Analysis of SUMOylation in the RENT Complex by Fusion to a SUMO-Specific Protease Domain

Author(s):  
Neus Colomina ◽  
Clàudia Guasch ◽  
Jordi Torres-Rosell
2013 ◽  
Vol 87 (11) ◽  
pp. 6537-6537
Author(s):  
M. Caduco ◽  
A. Comin ◽  
M. Toffoletto ◽  
D. Munegato ◽  
E. Sartori ◽  
...  

2012 ◽  
Vol 87 (1) ◽  
pp. 692-696 ◽  
Author(s):  
M. Caduco ◽  
A. Comin ◽  
M. Toffoletto ◽  
D. Munegato ◽  
E. Sartori ◽  
...  

2003 ◽  
Vol 160 (7) ◽  
pp. 1069-1082 ◽  
Author(s):  
Shyr-Jiann Li ◽  
Mark Hochstrasser

Protein modification by the ubiquitin-like SUMO protein contributes to many cellular regulatory mechanisms. In Saccharomyces cerevisiae, both sumoylating and desumoylating activities are essential for viability. Of its two known desumoylating enzymes, Ubl-specific protease (Ulp)1 and Ulp2/Smt4, Ulp1 is specifically required for cell cycle progression. A ∼200-residue segment, the Ulp domain (UD), is conserved among Ulps and includes a core cysteine protease domain that is even more widespread. Here we demonstrate that the Ulp1 UD by itself can support wild-type growth rates and in vitro can cleave SUMO from substrates. However, in cells expressing only the UD of Ulp1, many SUMO conjugates accumulate to high levels, indicating that the nonessential Ulp1 NH2-terminal domain is important for activity against a substantial fraction of sumoylated targets. The NH2-terminal domain also includes sequences necessary and sufficient to concentrate Ulp1 at nuclear envelope sites. Remarkably, NH2-terminally deleted Ulp1 variants are able, unlike full-length Ulp1, to suppress defects of cells lacking the divergent Ulp2 isopeptidase. Thus, the NH2-terminal regulatory domain of Ulp1 restricts Ulp1 activity toward certain sumoylated proteins while enabling the cleavage of others. These data define key functional elements of Ulp1 and strongly suggest that subcellular localization is a physiologically significant constraint on SUMO isopeptidase specificity.


Author(s):  
E. H. Egelman ◽  
X. Yu

The RecA protein of E. coli has been shown to mediate genetic recombination, regulate its own synthesis, control the expression of other genes, act as a specific protease, form a helical polymer and have an ATPase activity, among other observed properties. The unusual filament formed by the RecA protein on DNA has not previously been shown to exist outside of bacteria. Within this filament, the 36 Å pitch of B-form DNA is extended to about 95 Å, the pitch of the RecA helix. We have now establishedthat similar nucleo-protein complexes are formed by bacteriophage and yeast proteins, and availableevidence suggests that this structure is universal across all of biology, including humans. Thus, understanding the function of the RecA protein will reveal basic mechanisms, in existence inall organisms, that are at the foundation of general genetic recombination and repair.Recombination at this moment is assuming an importance far greater than just pure biology. The association between chromosomal rearrangements and neoplasms has become stronger and stronger, and these rearrangements are most likely products of the recombinatory apparatus of the normal cell. Further, damage to DNA appears to be a major cause of cancer.


1992 ◽  
Vol 67 (01) ◽  
pp. 095-100 ◽  
Author(s):  
Paul J Declerck ◽  
Leen Van Keer ◽  
Maria Verstreken ◽  
Désiré Collen

SummaryAn enzyme-linked immunosorbent assay (ELISA) for quantitation of natural and recombinant plasminogen activators containing the serine protease domain (B-chain) of urokinase-type plasminogen activator (u-PA) was developed, based on two murine monoclonal antibodies, MA-4D1E8 and MA-2L3, raised against u-PA and reacting with non-overlapping epitopes in the B-chain. MA-4D1E8 was coated on microtiter plates and bound antigen was quantitated with MA-2L3 conjugated with horseradish peroxidase. The intra-assay, inter-assay and inter-dilution coefficients of variation of the assay were 6%, 15% and 9%, respectively. Using recombinant single-chain u-PA (rscu-PA) as a standard, the u-PA-related antigen level in normal human plasma was 1.4 ± 0.6 ng/ml (mean ± SD, n = 27).The ELISA recognized the following compounds with comparable sensitivity: intact scu-PA (amino acids, AA, 1 to 411), scu-PA-32k (AA 144 to 411), a truncated (thrombin-derived) scu-PA comprising A A 157 to 411, and chimeric t-PA/u-PA molecules including t-PA(AA1-263)/scu-PA(AA144-411), t-PA(AA1-274)/scu-PA(AA138-411) and t-PA(AA87-274)/scu-PA(AA138-411). Conversion of single-chain to two-chain forms of u-PA or inhibition of active two-chain forms with plasminogen activator inhibitor-1 or with the active site serine inhibitor phenyl-methyl-sulfonyl fluoride, did not alter the reactivity in the assay. In contrast, inactivation with α2-antiplasmin or with the active site histidine inhibitor Glu-Gly-Arg-CH2Cl resulted in a 3- to 5-fold reduction of the reactivity. When purified scu-PA-32k was added to pooled normal human plasma at final concentrations ranging from 20 to 1,000 ng/ml, recoveries in the ELISA were between 84 and 110%.The assay was successfully applied for the quantitation of pharmacological levels of scu-PA and t-PA(AA87_274)/scu-PA(AA138-411) in plasma during experimental thrombolysis in baboons.Thus the present ELISA, which is specifically dependent on the presence of the serine protease part of u-PA, is useful for measurement of a wide variety of variants and chimeras of u-PA which are presently being developed for improved thrombolytic therapy.


1997 ◽  
Vol 77 (03) ◽  
pp. 535-539 ◽  
Author(s):  
J Schneider ◽  
R Hauser ◽  
H-H Hennies ◽  
J Korioth ◽  
G Steffens ◽  
...  

SummaryThe chimaeric molecule rscu-PA-40kDA/Hir (M23) comprises the kringle and protease domain of saruplase (rscu-PA) and a thrombin inhibitory domain fused to the C-terminus of the protease domain. The 27 amino acid long thrombin inhibitory domain contains a sequence directed to the active site of thrombin and a fragment from the C-terminal region of hirudin. 125I-radiolabelled M23 (0.03 µM) bound to thrombin that was immobilised onto CNBr-activated sepharose beads. Unlabelled M23 (0.01-10 |xM) and hirudin (0.001-10 µµM) concentra-tion-dependently displaced 125I-M23 from its binding to thrombin. Saruplase (up to 10 (iM) did not influence the thrombin binding of M23. The fibrinolytic properties of M23 and saruplase were compared in anaesthetized dogs with femoral artery and saphenous vein thrombosis. Under concomitant heparinization, the intravenous bolus injections of 1 mg/kg M23 or saruplase induced reperfusion of thrombotically occluded femoral arteries in 4 out of 5 treated animals in each case. There was one reocclusion in the M23-treated group. Time to reperfusion (23 ± 4 vs 25 ± 11 min) and maximal height of reperfusion blood flow (98 ± 21 vs 108 ± 15 % of baseline flow) did not differ significantly between the treatment groups. The time course of the lysis of incorporated 125I-fibrin radioactivity in thrombosed saphenous veins was similar after bolus injections of M23 and saruplase. The maximal dissolution of 125I-fibrin in the venous thrombosis model was 91 ± 1 % in M23-and 88 ± 5 % in saruplase-treated animals. Plasma levels of fibrinogen were not influenced and a2-antiplasmin levels were slightly reduced (-27 ± 3 %) after bolus injection of M23. In contrast, bolus injection of saruplase was accompanied by a significant decrease of fibrinogen (-55 ± 19 %) and a2-antiplasmin (-75 ±11%) plasma levels. Template bleeding times virtually did not differ before (2.8 ± 0.3 min) and 60 min after bolus injection of M23 (3.1 ± 0.3 min), whereas treatment with saruplase resulted in a significant prolongation of template bleeding time from 2.6 ± 0.2 min to 28 ± 13 min. It is concluded that the saruplase derivative M23, while inducing equieffective thrombolysis after intravenous bolus injection in dogs, causes much fewer haemostatic side effects than its parent molecule. The high thrombus-specific activity of M23 is tentatively attributed to its affinity to clot-bound thrombin.


Author(s):  
Luis Gustavo Perez Rivas ◽  
Marily Theodoropoulou ◽  
Francesco Ferrau ◽  
Clara Nusser ◽  
Kohei Kawaguchi ◽  
...  

2018 ◽  
Author(s):  
Stacy A. Malaker ◽  
Kayvon Pedram ◽  
Michael J. Ferracane ◽  
Elliot C. Woods ◽  
Jessica Kramer ◽  
...  

<div> <div> <div> <p>Mucins are a class of highly O-glycosylated proteins that are ubiquitously expressed on cellular surfaces and are important for human health, especially in the context of carcinomas. However, the molecular mechanisms by which aberrant mucin structures lead to tumor progression and immune evasion have been slow to come to light, in part because methods for selective mucin degradation are lacking. Here we employ high resolution mass spectrometry, polymer synthesis, and computational peptide docking to demonstrate that a bacterial protease, called StcE, cleaves mucin domains by recognizing a discrete peptide-, glycan-, and secondary structure- based motif. We exploited StcE’s unique properties to map glycosylation sites and structures of purified and recombinant human mucins by mass spectrometry. As well, we found that StcE will digest cancer-associated mucins from cultured cells and from ovarian cancer patient-derived ascites fluid. Finally, using StcE we discovered that Siglec-7, a glyco-immune checkpoint receptor, specifically binds sialomucins as biological ligands, whereas the related Siglec-9 receptor does not. Mucin-specific proteolysis, as exemplified by StcE, is therefore a powerful tool for the study of glycoprotein structure and function and for deorphanizing mucin-binding receptors. </p> </div> </div> </div>


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