title: A putative SUMO interacting motif in the B30.2/SPRY domain of rhesus macaque TRIM5α important for NF-κB/AP-1 signaling and HIV-1 restriction.
abstract: TRIM5α from the rhesus macaque (TRIM5αRh) is a restriction factor that shows strong activity against HIV-1. TRIM5αRh binds specifically to HIV-1 capsid (CA) through its B30.2/PRYSPRY domain shortly after entry of the virus into the cytoplasm. Recently, three putative SUMO interacting motifs (SIMs) have been identified in the PRYSPRY domain of human and macaque TRIM5α. However, structural modeling of this domain suggested that two of them were buried in the hydrophobic core of the protein, implying that interaction with SUMO was implausible, while the third one was not relevant to restriction. In light of these results, we re-analyzed the TRIM5αRh PRYSPRY sequence and identified an additional putative SIM ((435)VIIC(438)) which we named SIM4. This motif is exposed at the surface of the PRYSPRY domain, allowing potential interactions with SUMO or SUMOylated proteins. Introducing a double mutation in SIM4 (V435K, I436K) did not alter stability, unlike mutations in SIM1. SIM4-mutated TRIM5αRh failed to bind HIV-1CA and lost the ability to restrict this virus. Accordingly, SIM4 undergoes significant variation among primates and substituting this motif with naturally occurring SIM4 variants affected HIV-1 restriction by TRIM5αRh, suggesting a direct role in capsid recognition. Interestingly, SIM4-mutated TRIM5αRh also failed to activate NF-κB and AP-1-mediated transcription. Although there is no direct evidence that SIM4 is involved in direct interaction with SUMO or a SUMOylated protein, mutating this motif strongly reduced co-localization of TRIM5αRh with SUMO-1 and with PML, a SUMOylated nuclear protein. In conclusion, this new putative SIM is crucial for both direct interaction with incoming capsids and for NF-κB/AP-1 signaling. We speculate that the latter function is mediated by interactions of SIM4 with a SUMOylated protein involved in the NF-κB/AP-1 signaling pathways.
authors.affiliation: Laboratory of Retrovirology, Department of Medical Biology and BioMed Research Group, Université du Québec à Trois-Rivières. 3351 Boulevard des Forges, CP500, Trois-Rivières, QC, G9A 5H7, Canada.
authors.forename: Marie-Édith
authors.initials: MÉ
authors.lastname: Nepveu-Traversy
authors.affiliation: Department of Molecular Biosciences, University of Texas at Austin, Austin, TX 78712, USA.
authors.forename: Ann
authors.initials: A
authors.lastname: Demogines
authors.affiliation: Department of Microbiology and Immunology, Albert Einstein College of Medicine, Bronx, NY, USA.
authors.forename: Thomas
authors.initials: T
authors.lastname: Fricke
authors.affiliation: Laboratory of Retrovirology, Department of Medical Biology and BioMed Research Group, Université du Québec à Trois-Rivières. 3351 Boulevard des Forges, CP500, Trois-Rivières, QC, G9A 5H7, Canada.
authors.forename: Mélodie B
authors.initials: MB
authors.lastname: Plourde
authors.affiliation: Laboratory of Retrovirology, Department of Medical Biology and BioMed Research Group, Université du Québec à Trois-Rivières. 3351 Boulevard des Forges, CP500, Trois-Rivières, QC, G9A 5H7, Canada.
authors.forename: Kathleen
authors.initials: K
authors.lastname: Riopel
authors.affiliation: Laboratory of Retrovirology, Department of Medical Biology and BioMed Research Group, Université du Québec à Trois-Rivières. 3351 Boulevard des Forges, CP500, Trois-Rivières, QC, G9A 5H7, Canada.
authors.forename: Maxime
authors.initials: M
authors.lastname: Veillette
authors.affiliation: Department of Microbiology and Immunology, Albert Einstein College of Medicine, Bronx, NY, USA.
authors.forename: Felipe
authors.initials: F
authors.lastname: Diaz-Griffero
authors.affiliation: Department of Molecular Biosciences, University of Texas at Austin, Austin, TX 78712, USA; Department of Molecular, Cellular, and Developmental Biology and the BioFrontiers Institute, University of Colorado Boulder, Boulder, CO, USA.
authors.forename: Sara L
authors.initials: SL
authors.lastname: Sawyer
authors.affiliation: Laboratory of Retrovirology, Department of Medical Biology and BioMed Research Group, Université du Québec à Trois-Rivières. 3351 Boulevard des Forges, CP500, Trois-Rivières, QC, G9A 5H7, Canada.
authors.forename: Lionel
authors.initials: L
authors.lastname: Berthoux
keywords: Cellular aspects of innate immunity; Innate immune system; Proteins; Virology; Viruses