000235:genetics / Q000378:metabolism*; D008958:Models, Molecular; D011993:Recombinant Fusion Proteins / Q000378:metabolism
chemical_list: D016346:Gene Products, vif; D011993:Recombinant Fusion Proteins; D003564:Cytidine Deaminase
keywords: APOBEC3; FIV; Gene evolution; HIV; Homeobox; Homology modelling; Restriction factor; SIV; Vif