Disease relevance of SUMO1

• The SMT3IP2 expressed by Escherichia coli could cleave SUMO-1, Smt3a, or Smt3b from a SUMO-1/RanGAP1, Smt3a/RanGAP1, or Smt3b/RanGAP1 conjugate, respectively, and had the activity of a carboxyl-terminal hydrolase to produce a glycine residue in the carboxyl terminus of these ubiquitin-like proteins [1].
• Overall, the results presented provide a detailed biochemical characterization of post-translational modifications of the HHV-6 IE1 protein by SUMO peptides, contributing to our understanding of the complex interactions between herpesviruses and the SUMO-conjugation pathway [2].
• In prolonged hypoxia, CREB is posttranslationally modified by SUMO-1 [3].
• IE2 was efficiently modified by SUMO-1 or SUMO-2 in cotransfected cells and in cells infected with a recombinant adenovirus expressing HCMV IE2, although the level of modification was much lower in HCMV-infected cells [4].
• The vaccinia virus E3L protein interacts with SUMO-1 and ribosomal protein L23a in a yeast two hybrid assay [5].

Psychiatry related information on SUMO1

• SUMO modification of Huntingtin and Huntington's disease pathology [6].
• The aim of our study was to examine SUMO-1 in the alpha-synucleinopathy diseases, Multiple System Atrophy (MSA) and Dementia with Lewy Bodies (DLB) [7].

High impact information on SUMO1

• Small ubiquitin-related modifier (SUMO) family proteins function by becoming covalently attached to other proteins as post-translational modifications [8].
• SUMO modifies many proteins that participate in diverse cellular processes, including transcriptional regulation, nuclear transport, maintenance of genome integrity, and signal transduction [8].
• SUMO-conjugating enzyme is seen to be resident in plasma membrane, to assemble with K2P1, and to modify K2P1 lysine 274 [9].
• Here, the SUMO pathway is shown to operate at the plasma membrane to control ion channel function [9].
• The tumor suppressor and transcriptional regulator p53 is perhaps one of the most regulated proteins in the cell nucleus and is acted upon by a variety of protein kinases, acetylases, ubiqutin ligases and hydrolases, and SUMO-conjugating enzymes [10].

Chemical compound and disease context of SUMO1

• Inhibition studies and mutagenesis indicate that NEDP1 is a cysteine protease with sequence similarities to SUMO-specific proteases and the class of viral proteases typified by the adenovirus protease [11].
• High-Level Expression and Purification of Human Epidermal Growth Factor with SUMO Fusion in Escherichia coli [12].

Biological context of SUMO1

• In interphase, a significant fraction of vertebrate SUMO1-modified RanGAP1 forms a stable complex with the nucleoporin RanBP2/Nup358 at nuclear pore complexes [13].
• In response to TOP1-mediated DNA damage induced by camptothecin, multiple SUMO1 molecules are conjugated to the N-terminal domain of a single TOP1 molecule [14].
• The spectrum of human SUMO1 substrates identified in our screen suggests general roles of sumoylation in transcription, chromosome structure, and RNA processing [15].
• SUMO1 conjugation to the C-terminal K330 of TDG modulates the DNA binding function of the N terminus to induce dissociation of the glycosylase from the AP site while it leaves the catalytic properties of base release in the active site pocket of the enzyme unaffected [16].
• Using yeast two-hybrid system, bioinformatics, and NMR spectroscopy we define a common SUMO-interacting motif (SIM) and map its binding surfaces on SUMO1 and SUMO2 [17].

Anatomical context of SUMO1

• Using a cell line that constitutively expresses an epitope-tagged version of SUMO1, which was incorporated into high-molecular-mass conjugates, we observed SUMO1 accumulating in clusters around a subset of the NBs [18].
• Regulation of the SUMO pathway sensitizes differentiating human endometrial stromal cells to progesterone [19].
• In vitro binding studies revealed that Ubc9 and SUMO-1-modified RanGAP1 bind synergistically to form a trimeric complex with a component of the cytoplasmic filaments of the NPC, Nup358 [20].
• Keratinocyte differentiation requires the coordinated activation of a series of transcription factors, and as several crucial keratinocyte transcription factors are known to be SUMO substrates, we investigated the role of sumoylation in keratinocyte differentiation [21].
• The presence of the sumoylated form in HeLa cells solely transfected by OZF indicates the physiological activity of the endogenous SUMO-1 conjugation pathway [22].

Associations of SUMO1 with chemical compounds

• Systematic analysis has identified a single major SUMO1 conjugation site located between amino acid residues 110 and 125 that contains a single lysine residue at 117 (Lys-117) [14].
• Our findings demonstrate how dynamic changes in the SUMO pathway mediated by cAMP signaling determine the endometrial response to progesterone [19].
• In the NB4 cell line, which was derived from an APL patient and expresses PML:RARalpha, we observed a retinoic acid-dependent change in the modification of specific proteins by SUMO-1 [23].
• Mutation of lysine 1086 of SALL1 to arginine abrogates SALL1 sumoylation, suggesting the presence of a polymeric SUMO-1 chain in the wild type state [24].
• Phosphorylation of serine 303 is a prerequisite for the stress-inducible SUMO modification of heat shock factor 1 [25].
• We unambiguously show that serine 2 of the endogenous SUMO-1 N-terminal protrusion is phosphorylated in vivo using very high mass accuracy mass spectrometry at both the MS and the MS/MS level and complementary fragmentation techniques [26].

Physical interactions of SUMO1

• SUMO conjugation dramatically reduces the DNA substrate and AP site binding affinity of TDG, and this is associated with a significant increase in enzymatic turnover in reactions with a G*U substrate and the loss of G*T processing activity [27].
• We now propose that the mechanism of p14ARF action may involve the covalent modification of its binding partners with the small ubiquitin-related protein SUMO-1 [28].
• Furthermore, SUMO-1 overexpression stabilizes CREB in hypoxia and enhances CREB-dependent reporter gene activity [3].
• To establish the proteolytic mechanism, we determined structures of catalytically inactive SENP1 bound to SUMO-1-modified RanGAP1 and to unprocessed SUMO-1 [29].
• hZimp10 is an androgen receptor co-activator and forms a complex with SUMO-1 at replication foci [30].

Enzymatic interactions of SUMO1

• We demonstrate that the cytosolic pool of SENP5 catalyzes the cleavage of SUMO1 from a number of mitochondrial substrates [31].

Co-localisations of SUMO1

• HSF1 colocalizes with SUMO-1 in nuclear stress granules, which is prevented by mutation of lysine 298 [32].
• In acute myeloid leukemia (AML) of subtypes other than M3, PIC 1 was localized to the nuclear membrane and colocalized with PML within discrete nuclear bodies [33].
• We show that ADAR1 colocalizes with SUMO-1 in a subnucleolar region that is distinct from the fibrillar center, the dense fibrillar component, and the granular component [34].

Regulatory relationships of SUMO1

• We isolated PIAS1 (protein inhibitor of activated STAT1) as a SUMO-1 binding protein by yeast two-hybrid screening [35].
• We found that PML stimulated hSUMO-1 modification in yeast, in a manner that was dependent upon PML's RING-finger domain [23].
• A synergy control motif within the attenuator domain of CCAAT/enhancer-binding protein alpha inhibits transcriptional synergy through its PIASy-enhanced modification by SUMO-1 or SUMO-3 [36].
• Sumoylation analyses of HSF1 phosphorylation site mutants reveal that specifically the phosphorylation-deficient S303 mutant remains devoid of SUMO modification in vivo and the mutant mimicking phosphorylation of S303 promotes HSF1 sumoylation in vitro, indicating that S303 phosphorylation is required for K298 sumoylation [25].
• Here we describe the involvement of the small ubiquitin-like modifier-1 (SUMO-1) conjugation pathway in regulating the growth inhibitory and transcriptional responses of Smad4 [37].

Other interactions of SUMO1

• These data suggest that PIAS1 functions as a SUMO ligase, or possibly as a tightly bound regulator of it, toward p53 [35].
• Moreover, the modification depends on the presence of an intact nuclear localization signal and is catalysed by the nuclear pore complex (NPC) RanBP2 protein, a factor newly identified as a SUMO E3 ligase [38].
• Here we demonstrate that the class II histone deacetylase HDAC4 is covalently modified by the ubiquitin-related SUMO-1 modifier [38].
• We also investigated the localization of the SUMO conjugating enzyme, Ubc9 [20].
• Substitutions within this area specifically and dramatically affected the ability of both SUMO2 and SUMO1 to inhibit transcription and revealed that the positively charged nature of the key basic residues is the main feature responsible for their functional role [39].

Analytical, diagnostic and therapeutic context of SUMO1

• To identify novel human MR (hMR) molecular partners, yeast two-hybrid screenings performed using the N-terminal domain as bait, allowed us to isolate protein inhibitor of activated signal transducer and activator of transcription (PIAS)1 and PIASxbeta, described as SUMO (small ubiquitin-related modifier) E3-ligases [40].
• Site-directed mutagenesis of lysine residues K285 and K304 identifies them as SUMO acceptors in vivo and in vitro [3].
• A luciferase reporter gene assay suggested that SUMO-1 modification of this residue is required for transcriptional repression by PLZF, and an electrophoretic mobility shift assay showed that this modification increases the DNA binding activity of PLZF [41].
• Cell fractionation and immunoblotting demonstrated that PIC1/SUMO-1 immunoreactive Sp100 in IFN-treated and untreated cells was exclusively nuclear, whereas nonmodified Sp100 was also found in the cytoplasm [42].
• Here we used peptide mapping, mass spectroscopy analysis, and mutagenesis to identify the nature of the link between RanGAP1 and SUMO-1 [43].

References