title: MxA interacts with and is modified by the SUMOylation machinery.
abstract: Mx proteins are evolutionarily conserved dynamin-like large GTPases involved in viral resistance triggered by types I and III interferons. The human MxA is a cytoplasmic protein that confers resistance to a large number of viruses. The MxA protein is also known to self-assembly into high molecular weight homo-oligomers. Using a yeast two-hybrid screen, we identified 27 MxA binding partners, some of which are related to the SUMOylation machinery. The interaction of MxA with Small-Ubiquitin MOdifier 1 (SUMO1) and Ubiquitin conjugating enzyme 9 (Ubc9) was confirmed by co-immunoprecipitation and co-localization by confocal microscopy. We identified one SUMO conjugation site at lysine 48 and two putative SUMO interacting motifs (SIMa and SIMb). We showed that MxA interacts with the EIL loop of SUMO1 in a SIM-independent manner via its CID-GED domain. The yeast two-hybrid mapping also revealed that Ubc9 binds to the MxA GTPase domain. Mutation in the putative SIMa and SIMb, which are located in the GTPase binding domain, reduced MxA antiviral activity. In addition, we showed that MxA can be conjugated to SUMO2 or SUMO3 at lysine 48 and that the SUMOylation-deficient mutant of MxA (MxAK48R) retained its capacity to oligomerize and to inhibit Vesicular Stomatitis Virus (VSV) and Influenza A Virus replication, suggesting that MxA SUMOylation is not essential for its antiviral activity.
authors.affiliation: Department of Biological Sciences, School of Pharmaceutical Sciences, Univ Estadual Paulista - UNESP, Araraquara 14801-902, SP, Brazil; INSERM UMR-S 1124, Université Paris Descartes, Paris 75006, France.
authors.forename: Carlos Eduardo
authors.initials: CE
authors.lastname: Brantis-de-Carvalho
authors.affiliation: INSERM UMR-S 1124, Université Paris Descartes, Paris 75006, France.
authors.forename: Ghizlane
authors.initials: G
authors.lastname: Maarifi
authors.affiliation: Department of Biological Sciences, School of Pharmaceutical Sciences, Univ Estadual Paulista - UNESP, Araraquara 14801-902, SP, Brazil.
authors.forename: Paulo Eduardo
authors.initials: PE
authors.lastname: Gonçalves Boldrin
authors.affiliation: Department of Biological Sciences, School of Pharmaceutical Sciences, Univ Estadual Paulista - UNESP, Araraquara 14801-902, SP, Brazil.
authors.forename: Cleslei Fernando
authors.initials: CF
authors.lastname: Zanelli
authors.affiliation: INSERM UMR-S 1124, Université Paris Descartes, Paris 75006, France.
authors.forename: Sébastien
authors.initials: S
authors.lastname: Nisole
authors.affiliation: INSERM UMR-S 1124, Université Paris Descartes, Paris 75006, France.
authors.forename: Mounira K
authors.initials: MK
authors.lastname: Chelbi-Alix
authors.affiliation: Department of Biological Sciences, School of Pharmaceutical Sciences, Univ Estadual Paulista - UNESP, Araraquara 14801-902, SP, Brazil. Electronic address: valentsr@fcfar.unesp.br.
authors.forename: Sandro Roberto
authors.initials: SR
authors.lastname: Valentini
mesh_terms: D020816:Amino Acid Motifs; D000818:Animals; D001665:Binding Sites; D006367:HeLa Cells; D006801:Humans; D051379:Mice; D064547:Myxovirus Resistance Proteins / Q000737:chemistry / Q000378:metabolism*; D041681:NIH 3T3 Cells; D011485:Protein Binding; D025842:SUMO-1 Protein / Q000737:chemistry / Q000378:metabolism; D058207:Sumoylation; D044763:Ubiquitin-Conjugating Enzymes / Q000737:chemistry / Q000378:metabolism; D000098843:Ubiquitin-Conjugating Enzyme UBC9
chemical_list: C579071:MX1 protein, human; D064547:Myxovirus Resistance Proteins; D025842:SUMO-1 Protein; D044763:Ubiquitin-Conjugating Enzymes; D000098843:Ubiquitin-Conjugating Enzyme UBC9
keywords: EIL loop; MX1; MxA; SUMO; SUMOylation; Ubc9 and antiviral activity; Yeast two-hybrid