title: The cytidine deaminase CEM15 induces hypermutation in newly synthesized HIV-1 DNA.
abstract: High mutation frequency during reverse transcription has a principal role in the genetic variation of primate lentiviral populations. It is the main driving force for the generation of drug resistance and the escape from immune surveillance. G to A hypermutation is one of the characteristics of primate lentiviruses, as well as other retroviruses, during replication in vivo and in cell culture. The molecular mechanisms of this process, however, remain to be clarified. Here, we demonstrate that CEM15 (also known as apolipoprotein B mRNA editing enzyme, catalytic polypeptide-like 3G; APOBEC3G), an endogenous inhibitor of human immunodeficiency virus type 1 (HIV-1) replication, is a cytidine deaminase and is able to induce G to A hypermutation in newly synthesized viral DNA. This effect can be counteracted by the HIV-1 virion infectivity factor (Vif). It seems that this viral DNA mutator is a viral defence mechanism in host cells that may induce either lethal hypermutation or instability of the incoming nascent viral reverse transcripts, which could account for the Vif-defective phenotype. Importantly, the accumulation of CEM15-mediated non-lethal hypermutation in the replicating viral genome could potently contribute to the genetic variation of primate lentiviral populations.
authors.affiliation: The Dorrance H. Hamilton Laboratories, Center for Human Virology and Biodefense, Division of Infectious Diseases and Environmental Medicine, Department of Medicine, Thomas Jefferson University, Philadelphia, Pennsylvania 19107, USA. hui.zhang@mail.tju.edu
authors.forename: Hui
authors.initials: H
authors.lastname: Zhang
authors.forename: Bin
authors.initials: B
authors.lastname: Yang
authors.forename: Roger J
authors.initials: RJ
authors.lastname: Pomerantz
authors.forename: Chune
authors.initials: C
authors.lastname: Zhang
authors.forename: Shyamala C
authors.initials: SC
authors.lastname: Arunachalam
authors.forename: Ling
authors.initials: L
authors.lastname: Gao
mesh_terms: D000071480:APOBEC-3G Deaminase; D002460:Cell Line; D003564:Cytidine Deaminase; D004279:DNA, Viral / Q000096:biosynthesis* / Q000235:genetics*; D016346:Gene Products, vif / Q000172:deficiency / Q000235:genetics / Q000378:metabolism; D015497:HIV-1 / Q000235:genetics* / Q000254:growth & development / Q000502:physiology; D006801:Humans; D016296:Mutagenesis / Q000235:genetics*; D009700:Nucleoside Deaminases; D017354:Point Mutation / Q000235:genetics; D011506:Proteins / Q000235:genetics / Q000378:metabolism*; D012097:Repressor Proteins; D012692:Serial Passage; D014158:Transcription, Genetic / Q000235:genetics; D014779:Virus Replication; D054320:vif Gene Products, Human Immunodeficiency Virus
chemical_list: D004279:DNA, Viral; D016346:Gene Products, vif; D011506:Proteins; D012097:Repressor Proteins; D054320:vif Gene Products, Human Immunodeficiency Virus; D009700:Nucleoside Deaminases; D000071480:APOBEC-3G Deaminase; C464924:APOBEC3G protein, human; D003564:Cytidine Deaminase