title: Identification of a SUMO-binding motif that recognizes SUMO-modified proteins.
abstract: Posttranslational modification by the ubiquitin homologue, small ubiquitin-like modifier 1 (SUMO-1), has been established as an important regulatory mechanism. However, in most cases it is not clear how sumoylation regulates various cellular functions. Emerging evidence suggests that sumoylation may play a general role in regulating protein-protein interactions, as shown in RanBP2/Nup358 and RanGAP1 interaction. In this study, we have defined an amino acid sequence motif that binds SUMO. This motif, V/I-X-V/I-V/I, was identified by NMR spectroscopic characterization of interactions among SUMO-1 and peptides derived from proteins that are known to bind SUMO or sumoylated proteins. This motif binds all SUMO paralogues (SUMO-1-3). Using site-directed mutagenesis, we also show that this SUMO-binding motif in RanBP2/Nup358 is responsible for the interaction between RanBP2/Nup358 and sumoylated RanGAP1. The SUMO-binding motif exists in nearly all proteins known to be involved in SUMO-dependent processes, suggesting its general role in sumoylation-dependent cellular functions.
authors.affiliation: Division of Immunology, Beckman Research Institute of the City of Hope, 1450 East Duarte Road, Duarte, CA 91010, USA.
authors.forename: Jing
authors.initials: J
authors.lastname: Song
authors.forename: Linda K
authors.initials: LK
authors.lastname: Durrin
authors.forename: Thomas A
authors.initials: TA
authors.lastname: Wilkinson
authors.forename: Theodore G
authors.initials: TG
authors.lastname: Krontiris
authors.forename: Yuan
authors.initials: Y
authors.lastname: Chen
mesh_terms: D020816:Amino Acid Motifs; D000595:Amino Acid Sequence; D001665:Binding Sites; D016384:Consensus Sequence; D020690:GTPase-Activating Proteins / Q000737:chemistry / Q000378:metabolism; D006801:Humans; D066298:In Vitro Techniques; D046911:Macromolecular Substances; D008958:Models, Molecular; D018832:Molecular Chaperones; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D019906:Nuclear Magnetic Resonance, Biomolecular; D028861:Nuclear Pore Complex Proteins / Q000737:chemistry / Q000378:metabolism; D011499:Protein Processing, Post-Translational; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D025842:SUMO-1 Protein / Q000737:chemistry / Q000378:metabolism*; D025841:Small Ubiquitin-Related Modifier Proteins / Q000737:chemistry / Q000378:metabolism; D055672:Static Electricity
chemical_list: D020690:GTPase-Activating Proteins; D046911:Macromolecular Substances; D018832:Molecular Chaperones; D028861:Nuclear Pore Complex Proteins; C092317:RANGAP1 protein, human; D011994:Recombinant Proteins; D025842:SUMO-1 Protein; C117909:SUMO2 protein, human; D025841:Small Ubiquitin-Related Modifier Proteins; C094493:ran-binding protein 2