title: Interactions between the HIV-1 Unspliced mRNA and Host mRNA Decay Machineries.
abstract: The human immunodeficiency virus type-1 (HIV-1) unspliced transcript is used both as mRNA for the synthesis of structural proteins and as the packaged genome. Given the presence of retained introns and instability AU-rich sequences, this viral transcript is normally retained and degraded in the nucleus of host cells unless the viral protein REV is present. As such, the stability of the HIV-1 unspliced mRNA must be particularly controlled in the nucleus and the cytoplasm in order to ensure proper levels of this viral mRNA for translation and viral particle formation. During its journey, the HIV-1 unspliced mRNA assembles into highly specific messenger ribonucleoproteins (mRNPs) containing many different host proteins, amongst which are well-known regulators of cytoplasmic mRNA decay pathways such as up-frameshift suppressor 1 homolog (UPF1), Staufen double-stranded RNA binding protein 1/2 (STAU1/2), or components of miRNA-induced silencing complex (miRISC) and processing bodies (PBs). More recently, the HIV-1 unspliced mRNA was shown to containN⁶-methyladenosine (m⁶A), allowing the recruitment of YTHN⁶-methyladenosine RNA binding protein 2 (YTHDF2), an m⁶A reader host protein involved in mRNA decay. Interestingly, these host proteins involved in mRNA decay were shown to play positive roles in viral gene expression and viral particle assembly, suggesting that HIV-1 interacts with mRNA decay components to successfully accomplish viral replication. This review summarizes the state of the art in terms of the interactions between HIV-1 unspliced mRNA and components of different host mRNA decay machineries.
authors.affiliation: Molecular and Cellular Virology Laboratory, Virology Program, Institute of Biomedical Sciences, Faculty of Medicine, Universidad of Chile, Independencia 834100, Santiago, Chile. daniela.toroascuy@gmail.com.
authors.forename: Daniela
authors.initials: D
authors.lastname: Toro-Ascuy
authors.affiliation: Molecular and Cellular Virology Laboratory, Virology Program, Institute of Biomedical Sciences, Faculty of Medicine, Universidad of Chile, Independencia 834100, Santiago, Chile. barbara.rojas.araya@gmail.com.
authors.forename: Bárbara
authors.initials: B
authors.lastname: Rojas-Araya
authors.affiliation: Molecular and Cellular Virology Laboratory, Virology Program, Institute of Biomedical Sciences, Faculty of Medicine, Universidad of Chile, Independencia 834100, Santiago, Chile. fvaliente@med.uchile.cl.
authors.forename: Fernando
authors.initials: F
authors.lastname: Valiente-Echeverría
authors.affiliation: Molecular and Cellular Virology Laboratory, Virology Program, Institute of Biomedical Sciences, Faculty of Medicine, Universidad of Chile, Independencia 834100, Santiago, Chile. rsotorifo@med.uchile.cl.
authors.forename: Ricardo
authors.initials: R
authors.lastname: Soto-Rifo
mesh_terms: D015497:HIV-1 / Q000235:genetics*; D054884:Host-Pathogen Interactions; D006801:Humans; D020871:RNA Stability; D012367:RNA, Viral / Q000378:metabolism*
chemical_list: D012367:RNA, Viral
keywords: HIV-1 unspliced mRNA; REV; Staufen; UPF1; YTHDF2; m6A; mRNA decay