Systematic study of protein sumoylation: Development of a site‐specific predictor of SUMOsp 2.0

Background: Nucleolin is a multifunctional protein, but nucleolin-SUMO is unexploited. Results: Nucleolin-SUMO at Lys-294 facilitated binding with mRNA substrate gadd45␣ by maintaining its nuclear localization during cellular response to arsenite exposure. Conclusion: Nucleolin-SUMO promoted arsenite-induced apoptosis by increasing GADD45␣ expression. Significance: We identified a new modification of nucleolin and its contribution to the functional paradigm of nucleolin in mRNA stability regulation.

Section: Discovery Of Nucleolinmentioning

confidence: 99%

A Novel Post-translational Modification of Nucleolin, SUMOylation at Lys-294, Mediates Arsenite-induced Cell Death by Regulating gadd45α mRNA Stability

Zhang

Liang

Xie

et al. 2015

“…Mutations are indicated by carets and were designed to replace the consensus (K22Q) and nonconsensus (G19S) residues in the P-loop motif. A K66R mutation in the NMP-binding domain was designed to disrupt a predicted SUMO acceptor site (37). The designations for the ATP and NMP binding and the lid domains are taken from the crystal structure of CINAP (16) and are indicated by underlining.…”

Section: Methodsmentioning

confidence: 99%

ATP Binding to Hemoglobin Response Gene 1 Protein Is Necessary for Regulation of the Mating Type Locus in Candida albicans

Peterson

Pendrak

Roberts

2011

HBR1 (hemoglobin response gene 1) is an essential gene inCandida albicans that positively regulates mating type locus MTL␣ gene expression and thereby regulates cell type-specific developmental genes. Hbr1p contains a phosphate-binding loop (P-loop), a highly conserved motif characteristic of ATP-and GTP-binding proteins. Recombinant Hbr1p was isolated in an oligomeric state that specifically bound ATP with K d ϳ2 M. ATP but not ADP, AMP, GTP, or dATP specifically protected Hbr1p from proteolysis by trypsin. Site-directed mutagenesis of the highly conserved P-loop lysine (K22Q) and the less conserved glycine (G19S) decreased the binding affinity for soluble ATP and ATP immobilized through its ␥-phosphate. ATP bound somewhat more avidly than ATP␥S to wild type and mutant Hbr1p. Although Hbr1p exhibits sequence motifs characteristic of adenylate kinases, and adenylate kinase and ATPase activities have been reported for the apparent human ortholog of Hbr1p, assays for adenylate kinase activity, autophosphorylation, and ATPase activity proved negative. Overexpression of wild type but not the mutant forms of Hbr1p restored MTl␣2 expression in an HBR1/hbr1 mutant, indicating that ATP binding to the P-loop is necessary for this function of Hbr1p.

“…The data are representative of three independent experiments with similar results. a substrate of hDREF for the following reasons: 1) our twohybrid screen revealed an interaction between hDREF and a 400-aa region at the Mi2␣ C terminus; 2) SUMO plot analysis showed that human Mi2␣ possesses five putative consensus sequences for SUMO conjugation in its C terminus (42,43); and 3) the STRING database annotated a physical interaction between Mi2␣ and SUMO-1 and Ubc9. To test this hypothesis, HA-tagged Mi2␣ was transiently expressed with or without FLAG-hDREF and CFP-SUMO-1 in HeLa cells, and its SUMOylation status was examined by Western blotting analysis (Fig.…”

Section: Hdref Interacts With Factors Involved In the Sumoylationmentioning

confidence: 99%

Transcription Factor hDREF Is a Novel SUMO E3 Ligase of Mi2α

Yamashita

Moriuchi

Osumi

et al. 2016

The human transcription factor DNA replication-related element-binding factor (hDREF) is essential for the transcription of a number of housekeeping genes. The mechanisms underlying constitutively active transcription by hDREF were unclear. Here, we provide evidence that hDREF possesses small ubiquitin-like modifier (SUMO) ligase activity and can specifically SUMOylate Mi2␣, an ATP-dependent DNA helicase in the nucleosome remodeling and deacetylation complex. Moreover, immunofluorescent staining and biochemical analyses showed that coexpression of hDREF and SUMO-1 resulted in dissociation of Mi2␣ from chromatin, whereas a SUMOylation-defective Mi2␣ mutant remained tightly bound to chromatin. Chromatin immunoprecipitation and quantitative RT-PCR analysis demonstrated that Mi2␣ expression diminished transcription of the ribosomal protein genes, which are positively regulated by hDREF. In contrast, coexpression of hDREF and SUMO-1 suppressed the transcriptional repression by Mi2␣. These data indicate that hDREF might incite transcriptional activation by SUMOylating Mi2␣, resulting in the dissociation of Mi2␣ from the gene loci. We propose a novel mechanism for maintaining constitutively active states of a number of hDREF target genes through SUMOylation.