title: A SAMHD1 mutation associated with Aicardi-Goutières syndrome uncouples the ability of SAMHD1 to restrict HIV-1 from its ability to downmodulate type I interferon in humans.
abstract: Mutations in the human SAMHD1 gene are known to correlate with the development of the Aicardi-Goutières syndrome (AGS), which is an inflammatory encephalopathy that exhibits neurological dysfunction characterized by increased production of type I interferon (IFN); this evidence has led to the concept that the SAMHD1 protein negatively regulates the type I IFN response. Additionally, the SAMHD1 protein has been shown to prevent efficient HIV-1 infection of macrophages, dendritic cells, and resting CD4+ T cells. To gain insights on the SAMHD1 molecular determinants that are responsible for the deregulated production of type I IFN, we explored the biochemical, cellular, and antiviral properties of human SAMHD1 mutants known to correlate with the development of AGS. Most of the studied SAMHD1 AGS mutants exhibit defects in the ability to oligomerize, decrease the levels of cellular deoxynucleotide triphosphates in human cells, localize exclusively to the nucleus, and restrict HIV-1 infection. At least half of the tested variants preserved the ability to be degraded by the lentiviral protein Vpx, and all of them interacted with RNA. Our investigations revealed that the SAMHD1 AGS variant p.G209S preserve all tested biochemical, cellular, and antiviral properties, suggesting that this residue is a determinant for the ability of SAMHD1 to negatively regulate the type I IFN response in human patients with AGS. Overall, our work genetically separated the ability of SAMHD1 to negatively regulate the type I IFN response from its ability to restrict HIV-1.
authors.affiliation: Department of Microbiology and Immunology, Albert Einstein College of Medicine Bronx, New York.
authors.forename: Tommy E
authors.initials: TE
authors.lastname: White
authors.affiliation: Department of Microbiology and Immunology, Albert Einstein College of Medicine Bronx, New York.
authors.forename: Alberto
authors.initials: A
authors.lastname: Brandariz-Nuñez
authors.affiliation: Department of Microbiology and Immunology, Albert Einstein College of Medicine Bronx, New York.
authors.forename: Alicia
authors.initials: A
authors.lastname: Martinez-Lopez
authors.affiliation: Department of Pediatrics, Emory University, Atlanta, Georgia.
authors.forename: Caitlin
authors.initials: C
authors.lastname: Knowlton
authors.affiliation: Department of Pediatrics, Emory University, Atlanta, Georgia.
authors.forename: Gina
authors.initials: G
authors.lastname: Lenzi
authors.affiliation: Department of Pediatrics, Emory University, Atlanta, Georgia.
authors.forename: Baek
authors.initials: B
authors.lastname: Kim
authors.affiliation: Department of Biochemistry, University of Texas Health Science Center, San Antonio, Texas.
authors.forename: Dmitri
authors.initials: D
authors.lastname: Ivanov
authors.affiliation: Department of Microbiology and Immunology, Albert Einstein College of Medicine Bronx, New York.
authors.forename: Felipe
authors.initials: F
authors.lastname: Diaz-Griffero
mesh_terms: D020274:Autoimmune Diseases of the Nervous System / Q000150:complications / Q000235:genetics* / Q000821:virology; D015496:CD4-Positive T-Lymphocytes / Q000378:metabolism; D002460:Cell Line; D020022:Genetic Predisposition to Disease; D015658:HIV Infections / Q000150:complications / Q000235:genetics* / Q000821:virology; D015497:HIV-1 / Q000472:pathogenicity; D006801:Humans; D007370:Interferon Type I / Q000235:genetics*; D016086:Lentivirus / Q000235:genetics; D009154:Mutation; D009421:Nervous System Malformations / Q000150:complications / Q000235:genetics* / Q000821:virology; D000076106:SAM Domain and HD Domain-Containing Protein 1 / Q000235:genetics*
chemical_list: D007370:Interferon Type I; D000076106:SAM Domain and HD Domain-Containing Protein 1; C484280:SAMHD1 protein, human
keywords: Aicardi-Goutières syndrome; HIV-1; SAMHD1; interferon