title: Arginine methylation enhances the RNA chaperone activity of the West Nile virus host factor AUF1 p45.
abstract: A prerequisite for the intracellular replication process of the Flavivirus West Nile virus (WNV) is the cyclization of the viral RNA genome, which enables the viral replicase to initiate RNA synthesis. Our earlier studies indicated that the p45 isoform of the cellular AU-rich element binding protein 1 (AUF1) has an RNA chaperone activity, which supports RNA cyclization and viral RNA synthesis by destabilizing a stem structure at the WNV RNA's 3'-end. Here we show that in mammalian cells, AUF1 p45 is consistently modified by arginine methylation of its C terminus. By a combination of different experimental approaches, we can demonstrate that the methyltransferase PRMT1 is necessary and sufficient for AUF1 p45 methylation and that PRMT1 is required for efficient WNV replication. Interestingly, in comparison to the nonmethylated AUF1 p45, the methylated AUF1 p45(aDMA) exhibits a significantly increased affinity to the WNV RNA termini. Further data also revealed that the RNA chaperone activity of AUF1 p45(aDMA) is improved and the methylated protein stimulates viral RNA synthesis considerably more efficiently than the nonmethylated AUF1 p45. In addition to its destabilizing RNA chaperone activity, we identified an RNA annealing activity of AUF1 p45, which is not affected by methylation. Arginine methylation of AUF1 p45 thus represents a specific determinant of its RNA chaperone activity while functioning as a WNV host factor. Our data suggest that the methylation modifies the conformation of AUF1 p45 and in this way affects its RNA binding and restructuring activities.
authors: Institute of Biochemistry and Biotechnology (NFI), Martin Luther University Halle-Wittenberg, 60120 Halle, Germany.
authors: Susann
authors: S
authors: Friedrich
authors: Institute of Biochemistry and Biotechnology (NFI), Martin Luther University Halle-Wittenberg, 60120 Halle, Germany.
authors: Tobias
authors: T
authors: Schmidt
authors: Institute of Biochemistry and Biotechnology (NFI), Martin Luther University Halle-Wittenberg, 60120 Halle, Germany.
authors: Angelika
authors: A
authors: Schierhorn
authors: Institute of Biochemistry and Biotechnology (NFI), Martin Luther University Halle-Wittenberg, 60120 Halle, Germany.
authors: Hauke
authors: H
authors: Lilie
authors: Institute of Virology, Leipzig University, 04130 Leipzig, Germany.
authors: Grit
authors: G
authors: Szczepankiewicz
authors: Institute of Virology, Leipzig University, 04130 Leipzig, Germany.
authors: Sandra
authors: S
authors: Bergs
authors: Institute of Virology, Leipzig University, 04130 Leipzig, Germany.
authors: Uwe G
authors: UG
authors: Liebert
authors: Institute of Biochemistry and Biotechnology (NFI), Martin Luther University Halle-Wittenberg, 60120 Halle, Germany.
authors: Ralph P
authors: RP
authors: Golbik
authors: Institute of Biochemistry and Biotechnology (NFI), Martin Luther University Halle-Wittenberg, 60120 Halle, Germany.
authors: Sven-Erik
authors: SE
authors: Behrens
mesh_terms: D020413:3' Untranslated Regions; D001120:Arginine / Q000378:metabolism*; D045744:Cell Line, Tumor; D000081035:Heterogeneous Nuclear Ribonucleoprotein D0; D034502:Heterogeneous-Nuclear Ribonucleoprotein D / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D008745:Methylation; D020033:Protein Isoforms / Q000235:genetics / Q000378:metabolism; D011499:Protein Processing, Post-Translational; D011484:Protein-Arginine N-Methyltransferases / Q000378:metabolism; D012367:RNA, Viral / Q000235:genetics* / Q000378:metabolism; D012097:Repressor Proteins / Q000378:metabolism; D014779:Virus Replication; D014902:West Nile virus / Q000235:genetics / Q000502:physiology
chemical_list: D020413:3' Untranslated Regions; C000630986:HNRNPD protein, human; D000081035:Heterogeneous Nuclear Ribonucleoprotein D0; D034502:Heterogeneous-Nuclear Ribonucleoprotein D; D020033:Protein Isoforms; D012367:RNA, Viral; D012097:Repressor Proteins; D001120:Arginine; C099988:PRMT1 protein, human; D011484:Protein-Arginine N-Methyltransferases
keywords: AUF1; Flavivirus; RNA replication; West Nile virus; arginine methylation; host factor